US94996A - Improvement in the manufacture of iron and steel - Google Patents

Description

To allto whom "it may concern UNITED S-"iilntias PATENT OFFICE.

HENRY Bassanini, ori LONDON, ENGLAND.

` IMPROVEMENT IN1-HE MAN urac-111er: oF IRON AND STEEL.`

Specification forming part of Letters PatentiNo.`941-, 996, dated September 2l, 1869; patented in England,

' I March 2l, 1868.

Beit known that I, HENRY BEssEMEn, of Queen Street Place, Cannon street, in the city -of London, England, a subject offthe Queen of Great Britain, have `invented or discovered new and 'useful'` Improvements in the Manu7 facture'of Malleable Iron and Steel and in Ap-V paratus used insuchManufacture; and I, the said, HENRY BEssEMER, do hereby declare the nature of the said invention, and in what man These improvementsl relate, rst, to the man- Vufacture of malleable iron'and steel fromfcrude molten iron, from remelted pig-iron,and from f cast scrap, or other carburets of iron, by means and steel, such4 modifications of or additions having for their chief objects the production of cast-steel by a 'more complete purification oftheVV cheap or inferior kinds of pig -or cast iron, and the employment and admixture with such' purified inferior iron of molten iron of a more pure or betterI quality, such as `is now generally employed inA the'Bessemer process.

In carrying my said unprovements into practical operation, I prefer to employ a convertin gvessel made vof stout plate-iron, the vessel being flattened on the two sides 'where the trunnions are formed. These trunnions 'I prefer to make of cast-iron, having large ribbed flanges 'formed thereon, by means of.which y' they are securely fastened to the sides of the vessel, which is muchstrengthened thereby.

The' converting-vessel is provided with two Q tuyere-boxes, placed at about one-fourth of a circle from each other, sojthat if the tuyeres 4 in these separate boxes be directed toa pointv coincident with the trunnions of the vessel, 'they will be nearly at right angles to each `hearths,lseparated by'a sort of lowv mound between them, formed `of gannister or other refractory material with which thc vessels are usually lined. I

By way of distinction,- I will callthe first or small hearth, A, andthe second`- or larger hearth,.B. VThe irst hearth may, if found desirable, be lined or fettledwith bull-dog? or with red bre, as in paddling-fumaces,

While the rest of thevessely is lineld, by prei'-4 erence, with gannister. The vesselis `proi'idedwitli suitable openf ings, as usual, for putting in thefire-clay tuyeres, and also witlrther openings, n, at the sides, for the. introduction of an iron bar,

to. lift up or ystir the charge, if necessary.

In some cases I also provide other openings lfor the insertion of tuyeres or nozzles, for the of certain modifications of or additions to the i lBessemer vprocess of making malleable iron purpose of injecting Acertain lluids into the metal, when found desirable, and which will be hereinafter' referred to.

The vessel is further provided with a large opening or mouth, for receiving and discharging both the metal and the fuel employed. to

heat the vessel.

The,trunnions of the` vessel are so arranged i that air or steam maybe passed through oraround them, and, bymeans of suitable'branch pipes, be conveyed" into the tuyereboxes, as;

required.

The vessel :may be moved on .its trunnions byy hydraulic apparatus, as at present practiced, or by a small engine, acting on a suitab le gearing in connection with the trunnions. lnorder that the'constructimf'and arrange ment of the several parts of the convertingvessel may be fully understood, I have. represented the same on-fthe sheet of drawings] hereto annexed, 'where Figures 1, 2, and 3l are vertical sections on the line C D of Fig. 5.

The vessel is shown in side elevation at Fig. 4,'and in vertical section at Fig. 5, the

section being taken on the line E F of Fig. 4.

An end elevation'isalso shown at Fig. v6.

.In these several figures, a represents the outer shell of the vessel, lnadeof wroughtron plates, and-'b b are lthe cast-iron ribbed trunf The vessel is lined ywith gannister, or other suitable material, throughout, as shown at d or a part of it may be lined or fettled with bull-dog, red ore, or other materials used to line or fettle puddling-furnaces. The vessel is so formed internally as to divide its interior into two hollows or hearths, A and B, the lining being raised at d, so as to form a low mound or division between them. Each of these hearths is provided with tuyere-boxes, the hearth A having a tuyere-box, c, with fire- ,clay tuyeres 1', (shown, also in plan at Fig. 7,) and the hearth B having a tuyere-box, f, and tuyeres s. (Also shown in plan at Fig. 8.) These tuyese-boxes are both supplied with air from a blast-engine, in the usual manner, 'by means of the pipes g and h, which communi'- cate with the hollow axis of the vessel, Where stuin'g-boxes of the ordinary kind may 'be employed, and thus admit of the rotation of the vessel on its axis without disconnecting the said pipes. The means of giving axial motion to the vessel are not yshown,as the samemaybe readily accomplished by hydraulic apparatus, as already practiced. The pipe g, which conveys air into the tuyere-box e, serves also to conveyv steam thereto, when required, by means of two cocks, one of which communicates with a steam-boiler or steam-superheater, and the other with the reservoir of eompressed air, so that during the process either air or steam, or air and steam mixed, may be passed together,at will, through the tuyeres.

The converting-vessel having been heated by blowing up a coke re, as usual, therein, and .the residueeof the fuel turned out, the vessel is to be turned into a position suitable for receiving the iud iron. Some millscales,7 hammer slag, red ore, or any other matters, such as it has hitherto been found desirable to use in puddling iron, maybe putinto the hearth A, and then a charge of molten iron p of a cheap or inferior quality may be run in. The position of the vessel at this time is shown atFig. 3, whereitwillbe observed that the metal t' is kept below the level of the tuyeres prior to the commencement of the process. A blast of air or steam is then turned on through the tuyeres into the small hearth A, and the vessel turned up, so as to cause the molten metal to run into the hearth A, as shown in Fig. 2, and be operated upon by the blast.

It must be understood that the tuyeres in the small hearth A are of a smaller size and are less in number than is usually employed.

in the Bessemer process.

As soon as the iron is somewhat raised in temperature, the workman, by means of a suitable valve or cocks, will turn on steam with the air, or he will use steam alone. The result of the partial decarbonization of the metal, by the slow action ofa restricted supply of air and the cooling effect of steam operatin g with the mill-scales and other matters, will tend to convert the metal into a pasty or granular mass, mechanically mixed with iiuid cinder.l The constant and somewhat violent heaving up of the mass by the jets of air or steam tends to divide the metal and dissemminate it in a more or less granular form throughout the fluid cinder. mill-scales iron ore, or oxide of manganese, or

other substances used to form puddling cinkMeantime the use of steam may be discon-v tinued and replaced by a blast of air, which will rapidly restore the temperature necessary to carry on the process.

The management of the heat and the employment of air or steam from time to time will'ithus be left to the judgment and experience of the operator, who will judge of the state of the metal partly by the heavy sound of the escaping blast as it heaves up the metal, and also by the condition of the dame anld sparks emitted from the mouth o f the'vesse As soon as the workman.. j udges that the process has been carried far enough, he will turn down the vessel and run therein a charge of molten iron from; a neighboring furnace. The iron so added may be a good gray hematite or some other good quality of iron, preferably containing a little manganese and sufii cient carbon. He will then turn up the vessel so far that both portions of the/.metal will run i'nto the second or larger hearth, B, as shown at Fig. 1, where the tuyeres and tuyere-holes are larger and more numerous than in the rst hearth, so that a powerful blast of air may be driven through the metal and increase its temperature, and completely melt the rst charge and unite therewith. The metal may then be run from the vessel into a ladle in the state of steel; but'I prefer to entirely dccarbonize the double charge of metal before running it from the vessel, and add thereto' a known quantity ot' manganesian pig-iron in a duid state, as commonly practiced in making Bessemer steel.

' Although I have herein described how t-he first portion of the charge, consisting of anl inferior iron, may be purified by va process similar in its eiects to the process of puddling, I desire it to be understood that the first portion of the charge in the hearth A may be, in part, decarbonized and refined by forcing into the fluid metal jets or currents of fluid nitrates of soda or nitrates of potash, or other fluid matters containing or capable of evolving oxygen when brought in contact with molten iron by means of tuyeres or nozzles in the manner fully described in the specification of a patent granted to me in England, No. 965, and'be'ar ing even date with this patent, of which this is the specification, my claim to the use of such modes of decarbonizin g or purifying crude iron by means of nitrates or chlorates under these Letters Patent being restricted to their einployment on a portion only of the metal to be Additions of "converted at one` time in the vessel, as de-A scribed. y u In order to prevent the rapidwear of fur,-

'npaces employed inj fusing malleable iron or steel on. the hearth ofs'uch furnaces", I l,con-- 'i struct the roof and parts mostexposed to heat l with hollow bricks, or with passages beinveeuf` them, 'through'which-I passa 'current of air to keep down their temperature, and I also -utilizef the heaty o Vabstracted by using the heated air to sustain combustion in such furnaces.

In carryin g into practical operation'this part of my iuvention,Ipreter to mold the bricks of the form shown in Fig. 9, (although many other forms may be used,) the sides of such bricks being taperedfas'required to form an arch. Their arrangement in the root of a furnace is shown in Fig. 10, where theyform several passages, m, which" may extend from. end p to end of the furnace, a current of air being either forced through'them or caused to flow through by means of chimney-draft,ithe cooling effect of which will prevent the bricks from -being so rapidly destroyed as would. be the case ifsolid bricks wereemployed.

My invention also .Consists inapplying the combined action offurnace-heat with lthe heat ,developed by jets or currentsof air forced, -lnt'o fluid iron,when applied" to-mixtures of solidified-iron or steelwith- 'molten carburets 4of iron, forfthe-purposeof fusing such solid portion and -for -decarbonizing the sainev to produceyfroin suchV mixed materials fluid or malleable iron or steel.;

Crude or pig iron'of aninferior quality lmay c be' more or less purified by puddlin g, and, either in the state of malleable iron'or puddled steel,`

and in a loose granular-condition, or as puddle'- i balls, maybe `removed to'anotherfsuitable furnace; or it may be treatedfjvin .theffurnace' in which `the pnddling :process has been carried -.'on. ,"Sbme molten iron: in either case is then added, and ja blast of air isd'riven up through the metal,raisin g its temperature, andcausing,

by its joint action with the furnaceheat,the

conversin of wronghts'crap-.iron of any kind,

and other masses of V'wrought-iron, such as old iron,frailwaylar's,y and also any steel-scraps, slnlls,spillings, -and'erep ends ofsteel rails or forgings.- I prefer to employ, for the pur- Vposesioftliis second `part of? my invention, a reverberatory gas regenerative furnace, or other gas-.furnacein whichlheated air and gas are-used.

f/pipes lor tuyeres; but I prefer vt0 employ -xed tuyeres madeof reclay,jandto stop np'orever The jetsvor currents ofair may be' forced into the moltenmetallthrough movable` over the ends .thereof withfre-cl'ay, loam, or gannister previous to turning onthe air, the stopping being removed with an iron rod or by the pressure of the air, 'asfnay be foundinost convenient. `This mode of treatment is also applicable to ironwhichhas been -rriorc 'or less purified or rendered into steel ormalleable iron 'by the action ther-een' of nitrateof soda or nitrate of potash, or other substances which yield oxygen on coming in contact with-.molten iron.

Should such` metal have become solidied i wholly or partially, I render it again uid by ,mixing 'with Ait'lnoltenl pig-iron, ina furnace heated by fuel, and I alsoforce jets of air.- into theiluid portion ofthe mixture; or the process. may bev conducted in the vessel in which the nitrates or similar substances were applied,

the lire-heat and' air-jets being used in this .Vessell i Having described the several parts oflmy 'invention and the manner in-which the' ,same

may be carried into practical operation, Idesi-re it to be understoodthat I donot confinev myself to the precise .details herein .1;i-ven,prol

videll'tll'e essential" arts of my lsaid improvements be retained; 1t f.

Wh t I claim in the manufacture of malleableiron and steel, and ia'iapparatus used in .such manufacture, is as follows:

'v 1. I claimthetreatment and purification of molten pig 'or other carburet of iron in a converting-vessel'by means of currents of air and steaurused separately, or combined and applied in such manner that the metal shall thereby be lrendered.'semi-fluid, pasty, or granular, and .A

become mechanically mixed with the slags or y cinder formed in the process, and subsequent-ly the admixture therewith in the saine vessel of a further portion of molten pig or other carburet'of iron, and the effecting the'complete fusion of such metallic vmixture intoI fluid Amalleable iron or steel by forcing air in sutcient quantitiesupward throughr it.

2. I claim the employment of nitrates of soda or nitrates ofpotash to act on and purify molten. pig or othercarburet of iron in a converting.

vessel, and the subsequent admixture in the same vessel ofthe iron so treated with another portion f pig or other carburet of iron, and the conversion of such mixture into fluid steel or malleabley iron by means of. currents of air forced upward through the metal.

3. I claim the construction and employment, in the manufacture of malleable iron and steel,

Iof' converting-vessels having two 'hearthsy or cavities and separatetuyereboxes, as herein described.

l 4. I claim, in the construction of furnacesl A suitable forfusingmalleable iron or steel on the hearths thereof, the use 'of hollow lire-bricks -arranged to form iiues cr passages, through which currents of air may be caused to pass,gas described. f

5. I clailn -the fusion of malleable iron, or

steel, or other partiallydecarbonized, puddled,

or purified iron on the sole or hearth of a gas mixtures, Couverts the whole into Huid malleor other reverberatory furnace by adding to the able iron or steel.

materials Ito be fused a portion of pig-iron or HENRY BESSEMER. cnrburet of iron and forcing air into it, so as' Witnesses:

to cause heat to be generted, which heat, act- DAVD. S. LoNGDON, in in conjunction with the heat of the fur- Oatford Hill, Forest Hz'llfnace and by joint action therewith, fuses the G. F. WARREN,

solid portions of the metal, and, blending-the No. 17 Graceuhurch Street, London, E. 0..

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