USRE9834E - siemens - Google Patents

Description

- 3 Sheets-Sheet 2. 0. w. SIEMENS. MANUFACTURE OF IRON AND STEEL.

Nd. 9,834. Reissued Aug. 9,1881.

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' MANUFACTURE OF IRON AND STEEL.

No. 9,834. Reissued Aug. 9,1881.

Q 7 4 ML .15 by Letters Patent.

UNITE STATES I PATENT OFFICE CHARLES WILLIAM SIEMENS, or WESTMINSTER, COUNTY OF MIDDLESEX,

- ENGLAND.

MANUFACTURE OF IRON AND STEEL.

SPECIFICATION forming part of Reils'ued Letters intent No. 9,834, dated August 9, 1881.

' Original No. 150,719Ldsted February 9, 1875. Application for reissue flied December 3,1880.

To all whom it may concern:

Be it known that I, CHARLES WILLIAM Smmnns, of Westminster, in the county of Middlesex, England, have invented aProcess 5 of Manufacturing Cast-Steel Directly from the Ore; and I do hereby declare that the following description, taken in connection with the accompanying sheet of drawings hereinafter referred to, forms a full, clear, and exact speci- IO fication of the same, wherein I have set forth the nature and principles of my said improvement, by which my invention may be distinguished from others of a similar class, together with such parts as I claim and desire to secure Steel has been heretofore produced from blooms made direct from the ore by preheating the blooms and dissolving them in a small bath of crude iron; but processes of this char- 2o acter are expensive and have therefore not been commercially developed.

Attempts have been made to manufacture steel by deoxidizing the ore without fusion, withdrawing the sponge in a cold state, and charging it into an open-hearth bath.

In British Letters Patent granted to me September 20, 1866, No. 2,413, a process for the production of cast-steel directly from the ore, with or without the addition of pig-iron and of form-manganese, is described. This process consisted, essentially, in eflecting the reduction or deoxidation of the ore by the reaction upon it of carbonaceous matter under the influence of intense furnace-heat, and in efi'ecting the liquefaction of the reduced ore-within the same furnace by the further addition of cor bonaceous matter. I subsequently separated the process of deoxidizing the ore from that of effecting its liquefaction and chemical adjustment by the introduction of vertical retorts for the reduction of the ore, as described in Letters Patent of the United States granted to me April 27, 1869, No. 89,441, and rotating muflles, for the same purpose as described in. 45 Letters Patent of the United States granted to me August 17, 1869, No. 93,758.

/ Cast-steel may be produced by the concerted action of two separate p A as described 'inlictters Patent of the United States granted DlVISION O. to me April11,1871, No. 113,584, the one serving, .to convert theraw ore into lumps or loaves of calcined, fluxed, and partially or wholly deoxidized material, and the other to smelt and convert thismaterial, with or without the addition of-pig-metal, into cast-steel.

My present invention consists in exposing the ore mingled with fluxing materials and carbonaceons matter to intense heat while imparting to such mixture themotion incidental to the rotation of the combustion-chamber containing it for the purpose of separating the metallic particles from the ore, then subjecting' the mixture tea more rapid rotation for the purpose of forming the separated .metalinto and finally'snbjecting the balls to a bath.

balls, of highly-heated pig-metal, as herein described.

According to my presentinvention I also expose the ore, mingled with fluxing materials and carbonaceous matter, to intense heat'while imparting to such mixture the motion incidental to the revolution of the combustion-chamber containing it. I then subject the mixture to a more rapid rotation for the purpose of forming the separated. metal into balls, and

finally I subject the balls within the furnace to the action of carbonaceous matter, spiegeleisen or ferro-manganese.

In the accompanyingdrawiugs, in which corresponding parts are designated" by similar letters, a rotative regenerativefurnace is shown which may be used in carrying out my process.

Figure 1 represents a longitudinal section on line a: wet Fig. 2. Fig. 2 represents a sectional plan on l'nes 3 guy 3 of Fig, 1. Fig. 3

represents on the left-hand side *a half-transverse section on on the line front view.

A is the rotative furnace, in shape cylindri the line z z'of Fig. 1, and on the right-hand side a half-transverse section z z of Fig. 1; and Fig. 4 shows a pose the gearing B consists of awheel, b, and

pinion b, loose onthe shaft of the drivingwhel b, and gearing respectively with pinion o and wheel 0 on shaft c,\which drives the rollers d. By means of a clutch, b, either the wheel b or the pinion b is geared with the driving-shaft, and thus a slow or quick speed is imparted to the rota-tive furnace; or by throwing the clutch out of gear the furnace is brought to rest. The throat of the furnace A is in communication with two flues, O and 0, each of which has two branches communicating respectively with Na of four regenerative chambers, D D D D. The outer regenerative chambers, D D, are for heating the air, and the twoinner chambers, D and D, are for heating thegas supplied to the furnace.

The air is supplied by a main duct, E, provided with a reversing-valve, e, by which the supply can be turned toward either of the chambers D or D, and the throttle-valve 0, whereby the supply can be regt.ated.

In order to increase the flow of air when intense heat is required in the furnace, a jet of compressed air, 0, is introduced from a blast-- pipe into the middle of the duct E.

The gas from the main supply-trunk F is introduced by a duct, F, which is provided with a stop-valve, f, and with a reversingeither of the chambers D 'or D.

valve, f, whereby the gas can be directed to The air and as thus supplied to the two regenerative chambers on the one side of the structure flow thence heated into one of the fines, U or G, where they mingle and produce a powerful flame, which plays into and sweeps around the furnace A, the products of combustion escaping by the otherflues, O or Q, through the other tworegenerativechambers,audthence byaflue, G, to the chimney or other'outlet. hen one of the two pairs of regenerative chambers has been sufliciently heated by the escaping products of combustion, and the other pair cooled by passage ofthe incomingair and gas through them, the valves are moved so as to alter the direction of the inflowing and outflowing currents in the manner well understood in reference to the working of regenerative gas-furnaces.

At the end A of the furnace opposite the throat is mounted, between the guides a, avertical sliding door, a, with a counterbalanceweight, a". At the front of the furnace is formed a tap-hole, a, which can be plugged with refractory material, and under this there is a chute, a, by which material tapped from the furnace can be run into forms or molds or into a truck in a pit below the furnace.

The lining of the furnace A may be of any known suitable refractory material that is not readily allected by scoria, but I prefer to use for' it a lining formed in the following manner: I take the mineral known as bauxite, consisting, chiefly, of alumina, with a proportion of peroxide of iron. I calcine it and reduce it to powder, and mix with it from ten to fifteen sion.

per cent. of powdered plnmbago, graphite, or other carbonaceous matter in a dense form, and

such a quantity of argillaeeous clay .or other binding material as is necessary to give cohe- I form this mixture into bricks or blocks of suitable form, and burn them in a kiln 1n the usual way. In burning such bricks the oxide of iron contained in'the bauxite. is converted by the carbonaceous matter into. metallic iron, and a very refractory material is thus produced, capable of resisting the action of scoriaforaconsiderable time. These-bricks may be built inside the rotating furnace with cement made from the abovenamed mixture used inan unburned condition; .but I prefer to build them in loosely, and after heating the furnace to a white heat to charge it with pure oreor hammer-slag while rotating slowly. The ore or slag is melted and sinks into the crevices between the bricks, serving as a cement, which binds them firmly together, and also as a glaze which prevents access of air to the in-.

terior of the bricks. When the bricks are so cementedthe excess of fused ore or slag is tapped off, and the furnace is ready for work.

Having thus described a rotative rcgenera tive furnace which may be employed, I will proceed to explain my improvements in the manufacture of steel.

The ore to be treated iscrushed and mixed with a suitable proportion of lime, manganese,

or other fluxing material, according to the relative amountand nature of the gangue which the ore contains, in order to form a fluid scoria; or a mixture of ores may be employed which produces a fusible slag without admixture of lime or other fluxing material. The mixed material is introduced into the slowly rotating furnace A by way of the door a and heated nearly to the fusing-point of the ore, whereupon is added a quantity of the reducing-agent, such as coal or anthracite or coke, previously crushed, but not ground fine, or charcoalor wood,previonsly dried and cut into pieces. The proportion of carbonaceous matter required for the conversion of a certain quantity of ore depends upon the richness of the ore and upon the nature of the carbonaceous matter employed, as well as on the nature of the iron to be produced. In each case the proportions should be deterrio mined by experience; but under ordinary circumstances about half a ton of solid carbonaceous matter to a ton of metal to be produced would be sufiicient. If the reducing-agent employed be anthracite or hard coke, it may be crushed moderately fine and charged into the. furnace with the ore and heated simultaneously therewith. By the slow rotation of the furnace the carbonaceous matter becomes covered by the heated ore with which it is gradually mingled, while fresh intensely-heated surface is being continually presented to the mixture. A very powerful reaction is thus produced, a quantity of carbonic oxide is evolved, which, in burning with the highly-treated air supplied from the regenerator, nearly suffices to maintain intense heat in the furnace without maybe employed for the same purpose, spienccessitatin the admission of additional gasegeleisen or farm-manganese being especially ous fuel. T ereduction of theore under these esirable or necessary if malleable cast-steel conditions is eflected rapidly, the gangue comis to be produced.

5 bining with thefluxing material, so as to forms 7 Having thus describedmyinvention, I claim fusible slag, and the rotation of the furnace and I desire to secure by Letters Patent of the s I ng very slow, (from four to six revolutions United Statesper hour the particles of metallic iron in the 1. The process of making steel which con- 45 f course of separation are not prematurely agsists in exposing theore mingled with fluxing to glomerated. When the reaction is complete materials and carbonaceous matter to intense the rotation of the furnace is stopped and the heat while imparting to such mixture the moscoria is tapped ofl', mastolibe'rate themetal: .tiomincidentattc-the rotationofithe-combuslic iron resulting from the reaction. A fuller tion-cham r containing it for the purpose of 5csupply of gaseous fuel is then turned on; and separating the metallic particles from the ore, 1 the furnace is caused to rotate five or six times then subjecting the mixture to a more rapid tomore rapidly than before. This more rapid rotationfor the purpose of forming the separated tation has the effect of agglomerating the iron metal into balls, and finally subjecting the into balls, which are then taken out of the fur. balls to a bath of highly-heated pig-metal, as 5 5 4 nace and transferred, in a heated condition,to herein described. a bath of highly-heated pig-metal in aseparate 2. The process of making steel which con furnace for conversion into cast-steel. If the sists in exposing the ore mingled with fluxing balls are not removed from thefurnace, they are materials andcarbonaceons matter to intense converted into cast-steel, or a pure cast metal heat while imparting to such. mixture the mo- 60 intermediate between cast-steel and cast-iron,- tion incidental to the revolution of the com- :5 in the following. manner: After the balls are bnstion-chambercontaining it, then subjecting formed the rotation of the furnace is again the mixture to a more rapid rotation for the stopped and the fluid scoria is again tappcdofl, purpose 'of forming the separated metal into whereupon the furnace is'again caused to roballs, and finally subjecting the balls within 6 5 tate slowly. Some hard carbonaceous subthe furnace to the action of'carbonaceous mat- 0 stance. such as crushed anthracite or coke, is ter, spiegeleisen or ferro-manganese, ashereinthen introduced, while the heat of the furnace described. t is raised to a high intensity. The balls, GORP. I ,0. WILLIAM SIEMENS. .bining with the carbon, become fused intoa fluid masgr whiclican be tapped aml'cast into. GEO;VlTO LLETT, formsormolds or,-instead of introducing hard I H. T. TBBUPP, y 4

carbonaceous substances to effect the fusion le'rketo Ridgway Bros" 2 Waterloo Place, Pall of the balls, spiegeleisen or ferro-manganuse Jfall, Londom lvotaries.

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