USRE10984E - Open-hearth furnace - Google Patents

Description

H. W. LASIL' H. AIKEN 8u D. E. PARK.

UPEN- HEARTH FURNAGE.

lisslmv Feb. 5, 1889.

f lOrrien-.1

HORACE w. LAS-H, or PITTSBURGI.-,HENRYiKNQ- or HOMESTEAD, AND y DAVID' n PARK, 'orrirrsnnna mitnfsYLvANrn oPEN-H'EARTH FuRNjAcE-.g

srnctrxcnnolv farmi-ng pm of misma Least-g ratenfi'no. 10,984, mea February s, lese. Original No. 385,936, dated July 5,1887'. Application for reissue tiledlugust. 6,1888. Serial Nol 282,107.

To all whom it may concern.-

Be it known that'we, HORACE WV.LAsH, rci Vsiding'atPittsbnrg, in the county of Allegheny i and vState of- Pennsylvania, HENRY'AIKEN formerly of Pittsburg, but now residing atl Homestead, in the county of Allegheny and 1 State of Pennsylvania, Aand DAVID E. PARK, residing at Pittsburg, in the countyr oi Alleghen'y-and State ot' Pennsylvania, citizens of the United States, have invented or discovi ered certain new and useful Improvements inv i OpcnlI-Iearth Furnaces, of which 'improvements the following is a spcification. ln the accompanying drawings, whichmake part of this specification,:Figure l is a sec-- tional elevation of our improved furnace and plant foi-'the production and casting of openf hearth steel. Fig. 2 is a top plan View of the same..

vIn 'building furnaces forA the production of openLhearth steel it .is usually customary to arrange the regen crati ve chambers for heating the gas and "air on the ground-level, and on these chambers as a founilation or support the melting hearthand'chainberis built: The fines-for conducting theair and gas to the lmeltingchamber are arranged alongside thereof, thc-walls forming such fines formingpart of the outer shell orjvall of the Vmelting chamber and hearth. The brick` walls Vbetween the dues and melting-chamber become highly heated, and consequently are rapidly burned outallowingthe mol-ten steel to escape in the regenerative chambers; and 4this defect also exists in Athose furnaces where a slight airspace is vleft between the chamber andthe fines, as suchair-space does not ext-end for the ,full height of the melting-chamher. Another detect incident to the usual arrangementof the open-hearth furnace arises from the heightof the regenerative chambers and the consequentnecessity of lifting ythe metal charge to the chai-ging-tloorusnallya heightot' tenor twelve feetand thclowering of the molten lmetalto theingot-pin A .st-ill further 'objec. tion'able featureol this construction is the t'nct thatthe furnace 'can be charged from one side only, unless a movable platform is employedan expedient seldom resorted to, as such plutform would' interfere with the movements of the ladle. Y n

The object of our invention 1s to soarrangc l and construct a `furnace of the class described as Vto permit of easy andV ready access on all sides for the purpose of charging and repair;

to .so-arrange the ai r-fl'ues as to cntirel y isolate the melting-chamber and hearth lthcret'ron'r, except at such points wherey the tlues enter the chamber; to permit ofa vfull and free circulation of air around and under the meltingchamber and hearth, therebyavoiding an excessive heating lof the walls .of the chamber .and hearth,and consequently preventing thc rapid burningout ot such walls; to obviate the hoisting ot' the materials charged into the furnace; to permit of theveasy discharge of the molten metal' into the ladle and 'its casting into ingots, and, finally, to avoid the use ot stays-and braces int-he construction of the furnace.

. To these ends our invention. consists in the construction andcombin'ation' substantially as yhereinafter more fully described and claimed.

The shell of the hearth 1 is supported on a v series of I-beams, 2, which are supportedv at' their ends by the side wal'ls'ofA the pit 3, sunk k gnlar in shape,4 and is` made of such sizerin proportion to the `diameter ofthe hearth as to leavea considerable air-space betweenthe Walls of: the pit and the shell of thev hearth.

The hearth of melti'ng-chamber` isforined bv a shell consisting of a series of plates riveted together, lined with firebrick, las vshown'in Fig. 2, and. through the sides of the shell are formed a series of openings, through which the material can he charged into the hearth.

These openings, which are closed by sliding doors 5, can be located at any point. around the furnace, except in line with the air-hues, and in any desired number, thereby greatly increasing the facility"'in-.-charging the furunce.- The cover or 'top Got the hearth is within the retaining-baud, the eovercan be builtou the ground away from thchca'rt-h, and

then can be lifted by a suitable crane into place on the hearth and removed therefrom,`

if desired. .lly making the cover detachable it is possible to vhave an extra .cover in readi ness --to be placed in position whenever the` -cover in use is destroyed or `broken down, thus avoiding the delay no w necessary'to permit the hearth cooling-oft before a new roof can be built, and in case It is necessary to re pair the hearth itself the cover can be removed,

thereby facilitating the cooling down of the hearth, and also -permitting ready access to the damaged parts. In the eenterof the cover (i is formed an opening, R,- of la-rger capacity than the openings 4 in the side .of the hearth for the admission ot' large pieces of metal which cannot be broken-up suieiently small to pass through the openings 4. Over the opening 8 is placed the cover 9, provided'with .snit-able hooks, whereby it may be lifted. 0n

opposite sides of the pit 3 are built the horizontal flues 10,which, extending some distance underground beyond the-pinconverge toa common chamber, 11, said chamber opening into the stack 12. These flues 10 are enlarged vertically at their ends adjacent to the chamber l2, forming chambers 13, their contiguous sides opening into what mayv be 1 the common chamber 1 1 will be unobstructed.

termed the air-pit? 14. Over the openings of the "flues and the-chamber. 1 3 into the chamber 1 1 and airpit 14 are arranged the vertically-movable valve-plates 15,'which are made of sucha size as to cover only one of the openings at the same time-as, for example, when the plates 15 are raised, so as to close the openings from' the chamber. 13 into the air-pit, the openings from the fines into From the furnace ends ofv the fines 10 extend two or more vertical fines, 16, which, passing along the sides ofthe hearth ormelting-chamber,but at a distance therefrom, are connected at their upper ends to the meltingchamber by the horizontal -flues 1 7 which en- .ter the melting chamber"throughl suitable openings in the top or cover 6. Through the wall of the hearthbelow theuesl are formed openings for the admission-of gas,

'which is suppliedthrough a system' of pipes,l

18, from any suitable'source; The doors 5 in front .of the openings 4 in the'hearth are 'c011-v v'n'ectcd by chains or wire ropes 19, passing around snita-'bly-arranged guide-pulleys to the operating-levers 20, pivoted on posts secured on a platform or pulpit located at oneside of pit 23,1ocateda short distance' fromthe pit 3,

located the iugot casting pit 24. Between t-he'ladle and casting pits is placed a hydyraulic ladle-crane, 25, having a jib'of such a.

tem of pipes 18, and thevalvc-plates .are so adjusted by; raising one and lowering the other as to open communication between one i 'of the flues 1()..an d' the stackthrough the ehamberll and close theopening of thatfiue i and the air-pit;` but the otherflue is cut .off

from the stack, but is in communication with t-he'air-pit through its vertical extension 13. While the valve-plates are inthe position stated air .will enter the flue in communication v with the air-pit, and, passiugalong-su'eh flue,

.will enter the hearth j ust above the gas-inlets, and combining with the gas will increase and.

accelerato the combustion ot the latter. The

products of combustion will escape through the flue in communicationwith the stack., and in their passage through such flue will highly heat the walls thereof. AsI soon as the'walls of the. flue in communication with'- 'the stack areA highly heated' throughout theirv 'entire' length, by which time the walls of the other will be cooled'down'by the air passing therethrough, the position of the valve-plates 15 is reversed, so that the air will enter the hearth through the Vflue previously heated by the' productsof combustion, whichwill now es cape through the opposite flue and heat. its

walls.. .The air-as it passes along the heated fines' will be rais-ed 'to a high temperature,

the necessity of curving theover downward,

as is now the usual practice.

The metal is chargedy into the hearth through the openings 4, arranged around the. furnace at such distances apart as .to enablea gang of men to work at each opening without interference. with each other," thus providing for a more rapid charging than is possible in other formsof furnace As soon as the metal has been properly-. treated, the tap hole is IIO opened and the molten metal iiows along the conductor 21 into the ladledepending from -the'jibot the crane `25. As soon as all the metal has been'frun. into theladle, the latter is'rai'sed and swung over the ingotxnolds ar the furnace. A trough or conductor, 21,-isar i .ranged between the tap-hole 22 and the ladlez ranged inthe pit 24. It will be understood thatl the gas is reversed, as is customary', at' the same time thatthe air is reversed.

It will be observed that al1 hoisting of the vmateraval to be charged'is avoided in the above construction of furnace, and that the material i for the next charge can be placed in eonvcnhearth furnaces, on' account of the necessalof , newal or repair, it isr only neccssarv to relze two eathree doors at the most. y

-will run down into the pit without. causing f the Work to be performed may dictate.

rily-contractegl 4area of charging-Hoor; nor can the 01d form of ,furnace be charged from more'than one side, and then through only"x dlnother prominent characteristic Aof our furnace is the possibility .of changing the hearth itself without the necessity of 'tearing down all of t e air and gas lines at the sides. When the hearth of our furnace needs re-v move'a portion of the horizontalues 17, when the whole hearth can be lifted from itsl supporting-beams and another Ahearth placed' in posit-ion. In caseofthe burning through of the shell of the hearth, the vescaping metal any further injury to any other part. of lthe furnace; but in the usual form of furnace the metal escaping from thehearth will run down into the checker-workin the regenerative' chambers, thereby clogging them and ren? dering them useless. If desired, a sand pighed ma)T be made in the bottom of' the pit 3,l thereby providing for molding of any escaping steel into con vcnient. forni for subsequent use. There islittle liability, however, of the i hearth being burned througlnas it is entirely detached except where the air-fines enter from other parts of the furnace, and the air having ready access to all parts will rapidly carr Y'olii the radiant heat. Another important feature of our invention is the accessibiiit)y of vthe tapping-hole and ladle from the ground, thus avoiding the neccssity of swinging ll'ilatforms and stages from which to reach either the tapping-hole of the hearth or the stopper operating mechanism of the ladle. '.lhc hearth may be circular or. slightlyfoval, as circumstances or the nature of This furnace is applicable not only to lthe pwductionof steel, but maybe'used asaheating-furnace or 'for any other metallurgical purpose.

i our hands.

'c are aware that a Siemens open-hearth furnace has been constructed with its charging-doors accessible from the ground-level, ltsA tapping-holcl at or ucar the groundlcvel,a1ul

its rcgencraiors underneath the hearth, and therefore make no claim to such construction.

\\'c claim ln-rciJn as our invcntionl. ..v\nop -nh(v-ni'h furnacchaviug its charging-doors accessible from the ground-levehin g combination with umlergroul'nl tlues'lea-ding from oppositel sides ot' thel furnace downward clear ot' the vwalls of the same'and converging to a common stack, substantially as set forth. An open-health furnace having an underlying pit, 3, suitably proportioned to the diameter of the hearth to provide an open airspace which-extends beneath the hearth and up its sides, and having its charging-doors accessible from the ground-level, in combination with underground fines leading from opposite sides of the furnace. and converging to a common stack, substantially as set forth.

3, Thecombination of an openhearth furnace circular in form andhaviug its tappinghole at or near vthe ground-level, a ladlepit located in convenient pgoxlnit-y to the tapping-holo, a casting-pi t located in convenient proximity to the ladle-pit, and a cranelocatedbetween the ladle and casting pits, substantially as set forth. l

4. An open-hearth furnace, in combination with anund crl yin g pit, 3,-])1'op1'ntioncd tothe 'diameter of thc hearth to provide an open the filles alternately with the stack' and with the air-inlets, substantially as sci' forth. I

In testimony whereof wehavc hereunto set HORACE W. v LASl-I. HENRY ATHEN. DAVID PARK.

"itnesses for Lash and Aiken:

DARWIN S. WoLCoTT, y R. H. WHITTLESEY- Witnesses for Park:

JOHN NEELY, GEO. WRIGHT, J 1`4

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