US851992A - Furnace. - Google Patents

Description

No. 851,992. PATENTED APR. 30, 1907. J. P. MONNOT.

FURNACE.

APPLICATION rmm DEO.26,1905.

3 SHEETB-BHEET 1.

INVENTOR x a Manna WITNESSES:

ATTORNEYS PATENTED APR.-30, 1907.

J. P. MONNOT.

FURNACE.

APPLICATION nun nno.2e,19o5.

3 SHEETS-SHEET 2.

INVENTOR WITNESSES MMMHAQZE.

murmurs PATENTED APR. 30, 1907.

J. P. MONNOT.

FURNACE. APPLIOATION FILED DEO.26,1905.

3 SHEETS-SHEET 3.

WITNESSES INVENTUR MiIAMaQcNM' Mme; uM iwa ATTORNEY in the city,

naces for flame around UNITED STATES PATENT OFFICE.

JOHN FERREOL MONNOT, OF NEW YORK, N. Y.

FURNACE.

Specification of Letters Patent.

. Patented April 30, 1907.

Application filed December 26. 1905- Serial No. 293,409.

1'0 all whom it may concern: Be it known that I, JoHN F ERREOL Mon- NOT, a citizen of the United States, residing have invented certain-new and useful Imrovements in Furnaces; and I hereby declare the following to be a full, clear, and

exact description of the same, such as will is. especially intended to be used in the coating of metal articles by dipping same into a bath of molten metal maintained at a high tem erature. Said furnace com rises in com ination a crucible furnace an a rever ,beratory furnace and means for circulating the crucible and thence through the reverberatory furnace, and comprises also means whereby an article to be coated may be introduced into the moltenmetal without exposing such article to a'ction of the furnace gases. Customarily the crucible ,of said furnace is set into the hearth of the Y reverberatory chamber, forming a down- .plet 'ely isolatin ward extension or well; and coating metal, which I first customarily melt on the hearth of the reverberatory furnace, flows downward as it is melted, into the said crucible or well. In the arch of the reverberatory chamber is an o ening directly above the said crucible or we l, for the introduction of the core, billet or other object tobe coated;

and to protect such core or billet from the action of the heated air and furnace gases, and also to prevent the esca e of such heated air and furnace vgases, an the chilling of the furnace, I provide a cut-off sleeve or passage, by whichI may substantially connect the said opening and the crucible or well, form'- ing-a passage for the direct introduction of the articles to be coated into the molten metal in such well or crucible, while comsuch articles from the furnace gases and eated air of the furnace. further provide means for locally intensifying the flame immediately above the well or crucible. Furthermore,

molten metal, --I provide a safety. reservoir which will receive the molten contents of the crucible incase of breakage of the latter,

county, and State of New York,

to provide for the. possible breaking of a crucible while full of and ' I further provide emergency molds into which the molten metal may be run directly may be cast into pigs of convenient size for breaking up and remelting. I

, Customarily the ingots or other articles to be coated, are heated preliminarily to nearly the temperature of the molten metal before introduction therein. For this purpose I customarily use flux baths containing molten borax, molten cuprou'schlorid or other suitable fiux or heating agent; and these flux tanks I cause to be heated by the gases escaping-from the furnace. I further provide a storage reservoir for molten flux likewise and connected to the various flux baths in such manner thatthere may be aflow of molten flux back and forth between baths and reservoir, so that a substantially uniform level of flux in the heating baths may be maintained during the insertion and re- .moval of the billets or in ots heated.

In the operation of the i urnace, the level of the molten metal is maintained customarily, somewhat above the top of the crucible; the hearth of the reverberatory furnace formmg substantially a large reserve reservoir, to receive the overflow from thecrucible due to the introduction of large cores or billets therein. Therefore, durin the operation of the furnace and the intro uction and withdrawal of cores-0r billets or the like into and from the crucible or well, there is a continual surging of the molten metal from the crucible to the hearth of the reverberatory chamber and back, which keeps the molten metal thoroughly stirred, preventing accumulation of relatively cold metal either near the bottom of the crucible or along the bottom of the reverberatory furnace hearth; all of which is exceedingly desirable. I customarily maintain a layer of molten flux over the top of the crucible during the dip ing, and to prevent diffusion of this body 0 flux over the entire is provided for confining this flux.

My invention consists in the combination of a reverberatory furnace and a crucible furnace havin a hearth and a relatively deep well exten ing downwardly therefrom; in the means rovided for dip ing articles to be coated in t e molten meta in such Well; in the means rovided for isolating the object to be coatedj from furnace gases and the like,

surface of molten metal in the hearth, means from such safety reservoir, so that the metal heated in the same or other suitable manner, I

and for preventin the-escape of the furnace gases and the chi] ing of the furnace during the dipping; in the means provided for accentuatln the combustion in the immediate vicinity of the well; in the means for heating flux baths and the like by waste heat of the .tion with re furnace; in means for maintaining a substantially uniform level of flux in such tanks, durin the insertion of objects therein and remova of the same therefrom; and generally in the features of invention hereinafter described and particularly pointed out in the claims.

The objects of my invention are to provide an improved and economical furnace for car rying out the processes set forth in my above mentioned applications and other similar processes; to permit continuous operation of the furnace as distinguished from alternate periods of heating up and of dipping; to rovide for the maintenance of a great dept of the molten metal in a highly heated condition and for the heating of such metal while spread out in a relatively thin layer; to rovide for the convenient and economical me ting of the coating metal; to provide for the convenient introduction of articles to be coated into the furnace; to isolate such articles from the furnace gases and heated air during their introduction into and removal from the furnace; -to revent the escape of the furnace gases and the chilling of the furnace, during the dip ing; to locally concentrate combustion in t e'immediate vicinity of the point where the highest temperature of the metal is required; to utilize the waste heat of the furnace for the preliminarfy heating of the ob jects to be coated, and or other similar purposes; and to make adequate provision for the collection and casting into convenient sha es of the metal in the well, in the event of reakage of the latter; and generally to make the furnace simple, efficient, easy to operate and relatively inexpensive.

I will now roceed to describemy invenfhrence to the accompanying drawings, illustrating one embodiment thereof, and will then point out the novel features in claims.

In said drawings, Figure 1 shows a vertical longitudinal section of one form of such furnace, and Fig. 2 shows a horizontal section thereof. Fig. 3 is aview similar to Fig.1, "-i llustrating an alternative arrangement in which the crucible and the reverberatory chamber are heated by independent flames.

In thedrawings, -1 designates the main or reverberatory chamber of the furnace, 2 the hearth thereof dished to contain molten metal, 3 the :crucible'orwell, which is set into the hearth and forms substantially a downward extension thereof, of relatively great depth as compared with the hearth, and in fluld connection therewith so that molten or set at any desired height.

metal may flow back and forth between the crucible and the hearth, said crucible being supported by a masonry pier, 14 as shown.

4 designates a flame passage surrounding the crucible and thence extending upward andinto the reverberatory chamber 1, 5 designates an opening through which an oil or gas burner may be inserted or'through which an oil or gas flame may be projected, and 6 des ignates a similar opening through which a sup lementary burner or flame may be intro uced to increase the heat in the reverberatory chamber. It is not always necessary or desirable to use this supplementary heating means, and therefore I have shown said opening 6 closed by a plug 7, which it will be understood may be removed to introduce the supplementary burner or flame, when one is to be used.

9 designates the above-mentioned cut-off or isolating sleeve, located directly above the crucible 3, projecting through an opening in the archof the furnace, and provided with means, as for example a counter-weighted lever 8, whereby it may be raised or lowered 10 designates an adjustable closure, within this sleeve, and normally substantially closing the same, said closure adapted to be liftedout of the sleeve to permit the introduction of articles to be dipped, and also adjustable up and down within the sleeve to accentuate the combustion in the immediate proximity of the top of the crucible, in the manner hereafter described. When heating up the metal in the furnace, the sleeve is raised to near the top of the arch, as shown in full lines, in Fig. 1, the I closure 10 being somewhat above the lower edge of the sleeve, so that a cavity is formed in the arch, directly above the crucible; but when objects are to be dipped said sleeve is lowered until its lower edge is near or even below the surface of the molten metal in the hearth; and just before the object to be dipped is inserted, the. closure 10 is raised and moved out of the way, after which the article to be dipped is inserted through the sleeve into the molten metal in the crucible or pit 3, and after remaining therein a sufficient time (a few seconds usually suflices) is raised again. It will be seen that sleeve 9 forms a passage whereby the articles to be dipped in the molten metal may be introduced therein while completely isolated from the atmosphere of the furnace.

1 1 designates a series of flux baths, located within a suitable chamber 12 of the furnace, through which chamber and around the flux baths the furnace gases pass after leaving the reverberatory chamber 1. 13 designates a reservoir for molten flux, similarly heated, and connected to the several flux baths 11, so that the molten flux may flow freely from the reservoir to-said baths, and back again,

' the charging door ob ba of the high temperature em so that a substantially. uniform level of the flux may be maintained in all of the 'baths during the insertion and removal of objects therein and therefrom. The gases, after heating the said reservoir, may be used for heating pickling baths, or other apparatus and may then be assed into a suit'able'stack.

14 designates t e above mentioned safety reservoir, surrounding and beneath the cru-- cible or well 3, and adapted to receive the molten metal in case said crucible or well should break. I

15 designates a series of emergency-molds and 16 a passage to convey the molten metal from the reservoir 14 thereto.

The safety reservoir and emergency molds constitute an important feature of my invention, as it is substantially impossible to insure absolute reliability of the crucibles, in view loyed and the great weight of metal whic said crucibles are required to hold. It would not'do to allow the molten metal escaping from a broken crucible to solidify in a single mass, as a large mass of metal, particularly of a.

metal like copper, which is one of the coating metals commonly employed, is very difficult, if not impossible, to utilize.

The operation of my furnace is substantially as follows: For filling the crucible with molten metal, the solid metal isintroduced into the reverberatory chamber 1 through 17, the metal therein flowing downward as it melts, into the crucible. The body of molten metal thus obtained should be sufficient to completely fill the crucible and to completely cover the floor of the hearth. The furnace gases circulate around the crucible and thus heat the same to a high degree, preventing the accumulation of relatively cold metal in the crucible, as would otherwise be the case; and said gases then flow through the chamber 1 in the manner customary in reverberatory furnaces, heating the molten metal in the hearth. Said furnace gases then pass around the flux baths and the flux reservoir and thence outward. The cavity in the arch of the chamber 1 formed by the sleeve 9 and closure 10 when in the position indicated in full lines in Fig. 1, has an im ortant effect upon the heating of the metal, or such a cavity in the arch of a reverberatory furnace, has the effect of accentuating the combustion in and immediately below such cavity, with a result that at this point an especial T high temperature is obtained, and the heat so obtained, is reflected downward upon the surface of the metal immediately above the crucible, it being especially important that the metal in and above the crucible be highly heated. The cores, billets, or other 'ects to be coated are deposited in the flux lbs, and when heated therein to a suffi- .the way,

'ters the crucible,

' may be moved back underneath the cientdegree, and when the metal in the crucible has been raised to the desired temperature, are successively removed from the flux baths and dipped in the metal in the cruci-' ble. To so dip them, the sleeve 9 is first low-i ered to the position indicated in dotted lines in Fig. 1, the lower edge being in contact with or below the surface of the molten metal. The closure 10 is then moved out of flux is then introduced through the sleeve, and the object to be dipped passed down through the sleeve 9 and through the flux into the molten metal and, as soon as sufficiently acted upon by the moltenmetal, is removed. The object so dipped displaces a great volume of themolten metal, as it enand this displaced metal surges up into the hearth; and upon removal of the coated object, the molten metal flows down from the hearth into the crucible again. This insures a very ellicient stirring of the molten metal in the crucible, a large part of the metal therein being intermittently expelled into the hearth where it spreads out into a relatively shallow body of molten metal and so exposes a very large surface to the heating action of the gases. metal ble, greater when a'large surface of the metal is exposed to the radiated and directly applied. heat, as is the case in the reverberatory chamber 1. For the same reason it is much rnace This 1s important, because molten cannot be heated efficiently. in a crucimore economical to melt the metal in thefirst instance in said chamber 1, rather than in-the crucible itself. To protect the object coated from oxidation upon.- removal from the coating bath, I cover the surface of the molten metal immediately above the crucible, with a coating of flux. To retain this flux in position while permitting the outflow of the molten metal upon the introduction of the object to be coated, I provide a ring or rib 18which may be of graphite, .clay, or other refractory material, shown in the drawing on the hearth, but which floats on the molten metal during the operation of the furnace, retaining the molten flux and preventing it from spreading out over the main body of metal in the hearth, while permitting the molten metal to flow beneath it into and out of the crucible. At the conclusion, of the dipping, if the sleeve 9 be. raisedfor any reason, as for heating up, for example, the ring 18 may be pushed to one side, said ring then carrying with it the molten flux within it and still preventing said flux from spreading out. In this way the metal above the crucible is exposed for reheating, without waste of flux. When desired, the ring 18 sleeve 9 and said sleeve lowered through it. The object to be coated will pass through the layer the efficiencyof heating being much.

, coating of the flux as it is withdrawn, which coating will protect it from oxidation by the air. Once. the metal in the furnace has been heated sufliciently, the dipping of objects to be coated, may go on continuously, provided the flux baths are of sufficient capacity to keep ready a sufficient supply of objects to be dipped. To compensate for the copper withdrawn from the furnace, new copper may be added from time to time through the charging door or otherwise, the metal being added either in the solid condition, (in which case it should be added at the extreme end of the furnace) or in molten form. The sleeve 9 may be left down so long'as dipping is going on, but may be raised and the closure 10 replaced when or any reason heating up of the metal is necessary. By properly regulating the position of this sleeve and that of the closure a considerable variation of heating action may be obtained.

By proper regulation of the flame, the temperature in .and around the crucible may be kept very high, and the furnace will ordinarily be operated in this manner. To reduce metallic oxids which may form in the molten metal in the hearth, I preferably place powdered charcoal on the surface of the molten metal and renew the same from time to time. v

19 designates an inspection door throu h which the operation of the furnace may be watched.

20 designates a crane for handling the 'articles to be coated.

Instead of heating the crucible and reverberatory chamber by the same flame I may provide different burners for the purpose. This is illustrated in Fig. 3, in the furnace shown, in which there is no direct connection between the cruciblefurnace and the reverberatory furnace. This permits complete independent regulation of the flames in the two heating chambers of the furnace. The prod nets of combustion from both furnaces may be caused to unite to heat the flux baths as shown in this figure.

In the normal continuous operation of the furnace, the crucible will in time wear out, and must be renewed. To do this it is necessary to empty it of the molten metal it contains. The emergency mold above menti oned affords a convenient receptacle for the copper when itis necessaryto empty the furnace.

surrounding the same, said chambers being conjointly adapted to contain and maintain a body of molten metal, the heating chamber comprising a relatively broad and shallow dished hearth and the dipping chamber extending from the lowest portion of the dished hearth and being relatively deep as compared with the heating chamber and in fluid connection therewith.

2. In a furnace of the class described, the combination of a main internally-fired and reverberatory-roofed heating chamber and an externally-fired dipping chamber having a flame passage completely surrounding the same, said chambers being conj ointly adapted to contain and maintain a body of molten metal, the heating chamber comprising a relatively broad and shallow dished hearth and the dipping chamber extending from the, lowest portion of the dished hearth and being relatively deep as compared with the heating chamber and in fluid connection therewith.

3. In a furnace of the class described, the

combination of a reverberatory furnace and a crucible furnace conj ointly adapted to contain andvmaintain a body of molten metal, the former comprising a relatively broad and shallow dished hearth and the latter having a crucible in fluid connection with the dished hearth at the bottom of the dishing.

4. In a furnace of the class described, the combination with a main heating chamber having a shallow dished hearth for containing molten metal, of a well extending down from the bottom of the dishing of said hearth and receiving molten metal therefrom, said well and heating chamber being conjointly adapted to contain and maintain a body of molten metal, and means for heating the metal in said chamber.

5. In a furnace of the class described, the .combination'with a main heating chamber having a hearth dished to contain molten metal and a relatively deep dippin chamber or well extending downward from t e level of the lowest place in the dishing for receiving molten metal therefrom, said well and heating chamber being conj ointly adapted to contain and maintain a body ofmolten metal, of means for circulating heating gases around said Well and for introducing such gases into said main chamber.

6. In a furnace of the class described, the combination of a reverberatory heating chamber having a hearth dished to contain molten metal and a relativelydee dipping chamber or well extending downward from the level of the lowest place in the dishing for receiving molten metal therefrom, said well and heat ing chamber being conj ointly adapted to contain and maintain a body of molten metal, and means for circulating heating gases completely around said well and for introducing such gases into said reverberatory chamber.

'7. In a furnace of the class described, the

IIO

combination with a heating chamber having a well for containing molten metal and means for passing heating gases over said well, of-

means for isolating said well from the atmosphere of said chamber while permitting introduction of objects into said well.

8. In a furnace of the class described, the combination with a heating chamber having a well for containing molten metal and means for passing heating gases over said well, of means for isolating said well from the atmosphereof said chamber while permitting flow of metal between said chamber and well.

9,. In a furnace of the class described, the combination with a heating chamber having a well for containing molten metal and means for passing heating gases over said well, of an imperforate sleeve cxtendible into said chamber to a point at or just above the top of said well.

It). In a furnace of the class described, the combination with a heating chamber having a well for containing molten metal and an opening above the same, of a sealing imper forate sleeve substantially connecting said opening and well, extendablc into said chamber to a point at or just above the top of said well.

11. In a furnace of the class described, the con'ibination with a heating chamber having a well for containing molten metal and an opening above the same, of an adjustable cutoff passage which in one position substantially connects said opening and well and in another position permits passage of heating gases over said well 12. In a furnace of the class described, the combination with a rcverberatory heating chan'iber, and a well extending downward from the hearth thereof, said chamber having an opening above said wellfor the introduction of articles into the latter, of a ver tically adjustable cutotl' sleeve which in one position substantially connects said opening and. well, forming an isolated passage for the introduction of articles into the well, and which in another position permits passage of furnace gases over said well.

13. In a furnace of the class describeththe combination of a heating chamber, a well, said chamber having an opening above said well, a sliding cut-off sleeve, and means for raising and lowerii'ig the same.

14. In a furnace of the class described, the combination of a heating chamber, a well, said chamber having an opening above said well, a sliding cutoff sleeve, and means for closing the same.

15. In a furnace of the class described, the combination of a heating chamber, a well, said chamber having an opening above said well, a sliding cutoff sleeve, a closure for the same, and means for raising and lowering said closure.

16. In a furnace of the class described, the

combination of a heating chamber, a well, said chamber having an opening above sai well, a sliding cutoll' sleeve, means for adjusting the position thereof, a closure for closing said sleeve, and means for raising and lowering the closure with respect to said sleeve.

17. In a furnace of the class described, the combination of a reverl'ieratory heating chamber, a well, said chamber having an opening above said well, a sliding cutoff sleeve, means for adjusting the osition thereof, a closure for said sleeve, ant means for raising and lowering the closure with respect to said sleeve.

18. In a furnace of the class described, the combination with a revcrberatory heating chamber comprising a dished hearth having in its bottom at the lowest point in the dishing a well for receiving the molten metal, said hearth and well being con'ointly adapted to contain and maintain a body of melt metal, said chamber having also above san well a recess whereby heat is concentrated over the well, of means for supporting combustion in said chamber.-

It). In a furnace of the class described, the combination with a reverberatory heating chamber comprising a hearth having in its bot tom a well for receiving the molten metal, said chamber having also above said well a recess whereby heat is concentrated over the well, of means for supporting combustion in said chamber, and means for adjusting the depth of said recess.

'20. In a f urnaee of the class described, the combination with a revcrberatory heating chamber con'iprising a hearth having in its bottom a. well for receiving the molten metal, said chamber having also above said well a recess whereby heat is concentrated over the well, of means for supporting combustion in said chamber, and means for adjusting the vertical position of such recess.

21. In a furnace of the class dcscribeththe combination of a main heating chamber having a hearth and a well extending downward -rom, said hearth having a floatable thcrel' flux-localizing ring normally above said well. 2'2. In a furnace of the class described, the combination with a heating chamber ada ted to contain molten metal and provit ed with means for introducing articles into such metal, of heating baths heated by the gases from such heating chamber, and a reservoircmmected to said baths and adapted to maintain approximately uniform level therein.

' 23. In combination, a reverberatory furmice and a crucible furnace, the former comprising a relatively broad and shallow dished hearth and the latter having a crucible in fluid connection with the dished hearth, said furnaces each having independentmeans for heating it and said hearth and crucible being conjointlv adapted to contain and maintain a body of molten metal.

24. In a furnace of the c-lassdescribed, the In testimony whereof I afl'ix my signature, corxbingtion \vitlli a linaindheatilllg chamber in the presence of two witnesses: an a i ing 0 am er a a tecto receive T T molten m e zal therefrom, said ehambers inde- JOHA FERREOL MONAOT' 5 pendently heated, of heating baths and Witnesses:

. means for heating same bygases discharged JNo. B. HANNUM, J12,

from said furnaces. W. J. SOHAFFER.

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