US2772075A

US2772075A - Temperature control for rollers subjected to heat

Info

Publication number: US2772075A
Application number: US61789A
Authority: US
Inventors: John J Mayer
Original assignee: Individual
Current assignee: Individual
Priority date: 1948-11-24
Filing date: 1948-11-24
Publication date: 1956-11-27
Anticipated expiration: 1973-11-27

Description

J. J. MAYl-:R

Nav.' 27,- 195e TEMERATURE CONTROL FOR ROLLERS SUBJECTED TO HEAT.

Filed NOV. 24,' 1948 JNVENTVoR. JH/v J.' Mn YER HTTENEY m mEl Nov. 27, 1956 J. M 2,772,075

TEMPERATQRE co FOR R Rs SUBJECTED To HEAT Filed Nov. 24' 1 2 Sheets-Sheet 2 T 'lI lu- [nl i L J I, 6 \\l| .f

United States Patent TEMPERATURE CONTROL FOR ROLLERS SUBJECTED T HEAT John J. Mayer, Wood-Ridge, N. J.

Application November 24, 1948, Serial No. 61,789

3 Claims. (Cl. 257-95) My invention relates to temperature control and more particularly to means and/ or method for maximizing heat transfer in components employed for treating heated material by the application of a refrigerant to the components.

In machines or apparatus for treating or processing mastic or similar materials, rotating hollow cylindrical rolls are usually employed to gauge a mass or blanket of the material to conform to a specific size or to other- Wise Itreat the material in accordance with a preestablished process. Inasmuch as the temperature of the material being treated or processed is such that it effects heating of the rolls above a temperature deemed conducive to satisfactory processing, refrigerants, for instance, cold water, brine, etc., are utilized and introduced within the rolls for cooling the latter. This invention, in its solution of the problem of heat transfer, involves consideration of numerous factors many of which have been ignored or unrecognized in previous attempts to properly cool mill, calender and other rolls. The function is not to cool the stock being worked by the roll, but rather, to maintain the roll at a low enough temperature so it can be kept in continuous operation without becoming overheated. The metal of the roll conducts heat readily. Therefore the thickness of the roll does not introduce a limiting factor. But the inside surface is of prime importance. For purpose of strength, the rolls have thick walls and consequently the inside surface area of the roll is far less, usually about half, the outside surface area. To maintain heat equilibrium, heat transfer from the inside area therefore must be increased to equal the heat transfer received from the stock by a proportionately greater outside area. Mere flow of fluid within the roll does not attain this desired cooling. Unfortunately an insulative film of the fluid forms on the inside surface of the roll. This is because, as smooth as the inside surface of the roll may seem, microscopically it reveals mountains and valleys which entrap the molecules of the cooling uid. The lms trapped in the valleys quickly become hot, and since they are not constantly replaced with cool films or layers, they quickly form and `remain as an insulative film which slows down heat transfer from the roll to the transitory uid beyond said film. Based on these factors, the present invention presents construction and method primarily directed to the elimination of the insulative film normally entrapped in the valleys of the inner surface of the roll.

In addition to the formation of film due to the valleys in the inner wall surface of the roll, there are other factors the presence of which also tends to form and increase the thickness of the insulative film. One of these film-forming factors is inherent to the roll construction which, because of greater inside diameter thereof than diameter of the fluid outlet, forms a basin or sump wherein 'a considerable volume of liquid always remains liquid remain in a state of quiescence or at the most,

ICC

affected only by a very sluggish tlow toward the exit. The present invention recognizes this inherent detrimental structural and operational characteristic of prior art rolls and provides a means and method of overcoming the same by both creating turbulence in the liquid in the basin-like hollow of the roll and by displacing trapped liuid in the surface valleys while submerged.

Another of said factors, the presence of which tends to form and increase the thickness of the insulative film, is the operation of centrifugal action forcing the liquid against the inner wall of the roll so that a very considerable thickness of the liquid becomes fixed with respect to the roll and just revolves with or follows the roll without dislodgement even when carried to zenith location above the pool in the basin-like hollow of the roll. This centrifugal action is exceedingly detrimental to the cooling procedure, since it not only tends to lodge and retain the fluid more securely and immobily in the valleys in the roll inner surface, but results in a very considerable increase in the film thickness, thereby adding greatly to the insulative effect adverse to the desired heat transfer from the roll to the discharging coolant. According to the present invention, the e'ects of this centrifugal action are decreased and largely overcome.l

This objective is achieved by use of jets of cooling uid having a strong downward velocity carrying the jets through the fluid in the basin-like hollow to the roll inner wall thereby both forming :a barrier transverse to the rotational direction of the roll and functioning to extract uid trapped in the inner surface valleys.

In addition to the essential objects of the invention indicated above, another object of my invention is to provide means of the foregoing described character capable of being incorporated in rolls having boresof :a relatively small diameter.

A further object of my invention is to provide means of the foregoing described character capable of being incorporated in rolls already in use without modifying the rolls.

An important object of my invention is to provide a roll of the foregoing described character which is so constructed and arrangedY as to limit the refrigerant content to a predetermined amount and equipped with means effective for agitating the content and to preclude formation of an endless coating path about the interior peripheral surface of the roll.

Another important object of my invention is to provide means of the foregoing described characterwhich is simple in construction, durable in use, efficient in operation, economical in Imanufacture and easy to assemble and disassemble.

With the above and `other objects in View, as will hereinafter appear, the invention consists in the combination and arrangement of parts hereinafter set forth'and illustrated in the accompanying drawings from which the several features of the invention and the advantages attained thereby will be readily understood by those skilled in the art.

Referring to the drawings wherein like reference char-v acters designate like parts throughout the several views:V

trunnions' 40 -and '-11, '-respectively. The trunnions are adapted -to be rotatably journaled in bearings to permit rotation of the roll which-constitutes a component .oan apparatnsgor machine fortreating ortrprocess'ing 'heated `mastic `material or lthe like, tit being understood Vthat the-temperature'of the material being' treated or processed issuch tlratjt causes heatingof the roll above a `ternperature deemed conducive .to satisfactory processing.V

, Thetrunnion It) Ais provided with a centraiized opening or passagelZ extending therethrough and'haing 'its Outer end `diarnetrically lenlarged as at i3 and itsfinner cndcommunicating 'with the chamber I6 through the end Vwall 8. The opening V12 Vconstitutes an outlet'rneans orjpassage having an apprecibly Vsmaller diameter than the :chamber :6 as a result of which'tbe hollow of the roll forms a sump or "basin, 'in 'the nadir zone of the harnber, "lower than the .outletpassage 12 and therefore will retain a :pool of 'the refrigerantY or liquid therein. 'The outer end of the `trunnion ldhasrsecured thereto a`stu"l`flng1box or gland I3 'through which extends` a conduit -or 'tubular casing 14 communicating with the end 'i3 ofthe passage l2, thestufiing box or gland serving `asa seal *andperrnitting rotation of the roll 5 relative `to the casing 154. The outer end section of Vthel'casing 14 2 has connected thereto `a radially extending outlet pipe 15 and ispr'ovide'd with Va radial end wallthrough which extends a'refrigerant supply conduitlt).

The-.refrigerant supply conduit'Z .is provided with fa pair of sections "21 and 22 with .the section .21be1ing tubular and extending through .the passage 12 into 'the casing i4. The section 22, which maybe structurally integrally "formedwith the section 21, is disposed within the chamber i6 and is substantially'ovato-oblong intransversali'ty'to'providepairs of oppositely disposed plane'and -arcu'atewalls and'has lits outer end, .adjacent'the end .wall

9., closed. The arcuater walls constitute Asidewalls 22 which are disposed appreciably out of the axially projected outer circumferential connes'of the section I21 while theplane walls constitutespaced'upper andlower 4o'

Walls

23 and 24, respectively, and `are disposed Vwelll within 'said contines.

The upper wall .23'has mounted .thereon a plurality of fspaced spray'heads '25 of .the l'high velocity "type whereby `sprayed Ystreams yof refrigerant or cooling' liquid, under pressure, from the conduit 20, will be impelled against the inner wall of the rollor peripheral face `of the'chamber in the zenithal zone thereo'f so forcibly asto 'penetrate intothe valleys o'flthe inner sur-- face of the roll and break up, dislodge 'and dispersethe 50 heat-insulating lm. ,Itis to be understood lthat 'th'espray l heads '25 are constructed and spacedin amanner causing the spray streams to fan outward and roverlap or intermingle "in their approach y-to the vroll wall so "that 'the series of spray streams from the several Vspray heads willprovide an uninterrupted expanse of lmfpunctur'ing and '-dispersing stream throughout the length l of the zeni-Y Y tha'l zone between end walls 8 `and 9.

`The lower wall '24 of "conduit vsection 22 .'is provided with a plurality 'of jet Vnozzles 26, of the high-velocity typejwherebya row 'of'high pressure jetsofrefrigerant VIor cooling liquid from the conduit 20 will be .directed toward and 'will `pierce the pool of duid to the 5bottom thereof and will forcibly impinge 'againstitlre inner surface ofthe Vroll within the basin or sump, the force `ot' thejjets being great enoughjto `lboth agita'te`.tl1efp'oci'l of refrigerant contained -within `the :sump `and 'to Aalso irupture and 'disperse the` lm on the wall 'oftheroll at the bottom ofthe pool. `ltmay 'also be lrerementioned-that the spray heads 25 and jet .nozzles .26 arearranged .at top and lbottom respectively of #the conduit vsection 122, and :alternate in longitudinal location, and thus '-coact .to resist 'displacement 'of the S.conduit section within 'the' chardherfrom'reactionaryforce of .the ejected streams.

"'jy'utihinglliigh velocity 'jet.jnozz`les ,'l electively disrupt, within Ithe nadiral zone, that portion of the re- `frigerant which had either become 'quiescent'for which had established anity toward the surface from centrifugal action 'or which had established a heat-insulating lrn next said surface by reason of the depth of the pool, or by reason of the rotation of the roll and centrifugal force or by reason .-of the inherent presence of valleys in the roll surface. The impinging of the jets against Ithe -innersuace of ythe roll is A-eeQted 'with vsuch force as to deflect the Ajets laterally Aover adjacent por.

tions of the surfac'eandjthus'extend.thejlm-disrupting effect over a considerable area. It' is furtherpointed out thatr'the -jets-'coactftogether toestalilish'a id in a plane radial to end longitudinalof :the conduit section and extending from theV conduit section to'the inner sur@ face of the roll. thereby interrupting'or dislodging the lm or layers of Huid from following 'the rotational impulse of ,the roll under 'inuence .of centrifugal retention.

and is .thus .disposed in a plane in .parallelism with .the axis of the roll and superjacent thereto whentheroll is disposed horizontally, :as clearly illustrated .in .the drawings. By thus .mounting the conduit .in closer .re-

lation to 'the zenithal zone of the chamber, vthe'jet nozlation tothe conduit; .insome 'instances .the ,passage `being Y.

only 2'1/2'" and the conduit, as fordinarily constructed, approximately 7A11/2 it will'be apparent that the distances the .heads andnozzles project outwardly 'from the Leon-V i duit must'be less .than l" in .order to permit insertion ofV theV conduit with the 'heads' and .nozzles .assembled .there-V on. V"Obviously, in these "instances, .only relatively .small heads and :nozzles could be :employed .-and which, in practice, .would 'be ineicient. Y

However, the spec'ic .construction .of the section .22

' f .the conduit as .'here'in disclosed with .respect .to the spacing of the

walls

23 and 24, permits the ruse @ofimater'ia'lly 'larger and more -etective -heads and .nozzles than would yordinarily 'he .feasible .in view of .the relatively small 'diameter of the passage `andthe ,fact that (the. rolls 4'areordinarily :of a .one-piece .cast construction with-V outrelatively/large 4removable components to .permit ac cess 'to the chamber 6. It 'is to be understood, that l.the

. refrigerant is 'introduced .into -the conduit 20 `under .an

eiectivepressure .and .that the .overflow .of .refrigerant from ,the :sump will pass outof'fthechamber'.throughthe Y In actual .reduction Y to practice, .I have ascertained that in .comparison with.

. the ordinary method, wherein .a .roll has .incorporated passage .12, ycasing and outlet pipe.

therein .a ,refrigerant supply pipe .of .ordinary construction .equipped with relatively .low velocity spray means, that .the `heat transfer .in .the same roll hav'ing -my -in-V vention incorporatedltherein is increased more Athan .live

. times over .the ordinary .method and .under the same operating conditions. Furthermore,`by theuse .of .my

invention, coating jis not only .ruptured and .dispersed from'.the .mounds .on .the surface' f vthe chamber, *but* actually from within theindentations 'between fthe mounds 1t isgto'be understood .that thelanguag'e used "herein islintended to cover all the genericland spec'iic eaturesQo'i the Iinvention .herein described, 'andall statements .df ,thes'cope o'f theinvention which, "as 'a-.rnatter oflanguage, maybe said to 'fall therebetween. `Fur- The conduit .is .eccentrically mounted within the .ro/ll.

purpose of description and not by way of limitation, it being understood, in some instances, that the various components may be arranged in a manner whereby the foregoing terms would not appropriately describe their relative positions.

Without further elaboration, the foregoing will so fully explain the invention that others may, by applying current knowledge, readily adapt the same for use under various conditions of service. Moreover, it is not indispensable that all the features of the invention be used conjointly since they may be employed advantageously in various combinations and subcombinations.

It is obvious that the invention is not coniined to the herein described use therefor as it may be utilized for any purpose to which it is adaptable. It is therefore to be understood that the invention is not limited to the specic construction as illustrated and described, as the same is only illustrative of the principles involved which are capable of extended application in various forms, and the invention comprehends all construction within the scope of the appended claims.

What I claim is:

1. In combination with a heat exchange hollow roll having a peripheral working surface, the temperature of which is to be controlled, and having an inner cylindrical wall the surface whereof has microscopic valleys conducive to formation of liquid film and said roll having partial end walls adapted to retain a pool of liquid in the roll, whereby as the roll rotates part of said cylindrical wall is submerged in and part is above said pool, means for injecting concentrated, high velocity jets of duid on the submerged part of said wall, and means for directing high velocity sprays of uid upwardly away from the pool for dispersing film on a part of said wall above said pool.

2. In combination with a material treating roll of a type provided with a cooling chamber defined by a peripheral wall and a refrigerant outlet passage communicat ing with said chamber above the bottom thereof whereby the nadiral zone of the chamber constitutes a refrigerant sump, said wall having an inner face on which refrigerant introduced into the chamber tends to form a film during rotation of the roll and thus establish a surface seal on said face to render refrigerant, engaging said seal, ineective for cooling said wall below a denite temperature; a refrigerant supply conduit extending through said passage disposed within said chamber and equipped with refrigerant high velocity spray heads effective for directing refrigerant sprays from said supply means against said face within the zenithal zone of said chamber and with sufficient force to counteract said iilm, and refrigerant jet nozzles eiective for directing refrigerant jets from said supply means through refrigerant in said sump and against said face with sufficient force to agitate refrigerant in said sump and to rupture and remove film on said face, whereby, refrigerant from said supply means is rendered eiective for cooling said wall below said temperature, said heads and nozzles being arranged in opposed relation to counteract reaction by said sprays and jets and maintain said conduit against displacement.

3. In combination a heat exchange hollow roll having a peripheral Working surface, the temperature of which is to be controlled, means for distributing a cooling uid Within the roll comprising an inlet conduit positioned Within the hollow portion of the roll and spaced from the inner surface thereof, the said conduit being provided with a plurality of spaced, aligned high velocity spray heads on one side thereof and with a plurality of spaced, aligned high velocity jet nozzles on the lower side thereof; means positioned at an end of the roll whereby the cooling uid may be drained from the roll, the said means comprising a trunnion having a passage extending therethrough communicating with the hollow portion of the roll, the diameter of the passage being smaller than the diameter of the hollow portion of the roll to provide a sump within the roll, and the diameter of the passage being larger than the external diameter of the conduit; and wherein a stuiiing box is secured to the outer end of the trunnion, through which box extends a casing provided with a drain outlet and having substantially the same internal diameter as the trunnion passage and communicating therewith; and wherein a portion of the conduit is positioned centrally of the casing and trunnion passage to thereby permit fluid from the roll to be discharged through the trunnion passage, casing and outlet pipe.

References Cited in the file of this patent UNITED STATES PATENTS 1,564,171 Brown Dec. l, 1925 1,783,465 Fox Dec. 2, 1930 1,819,988 Jones Aug. 18, 1931 1,820,074 Kilborn Aug. 25, 1931 2,435,959 Eaby Feb. 17, 1948 FOREIGN PATENTS 438,490 Germany Dec. 18, 1926