A broken lump would then be heated to softness in the furnace; rolled out under a bar of metal, held diagonally across the roll; and when reduced to a rod of a quarter of an inch thick, it was heated and pulled out into even rods about an eighth of an inch thick.
A certain proportion of soda ash (carbonate of soda) is also used in some works in sheet-glass mixtures, while " decolorizers " (substances intended to remove or reduce the colour of the glass) are also sometimes added, those most generally used being manganese dioxide and arsenic. Another essential ingredient of all glass mixtures containing sulphate of soda is some form of carbon, which is added either as coke, charcoal or anthracite coal; the carbon so introduced aids the reducing substances contained in the atmosphere of the furnace in bringing about the reduction of the sulphate of soda to a condition in which it combines more readily with the silicic acid of the sand.
A coke furnace was kept burning 24 hours a day to draw a continuous flow of air through the sewer.
A combined brickand water-cooled furnace has been adopted by the Iron Mountain Company at Keswick, Cal., for matte concentration.
A fire was then lit inside the furnace and hot layers of charcoal and crushed iron ore were added alternately.
A fourth Bristol site has produced possible evidence for the structure of the furnace into which tipping muffles were set.
A large furnace and a Bessemer converter, the pair capable of making a million pounds of copper a month from a low-grade sulphuretted ore, will not occupy a space of more than 25 ft.
A self-contained water coolant supply is fully interlocked to prevent furnace operation without coolant flow.
A sheet iron case is then placed within the furnace, and the space between it and the walls rammed with limed charcoal; the interior is filled with fragments of the iron or copper to be alloyed, mixed with alumina and coarse charcoal, broken pieces of carbon being placed in position to connect the electrodes.
A somewhat impure silicon (containing 90-98% of the element) is made by the Carborundum Company of Niagara Falls (United States Patents 745 122 and 842273, 1908) by heating coke and sand in an electric furnace.
About 1740 Benjamin Huntsman introduced the " crucible process " of melting steel in small crucibles, and thus freeing it from the slag, or rich iron silicate, with which it, like wrought iron, was mechanically mixed, whether it was made in the old forge or in the puddling furnace.
According to Arabic lore, based on Jewish legends, at this spot Nimrod sought to throw Abraham into a fiery furnace, from which he was saved by the grace of God.
After the remarkable development of the blast furnace, the Bessemer, and the open-hearth processes, the most important work of this, the third period of the history of iron, is the birth and growth of the science and art of iron metallography.
After various assaults upon his constancy, he was sentenced to be cast into the fiery furnace, through which he passed wholly unharmed.
Again, in direct-fired furnaces there are commonly seven or eight rows of retorts, one above another, so that to serve the upper rows the workman must stand upon a table, where he is exposed to the full heat of the furnace and requires a helper to wait upon him.
Again, the construction of electric furnaces may often be exceedingly crude and simple; in the carborundum furnace, for example, the outer walls are of loosely piled bricks, and in one type of furnace the charge is simply heaped on the ground around the carbon resistance used for heating, without containing-walls of any kind.
Aim for one with a rating of at least 90% to see significant savings over the life of the furnace.
Although this primitive furnace could be made to act, its efficiency was low, and the use of a separate fire was disadvantageous.
Alumina and lime, for example, which cannot be reduced at ordinary furnace temperatures, readily give up their oxygen to carbon in the electric furnace, and then combine with an excess of carbon to form metallic carbides.
Among the chief localities are the neighbourhood of Stourbridge in Worcestershire and Stannington near Sheffield, which supply most of the materials for crucibles used in steel and brass melting, and the pots for glass houses; Newcastle-on-Tyne and Glenboig near Glasgow, where heavy blast furnace and other firebricks, gas retorts, &c., are made in large quantities.
And while 78% AFUE is a significant improvement over a 20 year old furnace you may have in your home, it's not classified as high efficiency by the DOE.
Another method of making Portland cement which has been proposed and tried with some success consists in fusing the raw materials together in an apparatus of the type of a blast furnace.
Arc furnace A steel melting furnace in which heat is generated by an arc between graphite electrodes and the metal.
Arrived here, the material is introduced into the furnace by an ingenious piece of mechanism which completely prevents the furnace gas from escaping into the air.
As a rule every furnace accommodates ten muffles.
As each retort in a furnace is in all essentials a separate crucible, and as the metal from only a few of them goes into a single ingot, there can be no uniformity either in the ingots made from the same furnace during a day's run or in those made from several furnaces treating the same ore.
As soon as a hot billet A is withdrawn by pushing it endwise out of the exit door B, the whole row is pushed forward by a set of mechanical pushers C, the billets sliding on the raised water-cooled pipes D, and, in the hotter part of the furnace, on the magnesite bricks E, on which iron slides easily when red-hot.
As soon as the adapters have been cleaeed of their contents, they are replaced, and again left to themselves for two hours, to be once more emptied and replaced, &c. The complete exhaustion of the charge of a furnace takes about eleven hours.
As soon as the bricks have become red hot, the current is diverted to an adjacent chamber or pair of chambers, and the acquired heat is removed by a current of cool gas or air passing towards the furnace, where it arrives at a temperature sufficiently high to ensure the greatest possible heating effect in combustion.
As the foremost end of the billet emerges from the furnace it enters the first of a series of roll-trains, and passes immediately thence to others, so that before half of the billet has emerged from the furnace its front end has already been reduced by rolling to its final shape, that of merchant-bars, which are relatively thin, round or square rods, in lengths of 300 ft.
As the iron melts it runs out through a tap hole and spout at the bottom of the furnace, to be poured into the moulds by means of clay-lined ladles.
Associated with franklinite at Franklin Furnace, and found also at some other localities, is another member of the spinel group, namely, gahnite or zinc-spinel, which is a zinc aluminate, ZnAl 2 O 4, with a little of the zinc replaced by iron and manganese.
At a red heat it absorbs large volumes of hydrogen and nitrogen, the last traces of which can only be removed by fusion in the electric furnace.
At each end of the furnace is a trough of water which covers the furnace mouth, so that air is prevented from entering the furnace.
At Hourpes, in order to save the expense of this remelting, the molten cast iron as it comes from the blast-furnace is poured directly into the puddling furnace, in large charges of about 2200 lb, which are thus about four times as large as those of common puddling furnaces.
At length when the furnace was tapped a white slag was drawn off from the top, and the liquid metal beneath was received into a ladle and poured into cast-iron moulds.
At the Carnegie works Mr Monell gets the two dephosphorizing conditions, low temperature and basicity of slag, early in the process, by pouring his molten but relatively cool cast iron upon a layer of pre-heated lime and iron oxide on the bottom of the open-hearth furnace.
At the expiration of this time, when the charge should be perfectly liquid and in a tranquil state of fusion, the crucible is removed from the furnace and the contents are poured into a mould.
At the temperature of the furnace the silica (sand) attacks the calcium phosphate, forming silicate, and setting free phosphorus pentoxide, which is attacked by the carbon, forming phosphorus and carbon monoxide.
Barium chloride, BaCl 2.2H 2 O, can be obtained by dissolving witherite in dilute hydrochloric acid, and also from heavy spar by ignition in a reverberatory furnace with a mixture of coal, limestone and calcium chloride, the barium chloride being extracted from the fused mass by water, leaving a residue of insoluble calcium sulphide.
Be sure to read through your furnace manufacturer's instructions before cleaning to avoid causing damage.
Beryllium oxide, beryllia or glucina, BeO, is a very hard white powder which can be melted and distilled in the electric furnace, when it condenses in the form of minute hexagonal crystals.
Beyond this sulphur and phosphorus can be removed in the electric furnace, whereas in the crucible process they cannot.
Biodiesel blends can also be used in a standard oil fired furnace or boiler, making it an alternative fuel source for heating residential homes.
Borchers predicted that, at the high temperatures available with the electric furnace, every oxide would prove to be reducible by the action of carbon, and this prediction has in most instances been justified.
Borchers predicted that, at the high temperatures available with the electric furnace, every oxide wouldrprove to be reducible by the action of carbon, and this prediction has in most instances been justified.
Broken bricks or tiles and broken furnace slag are sometimes used, the essential points being that the aggregate should be hard, clean and sound.
But care must always be taken to place the producers at such a low level that the gas has an upward tendency, in order to facilitate its passage to the furnace where it is to be burned.
But even when the old type of reverberatory is preferred, as at the Argo works, at Denver, where rich goldand silver-bearing copper matte is made, the growth of the furnace in size has been steady.
But extreme narrowness would not only cause the escaping gases to move so swiftly that they would sweep much of the fine ore out of the furnace, but would also throw needless work on the blowing engines by throttling back the rising gases, and would lessen unduly the space available for the charge in the upper part of the furnace.
But in some cases in which the current is used for electrolysis and for the production of extremely high temperatures, for which the calorific intensity of ordinary fuel is insufficient, the electric furnace is employed with advantage.
But in the crucible and the open-hearth processes the temperature attainable is limited by the danger of melting the furnace itself, both because some essential parts of it, which, unfortunately, are of a destructible shape, are placed most unfavourably in that they are surrounded by the heat on all sides, and because the furnace is necessarily hotter than the steel made within it.
But in the latter case their edges still determine the effective profile of the furnace walls because the depressions at the back of these edges become filled with carbon and scoriaceous matter when the furnace is in normal working.
But it is not very well adapted to large furnaces, and especially not to those cases where all the space round the furnace is required for manipulating heavy, white-hot masses of iron, or for similar purposes.
But the state's iron foundries moved rapidly westward after the first successful experiments in making pig-iron with bituminous coal, in 1845, and the discovery, a few years later, that rich ore could be obtained there at less cost from the Lake Superior region resulted in a decline of iron-mining within the state until, in 1902, the product amounted to only 822,932 long tons, 72.2% of which was magnetite ore from the Cornwall mines in Lebanon county which have been among the largest producers of this kind of ore since the erection of the Cornwall furnace in 1742.
But this ancient furnace does its fourfold work of deoxidizing, melting, removing the gangue and desulphurizing, so very economically that it is not likely to be driven out in other places until the exhaustion of our coal-fields shall have gone so far as to increase the cost of coke greatly.
But whereas, from its construction, the Siemens furnace was intermittent in operation, necessitating stoppage of the current while the contents of the crucible were poured out, many of the newer forms are specially designed either to minimize the time required in effecting the withdrawal of one charge and the introduction of the next, or to ensure absolute continuity of action, raw material being constantly charged in at the top and the finished substance and by-products (slag, &c.) withdrawn either continuously or at intervals, as sufficient quantity shall have accumulated.
By continuing the walls of the hearth above the tuyere, into a shaft or stack either of the same or some other section, we obtain a furnace of increased capacity, but with no greater power of consuming fuel, in which the material to be treated can be heated up gradually by loading it into the stack, alternately with layers of fuel, the charge descending regularly to the point of combustion, and absorbing a proportion of the heat of the flame that went to waste in the open fire.
By placing ingots in a furnace and observing which one melted a fair idea of the temperature was obtained.
By rapidly stirring molten iron oxide into molten pig iron in a furnace shaped like a saucer, slightly inclined and turning around its axis, at a temperature but little above the melting-point of the metal itself, the phosphorus and silicon are removed rapidly, without removing much of the carbon, and by this means an extremely pure cast iron is made.
Calcination in reverberatory furnaces and a subsequent smelting in the same type of furnace with the addition of about 3% of coal, lime, soda and fluorspar, has been adopted for treating the Bolivian ores, which generally contain the sulphides of bismuth, copper, iron, antimony, lead and a little silver.
Calcium carbide, as formed in the electric furnace, is a beautiful crystalline semi-metallic solid, having a density of 2.22, and showing a fracture which is often shot with iridescent "non-automatic."
Calcium cyanamide has assumed importance in agriculture since the discovery of its economic production in the electric furnace, wherein calcium carbide takes up nitrogen from the atmosphere to form the cyanamide with the simultaneous liberation of carbon.
Calcium phosphate, mixed with sand and carbon, is fed into an electric furnace, provided with a closely fitting cover with an outlet leading to a condenser.
Carbon monoxide can escape from any fuel-burning appliance, furnace, water heater, fireplace, woodstove, or space heater.
Change your Furnace Filters -- It's a good idea to change your furnace filters at least once a month for maximum efficiency and fuel savings, but make sure that you start the season with new filters.
Chaplet has patented a muffle or tube furnace, similar in principle, for use on a larger scale, with a number of electrodes placed above and below the muffle-tube.
Charcoal is fed through a stoke hole into a constantly burning furnace at the side of the building to provide heat.
Clean off your furnace or air conditioner filter to remove more dust from the air.
Cynthia let out a gasp and wilted like a flower in a furnace; a dead faint.
Depending on the season, either the AC or the onboard furnace must be checked to assure it is operational.
Deville's portable blast furnace is very similar in principle to the above, but the body of the furnace is formed of a single cast iron cylinder lined with fireclay, closed below by a cast iron plate perforated by a ring of small holes - a hemispherical basin below forming the air-heating chamber.
Discuss with him the models of furnace you are considering and see if one has a more complex installation process than another.
Draught is regulated in the ashpit by opening or closing the bottom door of the furnace and by the damper on the smoke shaft.
Each blast-furnace is now provided with three or even four of these stoves, which collectively may be nearly thrice as large as the furnace itself.
Electric furnaces are at an advantage over others as regards the removal of sulphur and of iron oxide from the molten steel, because their atmosphere is free from the sulphur always present in the flame of coal-fired furnaces, and almost free from oxygen, because this element is quickly absorbed by the carbon and silicon of the steel, and in the case of arc furnaces by the carbon of the electrodes themselves, and is replaced only very slowly by leakage, whereas through the Bessemer converter and the open-hearth furnace a torrent of air is always rushing.
Ensure no spillage occurs from fireplaces through the operation furnace blowers, range vents dryers and exhaust fans.
Even the cement was produced using powdered ground granulated blast furnace slag (GGBS ).
Even the lizards had gone on holiday to escape the furnace heat, leaving only barbed wire bushes and a tap 500 yds away.
Fall is also a good time to have your furnace checked by a technician.
Female worker stoking a furnace in a gas works.
Finally, fluid steel can be run or poured off, since it is perfectly fluid, while glass cannot be thus treated, but is withdrawn from the furnace by means of either a ladle or a gatherer's pipe, and the temperature required for this purpose is much lower than.
For higher temperatures the bulb of the vapour density tube is made of porcelain or platinum, and is heated in a gas furnace.
For homeowners hoping to keep their heating bills lower in the winter, a propane heater can warm the most frequently used rooms of the home, allowing you to turn down the heat of the main furnace.
For manufacturing purposes a furnace similar to that used for the making of glass was employed to heat a circular row of crucibles standing on a shelf along the wall of the furnace.
For the acid Bessemer process the sulphur-content must be small and the silicon-content should be constant; for the basic openhearth process the content of both silicon and sulphur should be small, a thing difficult to bring about, because in the blast furnace most of the conditions which make for small sulphur-content make also for large silicon-content.
For the commoner grades of dark-coloured bottles the glass mixture is cheapened by substituting common salt for part of the sulphate of soda, and by the addition of felspar, granite, granulite, furnace slag and other substances fusible at a high temperature.
For the production of coloured sheet-glass, however, the employment of pot furnaces is still almost universal, probably because the quantities of glass required of any one tint are insufficient to employ even a small tank furnace continuously; the exact control of the colour is also more readily attained with the smaller bulk of glass which has to be dealt with in pots.
For the purpose of the removal of the glass, the cooler end of the furnace is provided with a number of suitable openings, provided with movable covers or shades.
For this purpose a cylinder of fireclay, provided with a square axial hole at the upper end, is heated in a small subsidiary furnace and is then introduced into the molten glass.
For this reason every piece of pressed glass-ware, as soon as it is liberated from the mould, is exposed to a sharp heat in a small subsidiary furnace in order that the ruffled surface may be removed by melting.
Formerly they were allowed to burn to waste at the mouth of a short chimney place above the furnace top, forming a huge body of flame, which was one of the most striking features of the Black Country landscape at night.
From A and B the materials are drawn as they are needed into large buckets D standing on cars, which carry them to the foot of the hoist track EE, up which they are hoisted to the top of the furnace.
Furnaces are constructed according to many different patterns with varying degrees of complexity in arrangement; but all may be considered as combining three essential parts, namely, the fire-place in which the fuel is consumed, the heated chamber, laboratory, hearth or working bed, as it is variously called, where the heat is applied to the special work for which the furnace is designed, and the apparatus for producing rapid combustion by the supply of air under pressure to the fire.
Gases, like atmospheric air, hydrogen or carbon dioxide do not become luminous if they are placed in tubes, even when heated up far beyond white heat as in the electric furnace.
Gerstenhofer's pyrites burner is a furnace of this class.
Good crystals have also been obtained as a furnace product.
Good hydraulic mortars may be made from lime mixed with furnace ashes or burnt clay as the pozzuolanic constituent.
Grey iron castings are made by remelting the pig iron either in a small shaft of " cupola " furnace, or in a reverberatory or " air " furnace, with very little change of chemical composition, and then casting it directly into suitable moulds, usually of either " baked," i.e.
He then pours or taps the molten charge from the furnace into a large clay-lined casting ladle, giving it the final additions of manganese, usually with carbon and often with silicon, needed to give it exactly the desired composition.
Heap, stall or shaft furnace roasting is not very satisfactory, as it is very difficult to transform all the sulphide into oxide.
Heated in the electric furnace in a current of air, it yields calcium cyanamide (see Cyanamide).
Hence in the intermittent system most of the heat generated within the furnace escapes from it with the products of combustion.
Hence the blast furnace process, thus freed from the hampering need of controlling accurately the silicon-content, can be much more effectively guided so as to prevent the sulphur from entering the pig iron.
Here A is the iron cover surrounding the furnaces, B is the revolving lid of a furnace, save time and to reduce the loss of the precious metals.
Here the charging machine lifts one box at a time from its car, pushes it through the momentarily opened furnace door, and empties the metal upon the hearth of the furnace by inverting the box, which it then replaces on its car.
Here, as soon as the ingots have so far solidified that they can be lifted without breaking, their moulds are removed and set on an adjoining train of cars, and the ingots are charged directly into the soaking furnace.
High efficiency models have upfront costs slightly higher than mid-efficiency models, but you can reap the savings many times over the life of the furnace.
Homes in Northern climates that run the furnace for longer stretches of time truly need a higher efficiency model, while homes in Southern climates that use the furnace more infrequently can get away with a less efficient model.
Homes that are set to a slightly higher temperature will get better results with a furnace with a higher efficiency rating.
Hot gases from the furnace will pass to a boiler, which will convert the energy from the gases into superheated steam.
However, entering the cubicle to discover how to become a fireman, Steelhorn found himself falling into a fusion furnace.
However, provided these furnaces are installed properly, you can expect to see that money back very quickly in lowered gas bills that will continue over the life of the furnace.
Huge amounts of furnace slag were used in building Roman roads.
If he had, so to speak, thrown into one furnace all the law contained in the treatises of the jurists and in the imperial ordinances, fused them down, the gold of the one and the silver of the other, and run them out into new moulds, this would have been codification.
If his questing had been unsuccessful, he appeased the rage of hunger with some scraps of broken meat, and lay down to rest under the piazza of Covent Garden in warm weather, and, in cold weather, as near as he could get to the furnace of a glass house.
If it's time to replace the furnace in your home, consider using a high efficiency furnace in its place.
If the lead is to be liquated and then brought to a bright-red heat, both operations are carried on in the same reverberatory furnace.
If they are supported at intervals along a flat side, they are called muffles, and the furnace is known as a Silesian furnace.
If you have a furnace in the wall, can it be moved higher or removed altogether?
If your home needs a new central air conditioning unit or an updated furnace, a professional contractor will be required as these are not DIY jobs.
In 1428 a Muranese glass-worker set up a furnace in Vienna, and another furnace was built in the same town by an Italian in 1486.
In 1878 Sir William Siemens patented a form of furnace' which is the type of a very large number of those designed by later inventors.
In 1893 Girard and Street patented a furnace and a process by which this transformation could be effected.
In a sheet-glass tank there is therefore a gradient of temperature and a continuous passage of material from the hotter end of the furnace where the raw materials are introduced to the cooler end where the glass, free from bubbles and raw material, is withdrawn by the gatherers.
In a very few places the molten cast iron as it issues from the blast furnace is cast directly in these moulds, but in general it is allowed to solidify in pigs, and then remelted either in cupola furnaces or in air furnaces.
In addition to this work of purification, the furnace may be used for melting down the initial charge of cold metal, and for beginning the purification - in short not only for finishing but also for roughing.
In all cases, therefore, where it is desired to do the work out of contact with the solid fuel, the operation of burning or heat-producing must be performed in a special fire-place or combustion chamber, the body of flame and heated gas being afterwards made to act upon the surface of the material exposed in a broad thin layer in the working bed or laboratory of the furnace by reverberation from the low vaulted roof covering the bed.
In America the usual method is to roast ores or concentrates so that the matte yielded by either the reverberatory or cupola furnace will run from 45 to 50% in copper, and then to transfer to the Bessemer converter, which blows it up to 99%.
In connexion with these experiments he developed the electric furnace as a convenient means of obtaining very high temperatures in the laboratory; and by its aid he prepared many new compounds, especially carbides, silicides and borides, and melted and volatilized substances which had previously been regarded as infusible.
In England gold and copper blanks are protected from oxidation, and after their passage through the furnace are merely washed in colanders with water and dried with sawdust in a rotating drum.
In graphitizing en masse large lumps of anthracite are treated in the electric furnace.
In it the steel heats the converter, whereas in the open-hearth and crucible processes the furnace heats the steel.
In its simplest form the apparatus consists of a straight tube, made of glass, porcelain or iron according to the temperature required and the nature of the reacting substances, heated in an ordinary combustion furnace, the mixture entering at one end and the vapours being condensed at the other.
In large works the silver-lead alloy is removed when it contains 60-80 silver, and the cupellation of the rich bullion from several concentration furnaces is finished in a second furnace.
In limiting the diameter at the tuyeres to 122 ft., the height of the boshes to one which will keep their upper end below the region of pastiness, and their slope to one over which the burning coke will descend freely, we limit the width of the furnace at the top of the boshes and thus complete the outline of the lower part of the furnace.
In many respects the glassmelting tank resembles the open-hearth steel furnace, but there are certain interesting differences.
In modern practice degreased bones (see Gelatin), or bone-ash which has lost its virtue as a filtering medium, &c., or a mineral phosphate is treated with sufficient sulphuric acid to precipitate all the calcium, the calcium sulphate filtered off, and the filtrate concentrated, mixed with charcoal, coke or sawdust and dried in a muffle furnace.
In order to prepare pure alumina, bauxite and sodium carbonate were heated in a furnace until the reaction was complete; the product was then extracted with water to dissolve the sodium aluminate, the solution treated with carbon dioxide, and the precipitate removed and dried.
In order to utilize this power, the converting mill, in which the pig iron is converted into steel, and the rolling mills must adjoin t h e blast - furnace.
In other furnaces the ore rests on a series of horizontal plates, and either remains on the same plate throughout the operation (0111vier and Perret furnace), or is passed from plate to plate by hand (Maletra), or by mechanical means (Spence and M`Dougall).
In reverberatory and air furnaces used in the different operations of iron manufacture, where an extremely high temperature has to be maintained in spaces of comparatively small extent, such as the beds of puddling, welding and steel-melting furnaces, the temperature of the exhaust gases is exceedingly high, and if allowed to pass directly into the chimney they appear as a great body of flame at the top. It is now general to save a portion of this heat by passing the flame through flues of steam boilers, air-heating apparatus, or both - so that the steam required for the necessary operations of the forge and heated blast for the furnace itself may be obtained without further expenditure of fuel.
In short electric furnaces replace the old crucible furnace primarily because they work more cheaply, though in addition they may be made to yield a better steel than it can.
In short the electric furnaces can be used to improve the molten product of the Bessemer converter and open-hearth furnace, essentially because their atmosphere is free from sulphur and oxygen, and because they can therefore remove sulphur, iron oxide and mechanically suspended slag, more thoroughly than is possible in these older furnaces.
In short, to increase the rate of production by lengthening the furnace increases the frictional resistance of the rising gases, both by increasing their quantity and hence their velocity and by lengthening their path.
In small works the cupellation is finished in one furnace, and the resulting low-grade silver fined in a plumbago crucible, either by overheating in the presence of air, or by the addition of silver sulphate to the melted silver, when air or sulphur trioxide and oxygen oxidize the impurities.
In some cases, especially in dry distillations, the furnace flames play directly on the retorts, in others, such as in the case of nitric acid, the whole still comes under the action of the furnace gases to prevent condensation on the upper part of the still, while in others the furnace gases do not play directly on the base or upper portion of the still but are conducted around it by a system of flues (see Coal-Tar).
In some processes of lead-smelting, where the minerals treated contain sand, the long calciner is provided with a melting bottom close to the fire-place, so that the desulphurized ore leaves the furnace as a glassy slag or silicate, which is subsequently reduced to the metallic state by fusion with fluxes in blast furnaces.
In starting the furnace, the bottom is prepared by ramming it with charcoal-powder that has been soaked in milk of lime and dried, so that each particle is coated with a film of lime, which serves to reduce the loss of current by conduction through the lining when the furnace becomes hot.
In such a furnace a continuous current, for example, of 3000 amperes, at 50 to 60 volts, may be used at first, increasing to 5000 amperes in about half an hour.
In such an arrangement, after the first instant, the melted metal in the furnace does not come in contact with the cathode material.
In the basic open-hearth process, on the other hand, silicon is harmful because the silica which results from its oxidation not only corrodes the lining of the furnace but interferes with the removal of the phosphorus, an essential part of the process.
In the Bessemer process, and indeed in most high-temperature processes, to operate on a large scale has, in addition to the usual economies which it offers in other industries, a special one, arising from the fact that from a large hot furnace or hot mass in general a very much smaller proportion of its heat dissipates through radiation and like causes than from a smaller body, just as a thin red-hot wire cools in the air much faster than a thick bar equally hot.
In the duplex process the conversion of the cast iron into steel is begun in the Bessemer converter and finished in the openhearth furnace.
In the Fery radiation pyrometer this difficulty is obviated, as the instrument may be placed at a considerable distance from the furnace.
In the first method the substance, mixed with quicklime free from chlorine, is heated in a tube closed at one end in a combustion furnace.
In the hearth of the blast furnace the heat made latent by the fusion of the iron and slag must of course be supplied by some body which is itself at a temperature above the melting point of these bodies, which for simplicity of exposition we may call the critical temperature of the blast-furnace process, because heat will flow only from a hotter to a cooler object.
In the King furnace, for example, the crucible, or lowest part of the furnace, is made detachable, so that when full it may be removed and an empty crucible substituted.
In the manufacture of calcium carbide in the electric furnace, lime and anthracite of the Manufac- highest possible degree of purity are employed.
In the more recent form of the hearth process the blocks of cast iron forming the sides and back of the Scottish furnace are now generally replaced in the United States by water-cooled shells (waterjackets) of cast iron.
In the most promising form of this process an acid converter and a basic open-hearth furnace are used.
In the production of zinc New Jersey once took a prominent part; in 1907 the only producer was The New Jersey Zinc Company's mine at Franklin Furnace, Sussex county, with an output of 13,573 short tons, valued at $1,601,614.
In the Royal Mint silver bars are annealed once during rolling by passing through a Bates & Peard gas furnace.
In the Silesian process the distillation is conducted in specially constructed muffles of a prismatic shape arched above, which are arranged in two parallel rows within a low-vaulted furnace, similar to the pots in a glass furnace.
In the simplest cases the functions of two or more of these parts may be combined into one, as in the smith's forge, where the fire-place and heating chamber are united, the iron being placed among the coals, only the air for burning being supplied under pressure from a blowing engine by a second special contrivance, the tuyere, tuiron, twyer or blast-pipe; but in the more refined modern furnaces, where great economy of fuel is an object, the different functions are distributed over separate and distinct apparatus, the fuel being converted into gas in one, dried in another, and heated in a third, before arriving at the point of combustion in the working chamber of the furnace proper.
In the United States a revolving furnace is used which is quite continuous in action.
In the White-Howell revolving furnace with lifters - a modification of the Oxland - the ore is fed and discharged in a continuous stream.
In the year before (1742) he had planned the " Pennsylvania fire-place," better known as the " Franklin stove," which saved fuel, heated all the room, and had the same principle as the hot-air furnace; the stove was never patented by Franklin, but was described in his pamphlet dated 1744.
In these arrangements, which were similar if not identical, the furnace charge was crushed to a fine powder and passed through two or more electric arcs in succession.
In this article the general principles of metallurgical furnaces will be treated; the subject of gasand oil-heated furnaces is treated in the article Fuel, and of the electric furnace in the article Electrometallurgy.
In this case the testpiece monitoring thermocouple must have sufficiently long trailing leads to accommodate the opening of the furnace.
In this life, Christ has his fire in Zion and his furnace in Jerusalem, and there he sits as a refiner.
In this respect the Kessler furnace has also proved to be very efficacious, so that it is at the present time considered the best apparatus for the concentration of sulphuric acid found in the trade.
In this system there is for each ingot and each mould only one handling in which it is moved as a separate unit, the mould from one train to the other, the ingot from its train into the furnace.
Indeed some blast furnace slag is used to make glass and cement.
Inside the furnace, the pilot light ignites the burner in the combustion chamber.
Into the square axial hole fits the square end of a hooked iron bar which projects several yards beyond the mouth of the furnace; by means of this bar a workman moves the fireclay cylinder about in the glass with a steady circular sweep. Although the weight of the iron bar is carried by a support, such as an overhead chain or a swivel roller, this operation is very laborious and trying, more especially during the earlier stages when the heat radiated from the open mouth of the crucible is intense.
It acquired considerable application in platinum works, this metal being only fusible in the oxyhydrogen flame and the electric furnace; and also for the production of limelight, as in optical (magic) lanterns.
It can be distilled in the electric furnace.
It is a high grade block, or " splint " coal, remarkably free from sulphur and rich in carbon, peculiarly adapted to blast furnace use.
It is by forming calcium sulphide that sulphur is removed in the manufacture of pig iron in the iron blast furnace, in the crucible of which, as in the electric furnaces, the conditions are strongly deoxidizing But in the Bessemer and open-hearth processes this means of removing sulphur cannot be used, because in each of them there is always enough oxygen in the atmosphere to re-oxidize any calcium as fast as it is deoxidized.
It is called a " black-ash " furnace, and belongs to the class of reverberatory furnaces.
It is for this reason that Siemens, Borchers and others substituted a hollow watercooled metal block for the carbon cathode upon which the melted metal rests while in the furnace.
It is found that the ingot of calcium carbide formed in the furnace, although itself consisting of pure crystalline calcium carbide, is nearly always surrounded by a crust which contains a certain proportion of imperfectly converted constituents, and therefore gives a lower yield of acetylene than the carbide itself.
It is in the metal in these channels and in that part of the main mass of metal which immediately adjoins the coils that the current is induced by means of the coils and cores, as in the Kjellin furnace.
It is known that he purchased prisms and lenses on two or three several occasions, and also chemicals and a furnace, apparently for chemical experiments; but he also employed part of his time on the theory of fluxions and other branches of pure mathematics.
It is made by granulating blast furnace slag of suitable composition and finely grinding the product, either alone or with an admixture of about To% of Portland cement clinker.
It is more conveniently prepared by heating the oxide with carbon in the electric furnace.
It is now manufactured by heating lime and carbon in the electric furnace (see Acetylene).
It is now usually performed by a series of muffles, superposed one over another, so that the whole forms a kind of shelfburner, with internally heated shelves (the" Rhenania "furnace).
It is practically unattainable in the open-hearth furnace, because here the oxygen of the furnace atmosphere indirectly oxidizes the carbon of the metal which is kept boiling by the escape of the resultant carbonic oxide.
It is set to span the furnace, additional exposure to heat being secured in a variety of ways by flues.
It is then raked out on the work-stone and divided into a very poor "grey" slag which is put aside, and a richer portion, which goes back into the furnace.
It is usual to have a separate furnace for each setting, the retorts resting upon walls built transversely in the furnace.
It then takes in heat from the furnace, expanding in volume and forcing the piston (B) to rise, which completes the cycle.
It thus resembles magnetite in external characters, but is readily distinguished from this by the fact that it is only slightly magnetic. It is found in considerable amount, associated with zinc minerals (zincite and willemite) in crystalline limestone, at Franklin Furnace, New Jersey, where it is mined as an ore of zinc (containing 5 to 20% of the metal); after the extraction of the zinc, the residue is used in the manufacture of spiegeleisen (the mineral containing 15 to 20% of manganese oxides).
It was also necessary to give the fine charcoal a thin coating of calcium oxide by soaking it in lime-water, for the temperature was so high that unless it was thus protected it was gradually converted into graphite, losing its insulating power and diffusing the current through the lining and walls of the furnace.
It was then allowed to expand further, taking in heat from a furnace under the cylinder and falling in pressure.
It was then, in 1735, that Abraham Darby showed how to make cast iron with coke in the high furnace, which by this time had become a veritable blast furnace.
It's humiliating to think you'd come to this empty furnace just to get away from me.
James Beaumont Neilson Open Each hot blast furnace gave work to 400 men.
Johnson in England Arc appear, in 1853, to have introduced the earliest practical form of furnace.
Just as with iron, smelting the metal from the ore required a furnace.
Knowing this, and having in the Siemens regenerative gas furnace an independent means of generating this temperature, the Martin brothers of Sireuil in France in 1864 developed the open-hearth process of making steel of any desired carbon-content by melting together in this furnace cast and wrought iron.
Later in that year they patented a process for the reduction of aluminium by carbon, and in 1886 an electric furnace with sliding carbon rods passed through the end walls to the centre of a rectangular furnace.
Lead ores are smelted in the reverberatory furnace, the ore-hearth, and the blast-furnace.
Like the Heroult furnace, the Kjellin furnace may be lined with either magnesite or chromite, and it may be tilted for the purpose of pouring off slag and metal.
Liquation, if not followed by poling, is carried on as a rule in a reverberatory furnace with an oblong, slightly trough-shaped inclined hearth; if the lead is to be poled it is usually melted down in a cast-iron kettle.
Liquid metal coming in contact with such a surface forms a crust of solidified metal over it, and this crust thickens up to a certain point, namely, until the heat from within the furnace just overbalances that lost by conduction through the solidified crust and the cathode material to the flowing water.
Long experience has fixed the mixtures, so far as ordinary furnace temperatures are concerned, which produce the varieties of glass in common use.
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Luther was thrust almost immediately out of the frying pan of religious disputation into the fiery furnace of high politics.
Manganese Carbide, Mn 3 C, is prepared by heating manganous oxide with sugar charcoal in an electric furnace, or by fusing manganese chloride and calcium carbide.
Many of the furnaces now in constant use depend mainly on this principle, a core of granular carbon fragments stamped together in the direct line between the electrodes, as in Acheson's carborundum furnace, being substituted for the carbon pencils.
Many of the furnaces used for this heating are in a general way like the puddling furnace shown in fig.
Moissan (Comptes rendus, 1893, 116, p. 349; 1894, 119, p. 185) reduces the sesquioxide with carbon, in an electric furnace; the product so obtained (which contains carbon) is then strongly heated with lime, whereby most of the carbon is removed as calcium carbide, and the remainder by heating the purified product in a crucible lined with the double oxide of calcium and chromium.
Moissan (Comptes rendus, 1896, 122, p. 1297) obtained a vanadium containing from Io to 16% of carbon by fusing vanadic anhydride with carbon in the electric furnace.
Moissan (Coniptes rendus, 1896, 122, p. 1297) by heating vanadium pentoxide and carbon for a few minutes in the electric furnace.
Moissan (ibid., 5906, 142, p. 673) has distilled this metal in a very intense electric furnace.
Moissan and P. Williams (Comptes rendus, 1897, 12 3, p. 6 33) by reducing the borate with aluminium in the electric furnace.
Moissan found that the oxide resisted reduction by carbon in the electric furnace, so that electrolysis of a fusible salt of the metal must be resorted to.
Moissan has also shown that it will combine with many metals at the temperature of the electric furnace, to form carbides (q.v.).
Moissan in France that if lime and carbon be fused together at the temperature of the electric furnace, the lime is reduced to calcium, which unites with the excess of carbon present to form calcium carbide.
Moissan obtained a carbon-bearing metal by fusing the pentoxide with carbon in the electric furnace.
Moissan succeeded in fusing about 4 lb of either of these metals in 5 or 6 minutes in a furnace similar to that last described.
More modern inventors have therefore adopted the plan of drawing the glass direct from the furnace.
Moreover, since the mould acts as a covering to retard the loss of heat, it should not be removed from the ingot until just before the latter is to be placed in its soaking furnace.
Moreover, this resistance increases much more rapidly than the height of the furnace, even if the rapidity with which the blast is forced through is constant; and it still further increases if the additional space gained by lengthening the furnace is made useful by increasing proportionally the rate of production, as indeed would naturally be done, because the chief motive for gaining this additional space is to increase production.
Mother and father and their friends have gone to see a huge furnace.
Mourlot has shown that aluminium sulphide, zinc sulphide and cadmium sulphide are the only sulphur compounds which can resist the heat of the electric furnace without decomposition or volatilization, and of these aluminium sulphide is the only one which is decomposed by water with the evolution of sulphuretted hydrogen.
Much information as to the nature of an alloy can be obtained by placing several small ingots of the same alloy in a furnace which is above the melting-point of the alloy, and allowing the temperature to fall slowly and uniformly.
Nearly every furnace on the market today is billed as "high efficiency".
Neilson's invention in 1828 of heating the blast, which increased the production and lessened the fuel-consumption of the furnace wonderfully.
Neither metal, when it emerges from the furnace, has any beauty, shakudo being simply dark-colored copper and shibuichi pale gun-metal.
Nevertheless, it was found impracticable to smelt alumina electrically except in presence of copper, so that the Cowles furnace yielded, not the pure metal, but an alloy.
No furnace no matter how efficient, can keep a home warm if the home isn't properly insulated.
On a direct-fired furnace at least one man, the brigadier, must be an expert in all the operations involved; but with a gas furnace a division of labour is possible.
On a larger scale several pencils are used to make the connexions between carbon blocks which form the end walls of the furnace, while the side walls are of fire-brick laid upon one another without mortar.
On a small scale it is obtained by reducing the trioxide in a current of hydrogen, or the chloride by sodium vapour, or the oxide with carbon in the electric furnace; in the last case the product is porous and can be welded like iron.
On account of its refractory nature, it is employed in the manufacture of crucibles, furnace linings, &c. It is also used in making hydraulic cements.
On view is the original Darby furnace where he first used his coke fired iron smelter.
Once you understand how the sun's rays can provide electricity to your whole house, any appliance or piece of equipment in your home, or replace a furnace altogether, you may be inspired to convert to this form of clean energy.
One for the fireplace and one for the natural gas furnace which is under the house in the crawl space.
One man is raking out the fire in a high furnace, while another behind is blowing the bellows.
One of the earliest and most exhaustive series of experiments was made on Rio Tinto ores at the John Brown works by John Hollway, with the aim of both smelting the ore and concentrating the matte in the same furnace, by the heat evolved through the oxidation of their sulphur and iron.
One simple way to cut costs is to replace your furnace thermostat with a programmable one.
Originally the term cupola was used for the reverberatory furnace, but in the course of time it has changed its meaning, and is now given to a small blast furnace such as that used by iron-founders - reverberatory smelting furnaces in the same trade being called air furnaces.
Ostwald (ibid., 1900, 35, pp. 33, 204) has observed that on dissolving chromium in dilute acids, the rate of solution as measured by the evolution of gas is not continuous but periodic. It is largely made as ferro-chrome, an alloy containing about 60-70% of chromium, by reducing chromite in the electric furnace or by aluminium.
Owing to the conditions of the work, which require the maintenance of a sensibly reducing atmosphere, they contain a very notable proportion of carbonic oxide, and are drawn off by large wrought iron tubes near the top of the furnace and conveyed by branch pipes to the different boilers and air-heating apparatus, which are now entirely heated by the combustion of such gases, or mixed with air and exploded in gas engines.
Previous to this time frame, more than 30% of the gas used to fire the furnace was being wasted.
Pure crystalline calcium carbide yields 5.8 cubic feet of acetylene per pound at ordinary temperatures, but the carbide as sold commercially, being a mixture of the pure crystalline material with the crust which in the electric furnace surrounds the ingot, yields at the best 5 cubic feet of gas per pound under proper conditions of generation.
Remains of an ancient bronze furnace, discovered near the town, tend to prove that tinsmelting was practised here at an early period.
Round this core threads of glass were wound of various colors; the whole could be reset in the furnace to soften it for nsoulding the foGt or neck, or attaching handles, or dragging the surface into various patterns.
Sefstrom's blast furnace, used in Sweden for the assay of iron ores, is a convenient form of portable furnace applied to melting in crucibles.
Should several furnaces simultaneously make iron too rich in silicon, this may be diluted by pouring into the mixer some low-silicon iron melted for this purpose in a cupola furnace.
Siemens on the electric furnace was continued and greatly extended by Henri Moissan and others on its scientific side, and electro-chemistry took its place as one of the most promising departments of technical research and invention.
Since 1992, when the DOE tightened its standards, most furnace manufacturers have declared their furnaces to be "high efficiency", since they meet the minimum standard.
Since John Hollway's and other early experiments of Lawrence Austin and Robert Sticht, no serious attempts have been made to utilize the heat escaping from a converting vessel in smelting ore and matte either in the same apparatus or in a separate furnace.
Some fortysix or more retorts, arranged in parallel horizontal rows, are heated in one furnace.
Soon after the Civil War he went to Malden, West Virginia, where he worked in a salt furnace and then in a coal mine.
Steel Most of the molten iron from a Blast Furnace is used to make one of a number of types of steel.
Strontium carbide, SrC2, is obtained by heating strontium carbonate with carbon in the electric furnace.
Such a circulation of air can only be effected by mechanical means when the workings are of any extent, the methods actually adopted being - (i) The rarefaction of the air in the upcast pit by a furnace placed at the bottom; and (2) Exhaustion by machinery at the surface.
Such a furnace, to take a current of 4 H.P. (say, of 60 amperes and so volts), measured externally about 6 by 6 by 7 in., and the electrodes were about o 4 in.
Such a slag not only corrodes the furnace lining, but also impedes dephosphorization, because it is irretentive of phosphorus.
Talbot carries on the process as a quasicontinuous instead of an intermittent one, operating on Too-ton or 200-ton lots of cast iron in such a way as to draw off his steel in 20-ton lots at relatively short intervals, charging a fresh 20-ton lot of cast iron to replace each lot of steel thus drawn off, and thus keeping the furnace full of metal from Monday morning till Saturday night.
That this process did not depend upon electrolysis, but was simply an instance of electrical smelting or the decomposition of an oxide by means of carbon at the temperature of the electric arc, is shown by the fact that the Cowles furnace would work with an alternating current.
The " gatherer " gathers the glass from the tank furnace on the end of the blowing-iron, rolls it on a slab of iron or stone, slightly expands the glass by blowing, and hands the blowing iron and glass to the " blower."
The active portion of such a furnace is essentially that above the blast-pipe, the function of the lower part being merely the collection of the reduced metal; the fire may therefore be regarded as burning in an unconfined space, with the waste of a large amount of its heating power.
The advantage of this combination is that, by simplifying the conditions with which the composition of the pig iron has to comply, it makes the management of the blast furnace easier, and thus lessens the danger of making " misfit " pig iron, i.e.
The air is a thick haze of supersonic grit, the fire is burning in the wind like a blast furnace.
The air receives heat from an external furnace just as water does in the boiler of a steam-engine, by contact with a heated metallic surface, but it takes up heat from such a surface with much less readiness than does water.
The arc furnaces now widely used in the manufacture of calcium carbide on a large scale are chiefly developments of the Siemens furnace.
The articles are slacked transversely in a furnace, each being packed in granular coke and covered with carborundum.
The ballast consists of such materials as broken stone, furnace slag, gravel, cinders or earth, the lower layers commonly consisting of coarser materials than the top ones, and its purpose is to provide a firm, well-drained foundation in which the sleepers or crossties may be embedded and held in place, and by which the weight of the track and the trains may be distributed over the road-bed.
The blanks are charged into a hopper at one end of the furnace and conveyed towards the other end by a revolving Archimedean screw.
The blast furnace in its simplest form is among the oldest, if not the oldest, of metallurgical contrivances.
The blast of air forced in through the tuyeres near the bottom of the furnace burns the coke there, and the intense heat thus caused melts away the surrounding iron, so that this column of coke and iron gradually descends; but it is kept at its full height by feeding more coke and iron at its top, until all the iron needed for the day's work has thus been charged.
The boiler is heated by a furnace, and the oil is brought gradually to the point of ebullition, at which it is maintained for two hours, during which time moisture is driven off, and the scum and froth which accumulate on the surface are ladled out.
The Bruckner cylinder resembles the Elliot and Russell black ash furnace; its cylinder tapers slightly towards each end, and is generally 18 ft.
The bucket then descends along the hoist-track to make way for the next succeeding one, and K is lowered, dropping the charge into the furnace.
The calcination, or roasting, is conducted at a low temperature in some form of reverberatory furnace.
The calcium silicate remains in the furnace in the form of a liquid slag, which may be run off, so that the action is practically continuous.
The carbide BeC 2 is formed when beryllia and sugar charcoal are heated together in the electric furnace.
The carbide, SmC2, is formed when the oxide is heated with carbon in the electric furnace.
The carbons can thus, by the application of suitable mechanism, be withdrawn from or plunged into the furnace at will.
The central space of the furnace was filled with a mixture of corundum, coarsely-powdered charcoal and copper; and an iron lid lined with firebrick was luted in its place to exclude air.
The chain dips below the water, then rises into the furnace and passes down into the other trough on its way out.
The charge may be melted down on the " open hearth " itself, or, as in the more advanced practice, the pig iron may be brought in the molten state from the blast furnace in which it is made.
The charge of the retorts consists of a mixture of 1100 lb of roasted calamine and 550 lb of dry powdered coal per furnace.
The charge was reduced by means of a 50-volt current from a Soo-kilowatt dynamo, which was passed through the furnace for 12 hours till decomposition was complete.
The chilling stereotypes the structure existing in the ingot at the moment it was withdrawn from the furnace, and we can af terwards study this structure by means of the microscope.
The condenser and compressor are outside the home and the evaporator is installed inside a forced-air furnace.
The consuming power of the furnace or the rate at which it can burn the fuel supplied is measured by the number of tuyeres and their section.
The Cornish is cylindrical with the furnace occupying about half the length of the cylinder.
The cost of using a gas insert may be less than powering a gas furnace, but your furnace and fireplace technicians can help you to determine the benefit of this.
The crucible with the semi-solid glass which it contains is now allowed to cool considerably in the melting furnace, or it may be removed to another slightly heated furnace.
The crucibles or pots used for the production of optical glass very closely resemble those used in the manufacture of flint glass for other purposes; they are " covered " and the molten materials are thus protected from the action of the furnace gases by the interposition of a wall of fireclay, but as crucibles for optical glass are used for only one fusion and are then broken up, they are not made so thick and heavy as those used in flint-glass making, since the latter remain in the furnace for many weeks.
The DOE set about changing this by introducing stricter standards that would ensure that at least 78% of the gas going into the furnace was converted to heat, rather than wasted.
The drained crystals are dried and heated to redness in a reverberatory furnace; when " finished," the mass is of an impure white or light yellow colour and is sold as ordinary " soda-ash."
The early years of the furnace that was to become the world's largest ironworks.
The ebullition from the formation of carbonic oxide puffs up the resultant phosphoric slag enough to make most of it run out of the furnace, thus both removing the phosphorus permanently from danger of being later deoxidized and returned to the steel, and partly freeing the bath of metal from the heat-insulating blanket of slag.
The effect of this arrangement is that the great body of coal reaches a higher temperature than in an ordinary fireplace, and this, together with the reduction of the carbon dioxide formed immediately above the grate by the red-hot coal in the upper part of the furnace, leads to the formation of carbon monoxide which later on, on the spot where the greatest heat is required, is burned into dioxide by admitting fresh air, preferably pre-heated.
The electric furnace has led to the discovery of several important materials, which have been employed as furnace linings.
The electric furnace has several advantages as compared with some of the ordinary types of furnace, arising from the fact that the heat is generated from within the mass of material operated upon, and (unlike the blastfurnace, which presents the same advantage) without a large volume of gaseous products of combustion and atmospheric nitrogen being passed through it.
The empty crucible, having first been gradually dried and heated to a bright red heat in a subsidiary furnace, is taken up by means of massive iron tongs and introduced into the previously heated furnace, the temperature of which is then gradually raised.
The essential difference in construction is that in the first class the substances heated do not come into contact with either the fuel or the furnace gases, whereas in the second they do.
The fact that energy is being used at so high a rate as Too H.P. on so small a charge of material sufficiently indicates that the furnace is only used for experimental work, or for the fusion of metals which, like tungsten or chromium, can only be melted at temperatures attainable by electrical means.
The fillets are placed on an endless chain which moves slowly through the furnace, returning underneath.
The finished bottle is taken by the " taker in " to the annealing furnace.
The first of these resemble an ordinary reverberatory furnace by having a flat bed which, however, has the form of a circular disk mounted on a central shaft, and receives a slow movement of rotation from a water-wheel or other motor, so that every part of the surface is brought successively under the action of the fire, the charge being stirred and ultimately removed by passing under a series of fixed scraper arms placed above the surface at various points.
The flame issuing from the furnace by (o) is always further utilized for boiling down the liquors obtained in a later stage, either in a pan (p) fired from the top and supported on pillars (qq) as shown in the drawing, or in pans heated from below.
The furnace A is built of fire-brick, coke is charged at the top through the iron door B, and near the bottom are placed fire bars C, upon which the fuel lies.
The furnace consisted of a flat, rectangular, firebrick box, packed with a layer of finely-powdered charcoal 2 in.
The furnace in her belly was beyond hot, her blood roaring with need.
The furnace in which the reaction taks place is shown in fig.
The furnace is built of fire-brick, and may measure (internally) 5 ft.
The furnace is made rather narrow at the top or " stock line," in order that the entering ore, fuel and flux may readily be distributed evenly.
The furnace is to make iron.
The furnace used by Henri Moissan in his experiments on reactions at high temperatures, on the fusion and volatilization of refractory materials, and on the formation of carbides, suicides and borides of various metals, consisted, in its simplest form, of two superposed blocks of lime or of limestone with a central cavity cut in the lower block, and with a corresponding but much shallower inverted cavity in the upper block, which thus formed the lid of the furnace.
The furnace used for the production of optical glass is generally constructed to take one crucible only, so that the heat of the furnace may be accurately adjusted to the requirements of the particular glass under treatment.
The fusion process is preferably carried out in crucible furnaces; shaft furnaces are unsatisfactory on account of the disintegrating action of the molten bismuth on the furnace linings.
The gases are conducted from the furnace to the combustion chamber E through the nostrils D D, and the secondary air is FIG.
The general plan of the open-hearth process was certainly conceived by Josiah Marshall Heath in 1845, if not indeed by Reaumur in 1722, but for lack of a furnace in which a high enough temperature could be generated it could not be carried out until the development of the Siemens regenerative gas furnace about 1860.
The glass in process of fusion is contained in a basin or tank built up of large blocks of fire-clay and is heated by one or more powerful gas flames which enter the upper part of the furnace chamber through suitable apertures or " ports."
The glass is taken from the furnace in large iron ladles, which are carried upon slings running on overhead rails; from the ladle the glass is thrown upon the cast-iron bed of a rolling-table, and is rolled into sheet by an iron roller, the process being similar to that employed in making plate-glass, but on a smaller scale.
The hand-wrought black-ash furnace has been mostly superseded in the large factories by the revolving black-ash furnace, shown in fig.
The heat passes from the melting furnace into the annealing kiln.
The height of the furnace is rarely as great as roo ft., and in the belief of many metallurgists it should not be much more than 80 ft.
The Heroult furnace, the best known in the arc class, and the Kjellin and Roechling-Rodenhauser fur- lc naces, the best known of the induction class, will serve as examples.
The hot producer-gas formed in V is passed round the retort E in the flues n 2 n2, and ultimately goes away through K to the furnace FIG.
The hotter the furnace the greater is the rise of temperature of the couple.
The indirect process once established, the gradual increase in the height and diameter of the high furnace, which has lasted till our own days, naturally went on and developed the gigantic blast furnaces of the present time, still called " high furnaces " in French and German.
The industries comprise granite quarrying at Furnace and Crarae, distilling at Ardrishaig, gunpowder-making at Furnace and Kilfinan, and, above all, fishing.
The introduction and withdrawal of the charges in fusion furnaces is effected by gravitation, the solid masses of raw ore, fuel and flux being thrown in at the top, and flowing out of the furnace at the taphole or slag run at the bottom.
The junction of the edges of the silver and copper-blend was treated with a flux of borax and the whole was submitted to the heat of a furnace until the silver was seen to be melting, when it was instantly removed, care being taken to avoid pressing upon the upper or lower surfaces, as the liquid silver in that case would have been squeezed out from between the two enclosing plates and the operation ruined.
The large amount of soluble sulphates of iron and copper formed in the roast is made to act upon salt charged in a copper-bottomed amalgamating pan; the chlorides formed finish in the wet way the imperfect chloridation obtained in the furnace.
The last Wealden furnace was put out in 1828.
The latest cupelling furnaces have the general form of a reverberatory copper-smelting furnace.
The latter rests on a brick pillar; the remaining part of the sloping bottom is heated, either by the waste fire from a black-ash furnace or by a special fireplace.
The latter was formerly often constructed as a reverberatory furnace, which is easy to build and to work, but the hydrochloric acid given off here, being mixed with the products of the combustion of the fuel, cannot be condensed to strong acid and is partly, if not entirely, wasted.
The lead produced in the reverberatory furnace and the ore-hearth is of a higher grade than that produced in the blast-furnace, as the ores treated are purer and richer, and the reducing action is less powerful.
The leading products of the blast-furnace are argentiferous lead (base bullion), matte, slag and flue-dust (fine particles of charge and volatilized metal carried out of the furnace by the ascending gas current).
The legends of his escape from a fiery furnace may have a philological basis (Ur interpreted as " fire "), but the allusion to the redemption of Abraham in Isa.
The limits set to the furnace builder's natural desire to make his furnace as large as possible, and its present shape (an obtuse inverted cone set below an acute upright one, both of them truncated), have been reached in part empirically, and in part by reasoning which is open to question, as indeed are the reasons which will now be offered reservedly for both size and shape.
The lining of the crucible may be of either magnesite (MgO) or chromite (FeO Cr203) The whole furnace, electrodes and all, rotates about the line KL for the purpose of pouring out the molten FIG.
The losses are caused by volatilization, by the absorption of metal by the crucible, stirring rod, &c., and by occasional projection of particles from the pot into the furnace.
The lower end of the cylinder is opened, in the case of small and thin cylinders, by the blower holding his thumb over the mouthpiece of the pipe and simultaneously warming the end of the cylinder in the furnace, the expansion of the imprisoned air and the softening of the glass causing the end of the cylinder to burst open.
The M`Dougall furnace is turret-shaped, and consists of a series of circular hearths, on which the ore is agitated by rakes attached to revolving arms and made to fall from hearth to hearth.
The manufacture of iron was established on a commercial basis in 1716-1718, when a furnace was built on Manatawney Creek above Pottstown, and before the close of the colonial era Pennsylvania had risen to first rank among the iron-producing colonies, a position which it has always held among the states of the Union.
The material to be melted is introduced into the furnace from the hoppers HH through the charging holes in the roof.
The matte also, in all economically planned works, is conveyed, still molten, by electric cranes from the furnace to the converters.
The measure used to determine how well a furnace was running is known as an Annual Fuel Utilization Efficiency (AFUE) rating.
The medicinal preparations which required the aid of a furnace, such as mineral earths, were undertaken by the chymists, who probably derived their name from the Alchymists, who flourished from the 14th to the 16th centuries.
The melting can be done much more cheaply in a cupola or open-hearth furnace, and the first part of the purification much more cheaply in a Bessemer converter or open-hearth furnace.
The men who charge and empty the retorts, those who draw and cast the metal, and those who keep the furnace in repair, need not know anything about the making or using of gas, and the men who make the gas need not know anything about a zinc furnace.
The metal in the form of thin turnings is charged into hard glass or iron tubes heated to a full red in a combustion furnace.
The metal is so pure that it can be refined by a continuous operation in the same furnace.
The metal may be used uncombined, but large quantities of ferrotungsten are made in the electric furnace; other alloys are prepared by acting on a mixture of the oxides with aluminium.
The mixture of hydrochloric acid and air is taken directly from the " decomposing-pan " of an ordinary salt-cake furnace, is first cooled down in pipes sufficiently to condense most of the moisture present 1 ?i; \'\` (together with about 8% of the hydrochloric acid), and then passed through a cast-iron superheater and from this into the " decomposer."
The mixture of ore and charcoal is put into the crucible around the pipe, the crucible closed by a luted-on lid, and placed in a furnace constructed so as to permit of the lower end of the pipe projecting into the ash-pit.
The most common are the history of Jonah as a type of the Resurrection, the Fall, Noah receiving the dove with the olive branch, Abraham's sacrifice of Isaac, Moses taking off his shoes, David with the sling, Daniel in the lions' den, and the Three Children in the fiery furnace.
The native chrome-ironstone (Cr 2 O 3 FeO) may be used in this way as a source of such compounds, being fused in a reverberatory furnace, along with soda-ash and lime, the oxidizing agent in this case being atmospheric oxygen.
The new discovery of iron ore on their doorstep prompted them to build Teesside's first blast furnace in 1851.
The new Kessler furnace is a very ingenious apparatus, in which the fire from a gas-producer travels over the sulphuric acid contained in a trough made of Volvic lava, and surmounted by a number of perforated plates, over which fresh acid is constantly running down; the temperature is kept down by the production of a partial vacuum, which greatly promotes the volatilization of the water, whilst retarding that of the acid.
The next great improvement in blast-furnace practice came in 1811, when Aubertot in France used for heating steel the furnace gases rich in carbonic oxide which till then had been allowed to burn uselessly at the top of the blast furnace.
The normal use of the Kjellin induction furnace is to do the work usually done in the crucible process, i.e.
The opening on the bottom of the fireplace (called a firebox bottom) operates much like the air intake vents of a furnace.
The oxidation of the foreign elements must be very slow, lest the effervescence due to the escape of carbonic oxide from the carbon of the metal throw the charge out of the doors and ports of the furnace, which itself must be shallow in order to hold the flame down close to the charge.
The oxygenated metal is prepared by melting cast iron diluted with as much scrap steel as is available, and oxidizing it with the flame and with iron ore as it lies in a thin molten layer, on the hearth of a large open-hearth furnace; the thinness of the layer hastens the oxidation, and the large size of the furnace permits considerable frothing.
The part is then impregnated with furfural alcohol in a furnace to convert it to carbon.
The Peter Spence type of calcining furnace has been followed in a large number of inventions.
The pit was situated near the blast furnace about half a mile from the village.
The preparation of the pure metal was successfully effected by Werner von Bolton in 1905, who fused the compressed product obtained in the Berzelius process in the electric furnace, air being excluded.
The present article, as explained under Electrochemistry, treats only of those processes in which electricity is applied to the production of chemical reactions or molecular changes at furnace temperatures.
The primary advantages of gasfiring are that less fuel is required, that there is better control of the heat in the furnace, and that larger and more accessible furnaces can be built.
The process adopted for the Canadian ores, which are poor in copper and nickel, consists in a preliminary roasting in heaps and smelting in a blast furnace in order to obtain a matte, which is then further smelted with a siliceous flux for a rich matte.
The product is then distilled from Stourbridge clay retorts, arranged in a galley furnace, previously heated to a red heat.
The proportions in which these ingredients are mixed vary according to the exact quality of glass required and with the form and temperature of the melting furnace employed.
The radiation passing out from an opening in the furnace falls upon a concave mirror in a telescope and is focused upon a thermoelectric couple.
The reason for this is that in it the slag, by means of which all the purification must needs be done, is not heated effectively; that hence it is not readily made thoroughly liquid; that hence the removal of the phosphoric slag made in the early dephosphorizing stage of the process is liable to be incomplete; and that hence, finally, the phosphorus of any of this slag which is left in the furnace becomes deoxidized during the second or deoxidizing stage, and is thereby returned to befoul the underlying steel.
The reason why at this level the walls must form an upright instead of an inverted cone, why the furnace must widen downward instead of narrowing, is, according to some metallurgists, that this shape is needed in order that, in spite of the pastiness of the slag in this formative period of incipient fusion, this layer may descend freely as the lower part of the column is gradually eaten away.
The reason why the frictional resistance would be further increased is the very simple one that the increase in the rate of production implies directly a corresponding increase in the quantity of blast forced through, and hence in the velocity of the rising gases, because the chemical work of the blast furnace needs a certain quantity of blast for each ton of iron made.
The reduced aluminium alloys itself immediately with the fused globules of metal in its midst, and as the charge becomes reduced the globules of alloy unite until, in the end, they are run out of the tap-hole after the current has been diverted to another furnace.
The Reese River or pan-amalgamation process consists in drystamping crushed dried ore and dried salt (separately or together), charging them into a roasting furnace, and amalgamating the chloridized ore in an iron pan.
The rest of the apparatus (settler, retort, crucible, furnace) is the same as with the Washoe process.
The return air from fiery workings is never allowed to approach the furnace, but is carried into the upcast by a special channel, called a dumb drift, some distance above the furnace drift, so as not to come in contact with the products of combustion until they have been cooled below the igniting point of fire-damp. Where the upcast pit is used for drawing coal, it is usual to discharge the smoke and gases through a short lateral drift near the surface into a tall chimney, so as to keep the pit-top as clear as possible for working.
The Roechling-Rodenhauser furnace is unfitted, by the vulnerability of its interior walls, for receiving charges of cold metal to be melted down, but it is used to good advantage for purifying molten basic Bessemer steel sufficiently to fit it for use in the form of railway rails.
The salt is conveyed to the furnace by a chain of buckets running on the pulley (g), and passing into the hopper (h), and through the pipe (i) is mixed with the proper amount of acid supplied by the pipe (f).
The shape which the molten metal under treatment has in the Kjellin furnace, a thin ring of large diameter, is evidently bad, inconvenient for manipulation and with excessive heat-radiating surface.
The Silesian furnace has an oblong hearth sloping from the firebridge to the flue-bridge.
The smallness of the pipes renders it liable to damage by frost, but this accident may be prevented by always keeping in frosty weather a small fire in the furnace.
The space between the two cylinders serves as a heater and distributor for the blast, which is introduced through the nozzle at the bottom, and enters the furnace through a series of several small tuyeres arranged round the inner lining.
The special conditions of the blast-furnace actually exaggerate the saving due to this widening of the available temperature-margin, and beyond this drying the blast does great good by preventing the serious irregularities in working the furnace caused by changes in the humidity of the air with varying weather.
The spelter used must therefore be of a good grade, and the lead is usually first refined in a reverberatory furnace (the softening furnace).
The split cylinder is passed to the flattening furnace, where it is exposed to a red heat, sufficient to soften the glass; when soft the cylinder is laid upon a smooth flat slab and flattened down upon it by the careful application of pressure with some form of rubbing implement, which frequently takes the form of a block of charred wood.
The stages at which heat is taken from the furnace and rejected to the cooler (C) are approximately isothermal at the upper and lower limits of temperature respectively, and the cycle accordingly is approximately "perfect" in the thermodynamic sense.
The stages of the process so far described generallyoccupy from 36 to 60 hours, and during this time the constant care and watchfulness of those attending the furnace is required.
The study has also produced a model to help glassmakers optimize furnace efficiency at any combination of production level and cullet ratio.
The superconductor was then incinerated in a furnace... A moving electron is flying compared to the motion of the heavier ions.
The supply of borax is, however, mainly derived from the boric acid of Tuscany, which is fused in a reverberatory furnace with half its weight of sodium carbonate, and the mass after cooling is extracted with warm water.
The temperature of the electric furnace, whether of the arc or incandescence type, is practically limited to that at which the least easily vaporized material available for electrodes is converted into vapour.
The tests range from small scale charring tests (cone calorimeter) to large scale furnace tests.
The usual form of ventilating furnace is a plain fire grate placed under an arch, and communicating with the upcast shaft by an inclined drift.
The vases of Karl Koepping of Berlin are so fantastic and so fragile that they appear to be creations of the lamp rather than of the furnace.
The vertical section, on the other hand, is subject to considerable variation according to the work to which the furnace is applied.
The water is heated by a furnace, and is conveyed from the boiler into the houses by a main or " flow " pipe, connected by means of syphon branches with as many pipes as it is intended to serve.
The West Brandon furnace was discovered by George Jobey in 1961 at a wooden roundhouse, a type of building common for its period.
The whole legend of this stone, which is full of miraculous incidents, seems to have arisen from a misconception, the Maqam Ibrahim in the Koran meaning the sanctuary itself; but the stone, which is a block about 3 spans in height and 2 in breadth, and in shape "like a potter's furnace" (Ibn Jubair), is certainly very ancient.
The whole pot, with its contents of viscous glass, is then removed bodily from the furnace by means of huge tongs and is transported to a crane, which grips the pot, raises it, and ultimately tips it over so as to pour the glass upon the slab of the rolling-table.
The whole was thrown in several portions on to the hearth of a furnace previously heated to low redness and was stirred at intervals for three hours.
The working chamber indeed is the furnace proper, in which the whole of the open-hearth process is carried out, and the function of all the rest of the apparatus, apart from the tilting mechanism, is simply to pre-heat the air and gas, and to lead them to the furnace proper and thence to the chimney.
The zinc and some lead are oxidized; part of the zinc passes off with the fumes, part is dissolved by the litharge, forming a melted mixture which is skimmed off and reduced in a blast-furnace or a reverberatory smelting furnace.
There A is the externallyfired heating vessel, the lower part of which contains hot air which is taking in heat from the furnace beneath.
There are ferries at St Catherine's and Otter, and piers at Tarbert, Ardrishaig, Kilmory, Crarae, Furnace, Inveraray, Strachur and elsewhere.
There are some very evident disadvantages of excessive height; for instance, that the weight of an excessively high column of solid coke, ore and limestone tends to crush the coke and jam the charge in the lower and narrowing part of the furnace, and that the frictional resistance of a long column calls for a greater consumption of power for driving the blast up through it.
There are two distinct ways of making the steel objects actually used in the arts, such as rails, gear wheels, guns, beams, &c., out of the molten steel made by the Bessemer, open hearth, or crucible process, or in an electric furnace.
There is, however, one (not insuperable) drawback in the use of the electric furnace for the smelting of pure metals.
These are removed using quicklime (calcium oxide) which is added to the furnace during the oxygen blow.
These burners, or modifications of them, have also been applied to muffle furnaces, which are convenient when only a few assays have to be made - the furnace being a mere clay shell and soon brought to a working temperature; but the fuel is too expensive to allow of their being used habitually or on a large scale.
These can include a furnace, fans, drip pans, coils and the related housings of these items.
These distilling vessels are called retorts if they are supported only at the ends, and the furnace using them is termed a Belgian furnace.
These materials were heated in pans in the furnace so as to combine in a pasty, half-fused condition.
These regenerators are the essence of the Siemens or " regenerative furnace "; they are heat-traps, catching and storing by their -11, Ton Traver 7s 20 Tan Tra y.
These systems typically involve a condenser and compressor unit located on the outside of the home, which share the central air handling unit and ductwork used by the forced-air furnace.
These two things are done simultaneously by heating and melting the ore in contact with coke, charcoal or anthracite, in the iron blast furnace, from which issue intermittently two molten streams, the iron now deoxidized and incidentally carburized by the fuel with which it has been in contact, and the mineral matter, now called " slag."
These, though not showing a great resistance to extreme heat, are very slightly affected by sudden alternations in heating, as they may be plunged cold into a strongly heated furnace without cracking, a treatment to which French and Stourbridge pots cannot be subjected with safety.
They are heat-filters or heat-traps for impounding the heat developed by the combustion of the furnace gas, and later returning it to the blast.
They are long and narrow; the sole is plane, but slopes from the fire-bridge towards the flue, so that the metal runs to the latter end to collect in pots placed outside the furnace.
They are not likely to displace either the open-hearth furnace or the Bessemer converter, because their normal work is only to improve the product of these older furnaces.
They learned lessons in the fiery furnace they would never have learned in the cool of day.
This advantage is especially observed in some cases in which the charge of the furnace is liable to attack the containing vessel at high temperatures, as it is often possible to maintain the outer walls of the electric furnace relatively cool, and even to keep them lined with a protecting crust of unfused charge.
This and the previous type of furnace, owing to their large capacity, are at present in greatest favour.
This carburizing is an indispensable part of the process, because through it alone can the iron be made fusible enough to melt at the temperature which can be generated in the furnace, and only when liquid can it be separated readily and completely from the slag.
This causes the lead to collect at the coolest part of the hearth, whence it is tapped, &c., as in the English furnace.
This class of furnace is usually known as an open fire or hearth, and is represented in a more advanced stage of development by the Catalan, German and Walloon forges formerly used in the production of malleable iron.
This could possibly raise your electric or gas bill because the amount of time your furnace stays on can decrease if you choose a programmable thermostat.
This crude cast iron, called " pig iron," may be run from the blast furnace directly Ore FIG.
This furnace acts very well, and has been widely introduced both in Great Britain and in other countries, but it has one great drawback, apart from its high cost, viz.
This furnace is also very well adapted for impure acids, unsuitable for platinum or platinum-gold stills on account of the crusts forming at the bottom of the retorts; and it is more and more coming into use both in Great Britain and on the Continent.
This furnace may be used also for purifying the molten metal, but it is not so well suited as the arc furnaces for dephosphorizing.
This heating was formerly done by burning part of the gases, after their escape from the furnace top, in a large combustion chamber, around a series of cast iron pipes through which the blast passed on its way from the blowing engine to the tuyeres.
This is attained in the regenerative furnace of Siemens, detailed consideration of which belongs more properly to the subject of iron.
This is generally done by making the bed of the furnace very long in proportion to its breadth and to the fire-grate area, which may be the more easily done as a not inconsiderable amount of heat is given out during the oxidation of the ore - such increased length being often obtained by placing two or even three working beds one above the other, and allowing the flame to pass over them in_order from below upwards.
This may sound simple, but just because a furnace is more or less expensive than another doesn't mean it's higher or lower efficiency.
This method has received considerable extension, notably in furnace-smelting of iron ores containing manganese, where the entire hearth is often completely water-cased, and in some lead furnaces where no firebrick lining is used, the lower part of the furnace stack being a mere double iron box cooled by water sufficiently to keep a coating of slag adhering to the inner shell which prevents the metal from being acted upon.
This method is rarely practised except by the rollers of zinc. A certain amount of refined zinc can be dipped from the furnace; a further amount, nearly free from iron, can be liquated out of the ingots cast from the bottom of the bath in a subsequent slow remelting, and it is sometimes possible to eliminate a zinciferous lead which collects in the sump of the furnace.
This method of firing results in the saving of about one-third the weight of coke used in the old form of furnace per ton of coal carbonized, and enables higher temperatures to be obtained, the heat being also more equally distributed.
This principle is capable of very wide extension, the blast furnace being mainly limited in height by the strength the column of materials or "burden" has to resist crushing, under the weight due to the head adopted, and the power of the blowing engine to supply blast of sufficient density to overcome the resistance of the closely packed materials to the free passage of the spent gases.
This rich matte is then mixed with coke and salt-cake and melted down in an open hearth furnace.
This rod was connected with the negative pole of the generator, and was suspended from one arm of a balance-beam, while from the other end of the beam was suspended a vertical hollow iron cylinder, which could be moved into or out of a wire coil or solenoid joined as a shunt across the two carbon rods of the furnace.
This will help reduce your need for the furnace to be running.
This will lower the amount of gas you require to run the furnace, making even a furnace with a slightly lower AFUE rating more efficient.
Thomas realized that this furnace could work at Ynyscedwyn, thus allowing him to use the hard coal called anthracite from local coal mines.
Thus some 1700 tons of materials are charged daily into each of these furnaces without being shovelled at all, running by gravity from bin to bucket and from bucket to furnace, and being hoisted and charged into the furnace by a single engineer below, without any assistance or supervision at the furnacetop.
Thus the furnace may be said to have four zones, those of (1) deoxidation, (2) heating, (3) melting, and (4) collecting, though of course the heating is really going on in all four of them.
Thus the necessary slowness of the heating up of the molten charge would compel us to make the removal of the carbon slow, even if this slowness were not already forced on us by the danger of having the charge froth so much as to run out of the furnace.
TiN 2 is a dark blue powder obtained when the oxide is ignited in an atmosphere of ammonia; while TiN is obtained as a bronze yellow mass as hard as the diamond by heating the oxide in an atmosphere of nitrogen in the electric furnace.
Tissier, formerly his assistants, who had devised an improved sodium furnace and had acquired a thorough knowledge of their leader's experiments, also left, and erected a factory at Amfreville, near Rouen, to work the cryolite process.
Titanium monoxide, TiO, is obtained as black prismatic crystals by heating the dioxide in the electric furnace, or with magnesium powder.
To make sure that you are getting a furnace that will heat your home and save you money, while fitting into your current budget, consult this guide before you purchase.
To start a new furnace, the front side is closed provisionally by a brick wall, a fire lighted inside, and the temperature raised very gradually to a white heat.
To this objection it may in turn be answered that, though this degree of freedom of descent may suffice for a slowrunning furnace, particularly if the slag is given such a composition that it passes quickly from the solid state to one of decided fluidity, yet it is not enough for swift-running ones, especially if the composition of the slag is such that, in melting, it remains long in a very sticky condition.
To this very plausible theory it may be objected that in many slowrunning furnaces, which work very regularly and show no sign of scaffolding, the outward flare of the boshes continues (though steepened) far above this region of pastiness, indeed nearly half-way to the top of the furnace.
To widen it more abruptly would indeed increase the volume of the furnace, but would probably lead to grave irregularities in the distribution of the gas and charge, and hence in the working of the furnace.
To-day more than eight-tenths of the copper ores of the world are reduced to impure copper bars or to fine copper at the mines; and where the character of the ore permits, the cupola furnace is found more economical in both fuel and labour than the reverberatory.
Typically, thermocouple measurements around a furnace are highly correlated.
Underground boilers placed near the up-cast pit so that the smoke and gases help the ventilating furnace have been largely used but are now less favourably regarded than formerly.
Various combinations and modifications of these two types of furnace have given rise to distinctive names, and as each system has its advantages and disadvantages local conditions determine which is the better.
Ventilation may be produced by heating the air of the mine, as for example, by constructing a ventilating furnace at the bottom of an air shaft.
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Wellman's tilting furnace rolls on a fixed rack instead of on rollers.
When flattened, the sheet is moved away from the working opening of the furnace, and pushed to a system of movable grids, by means of which it is slowly moved along a tunnel, away from a source of heat nearly equal in temperature to that of the flattening chamber.
When God punishes he does so as a craftsman who uses a blast furnace to refine the metal he is working with.
When the " candles " of carbon monoxide appear, the pasty mass is quickly drawn out of the furnace into iron " bogies," where it solidifies into a grey, porous mass, the " black-ash."
When the desulphurization is sufficiently complete, the sulphurbearing slag is removed, the final additions needed to give the metal exactly the composition aimed at are made, and the molten steel is tapped out of the furnace into its moulds.
When the former is used it is roasted with calcium sulphate or alkali waste to form a matte which is then blown in a Bessemer converter or heated in a reverberatory furnace with a siliceous flux with the object of forming a rich nickel sulphide.
When the furnace with this well-known regulating device was to be used, say, for the melting of metals or other conductors of electricity, the fragments of metal were placed in the crucible and the positive electrode was brought near them.
When the gas which escapes from the furnace top is used in gas engines it generates about four times as much power as when it is used for raising steam.
When the glass has cooled so far as to become hard and solid, the furnace is hermetically sealed up and allowed to cool very gradually to the ordinary temperature.
When the Heroult furnace is used for completing the purification of molten steel begun in the Bessemer or open-hearth process, and this is its most appropriate use, the process carried out in it may be divided into two stages, first dephosphorization, and second deoxidation and desulphurization.
When the ingots had so far solidified that they could be handled, the moulds were removed and set on the floor to cool, the ingots were set on a car and carried to the soaking furnace, and the moulds were then replaced in the casting pit.
When the mine is free from gas, the furnace may be worked by the return air, but it is better to take fresh air directly from the downcast by a scale, or split, from the main current.
When the removal of the phosphorus is sufficiently complete, this slag is withdrawn from the furnace.
When this happens the plug being no longer covered with water is heated to such a temperature that it melts and allows the contents of the boiler to escape into the furnace.
When we have thus fixed the height of the furnace, its diameter at its ends, and the slope of its upper and lower parts, we have completed its outline closely enough for our purpose here.
Where the operation is simply one of fusion, as in the ironfounder's cupola, in which there is no very great change in volume in the materials on their descent to the tuyeres, the stack is nearly or quite straight-sided; but when, as is the case with the smelting of iron ores with limestone flux, a large proportion of volatile matter has to be removed in the process, a wall of varying inclination is used, so that the body of the furnace is formed of two dissimilar truncated cones, joined by their bases, the lower one passing downwards into a short, nearly cylindrical, position.
Where you live will also be a factor in how efficient a furnace you'll require.
While the metal lies tranquilly on the bottom of the furnace, any slag mechanically suspended in it has a chance to rise to the surface and unite with the slag layer above.
Whoever does not fall down and worship will immediately be thrown into a blazing furnace.
Wirthwein, the titanium mineral is fused with carbon in the electric furnace, the carbides treated with chlorine, and the titanium chloride condensed.
With producer gas it is necessary to pre-heat both the gas and the air which is supplied for its combustion by passing both through heated regenerators (for an account of the principles of the regenerative furnace see article Furnace).
With the width at the bottom thus limited, the furnace builder naturally tries to gain volume as rapidly as possible by flaring or " battering " his walls outwards, i.e.
Wood, of Sparrows Point, Md., in which the moulds, while receiving the steel, stand on a train of cars, which are immediately run to the side of the soaking furnace.
Wooden guides being of considerable size, block up a certain portion of the area of the pit, and thus offer an impediment to the ventilation, especially in upcast shafts, where the high temperature, when furnace ventilation is used, is also against their use.
Yet the use of an open-hearth furnace of very great capacity, say of 200 tons per charge, has the disadvantage that such very large lots of steel, delivered at relatively long intervals, are less readily managed in the subsequent operations of soaking and rolling down to the final shape, than smaller lots delivered at shorter intervals.
You can heat your home using these inserts and decrease your dependency on your furnace.
You can turn down the thermostat on your costly furnace and supplement the heat in the room where you will be spending the bulk of your time with that produced by the more efficient EdenPURE.
You need to see the actual AFUE of the furnace you are considering.