US1036500A

US1036500A - Metallurgical furnace.

Info

Publication number: US1036500A
Application number: US650494A
Authority: US
Inventors: Fred B Lamb
Original assignee: ALBERT B FRENIER
Current assignee: ALBERT B FRENIER
Priority date: 1911-02-28
Filing date: 1911-09-21
Publication date: 1912-08-20
Anticipated expiration: 1929-08-20

Description

P. B. LAMB. METALLURGIGAL FURNAGE. PP-LIOATION .FILED SEPT. 21, 1911.

Patented Aug. 20, 1912.

4 SHEETS-sauf 2.

P. B. LAMB. Y

METALLURGICAL FUBNAGE.

APPLICATION FILED SEPT. 21, 1911.

12,036,500( Patented 2o, 1912.

4 SH TS-SHBET 3.

F. B. LAMB.

METALLURGIGAL FURNAGE.

APILIGATION FILED s1 T.21. 1911.

1,036,500. YImrinedl Aug. 20, 1912.l

4 SHEETS-SHEET 4.

UNER-D STTES PATENT OFFICE.

FRED B LAMB, or BETTENDORF, IowA, Ass1GNoR or ONE-FOURTH To ALBERT B.

- FRENIER, or DAvE'NroRT, Iowa.

Specification of Letters Patent.

METALLURGICAL FURNACE.

Patented Aug; 20, 1912.

original application filed February 2s, 191i, 'seriai No. 611,409. Divided vana this appiicat'ion filed September 21', 1911.

To all whom 'it may concern.' Be it known that I,- lFRED B. v`LAMB, a

citizen ofthe United States, residing at -Betexact description.

tendorf,1in the county ofScott and State o`f- Iowa, have invented new and useful Improvements inf Metallurgical Furnaces, of

which the .following is a full, clear, and

This applicationv is a division of original application No. 611,409 filed February 28th, 1911.

The .invention embodies .a modified 'formof.the class of' furnaces generally known as "the tilting'open hearth furnace -of the-regenerative type, to which has been added a "lc'etiving or converting chamber.

The principal object of my invention is' 1 0 combine in a single unit the-well'known ppcnbeirtli furnace-with an ordinary vconf- 20,del Serfin a manner that when used for maklso Jing ,-s'teel, the recognized andftiine-pr'oven superior features only, .of each' device is' .to

Abe utilizedlimiting l the 'use of each to that which itaccomplishesbesg quickest, Vcheapest .andwith the least damage tovitself .and

minimum waste of materials.-

Another object of my invention is tol greatly increase the capacity of a steel. fur

nace and permit the use of raw materials' of a chemical content heretofore considered prohibitive, yet bringing forth a high grade of steel lwith a: degree of economyheretofore impossible. This I -accomplish'in the man'- ner hereinafter fully described and as particularly pointed out in the claims.

IIn the drawings: Figure lis a transverse section of a tilting furnace embodying my imp1ovements.- 'F ig. 2 Vis a similar view showing the furnace vtilted toward the converter. Fig. 3 is asimilar view sho'yvingthe furnace tilted in the o'ipositedirection' for pouring. Fi g. 4 is a view showing onelialf 'of the furnace in longitudinal central section'and the other half inv-side elevation.-

Serial No. 650,494.

hearth and A the converter so* arranged land cooperating yin such a manner that the supe.- riorl features only of each individual furnaceis tobe utilizcd--using onlythose fea- I tures lthat lcontribute to the saving of time,

-labor and fuel, eliminating the more expensive andlong drawn out operations which cannot be separated from those devices when used separately. AThis kind of a furnace comprises a substantially rectangular body having a front wall A, a rear wall B,end walls .C, a bottom D- and a `roof Rf The bottom or, Hoor consists of av 'supporting metal retaining sheet ,fv'v'l'iichi between its parallel upwardly flanged side .edges is concaved or di-shedfa'nd provided with theordi-l nary silica brick b,.which, in turn, is covered With thematerial c, for either an acid orba'sic lined bottom. The sheet 'a is reine forced both longitudinally and transversely,` l

and near rits ends it is lprovided with corresponding 'rockers d. Thecurved treads of these'- rockers rest and travel upona series of segment-ally. arranged Aanti-f riction roll-1A ers, e, that are journaledat equal` distances l ,apart in parallel 'segmental frames e', and

these rollers' rest and travel upgn vconcaved tracks E built upon a suitable foundation.`

The end walls C of the'furnace are provided with the usual gas or fuel ports F, through which` the vgas from the burner H andyheat from the-regenerative chambers (not shown)y vthrough the flues h are blown into the fur nace. TheI curved treads ofthe rockers d, and the-concaved tracks E are sir-nok from an' axis intersecting the center of the fuelports, so that,"no matter in wh' t tilted osition the furnace Vmay be, -theliaat vpro ucts will continue to blow intoI the furnace.

rI'he vfurnace may be ,tilted cir-:rolled through the' medium. offa. hydraulic 'cylinder G .having a ram orpiston-f, 'which connects' with the center of length .of one ofthe 'rockers, at a point abovefits tread. The ffront wall A of he furnace 'is provided with the usual Icharging doors. lThe lower portion, of the central charging `door is. formed ,by-v the bottom -of the furnace being extended out under this doorway .f'

forming the bottom of a pouring spout J, the side edges of which are raised sulficiently to confine. the met-al when pouring.

charging doorway is opened and `,ay.vertica-lly 'movable gate-,K,

operated through the medium of a chain or cable by suitable mechanism (not shown).

Opposite the charging door-way, the rear Wall of the furnace is provided with a coinparatively small'opening 2, which communicates with a blowing chamber or convert-er 3 at a point next the bottom thereof, which Ylatter and the floor of said opening are a continuation of the bottom of the furnace. This blowing chamber or converter 3 is built out from and removably attached to the rear wall of the furnace.r lts outer shell may be oflrectavngular shape and is made of sheet metal. It is lined by a course of brick and by an inner lining of the composition usually employed for lining converters. The inner contour of the inner lining is of flask shape with the mouth or opening drawn to one side as shown. This converter is retained in' place against the rear wall of the furnace by. any suitable means, such as lugs and key-wedges (not shown). lts outer wall terminates below the plane of the inner wall, and is constructed so that slag from the metal. thereincan be drawn or blown off, as

wil-l hereinafter more fully appear. The up-` per part of the -inner wall is built out so as to overhang, forming a partial roof ,of thc converter., At the bottom the innerwall is provided with an opening, which is made to register with opening 2 in the rear furnace wall when converter is clamped thereto. The bottom of the converter is provided with a series of openings or twycrs 5, communicatn in with an air-chest or box 6, that is suplled with air under pressure from. an air intake 7. A vertical pa age 8 is provided in the rear wall of f unace immediately above and separate fro opening 2. Its lower end is projected outward and discharges into the converter through a suitably provided opening. lf desired a suit-- able air blast pipe may extend down through this passage, through which a blast of air may be blown, or the passage may be suit ably prepared for doing this. While bottom blow converter is thus shown and described, it is evident that a side blow or a surface blow type of converter could be used.

'While the open hearth furnace of the present day practvlce, when lined basic, removes or reduces to within allowable limits, car bon, silicon, manganese, phosphorus and possibly sulfur, the length. of time, and amount of labor, fuel and expense required to make the proper reduction, depends altogether upon the manner in which the above elements. are chemically combined. If the cold charge be high in carbon, liquefaction begins promptly and the entire mass is melted downquickly,but thevat-tendin reduction of the vcarbon to within the a lowable limits is accomplished only after several hours of painstaking labor and the subjec tion of the bath to the fierce oxidizing action of the fuel. If sulfur is also present further time Inust be expended and more fuel consumed in what oft times proves a futile attempt to remove it. While it is possible to bring forth a very satisfactory grade of steel from the basic open hearth furnace, the baser the raw materials, the more difficult and more expensive does the operation be come and the more damaging to the furnace, due to the long exposure to the fierce action of the fuel, necessitating more frequent and expensive repairs and greatly increased cost of maintenance. Confining'its Vuse to that 'which it accomplishes quickest and best,.

namely, melting and dephosphorizing, leaving the reduction of carbon and silicon to other means, the first step toward lowering cost of production is achieved. As the open hearth excels in melting and dephosphorizing so does the converter excel in removing carbon and silicon. My improved furnace combines these two well known agencies and their individually superior functions are so manipulated that the highest grade of steel is brought forth from materials and at a cost heretofore impossible.

The operation of my improved furnace is substantially as follows: After the hearth or melting chamber, which is lined basic, has been raised to the proper temperature, limestone is charged to form a. slag, then 15 tons (presuming the furnace to be of 15 tons capacity) of cheap low grade pig iron, or part pig and part steel scrap, or all cast scrap or cast borings. As thecarbon content of an all pig charge or of a. cast scrapwould be. very high, liquefaction will begin promptly and the entire charge will be melted down in about two hours. lVhile a regular open hearth furnace would melt this high carbon charge just as quickly,theattending reduction of this carbon and silicon to within allowable limits can only be accomplished at the expense of much labor and hours of time. It is this feature of steel making by the open hearth that creates expense and contributesto the high cost of the finished product. If metal of lower carbon be charged into' an open hearth furnace, such as half pig and half scrap, it Will naturally take less time and expense to reduce the carbon to within allowable limits, but this gain will be offset by the increasedtime taken te melt, so that what is saved in one direction is lost'in another.' ln order to keep carbon' and, sulfur low as possible, half select pig and half select steel scrap are usually used in open hearth practice. This is high priced material. A. low grade cheap pig iron could be used at a great saving, if its first cost` were not offset by the excessive expense in curred in reducing carbon and other injurious elements. ln my improved furnace the open hearth department will not be called upon toperforrn this expensive part of the process,. b ut eonfined solely to melting and dephosphorlzmg, for, as soon as about 5tons of melted metal has .accumulated in the bath;

the blast'will be turned intot-he converting chamber 3 (if it be a bottom blow converter as shown) and the furnace tilted tof.-

wardthe converter Vuntil it is nearlyfbut not quite,l in. the position shown-in Eig.'2 of 10. "the-drawings, and the molten metal will How Y through the opening 2 Ainto same.- Inabout ten minutes' 'thisjveton -massof -inolten my improvedfurnace-accomplishes ina2 few minutes that which' {takes-hours by'tzheopen hearth furnace, and l'with noA fotherffuel. than- 'a/blastf. air.-A .Infaddition -to v-this great s a'iff z ing of At in e and expense, otherifnost fa'wzrrable conditions obtain.-conditionfsnon-ex? istantin thestraight open hearth pr fa ci ;iee. Theseare first, ahighlyacid Slag developsv during the act of blowinginl the" converter. This is removedby tilting the furnace'ffarj ther in thesame vdirection. unt-i1 the level of the-surfaceof t-hefmeta'l `reaches the lip-or p -upperedge-of 'thegouter' Wall offthe-f1- conmass .of highly 'acidulous 4andff impure .mat-A -tei'- Wit-hout' .interrupting the continued- 'the melting chamber, int-enninglilg With the bath Vand .materially raisingthe temperature 45 0f the' entire mass andgi'eatly hastening'the l -l" ufaction ofthe unmelted portion of-the clilarge at-'afg'reat saving-.of fuel.'

saving'in 'avoldingjthe'fus'efof ironoie 'asian .-55- .oxidizing agent. Aslv 'the fiinn'ace'1-v has been made totilt wfith'the gon-Ifuelf-portias an axis, the melting-operation inthe melting chamber ;ag not been :interrupted during the'.

60 massv to the parent bat h. Dephosphorizae tion, through the actionof the lime Slag has '11o-W made, andfitiliiiiswhigh. carbon., am

' ossiblev in the regular open -hearthffu'rnacei' gecond.- As tliefurnace'is' tilted back tolfitsf fnormalf'position', this Q -tons'. of Ametal at a i temperature oaboutl 3000". `{iows back `into "Turm This metal from .the converter'being thor?v oughly *impregnated with oxidizingf gases 50 'due :t0 the ction of the a'i-r'blow'n.A into it,f-the ca'rbonA in the bath will most eagerly combine? ``thereavith, acting exactly as iro noleidsl in t-he ordinary p'rac'tio'e, thus effecting "another" removal .'of a large portion of higlilyl-acidui vature of the bath. A t lthe end of about two lous slag and ina greatlyincreased te1nper` hours time the entirefcvhaige `will be 'meltedT vdecarbonized, desi1iconized,' deph'osphorized and .brought `t'ralizery *highv temperature. The furnace is thentilted 1n thedirection As hown 'in Fig, 3 of theydrawingsg. and thel contents' 1 drawn off i through, thief-pouring spoutfJ intoaladle ready'f'or teenii-n- Si I do -not confine 2. .Ai metallurgical furnacev .the hearth st y'fpe, comprising a-"ine ting ohumbl adapted ,to maintain operatie oom vu februar-hehehe? have@ nication with the hearth and having anoutlet separated therefrom, provided With air last slag removing means, and means for tilting the furnace.

7. A metallurgical furnace comprising a hearth, a blowing chamber outside of and chamber Communicating "therewith and having an outlet separated therefrom, fuel ports at the ends of the hearth communicating with re- I for rocking the furnace about the fuel porte as an axis.

9. A metallurgical furnace of the open hearth type, comprising a melting chamber, a blowing chamber exteriorly attached to one of the side Walls and having communi cation with the hearth and providedvvith an outlet independent thereof, air blast slag removing means in said wall, end Walls Drovided with fuel ports `communicating with the hearth and vregenerative chambers, and means for tilting the furnace about the fuel ports `as an axis.

10. A metallurgical furnace of the .open hearth type, comprising a melting chamber provided with fuel ports and regenerating chambers, a blowingchamber exteriorly 'attached to and communicating with the melting chamber and means whereby the act of melting in the melting chamber and conversion in the blowing chamber can be performed simultan eously.`

11. A metallurgical furnace comprising a hearth provided with fuel ports and regenerator chambers, a removably attached converter communicating With the hearth, and means whereby the blowing chamber may be operated Without-interrupting continuous liquefaction in the hearth.` 12. A metallurgical furnace comprising a hearth provided With.`fuel ports and regenerative chambers, a removably attached blowing chamber communicating With the hearth, and means whereby the blowing chamber may be removed without interrupting continuous liquefaction in the hearth.

In Witness whereof I have hereunto set my hand this 18th day of September 1911.