US2417345A

US2417345A - Cupola

Info

Publication number: US2417345A
Application number: US608273A
Authority: US
Inventors: Claud R Beebe
Original assignee: Individual
Current assignee: Individual
Priority date: 1945-08-01
Filing date: 1945-08-01
Publication date: 1947-03-11
Anticipated expiration: 1964-03-11

Description

Mmh M, 11947. c. R. BEEBE CUP OLA Filed Aug. 1, 1945 INVENTOR. CZ 400 F. 55555 Patented Mar. 11, 1947 UNITED STATES PATENT OFFICE CUPOLA Claud R. Beebe, Inkster, Mich.

Application August 1, 1945, Serial No. 608,273

3 Claims. (01. 2 66-41) The present invention relates to improvements in a cupola construction and more particularly to improvements in a cupola construction adapted by way of example to the melting of rock or slag for the manufacture of mineral wool. The invention, however, is not limited in its use to this particular field, but may be used in any field in which high temperatures are to be developed in a cupola to smelt, roast, sinter, refine or melt ores, ore bearing rock, glass, slag and the like.

In cupolas used in high temperaturefurnace smelting, sintering or refining operations, the

charge offuel and material to be melted is charged into the cupola and air under pressure is supplied at the zone of combustion through tuyeres which extend through the cupola from the air ,bustle pipe to the zone of combustion. Prior to the present invention the life of conventional types of tuyres in this type of service was very limited because of the failure of the materials from which the tuyres were constructed when subjected to the high temperatures .incident to their use.

1 It is an object of the present invention to provide an improved cupola construction in which a novel form' of tuyre is provided to supply air to the zone of combustion in the cupola, the tuyres'being characterized particularly in having a relativelylong life'in service.

-s It is a further object-of the present invention to'provide a novel cupola construction which is particularly adapted for use in high temperature operations, and in'which its novel construction gives it a long service life under difficult operating conditions.

It 'is another object of the present invention to provide. a novel cupola construction in which the refractory lining is uniformly cooled and air is supplied to the zone of combustion through --a plurality of jacketed tuyres, each of which is cooleclby a fluid coolant.

It is a further object of the present invention to provide'a'cup'ola construction in which a plurality of vertically extending jacketed tuyres are employed to discharge a supply of'preheated air into thecharge in. the cupola at the zone of comloustion inthe cupola, thereby confining the zone of greatest temperature in the cupola to a limited region adjacent the refractory lining thereof.

4 It is a further object of'the present invention to provide a cupola construction in which the water used in cooling the jacket surrounding the refractory lining of the cupola. and in cooling the'ituyeres .is supplied ..from a supply source through supply .conduit' systems in which the c'irf culation of the water is accomplished by the; thermo-siphon efiect resulting from the method of feeding the water to the jacket and to the tuyres and of returning it to the supply tanks. It is a further object of the present invention to provide a cupola construction in which a heat exchanging air bustle is provided above the water jacket of the cupola to provide for cooling the upper portion of the cupola and preheating the air which is supplied to the tuyres. Other objects of this invetnion will appear in the following description and appended claims; reference being had to the accompanying draw ings forming a part of this specificationwherein like reference characters designate corresponding parts in the several views. In the drawings: I Fig. 1 is a view showing the tuyere arrangement and construction in top plan and showing a section of a cupola embodying the present invention, the view being taken substantially 0n the line l-l of Fig. 2 looking in'the direction of the arrows.

Fig. 2 is a fragmentary enlarged side elevation partially, in section taken substantially on the line 2-2 of Fig. 1 looking in the direction of the arrows. and showing a cupola construction embodying the present invention and its associated accessory units for supplying air to the bustle and: water to the cupola water jacket and to the tuyere jackets. Y e

Before explaining in detail the present inven-" tion it is to be'understood that the invention is not limited in the-application to the details of construction and arrangement -of parts illustrated in the accompanyingdrawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that thephraseology or terminology employed herein is for the pur poseof description and not of limitation.

Referring to the drawings: A cupola embodying the present invention is indicated generally by the numeral l0- and com-' prises a hood II leading to a stack (not shown) and a combustion zone l2 provided'with a re-'" fractory lining [3 of any desired refractory ma terial, such for example as high temperature fire brick or the like. A water jacket 14 surrounds the lower portion of the combustion zone I0 and aids in dissipating heat from the refractory lining l3. Water is supplied to the jacket I4 by the' water supply pipe [5 leadi'ng'to the supply tankf' l6. Water is heated and rises in the waterjacket i4 and is returned fromthe top of the jacket through the water-return line l1 to the supply I ply of feed water may be maintained in the tank 16 by a. manual control (not shown) or it may be i maintained by any suitable type of automatic means such as a conventional float control valve or a metering r la lve, botl'i of which constructions are well known to those skilled in the art and hence are not here shown. The tank It is drained v through a suitable drain sillcock 9.

Immediately above the water jacket i4 is an air bustle 20 which acts as a heat exchanging member between the top portion of the retrace tory lining l3 and the air supplied to the bustle by an air supply duct 2! communicating with a power driven blower 22. The air is introduced from the duct 2| to the bottom of the bustle 23 and ise -w i e tis he te in th b l 21 heated air 1 drawn .irorn the top of the bustle .20

throu a p u ali f a r s pp uets 2!, lea ing to the tops of a plurality of vertically extending tuyres 24, each having an .angularly cut air discharge end .25 terminating adjacent the c mbust n zon sh n, th sh r st side of the angularly .cut discharge ends 25 .is located toward the center of the combustion chamber I2. This assists. in directing the air inwardly ofihe combustion chamber i2 and away fro the reiractory 13;. The tuyeres 2d are protected againstrapid,deterioration due to the heat eerierete w thin th ouioo y a'water Jac e to surroundin the bottomiiorti n of each tuy e 24 and extending over the portions thereof subjected to the highest temperatures during opera- 2 9 1 of he oiipo a. E h fT t e w ter jackets 2. a oundtheo e e 2B i u plied w th water from a. water supply tank 2] through a connecion 4. w the header ti rom which a t sup l onnec io 8': ea s to a h. o sa d .wate

jackets 26; The connections 28 lead from the header Mia-r d enter the b t m of the w e jacket 26 at anangle so as to discharge the water u ar ly iotohe wa r Jac 26 n thus to initiate the-upward how of water therethrough. The bottom pla Mon ea h water i o t is welded to the body thereof at an angle correspe ding to. thea e of e at fil -Dil :oonnection 28 and assists in directing the water upwar ly e water ac et 2. This al eliminate an pocket in s eam m t etherwiee orm he. bottom o he Wat r ac e s 2 .A retur line 2.3.1 .5 siedirom each water Jacket; .1 .ate oih e ...-.o .d ;ro.m.the o there he. eated water to t e header 2 l eer sbaokto the tan 1 .eaniel relopedin thewa er-ia ket zfiais colec e he; th ead-crowded in. ach-water jacket 5. ehoret. ano n oteonne io with the return line 29. The st eam is led from the tops o the we iaolsets 52. throu h steam r turn inestii extend n fro th h ad. rti n of each o the wa er ieohe s 2. to. the. a er. 44 from which the return. l'ne t5 leads to the top; of the tank 21.. The steam together with. the vapors irenrofii om h -returned h t wa r in the tank flar accum late in: th top po t on of the ank and-are t en t ken o hr ugh a steam li eal connectedto a-wa e e pere orez he e oon ehee wat r em ve fr m the-s amhe steam s en ed in o-a. team ine 33; eadineoa. boil r not sh wn) wher it may be suet d.i. ..-ees.ire.d.-. ih -steamline e lz eadstrom the main steam line '33 to a blow cap, of conventional construction and hence not shown, which may be utilized in the event that the cupola construction of the present invention is used in the manufactureof mineral wool. The water level in the tank 21 is maintained by feed water supplied from the feed water. supply line 35. The level of the water in the tank 2! may be regulated manually by the operator or it may be controlled automatically through any :desired conventional type of float control valve or metering valve, both of which are well known to those skilled in the art and hence not shown on the drawings.

,Sediment in the tank 21 may be drained therefrom through a drain valve 35.

The arrangement of the tuyeres 24 and the ,waterjackets 2e. ina circle spaced from the center of the cupola is a particularly desirable arrangement for it permits ready charging of the cupola from the top through the hood H and provides a clear centerspace into which the h eeds ook w l f rst iall an henflow owa d the circumference of the combustion zone i2. The tuvere arran ement. also serves to divide the h g v t al y andt assist in supporting th main weight of theeha ewhile ,nermittih the charge to flow outwardly toward "the refractory l n ng {3 in the plu ality .of .s.na ed pathsbetween the tuyer'es.

In p ote ting the tuyeres ae. from rapid-deterioration. dueto theheat. in the combustion zone, I have .iound it preferable .to use heated Water as the. cooling medium forsuch water will absorb a su sta t l m unt o heat in being conve ted t steam and wilLp ei/ nt the th rma .shookv which is noted when. cold waterisused and which is an added cause for .the rapid,deterioration-fot th t y res. I havealso. observedthat in usin h t water asthe. heat abso b g flu d, there is less t nd ne ior e. molten sla in the .o po a t ba l up. and. adher .totthe-wal s o th tuyere water j. cket. than .isjthe-oa se wherecoldwater sur s asmay leeuiltup. intheh ad o th water 7 jackets 26. It is pr ierahlet nsew er heated to it maxim m empe atur hero-rev changing t s amat the nr s ur s emp oyed in t e water tan nd th wat r l nes- This temperature is; r fe a ly in ex e s @12 2"- I?- hi ll. instances- Om 1 riqrfi qii l t t' willzbe seen. that the. cupola construction herein disclosed provides-an efilcient method for the heat; exchan ebetween the refractorylinirig i3: i;n :th.e:..combustion zone. 12 and the Water iaeket; M adjacent (thereto. Thisp-rovides a un-iiorm cooling. of :the refractory l3 adjacent the zones. of greatest temperaturetherein. The provision oftthe-airibustle. :2i'l also provides, a heat exchange. between the top portion of :the. :rerraetoryi3 vand. the .air 1 which. iscirculated through the bustle 2a which is utilized tosupportthe combustion in the combustion zone. This. constructionuti-lizes the heat units otherwiselost by radiation-:to. heat the pro-heated air SUPRliQd-to thei liylies; 2d.

The use oi the preheated .air in. the tuyeres 24 hasbeenxfound to provide a desirable-means ior regulating the temperatures and controlling the o bustion the-roombusti n' zone l2. since: it rey-ides a, more eonstantvelocity to theair and homeless-fluctuation theamount or air sup plieristot thehomhustionxthanisthewcase wliere air at atmospheric temperatures is supplied. Air

at atmospheric temperatures varies'in velocity and'hence' in amounts supplied as the atmospheric temperatures vary. t

The cupola construction of the present invention is particularly economical in use. The steam generated in the water jackets 26 surrounding the tuyres is carried away at relatively high temperatures and is sufiicient in temperature and in quantity to permit of its use for power in a plant in which the cupola construction is installed. I present invention has been found to have a long life in service as the refractory I3 is uniformly cooled as herein disclosed and the tuyres 24 are protected against deterioration by the high heat developed in the combustion chamber.

It will be noted also that the cupola construction of the present invention is simple to construct and operate for it is not necessary to provide for water pumps to supply the water either to the water jacket M or to the tuyere water jackets 26. There is a positive circulation of the water through the water jackets I 4 and 26 by its thermo-siphon action. In all instances where steam is generated, it is led out of the system so that there are no steam back pressures in the water jackets which otherwise would prevent the ready circulation of the water therethrough.

In operation it is to be noted that the spacing and placement of the tuyeres 2 3 permits a ready top charging of the cupola which provides a uniform feeding of the charge stock through the zone of combustion and hence this arrangement simplifies the charging of the cupola and its operation.

t will be seen also that the cupola construction of the present invention, while novel in many of its features and in its operation, is readily constructed of standard parts with a maximum utilization of the materials employed.

Two separate but interconnected water feeding systems are shown. ne supplying the water jacket I 4 surrounding the lower portion of the refractory i3 and the other supplying the water jackets 26 of the tuyres 25. The water in the water jackets l 4 is under no steam pressure while that in the tuyre water jackets is under steam pressures. Water is admitted to the tank H5 at approximately atmospheric pressures and is heated by its passage through the water jacket I4 after which it is pumped out of the line 8 to the feed water line 35 of the tank 21. Thus the water jacket I4 serves to heat the feed water for the tank 21, This constant circulation of the Water through the jacket I 4 prevents the water from boiling in the jacket M and the generation of steam therein.

In using conventional types of tuyeres in cupola operations, it is necessary to shut down the operations periodically to clear the bottom of accumulated waste and unburned materials. If this is not done, the fire placement in the cupola is changed, due to the build-up of such materials on the bottom and the operation of the cupola is impaired. As contrasted with such conventional constructions, a cupola embodying the present invention may be operated for very long periods of time without requiring shut downs and rebuilding of the bottom. This is due to the downwardly directed blasts of air from the tuyeres 25, which assures a distribution of air through the materials on the bottom so that full combustion is assured. This provides sufiicient heat at the bottom 01 the cupola so that the In addition the cupola embodying the charge stock on the bottomis melted and any waste or refuse, as for example molten iron which may form in the melting of slag androck in cupola without drawing-the fire therefrom. Thus the present invention permits the continuous operation of the cupola throughout prolonged periodswihout requiring bottom changes.

I claim:

1. A cupola including arefractory lined combustion chamber, a water jacket surrounding the lower portion of said chamber, an air, bustle surrounding the upper portion of said com bustion chamber, a plurality of vertically ex tending water jacketed tuyres connected at their upper ends with said air bustle and having their lower ends open to discharge air into a zone of combustion in said combustion chamber, Y an airsupply duct connected with the bottom of said bustle and communicating with a source of air under pressure an air supply duct leading from the top of said bustle to each of said plurality of water jacketed tuyeres, and a water circulating system for supplying water to said water jacket around said combustion chamber, and to the Water jackets surrounding said tuyeres, and including a water supply tank connected to the bottom portion of said water jacket surrounding said combustion chamber, and a second water supply tank having connections with the bottoms of each of the water jackets surrounding said tuyres and extending upwardly at an angle to the bottoms thereof, and a water return line leading from each of the said tuyere water jackets at a point removed from the top thereof, and a steam line leadin from each of the said tuyre water jackets at a point adjacent the top thereof.

2. A cupola including a refractory lined combustion chamber, a water jacket surrounding the lower portion of said chamber, an air bustle surrounding the upper portion of said combustion chamber, a plurality of vertically extending water jacketed tuyeres connected at their upper space for charging said cupola from the top portion thereof, an air supply communicating with said bustle to supply air thereto and to said tuyeres and a water circulating system for supplying water to said water jacket around said combustion chamber and to the water jackets surrounding said tuyeres, and including a water supply tank connected to the bottom portion of said water jacket surrounding said combustion chamber and a second water supply tank having connections with the bottoms of each of the water jackets surrounding said tuyeres and extending upwardly at an angl thereto and a water return line leading from each of the said tuyere water jackets at points removed from the top thereof, and a steam line leadin from each of said tuyre water jackets at a point adjacent the top thereof.

3. A cupola including a refractory lined combustion chamber, a water jacket surrounding the lower portion of said chamber, an air bustle surrounding the upper portion of said combustion chamber, a plurality of vertically extending water jacketed tuyeres connected at their upper ends with said air bustle and having their lower ends