US1999832A - Cooling chamber of heat treating furnaces - Google Patents

Description

April 30, 1935. H. A. DREFFEIN COOLING CHAMBER OF HEAT TREATING FURNACES 6 Sheets-Sheet l Filed Sept. 14, 1934 ll l/ H HH l/ April 30, 1935.

H. A. DREFFEIN 1,999,832

COOLING' CHAMBER OF HEAT TREATIG FURNACES y Filed Sept. 14, 1934 6 Sheets-Sheet 2 April 30, 19,35. H. A. DREFFEIN COOLING CHAMBER OF HEAT TREATING FURNACES Filed sept. 14, 1934 e sheetsLsheet 5 SS v KN Sv @eff/07': Wr //ff. @i d. 2

April H. A. DREFFEIN vCOOLINGr CHAMBER OF HEAT TREATING FURNACES Filed Sept. 14, 1954 e sheets-sheet' 4 April 30, 1935. H. A. DREFFEIN COQLING CHAMBER OF HEA'T TREATING FURNACES Filed Sept. 14, 1954 A6 ShqetS-Sheeb 5 April 30, 1935.

H. A. DREFFEIN ACOOLING: CHAMBER OF HEAT TREATING FURNACES Filed Sept. 14, 1934 6 Sheets-Sheet 6 Patented Apr- 30, 1935 c+ COOLING CHAMBER OF HEAT TREATING FURNACESi Henry A. Dreffein, Oak Park, Ill. v K Application September 14, 1934, Serial No. 744,003-

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This invention has reference to improvements in cooling chambers of heat treating furnaces and 'the like, that is, furnaces for subjecting metal sheets and other objects to normalizing or annealing temperatures for relieving the metal of internal stresses and strains, and also for producing in the metal such other advantageous results as follow from the normalizing orannealing operations. Usually the sheets or other objects are introduced into the `cooling chamber of the normalizing or annealing furnace at aV relatively high temperature, such for example, as eighteen or nineteen hundred degrees Fah., and as they pass through Athe cooling chamber of the furnace they have their temperature gradually reduced to, say twelve or thirteen hundred degrees Fah. The subsequent reduction of temperature to normal atmospheric temperature need not be under controlsince the action in the normalizing or annealing furnace serves to bring the' temperature down below the critical point, and accurate control of the `furtherreduction is not required. l

One object'of the present invention is to provide a cooling chamber wherein the temperatures at difierentrpoints may be closely controlled, so as to ensure the desired continuous reduction'of temperature from the entrance into the cooling chamber to the delivery point therefrom;v 1 This reduction of temperature is secured by the jet or spray is relatively smalLand the control` of water jet is conveniently'secured by valving the water drawn into the nozzle, so as to increase or decrease the amount of water introduced, thesteam flow remaining constant. Due to the high latent heat of evaporation of water, the water introduced at each jet or spray Will absorb a very large amount of heat from vthe gases iiowingthrough the cooling chamber of the furnace with corresponding reductionof 'the temperature of the said gases, so that a considerable cooling action is secured'with only a relativelyv small amount of waterintroduced.

The water so introduced will flash into'steam with the cooling action due toits-high latentv (ci. 2634s) A c heat of evaporation, and this steam will immediately becomesuperheated du'e to the high temperature existing within thecooling chamber vso that wet; steam will not be presenti within such chamber, and thus no damaging action will be produced on the metal sheets or other objects therein.V The temperature of the chamber even at the delivery end is sufliciently. high to keep the steam in superheated condition up to the time of outilowifrom the chamber.

Usually the steam and water jets will be so 'located as to provide the kcooling action in zones along the length of the chamber; and the.num` Y ber of jets in each ofl these zones maybe oo-related to the amount of cooling action which it'is desirable to secure in that portion of the structure. f

Another feature of the` invention relates to the provision Aof an arrangement such that the water and steam; vjets will naturally flow. or vsweep through Athe chamberV in the most advantageous manner with respect to the material being treated. This materialisconveniently carried on brackets or'stands which-travel through the length of the furnaceand cooling chamber; and

the jets or sprays are so placed in the chamber Wall or walls that the water and steam will flow` and circulate over and aroundthe` said material, thereby subjecting the material to the desired action `both above: and below, and ensuring the proper cooling action onall portions thereof. VIn this connection, When thevmaterial isfplaced in theform of piles or stacks on the stands or brackets, itis especially desirable to'ensure a flow of the yWater and steam suchas to` causeproper treatment of the lower portions of these piles, and this result is secured by the presentarrangement Vin which the now is such as to encirclethese piles'or stacks. f y f If desired there may be provided automatic means'for controlling the valving 'of' the water introduced into each orV all of .the jet's'or sprays,V

such means functioning according to the` temperature within the` cooling chamber,r so that theV amount of Water drawn in by each jet or spray will vary from time to time ask need be to maintain the desired temperatures within the various' zones of the chamber.

Y Other objects and uses of the inventionl will? appear from aV detailed description ofthe same which consists; in the features'of constructionand combinations of parts hereinafter described and claimed. 'Y v l In the drawings; 1

' Figure l shows 'a central vertical,longitudinal section through the cooling chamber of a normalizing or annealing furnace embodying the features of the present invention, at the delivery end thereof;

Figure 2 shows a continuation of Figure l towards the entry end thereof, and also includes a portion of the heating furnace from which the materials arrive into the normalizing or annealing furnace cooling.section;. j

y Figure 3 shows r a plan section corresponding to Figure 1; Y f

Figure 4 shows a plan section corresponding t Figure 2;. v

Figure 5 shows a verticalicross-section.'on the line 5--5 of Figure 4 looking in the direction of the arrows;

Figure 6 shows a longitudinal section throughA a form of jet or spray for introducing the water;

Figure 7 shows a perspective View of -arportion -sheets or other materials arriving from theheating furnace travel towards the left through the coolingchamber to the point of delivery. AThe heating and cooling V`chambers are relatively broad andfshal1ow;.and..there is a weir I2 between the chambersfsaidweir being formed by the yupwardly extendingportion i3 reaching up from the floor, and the downwardly extending portion AIll reaching ldownwardly from thefroof. I do not'hereinlconcern myself particularly with the details of construction of' thev heating furnacenor:with themeans for'heating the same,

sinceV these Vfeatures do not constituteany por-V tion4 of thepresent invention. y. .i f.

Extending lengthwise of both the heating and cooling. chambers there fare 'the slots l5,v l5, Il,

.i8 and i9. Beneath the floors of the heating and cooling chambers Vthere Vare the conveyorsl 20 lo, cated in 'line with the slots just referred to, andV these/conveyors have connected to. them the bracketsll which '.are of generally Y-shape. These bracketsfreach up'through therslots I5, t6, l1, land. I9', andinto the'furnace chambers, so that the prongs or forks4 of these brackets stand up within theV furnace chambers. The material to be treated'is carried by the upwardly extending arms 22 of these. brackets, saidmaterial being conveniently.` placed on the brackets in piles :as shown inFiguresl andV 2. In case said material is in the form of sheets, it is generallyfgood practice to place aspecial sheet at the bottom of each pile'to thereby'protect the sheets being treatedV from abrasioniorfother injury by the bracket arms on which the piles. arecarr'ied. f

. As the Yconveyors travel towardsthe left theV brackets move to the leftand carry the sheets or other material. from` the heating chamber through v.the vWeir andY into the.: cooling chamber. This action is apparent `fromfexamination of Figure- 2. Usually the sheets will `be *placedv crosswise'on thezbracketsgthe. chambers being broad '-.enough to accommodate thelengths ofthe sheets.

across .the chamberaiso that the sheets'advance edge-on. The piles of sheets are designatedby the numerals 23. When thefsheetshave com- Dletedftheir traverzthrough the cooling. chamber mme.

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they are delivered therefrom through the weir 24, the opening of which may be controlled Vby the gate 25.

A portion of the cooling action in the cooling chamber may be accomplished by the pipes or tubes 26 which are suspended from the roof of said chamber, and through these pipes or tubes may be flowed air for use in the heating furnace, so that said air performs a coolingaction proportionate to the heat so recuperatedfor the fur insufficient, and the advantage of this action sometimes lies principally in the delivering of preheated air tothe heating furnace.

.. The main feature Aof the lpresent invention resides in the provision of means for introducing spraysor jets of water into the cooling chamber andunder control, Aso that this `so-introduced water will be vaporized by the heat of the chamber and the material therein. and with corresponding abstractionof heat, and' cooling. For this purpose Lhave placed oneY spray designated 2l in one wall of the cooling chamber close to the entering` end, and a series of Vthree additional sprays designated v28, 29 and ,36in the'wall of said chamber nearV to the delivery end thereof. Each spray is of the'general form shown in Figure 6. It includes thecentral passage 3i through which the water is introduced, and the surrounding passage 32 4through which the steam for the Vjet is introduced. The water is delivered through the small Acentral opening 34 and immediately meets the conical formsteamjet delivered through the thin annular` orifice 35, so that the water is immediately taken .up lby the steam jet ,and atomized and delivered in the form of a long; cone. Generally the control of the action is best performed byleaving the steam Asetting constant, and adjusting the amount of the water stream. The details' of Ythe Vform of the. jets are not necessarily important, since various'forms of j ets maybe used-for introducingrthe. water into the cooling chamber, and therefore I do not deem it necessary to describe this jet in further detail. It is, however, in some cases desirable to .provide an outsideor protective pipe Btiaround the nozzle to protect the same from direct action of the heat inthe chamber; or when the nozzle is built directly into the wall ofthe chamber this outside pipev 36 serves to provide the means for atta ching the nozzle intov the Wall.

^ lReference to Figure 5 in particular shows that the jets aredi'rected upwardly somewhat so that the Vwater delivered Yinto-,the chamber is thrownv upwardly and across the chamber in the form of anarcr, This vcarries said water over the upper portions ofthe piles of material, to the opposite side of the chamber; There. the general current of flow or travel curves downwardly and returns .beneaththe piles oimat'e-rial towards the originating side of the chamber; sothat ultimately a large portion of this cool-streamof vaporizing water is Acaused to-travel completely over and around the material, thereby subjecting the bottom portions of the piles to the cooling effect,

and ensuring a-l well balanced cooling eect for material being normalized This cooling action is, however, usually such case each or all'of-the sprays may be placed Y under control of athermostatic device, so that as the temperature'rises in thecooling lchamber weight;

the amount of water introduced will also rise, and

so that a converse action will be produced in the case of falling of temperature Within the chamber. Such an arrangement is Ashown diagramrnatic'allyin Figure 8. In this'case the water '.linef to thejet is under controlof a valve 4|, -it being intended-that the steam ,line shall remain at a constant setting.` There Vis provided'a diaphragm motor 42 fthe diaphragm 43` whereof is connected to the valve 4| by the rod-44. There is a weight 45'which tends to raise -the valve to the full open-condition, but whenpressureis introduced on the top'of the diaphragm it is forced down, lifting the weight and seating the valve to a proportionate degree. A spring 44a may be provided to supplement, or as a substitute for the There is provided a pyrometer or other temperature measuring device 45 at that point in the chamberfwhere it-is desired to effect the-control, and which is affected by the spray' in question.

v' Ihis pyrometer may be any suitable form, and the details thereof 'do not require illustration herein since they' do not constitute any portion of the present invention. n

This pyrometer includes 'a chamber wherein there is suitable heat responsive mechanism such that upon rise Vof temperature within the chamber a cord 46 will be proportionately released, whereas when the temperature falls this cord will Vbe proportionately pulled back.` This cord in turn is'connected to a plunger valve 41 working within a chamber 48, there being an air inlet 49 at the lower portion of the chamber, and an air escape opening 58 at the upper portion of the chamber, and an air delivery connection 5| at one side of the chamber. Compressed air from any suitable source is delivered to thefconnection 49. When the plunger 4'| is in its lowered position it closes a port 52 and opens a port 53.` This discontinues the delivery of compressed air tothe connection 5| andalso permits said connection 5| to be vented.`r The connection`5| 'is in-turnconnected to the top face of the diaphragm, so that under these conditions the diaphragm is releasedgand the water valve opens fully. When the temperature' conditions so changel that the plunger valve 41 is raised, the escape of air from the connection 5| is proportionately cut oif, and the compressed air y connection 49 is permittedtodeliver compressed air to a greater or less extentV to the top face of thediaphragm, so'that the watervalve is correspondingly closed.. Thus there is secured an automatic control of the water supply'in accordance with the temperature conditions existingwithin the cooling-chambeigincreasing the water spray whenr the temperature rises, and decreasingthe water spray when the temperature falls. As above Vstated the pyrometer may be of any suitable form,

such as a Leeds & Northrup, or a Brown, or other suitable'type. A l v It will be noted that the cooling and control thereof eifected by the introduction of the water sprays serve also to prevent any abnormal or excessive rises of temperature, and'also serveto preventsuch rises of temperature suddenly, so thatV the tubes 26.of the recuperator are protectedv downwardly beneath the sheets vor other against any burning.` f

' Byintroducingthe water in the form ofseveral sprays located at different positions in the length of the furnace I am enabled to introduce-a total amount' of water `sufficient to produce the total desired cooling action but without such'a concentration of water vapor at Yhigh temperature-at any given point as might be injurious to the metal sheets or other objects at such location. Also', a considerable portion of the water is introduced at points or zones of ysuch lowered temperature aswill not cause any damage to the Vmetal sheetsdue to the presence of such water vapor'.

While I contemplate'as being within theY scope .of .my invention the. use of any-suitable'form of .spray Vor means for introducing the water into the cooling chamber of the normalizing or annealing furnace, still I wish to pointV outthat a steamactuated water spray is peculiarly adapted to the present-work, and there is a peculiar combination thereof with the cooling chamber of the normalizingor'annealing furnace. This is because the steam serves to ensure a constantatomizing action of the water and thus ensures .that vthere will not .be any drippage of atomizedwater or `unatomized water into the chamber. and onto the sheets or other materials being treated; Furthermore, the form of nozzle herein illustrated in'Figures and 6 is such that a small particle of dirt or other foreign mattercannot clog the nozzle since the nozzle openings are large andgthe power of the steam jet will atV all times serve to cause particles of foreign kmatter to'be carried cuil from the relatively large openings of .the'nozzle Also, the steam spray'is Adesirable since-it isnonoxidizing and serves to -carry and distributeY the waterV to all portions of the space within the cooling chamber with consequent distributionyof the .cooling effect. It also serves to producev a current across the direction of travel ofthe sheets or other objects so as to carry its effect'clear across the chambensaid current then turning objects, ,towards thepoint of origin. y

I `,wish to also point out that in some cases it may be desirable togplace Vthe `steam supply for lfurnace having means'fortransport of the-metalr objectsl through its length, 4ofprneans for cooling i and controlling the temperature within said cooling chamber', comprising -means for introducing f `iets of water into the chamber transversely thereofVV and above the objects being transported therethrough, tothereby absorb heat into the water andl evaporate saidv Water, substantially as described.

against any excessive temperatures and therefore 2. 'Ihe combination with a cooling chamberof .a furnace of the type described, said furnace'having meansrfor transportof metal objects lengthwise thereof, of means for cooling and controlling `the temperature within said cooling*v Vchamber comprising means for introducing jets or Vsprays of water vtransversely of the chamber, and above the metal gobjects, ,said sprays flowing over the f rmetallnbjectsand idownwarlyandfback beneath the metal objects, substantiallyrlasdescribed. Y T11-'he combination-with a coolingifchamber of :a :furnace :for v heat treating rmetal aobiectsnsad ffinnace `having aconyeyor .-for itransportingf the v.metal objects Jlengthwiseiof ithe furnace, pisa :series .ofspray nozzles inthe ;side Wallfof ,the ,cooling chamber, each nozzle -being iadaptednor :spray` of a. 'water jettransversely -;of, :the `cham-- .ber, and ithe several `nozzles being directed Y:upwardly to thereby :cause the sprays ,to Ilow nun iwardly and transversely oi 'the chamber, iwhere' lby 1the `sprays -flow,upwardly-fand aacross the chamber 4.above the .metal l`objects@andzthen :iiow downwardly and return below the metal objects, :substantially ras described; f u i Y 4,:*51he combination with a-,coolingchamberlof ia furnace for heatztreating metalpobjects, :said .fzumaceahaving fmeansfor conveying the objects -lengthwise thereof. awhile :supported above :the 'furnace oor, of 'meansifor v.cooling ,land'zrcontrolvling the temperature of the cooling 'chamber, -comprising k:a .series :of u'ets Yfor "Water Vlocated Y ein :they wall :of the V-chamber and .directed-up' .Wardly. .and rtransversely of Ythe fchamber, and

aada'pted :to :throw Water sprays upwardlyand across 'the `chamber,A 1whereby i said "sprays -travel racross the chamber .above lthe metal objects, :and return beneath vthe metal objects, substantially fas :described: I Y

5. The combination `with .a f'heatV treating -chamberor metallobjects, said chamber 'having fmeansfortransport of the objects lengthwiseof lthe chamber and `supportedabove the `floor Vof the chamber, of 4means for 'controlling the Etemperature-and eiecting cooling action A=withinthe chamber, ycomprising-aeser-ies of lsprays for Water -located in the walll-oflthe vchamber'anddirected 'across "the chamber, @together 'fwith means `for `controllingftlfie Iwater `jets' according to the tem perature existing ,withinV the Lohani-ber, fsbstan tially asdescribed.

y 6; The combmationvfwitha :heat treating chamber for metal-objects, said-chamber having means for `transport `o'f 'fthe I'objects through ithe chamber, of means for cooling `and =controlling itheftemperature Within the chamber, comprising a series-of Lsprays for water `located :at different positions 'lengthwise 1 of` tthe chamber and in dif- "ferent zones of-'control',-each oifisaid spraysbeing adaptedto direct a spray of Ywater Lacross the chamber, Etogether `-with means ffor controlling the several sprays 'individually :tothereby..control the-.cooling action'in'the diicrentz'ones :individually,substantia1ly as described@ L H 7. The combination with a chamberifor' )heat treating :metal iobjects; of means i*for lcontrolling 4the, temperature Within thefchamber :fandffor eiec'ting :cooling -action'fthereim `comprising means for :introducing 'jets fof iwater. into-'the chamber under lcontrol-. euzcording#to `,the .item- -perature existing witlriinfitheachamber, substantially 'as-described. I s

4r8. 'The combinationf-with'V a chamber ffor heat treating y-metal objects,=of aser-ies' 'of Waterasprays located at different positionsin the wall otithe chamber, together with` means for delivering 'to each v`of said sprays a `supply of Water according 'to the Y'cooling action tof-be produced "atl-the position 'of said spray,substantially as described.

9. 'I'he lcombination withla Achamber =for heat ytreating metal Aobjects, and foricoolingsaid ob'- jects under control, of `-means`ifor lowering the `temperature within the, chamber comprising means for introducing into ithe fchahibera lseries `ofjets of water :of lpcentnilled iamount v.aermrdine to the cooling action to be producedriatthe fpositionofzeach said jet, V:substantially vas vrle- :scribedig Y flo.v Thecombinationwith a chamberior ,heat -treatingsmetal objects, ,and ffor cooling .-the same,

spray -of Vwater ato :be 1evanorated -by l.the ,heat .of .the chamber, .to thereby iower v,and `control fthe .temperature within lthe-.chambeix substantially Kas f.des cribed. -v Y 1 Y j ,1`1. The combination withxafheat treating iur -nace having @cooling-chamber, and a recuper Afatoij-withinsaid cooling ,chamber :and subject l`to the heat thereof, (of 1means lor controlling the temperaturewithin :the cooling chamber com ,prising means forv introducing a spray Y`of mater ginto ,saidfcooling 4.chamber ato `thereby prey-,entex- `cessive temperaturas in said ,chamben `and .to

` maintain the temperature-within :said :chamber y under rontrol, Esubstantially xas fdescribed.

1-2. A.The:combination wit-ha hotchamber .anda :recupera-tor ssubjeet kto ,the 4heat tthereof', T,saidLregcuperator being composed of metal tubes, v`of means ifor .controlling the ftemperature within Ithe chamber :to thereby :controlthe temperature of lthe arecuperator, comprising +means -'for eintreducing .a vspray of water Linto .the chamber .to (thereby control :the temperaturewithin fthe same, and thereby prevent excessive tempera;- Ltures Within said -.,chamb1, :Substantially eas krde scribed. x l '13.illhefcombinationtwith:a hotzchamber fand a frecuperator subject .to eontact, fbyhe :gases and heatedby the heatof theggasesof meansrforconftrolling the temperature of .-sai-d gases comprising imeans ,for introducir;g-afspray of swater into .said

- gases to thereby prerent excessive .temperatures means fior cooling said chamber :and controlling the temperature thereof', comprising means `for -introducingasspray for `tva-ter into kseid chamber including :steam means #for atomizing'the vWater fof-said spray, -wherby .the -Water 01" said spray `is atomiaedfbytthe steam-andidrops of AseidWah-zr are prevented tfrom forming; and .coming into. contact with `the ,metal objects within the chamber, ,sub- .stantiallyasdescribexzllV Y Y 15. ,The combination .with the .cooling Chamber fof a' heat treatingjlfurnace havingmeans for transportiof metal objects'therethrougmof means fcr cooling said chamber and controlling'the` temperature thereof, comprising means -for -introjducingla spray of 'water into said chamber at an A`elevation above 'the metal objects -and lincluding `steam means for atomizing the Waterof'thespray, 'wherebyisaid-water isfullyfato'mized andthe-iormation'of drops-'ofwater islprevented-and :where- `byfsaid-waserisprevented:fromdrippingrontorsaid metal-objectsgsubstantiallyas;described.

A LrI.Yr'hecombinationamfithaachamber offtheftype -describe`d, zsaid fchamber-fhaving means forztranstransport of metal objectstherethrough, of means for cooling and controlling the temperature Within said chamber, comprising means for in-V troducing a spray ofwater into said. chamber under steam propulsion, substantially as` de` scribed.

HENRY A. DREFFEIN.

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