Cupolas

Cup lump grades Cupola cast Cupper as Cupramine Cuprammomum... 

J. R. RoteUa and G. A. Walzer, Estimating Cupola and Induction Melting Using a Computer Model, AES Transactions, American Eoundryman s Society, Chicago, fll.,pp. 331-335. 

HBI has been successfully melted in cupolas (hot or cold blast), induction furnaces (coreless or channel), and electric arc furnaces. It can be a valuable charge material for ductile and malleable irons as well as steel. It is of particular value in making ductile iron castings because of its very low residual element content. 

MFS Cupola Handbook, American Eoundrymen s Society, Chicago, HI., 1975, p. 210. 

Machinery nd Cupola. Cast Iron. This designation combines two cast-iron grades known as drop broken machinery cast and cupola cast. The former consists of clean, heavy machined cast iron that has been broken into pieces suitable for cupola charging. Cupola cast consists of a wide variety of cast-iron scrap, including automobile blocks and parts from agricultural and other machinery, in sizes suitable for the cupola. Machinery and cupola cast-iron scrap are primary sources of scrap for the iron foundries. 

Motor Blocks. Automobile and tmck motors prepared to varying degrees of quality constitute a grade of scrap called motor blocks. The higher quality grades are stripped blocks from which most of the steel and nonferrous and nonmetaUic parts are removed and the blocks are broken to cupola size. Degreasing the scrap further improves its quality. 

Ferrous foundries consist of two types steel foundries in which electric furnaces (EAF and induction) are used, and iron foundries in which hot-blast cupolas and/or electric furnaces are used. Electric furnaces use virtually 100% scrap charges. Cupolas are shaft furnaces which use preheated air, coke, fluxes, and metallic charges. Scrap is over 90% of the metallic charge. Cupolas accounted for about 64% of total iron foundry scrap consumption in 1994 and electric furnaces accounted for about 34%. The balance was consumed by other furnaces, such as air furnaces. Iron foundry products have a high carbon content and the scrap charge usually contains a high percentage of cast iron or is used in combination with pig iron. 

Table 1 shows the average percentages of scrap and pig iron used in the metallic charges for each of the three principal furnace types. DRI consumption averaged about 2% in electric furnaces and only a fraction of 1% in BOFs and cupolas. These percentages do not include the scrap consumed in blast furnaces and certain other special furnaces which amounted to 1.9 million t in 1994. DRI consumption in blast furnaces totaled 490,000 t in 1994. 

Refractories for Cupolas. In many ways, the use of carbon cupola linings has paralleled the appHcation of carbon in the blast furnace. 

Carbon brick and block ate used to line the cupola well (73) or cmcible. When properly installed and cooled carbon linings last for many months or even years of intermittent operation. Their resistance to molten iron and both acid and basic slags provides not only insurance against breakouts but also operational flexibility to produce different iron grades without the necessity of changing refractories. Carbon is also widely used for the tap hole blocks, breast blocks, slagging troughs, and dams. 

The Cupola and Its Operation, American Foundrymen s Society, Des Plaines, Dl., 1965. 

Iron and steel industries have been concerned with emissions from their furnaces and cupolas since the industry started. Pressures for control have forced the companies to such a low level of permissible emissions that some of the older operations have been closed rather than spend the money to comply. The companies controlling these operations have not gone out of business but rather have opened a new, controlled plant to replace each old plant. Table 6-3 illustrates the changes in the steelmaking processes that have occurred in the United States. 

Emissions from foundry cupolas are relatively small but stiU significant, in some areas. An uncontrolled 2-m cupola can be expected to emit up to 50 kg of dust, fumes, smoke, and oil vapor per hour. Carbon monoxide, oxides of nitrogen, and organic gases may also be expected. Control is... 

To develop an emission inventory for an area, one must (1) list the types of sources for the area, such as cupolas, automobiles, and home fireplaces (2) determine the type of air pollutant emission from each of the listed sources, such as particulates and SO2 (3) examine the literature (9) to find valid emission factors for each of the pollutants of concern (e.g., "particulate emissions for open burning of tree limbs and brush are 10 kg per ton of residue consumed") (4) through an actual count, or by means of some estimating technique, determine the number and size of specific sources in the area (the number of steelmaking furnaces can be counted, but the number of home fireplaces will probably have to be estimated) and (5) multiply the appropriate numbers from (3) and (4) to obtain the total emissions and then sum the similar emissions to obtain the total for the area. 

Cupolas Particulate matter Baghouses, wet scrubbers, and ESPs... 

Steel Basic oxygen furnace Open hearth Electric furnace Ore roasters Cupola Pyrites roaster Taconite roaster Hot scarfing... 

Tliis ignition source includes sparks released from foundry cupolas, furnaces, and incinerators. 

Dom, m. dome, cupola cover cathedral. Doma, n. Cryat.) dome. 

Kuppe,/. top, summit, tip, head meniscus. Kuppel,/. cupola, dome arch (of a furnace), kuppelartig, a. dome-like, dome-shaped, arched, kuppeln, v.t. [Pg.266]

Most cupolas still have no collectors but air pollution and public nuisance emphasis is creating greater interest in control equipment. 

Furnace types include cupolas, electric arc, induction, hearth or reverberatory, and crucible. Because of the different characteristics of metals, different inputs are required and different pollution is released from each type. Table 4.1 summarizes the types of furnaces depending on the type of metal being used. 

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