USRE2118E - Cheistiaxt shunk - Google Patents

Description

PATENT OFFICE.

CHRISTIAN SHUNK, YOUNGSTOWN, OHIO.

IMPROVEMEHTAIN REHNING |aoN.

Specification forming part of Letters-Patent No. 14,257, dated February 12, 1856; Reissue No. 1,686, dated` i May 3 1, 1864 Reissue No. 2, l 18, dated November 28, 1865.

To aZZ whom it may concern:

Beit knownthat I, CHRISTIAN SHUNK, formerly of Armstrong county, Pennsylvania, now of Youngstown, Mahoning county, Ohio, have discovered and invented a newand useful process .and improvement for refining molten crude iron from the ore 'or the re- Inelted pig-metal by the employment and application of compressed air forced in, which has for eiiect the decarbonizing or partially' decarbonizin'g the same and rendering it tit to mold into ingots for hammering'or rolling, and the use'of common 'salt as a fluxV for separating the impurities from the crude iron, as herein described, `and the same Abeing grounded on my application tiled in the Patent Odice the 28th day 'of August, 1854, and

y.for whicliaI4 patent was grantedthe 12th d ay of February, 1856, for a part only of saidiapplicationlof August 28, 1854, and the same A.

having been subsequently reissued under a renewed petition and statement filed on the 31st day of May, 1864, and embracing my original application of A\-ugust,1854,and with the accompanying statement and aiidavit explanatory thereto, and with renewed peti tit-ion herewith annexed.

Iron oresand mineral coalcontain foreign substances which require to be expelled in the process ot' manufacture or in the process of 'refining and decarbonizing the crude iron,`

with air-blast, and which is eii'ected by the use of fluxes or the proper calcination of the ores. By making the smelting-furnace widest at the top or tunnel-head. it aiords a larger vouter surface, and therefore a longer time at the entrance of the furnace-stack, and thereby a more `perfectcalcination of the ores is effected before they descend to the smeltingpoint'below, and also a free escape of the im#l purities [contained in the minerals. Three quarts of the dry salt is suiiicient to flux one ton of crude iron. The salt can be introduced into the furnace-hearth through one 0f the tuyere-pipes by the force and pressureof th blast, or it can be used in`\the refining appa-v ratus hereinafter described, atsthe time the reiining and decarbonizng process is com menccd. I am aware that the use of common salt has beenattempted before in some forms the iron business, but not to my knowledge in the manner and for the purposes used by me.

Crude pig metal of gray quality contains r about live per cent. of carbon, which requires to be reduced by decarbonization for convert ing into in gots for forging purposes, and

when in a iluid state the carbon freely combines with the oxygen of the air, forming carbonio gas, and increased heat is obtained, and the-refining and conversion of the crude iron is effected by the agency of its own carbon kcombining with the air forced in, and yielding the different grades ofrrened iron or steel, or refined semi-steel, or malleable iron, owing to the ti-me the blast is continued.

f Refined iron or steel is of dili'erent degrees of hardness and quality, according to the amount of carbon it contains in a lcombined statief-,from three-fourths-of one per cent. to onefandja half per cent. Common bar iron' contains 'but a trace of carbon.V

My decarbonizing process can be applied at the blast-furnace hearth after a deposit of metal has accumulated, but it is preferable to use a separate refining fire or apparatus, placed a convenient distance to the furnacehearth for the operation of decarbonizing the crude molten iron by compressed-air blast, the form of which is not particularly essential,

and which is readily suggested by any prac-f tical ironworker, and is made of east or .wrought iron plates, lined with the best quality of dre-brick or pure soap-stone, or any substance that will resist the heat, and made round or the shape and size desired, and of Y sulticieut height to allow room for the metal to rise, which it does during the refining process, and should not be made quiter half full when the blast is let in. The air can be in! troduced :in dilerent modes., but it is preferableto force the blast in at about half the depth of the molten metal, by attaching the tuyerepipes or apertures for the passageof the blast through the side of the converting fire, so that the air will penetrate the body of the molten metal to eiect the process of decarbonization;I

When the blast is let in the full quantity of metal is not necessary, but can be increased.

While the decarbonizing and converting process is going on to the amount and kind desired The process then consists in starting an air-blast under high pressure into the mass of molten iron, which at once kindles a blaze,

occasioned by the oxy gen'conlsuming a portion l ten minutes.

of the carbon from the' crude Imetal, and by' which the workman derives a clue as to the progress of combustion and the kind of yield.l

and which is readily distinguished by the flame 4 stopper, or a properly-arranged gate or'valve can be attached for the discharge of the refined metal, and which is then molded into ingots iit for rolling or forging purposes. If it is intended to blow the'metal into a mass ot reiined malleable iron, by reducing the carbon', for the purpose of forming balls to make blooms7 the refining fire or apparatus is made with a door or opening for the use of vthe workmans bar, which any practical ironworker will readily understand.

Twelve hundred cubic feet of air per minute discharged .under a pressure of ten pounds will convert one ton of crude iron in eight to The aggregate pipe section or apex tures for discharging the stated amount of blast is three square inches. Before the metal is tapped to mold into ingots it is al-- lowed tostand some minutes after the blast is letoi' for the metalto cease boiling and the dross to rise to the surface..

It 'has already been statedthat itis preferable to use a separate refining lire or converting apparatus. I will describe how the decarbonizingcan be done in the blast-furnace hearth. The tuyere pipe or pipes are introduced vat one of the tuyerearches, orvin front under the temp-stone E, through an aperture in the dam-plate G, and of sufficient length to dip down into the molten met-al for the discharge of the air-blast.

The refining tuy'ere-pipes or apertures to force the air through are made of black lead or pure soapstone or any substance thatwill resist 4the heat.

In the construction of the retinin g apparatus for converting molten metal with air-blast I do not confine myself to any specified form or details of the same, nor to any specified mode of introducing the blast therein to effect my de carbonizing process. Benning pig metal by the use of .V fuel to support combustion for paddling purposes to make bar-iron has been known before. Y Y

What I claim as my invention and discovery, and for which I ask Letters Patent, is-

'lhe refining of molten crude iron lfromthe ore or the remelted pig metal by the employment and the application of compressed air forced in combining with the carbon of the crude metal, and thereby decarbonizing or partially decarbonizing the same and rendering it t to mold into ingots or into a mass of malleable reiinediron to make blooms for forging or rolling purposes, and' the'use of common salt asa flux. These claims I make jointly and separately. v j

. CHRISTIANY SHUNK.

Attest:

. N. W. McKEowN, S. W. MoKEowN.

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