Word Finder - furnaces

definition

An industrial heating device, e.g. for smelting metal or baking ceramics.

definition

A device that provides heat for a building; a space heater.

definition

Any area that is excessively hot.

definition

A place or time of punishment, affliction, or great trial; severe experience or discipline.

Among the borough's manufactures are stoves and furnaces, malt liquors and silk.

In the next stage of the process, the glass is raised to a high temperature in order to render it sufficiently fluid to allow of the complete elimination of these bubbles; the actual temperature required varies with the chemical composition of the glass, a bright red heat sufficing for the most fusible glasses, while with others the utmost capacity of the best furnaces is required to attain the necessary temperature.

In Germany, Austria and the United States, gas furnaces are generally used.

In England directly-heated coal furnaces are still in common use, which in many cases are stoked by mechanical feeders.

The furnaces are driven to a white heat in order to fuse the mixture and expel bubbles of gas and air.

The temperature required in the fusion of sheet-glass and of other glasses produced in tank furnaces is much lower than that attained in steel furnaces, and it is consequently pos Since the discovery of the Rntgen rays, experiments have been made to ascertain the effects of the different constituents of glass on the transparency of glass to X-rays.

The fusion of sheet-glass is now generally carried out in gas-fired regenerative tank furnaces.

In Europe the gas burnt in these furnaces is derived from special gas-producers, while in some parts of America natural gas is utilized.

Thus the dimensions of the largest glass tanks greatly exceed those of the largest steel furnaces; glass furnaces containing up to 250 tons of molten sible to work glass-tanks continuously for many months together; on the other hand, glass is not readily freed from foreign bodies that may become admixed with it, so that the absence of detachable particles is much more essential in glass than in steel melting.

This workman stands upon a platform in front of special furnaces which, from their shape and purpose,.

The process of sheet-glass manufacture described above is typical of that in use in a large number of works, but many modifications are to be found, particularly in the furnaces in which the glass is melted.

In some works, the older method of melting the glass in large pots or crucibles is still adhered to, although the old-fashioned coal-fired furnaces have nearly everywhere given place to the use of producer gas and regenerators.

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.

Except for making bottles of special colours, gas-heated tank furnaces are in general use.

The glass to be used for the production of plate is universally melted in pots or crucibles and not in open tank furnaces.

These small furnaces are usually heated by an oil spray under the pressure of steam or compressed air.

Many of the examples of these processes exhibit surprising skill and taste, and are among the most beautiful objects produced at the Venetian furnaces.

In the 16th century it had become a trade of great importance, and about 1764 twenty-two furnaces were employed in the production of beads.

It appears that as early as 1295 furnaces had been established at Treviso, Vicenza, Padua, Mantua, Ferrara, Ravenna and Bologna.

Beginning in Sussex, Surrey and Kent, where wood for fuel was plentiful, the foreign glass-workers and their descendants migrated from place to place, always driven by the fuel-hunger of their furnaces.

They can be traced by cullet heaps and broken-down furnaces, and by their names, often mutilated, recorded in parish registers.

Slingsby for burning coal in furnaces, and coal appears to have been used in the Broad Street works.

The ore is smelted at Lubumbashi, where in 1918 were seven furnaces with a producing capacity of 40,000 tons a year.

In the neighbourhood of Millom there are blast furnaces and highly productive mines of red haematite ore.

The bagasse so used is now commonly taken straight from the cane mill to furnaces specially designed for burning it, in its moist state and without previous drying, and delivering the hot gases from it to suitable boilers, such as those of the multitubular type or of the water-tube type.

The chief industrial establishments are smelting furnaces for cobalt, meat-preserving works at Ouaco, sugar-works and distilleries at Noumea and La Foa, tobacco, oil and soap factories at Noumea.

Pliny explicitly speaks of a mineral Katiµ€ia or cadmic as serving for the conversion of copper into aurichalcum, and says further that the deposit (of zinc oxide) formed in the brass furnaces could be used instead of the mineral.

The furnaces are square and open in front, to allow the outlet ends of the retorts to project; they are grouped together by fours; and their several chimneys are within the same enclosure.

When hydraulic pressure to the amount of 2000 to 3000 lb per square inch is applied, the saving is unquestioned, since less time is required to dry the pressed retort, its life in the furnaces is longer, its absorption of zinc is less, and the loss of zinc by passage through its walls in the form of vapour is reduced.

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.

In Silesia the introduction of gas-firing has led to the use of furnaces containing eighty muffles.

In the United States, Belgian furnaces of type (a) are built to contain 864 retorts; of type (b), to contain 300 to 400 retorts; and of type (c), preferably about 600 retorts.

The use of gas-fired furnaces greatly simplifies manual labour.

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.

Furthermore, with the large furnaces which gas-firing makes possible mechanical appliances may be substituted for manual labour in many operations, such as removing and replacing broken retorts, mixing and conveying the charge, drawing and casting the metal, charging and emptying the retorts, and removing the residues and products.

A redistilled zinc, from an ordinarily pure commercial zinc, is often called chemically pure, but redistillation is seldom practised except for the recovery of zinc from galvanizer's dross and from the skimmings and bottoms of the melting furnaces of zinc rolling mills.

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.

Much of the earlier electrometallurgical work was done with furnaces of the (a) type, while nearly all the later developments have been with those of class (b).

Practically the first of these furnaces was that of Despretz, in which the mixture to be heated was placed in a carbon tube rendered incandescent by the passage of a current through its substance from end to end.

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.

It is not necessary that all electric furnaces shall be run at these high temperatures; obviously, those of the incandescence or resistance type may be worked at any convenient temperature below the maximum.

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.

The arc furnaces now widely used in the manufacture of calcium carbide on a large scale are chiefly developments of the Siemens furnace.

Among the other manufactures are food preparations, wooden ware, wagons and carriages, stoves and furnaces, boots and shoes, tobacco and cigars, flour, candy, gloves, bricks, tile and pottery, furniture, paper boxes and firearms. Utica is a shipping point for the products of a fertile agricultural region, from which are exported dairy products (especially cheese), nursery products, flowers (especially roses), small fruits and vegetables, honey and hops.

It is near the great mineral deposits of Virginia, Tennessee, West Virginia, Kentucky and North Carolina; an important distributing point for iron, coal and coke; and has tanneries and lumber mills, iron furnaces, tobacco factories, furniture factories and packing houses.

In Colorado the pyritic ores containing gold and silver in association with copper are smelted in reverberatory furnaces for regulus, which, when desilverized by Ziervogel's method, leaves a residue containing 20 or 30 oz.

The precipitate is collected in a filter-press, and then roasted in muffle furnaces with nitre, borax and sodium carbonate.

The trees were formerly felled for building the ships of the navy and for feeding the iron furnaces of Sussex and Hampshire.

The mining of these, together with blast furnaces and engineering works, occupies the large industrial population.

Among the leading products are those of the furnaces, foundries and machine shops, flour and grist mills, planing mills, creameries, bridge and iron works, publishing houses and a packing house; and brick, tile, pottery, patent medicines, furniture, caskets, tombstones, carriages, farm machinery, Portland cement, glue, gloves and?hosiery.