Carnegie Steel Co. v. Cambria Iron Co.

89 F. 721, 1898 U.S. App. LEXIS 3115
CourtU.S. Circuit Court for the District of Western Pennsylvania
DecidedSeptember 5, 1898
StatusPublished
Cited by4 cases

This text of 89 F. 721 (Carnegie Steel Co. v. Cambria Iron Co.) is published on Counsel Stack Legal Research, covering U.S. Circuit Court for the District of Western Pennsylvania primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Carnegie Steel Co. v. Cambria Iron Co., 89 F. 721, 1898 U.S. App. LEXIS 3115 (circtwdpa 1898).

Opinion

BUFFINGTON, District Judge.

This case concerns the art of steel-making. As the difficulties which the patent sought to obviate in that art arose in the Bessemer process, and its practical application has been wholly therein, an account of such process, and its relation to and effect on the art would seem proper, if not, indeed, indispensable, to a proper understanding of the case. And as this patent underlies, and in a measure possibly dominates, the successful commercial converting of Bessemer steel by the direct process, the [723]*723importance of the question involved must be a sufficient warrant for this unusually lengthy opinion. Tersely stated, the Bessemer process consists in blowing air through molten pig iron placed in a refractory lined vessel called a “converter,” whereby the oxygen combines with, and burns out, the carbon and silicon. It was probably the most potent factor in broadening the scope of the steel industry, cheapening its product, making possible its use in new and wider fields, and its substitution for iron. While (he foundation of this advance is based on Bessemer, improvements were made by others. Touching only on such as are pertinent here, we note that when iron was thoroughly decarbonized a certain necessary amount of carbon was restored to the metal by Mushet’s method of introducing ferro-manganese, or spiegeleisen. With the Bessemer invention was soon seen the possibility of making steel by what was known as the “direct process”; that is, taking the molten metal direct from a blast furnace. and subjecting it in a fluid state to the Bessemer process. The immense saving in both labor and plant appliances in case this could be successfully done was self-evident; hut grave difficulties in the way of such use soon became apparent, and threatened, unless met, enforced abandonment of such direct process. What these difficulties were will appear from a study of the thermal and chemical, or quasi chemical, elements of molten metal treatment. From the heat-yielding capacity of silicon the high temperature needed for heating, and keeping heated, the fluid in the converter was obtained. Such high stage of heat was imperative from the fact that as the fluid, by the consumption of carbon and silicon, approached the condition of pure iron, its melting point rose, and, unless a correspondingly high temperature was kept up, the fluid grew thick or pasty, — an objectionable condition. Much of the heat generated by carbon oxidation passed off with the carbonic oxide gas, but- the oxidized silicon formed slag, which remained in the converter, and the intense heat caused by (lie burning of the silicon was thus retained and utilized. Its varying degree, however, was a source of serious trouble. Such trouble arose; in this way: If the metal contained a high percentage of silicon, (he resultant heat was proportionately great. If such heat was excessive, and not controlled or neutralized, overblown or wild heats of steel resulted, which could only with difficulty he deoxidized with manganese, and which likely resulted in a bad product. On the other hand, if the fluid mass was too low either in initial temperature or in silicon percentage, these factors, if not corrected, produced chilled heats, or scrap. To neutralize or convert as far as possible these; adverse unfavorable conditions was the province of an adept, skillful, and expert blower or converter man. That such qualities were indispensable will appear from attendant conditions. The converter reactions were rapid, the entire operation lasting but 10 minutes. The peculiar appearance of flame jetting from the converter mouth was an index to the blower man of the thermal character of the charge. If he thought it too hot, he added varying, hut sometimes large, quantities of cold steel scrap, which absorbed the heat necessary to melt it, and so reduced the average temperature of the mass. Steam blown in with the air through the tuyeres was [724]*724also used to produce the same effect. By reducing the amount of scrap, or- omitting it altogether, varying conditions of heat were met. An excessively cold heat might also be “side-blown,” or the converter turned on its side, so that a portion of blast passing over the surface increased the heat by burning the iron itself. This, hdwever, greatly increased waste. The situation called for quick decision and rapid execution, and a mistake in either direction spoiled the steel. Moreover, one converter charge was neither an index of its successor nor a sequence of its predecessor. Each one was unique in character, and required individual and varying treatment. This arose from the shifting, unaccountable, and seemingly arbitrary working of blast furnaces, or, indeed, of a single furnace. As illustrative of such workings, we quote, as fairly representative, the testimony of Mr. James G-pyley, superintendent of complainant’s blast-furnace department, who says:

“Tlie conditions under which a bla^t furnace is operated are such that the slightest change in composition of the ore, fuel, or the limestone will produce a respective change in the composition of the metal; and even so slight a change in conditions as represented hy a change in the content of moisture in the atmosphere produces, all things being considered, the widest fluctuations in the composition of the pig metal; and, inasmuch as the conditions of the atmosphere are lieyond control, so it is impossible to control the product of a blast furnace in point of uniformity of composition. * * * For instance, a slight change in the composition of the material charged into the furnace produces an irregularity in silicon in the metal. This variation is again ’produced by a change in tlie volume or temperature of the air that is blown in, or by a change in the composition of the slag, and also in a very marked manner by the least change in the content of moisture in the atmosphere; as, for instance, a day in which the atmosphere is very humid, the moisture entering the furnace with the blast requires an undue expenditure of heat in the zone of Combustion, and xiroduces a metal that is low in silicon. Again, on a day when the atmosphere is very dry, the opposite conditions exist, and there is produced a metal unusually high in silicon, either of which is undesirable in Bessemer steel operations. * * * Blast furnaces of the same size and -interior shape, and charged with the same mixture and weight of ores, will vary in the character of metal produced just as much'as if all the above conditions were different. * * * In our furnaces of standard capacity we blow 35,000 cubic feet of air per minute. If the moisture in the air is one grain per cubic foot, on this basis we blow in about 25 gallons of water per hour. The average content for the year is about 5 grains of moisture in a cubic foot of air, which would represent 125 gallons of water per hour going into the furnace in the condition of aqueous vapor. As is well known, the humidity of the air may change decidedly from day to day; as, for instance, in summer time, while to-day we might have 5 grains of moisture in a cubic foot of air, to-morrow our hydrometer might show 8 grains, and sometimes 10 grains, thus changing suddenly from 125 gallons of water per hour to 200 or 250 gallons. This moisture must be dissociated in the hearth of the furnace, and absorbs heat rapidly, causing violent fluctuations, unless quickly perceived and controlled by manipulation of the hot blast. The change in the humidity of the air is the most troublesome element to contend with in the manufacture of pig iron, and the margin or surplus in the heating capacity of the stoves is not always sufficient to meet it.”

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89 F. 721, 1898 U.S. App. LEXIS 3115, Counsel Stack Legal Research, https://law.counselstack.com/opinion/carnegie-steel-co-v-cambria-iron-co-circtwdpa-1898.