US2346526A - Water-cooled tube cooler - Google Patents

Description

April 11, 1944.

' R. s'. WALKER ETAL WATER-COOLED TUBE COOLER Filed *Mayi 2'?, .1942

3 Sheets-Sheet l l April 1l, 1944. R. s.- WALKER E1- AL l 2,346,525

` "WATERv-GOOLED TUBE COOLER Filed-May 27, 1942 s sheets-sheet 2 3 Sheets-Sheet 3 April 11, 1944. R. s. WALKER ETAL wATER-cooLED TUBE COOLER I Filed May 27,P 1942 13| Y w a I I Marzi waz/ref wzmajeef de Patented Apr. 11, 1944 WATER-COOLED TUBE COOLERV Robert S. Walker APa., and Ruland and Fred A, Mertafnilentbwn, R. Shafter, Freeport, 'N. Y.,

-fassignors to Traylor Engineering and Manufacturing Company, tion of Delaware r i Allentown, Pa., a corpora- .Application Mayen 1942,'seria1 No'. 444,726' v (o1. asv- 34) y 3`Clams. This invention relates to the class of coolers known as tube coolers in which the hot material discharged from a heating kiln passes through a series of relatively `thin-Walled metal muille tubes mounted for rotation aboutia generally horizontal axis and exposed to-a cooling medium, the cooling medium serving. to carry off; the heat transmitted through the wallsiof the tubes and thereby hastening the cooling of the material.

Heretofore it has. been the usual. Practice to cool the tubes by passing a current or air through a housing surrounding the tubes, theheated air, after owingin contact with the tubes, being withdrawn from the housing and used in part as the combustion air for the burner ofl the kiln and, where pulverized coal is usedfor ring the kiln, for pre-drying the coal delivered to the burner. Such coolers, because they maintain the material outof contactwith the air are especially suitable for the cooling of `materials likelirne, for example, Which when highly heated'is extremely active in drawing moisture from the ain-.which causes air-slaking with consequent impairment of the quality of thelime. The factors primarily aiecting the coolingefciency of such class of coolers are the volume of the air flow through the cooler and the area of cooling surfacevpresentedby the muilie tubes; and the cooler must be sodesigned Witlidue re gard to these factors as to effect a cooling of the material from approximately kiln temperature down to a temperatureat which it may be safely placed in paper or fabric sacks without danger of charring or burning the sacks. For this reason, a fan of high operating capacit usually on the order of 50` horsepower, is required to deliver the large volume of air through the cooler and even under the most.v favorable conditions the cooler must be made quite extended in length in order to present a large area of tube surface to the air stream. Coolers of this type, therefore, are subject to the disadvantage that they are relatively expensive to operate, because .of their large consumption of power for driving the fan and for rotating the longiheavy cooler; and such coolers are subject to the further disadvantage that they take up a considerable amount of oor space which in many plants cannot conveniently be spared. y

It is an important aim of our invention to provide a rotary tube cooler which overcomes the above objections by utilizing water, or both air and water together, as the cooling medium or mediums, the water desirably being sprayed upon the mulile tubes for rapidly reducing the temper- (.which otherwise wouldbe lost)V for .cent ends telescopically ature of the material, contained within the tubes. This object is preferably accomplished by locatingthe Water spray within thecircle of travel .of the series of mule tubes andcausing;4 the Vspray to discharge in di'lerentdirections to drench'the tubes with cooling water throughout the entireor major part of their period of rotation. The `water spray may be. advantageously providedv by `extending a spray pipe longitudinally of the housing which encloses the tubes `(which housing may be either rotary or stationary) and externally connecting this pipewith a source of` watersupply. Asyaconsequence of suchl a coolerconstruction, the material is quickly; and` eilcie'ntlyv cooled without requiring a heavy duty fan for moving air through the cooler, yand the apparatus therefore maybemade, shorter in length and lighter in weight solas vto conserve .oor space and to economize. on powerconsumption. f Another object of our invention is to provide in a tube cooler ofthe abovecharacter means for 4utilizing both airY vand water as, the cooling mediumsthrughout different longitudinal zones of the cooler. By virtue of this constructionheated air is made available for use in apparatus corre; lated tothe cooler, such as for supplying the vair of combustion, to` the burner of the kiln or for drying `and heatingthefuel prior to Vitsintroduction intoljthe burner. According to the preferred'formof our cooler, the housing enclosing the mufile tubesis partitioned oi intermediate its length so as' -to fdivide it into two chambers, namely a chamber adjacent the forward or inlet 'end of the cooler through which'air isflOwed .in

contactwith the muiile tubes, an d ailonger spray chamber adjacent the rear or outlet` end of `the coolerffor `vwater-cooling the tubes. Besides providing meansfor recovering heat fromthe' cooler useful application elsewhere in the plant, the'forward aircooled compartment jadd-itionally'serves to gradually reduce the temperature of the highly heated material asfit enters the cooler from Athe kiln and thereby avoids the possibility of .damage to the thin-,walled metal-tubes by cracking or buckling,

such as mightoccur by a temperature.

Our invention .has a furtherobject to provide in a tube coolerof the above character, an im proved form of muille .tube composed of two longitudinah metal tube sectionshaving' their adjainterttedso-Jas to allow ,forv longitudinal expansion and .contraction of quenchingfrom too high the apparatus.

fthe tubes without transmitting dangerously high y l,stresses-to other partsof utilizing both air and water as the cooling medi-f ums, the cooler being shown associated. with` the discharge end of a rotary kiln;

Figure 2 is a slightly enlarged View in longitudinal vertical cross-section through the cooler kof Fig. l; v

Figure 3 is a plan view of the cooler;

Figure 4 is a transverse cross-sectional view through `.the cooler on theflin'e 4--4 of Fig. 2;

Figure is an. enlarged fragmentary ycross-sec'- -tionalyiew ofthe forward end of the cooler;

Figure 6 is' a longitudinal cross-sectional view lof a imodiedform of water-cooled rotary tube cooler;

Figure 'I is 'a longitudinal `cross-sectional View throughthe water-cooledspout for feeding materialinto the 'forward vend of the cooler; and

Figure 8 is anV enlarged cross-sectional view throughthe outlet end nof the cooler of Fig. 6.

vReferring now to the drawings, in Fig. l is shown the outlet end of a horizontal rotary ykiln K of 'a well-'known type such, for example, as is used lforthe calcining. of Iimestonein the manufacture of lime. The outlet end ofthe kiln is enclosed within a 'hood 'I and the hot vburned lime (indicated atl'L) issuing 'from the kiln drops through the open bottom of Vthe hood into a sump 2, from which it slides down onto an inclined pan conveyor schematically indicated at .3. The conveyor carries the 'material upwardly and finally delivers it into a hopper '4 supported above and adjacent the forward end of a rotary coolerC.

The cooler .C `is ofthe rotary tube type and, as Amore-clearly shown in Figs. 2' and 3, comprises generally a cylindrical housing in the form of a .drum 5, front and rear header plates 6 and 6a, respectively, closing opposite ends of the drum, and a series of spaced-apart, circularly arranged muflle tubes 1 extending longitudinallyof the drum and opening through the header plates. .The muiiie tubes are .preferably made of comparatively thin gage vheat-resistant steel possessing good vheat-conducting properties, and while illustrated as of circular, cross-section, they may be of oval, sector or 'any other desired cross-sectional shape. The forward end of the ydrum rests upon rollers 8 located upon opposite sides of the `drumand engaging ariding'ring 9, andthe rear end ofthe drum is supported in a saddle bearing `I`Il encircling a hollow trunni'on II extending axially outward from a dome-shaped closure member I2 at therear or outlet 4end of the drum. ll'ilie forward and rear 4supports for the drum are so arranged that the drum rotates about an axis inclining slightly upwardly and forwardly out of a vtrue 'horizontal position. l For taking -up the endwise thrust of the 4sloping drum, an antifriction lthrust 'bearing Illa encircles the hollow trunnion lII and kbears against one side of the saddle vbearing Ill. Aring gear I3 is circumferentially securedfto'the"closure-member, and this ring gear is engaged lby apinion I4 driven by a 75 pro ing air entering through the inlet motor M, through a suitable speed reduction mechanism, for imparting rotation to the cooler upon its supports 8 and I0.

The drum 5 is divided into two chambers I5 and I6a by a transverse partition plate I5 located inside the drum and about one-third of its length from its forward end. The forward 4chamber Iii is designed for the circulation of air about the inlet ends 4of the muille tubes, and for this purpose a series of air-inlet ports I1 are circumferentially 'ded in the wall of the drum at the forward end of the 4chamber I6, while similarly a series of air-outlet ports I1a are circumferentially provided in the drum adjacent the rear end of this chamber. A transverse baffle ring I8 is supported within the chamber I6 about midway of its length, and this bailie ring deflects the coolports I1 across the tubes in its travel toward the outlet ports Ila. A stationary casing I9 surrounds the drum so as to include the-outlet ports I'Ia, this casing serving as a collector -for the heated Yair issuing from these ports. The casing may be connected through a pipe 2li' with a suction fan (not shown) for inducing a rapid flow of air through the chamber I6 and for-delivering the heated air 'either to theyburner of the vkiln or to a coal pulverizing mill for pre-drying the fuel used inthe burner; or if desired the heated air Amay be a1- lowed to escape up the chimney into the outside atmosphere.

At the forward end of the cooler a frusto-conical shaped closure member -2I is. secured to the front header plate v6 and this member projects outwardly from the header plate so as to form therewith a material-receiving compartment 22. An inclined feed spout 23 directs the hot material to be cooled from thephopper 4 downwardly through a centrally located opening Vin the front closure member 2l and 'into the compartment 22. The closure member isA provided'with a refractory lining 24, vand the incoming material discharging onto the sloping interior surface of the closure member slides down into the open ends of the mufiie tubes 1. A stationary cover plate 25 supported on stanchions 28 for bodily swinging movement toward and away'from the closure member, abuts a sealing ring 26 supported on a bearing flange 21 surrounding the opening in the front closure member; i

The rear closure member l2 projecting outwardly away from the header plate 6a provides a compartment for receiving the material spilling from the munie tubes 1. Secured to the rear header plate 5a and directed axially outward through this material-receiving compartment and the hollow trunnion II is a bell-shaped deflecting member 29. The position and arrangement of the deilecting member is such as to guide the material out through the hollow trunnion il, this action being assisted by a plurality of radial lifting blades 39 supported upon the interior of the'closure member I2. The deecting member affords support for one end of a spray pipe SI extending axially into the drum through the hollow trunnion and having its forward end closed and resting in a socket 32 on the partition plate l5. The spray pipe is circumferentially provided with a multitude of orifices 33 located Vin diiferent positions `upon its circumference so that the pipe will discharge in di'ierent radial directions toward the tubes 1. The clearance around the opening through which the spray pipe extends through the bell-shaped deflector v251 is sealed by a packing gland V35, and the end of -the spray pipe projecting ,exteriorly of` the drum is adaptedto be connected to a source of water pressure through a swivel coupling 36..

' The muiile tubes l are each composed of two longitudinal sections 'Ia and 'lb of different diameters. The sections la, which extend entirely through and rearwardlybeyond the front chamber It, are of smaller diameter than the tubes lb which extend through substantially the length of the rear chamber ld. The smaller size tube Sections'l'a at their forward ends are welded to the front header plate 6, while the larger size tube sections l'b are welded to the rear header plate 6a. The tube sections lcrmay be also welded t the partition plate .I5 if nottoo long, or they may have a sliding t with the partition plate in those cases where changes in length of the sections under expansion or contraction must be reckoned with. The rear and forward ends of companion tube sections are telescoped to provide a sliding t (as shown in Fig. `and also indicated in dotted lines in Fig. 2) at a location adjacent but to the rear of the partition plate I5, this construction permitting sliding movement of the tubes, one within the other, under the influence of expansion and contraction. A centrally apertured disk 3l is provided upon the inside of the drum midway of the length of chamber ld for supporting the tube sections` 1b, the aperture of this disk allowing free passage for the spray pipe 3l. Cut-outs 31a located adjacent the edge of the disk (Fig. 4) allow the passage of spray water longitudinally of the drum. A series of circumferentally-spaced drain slots 38 open through the wall of the drum, and below the drum in line with these slots is a basis 39 for receiving the water draining out of the drum through these slots. Shields tl) encircle the drum upon opposite sides of the drain slots.

The drum 5 may be composed of two longitudinal sections, namely a forward section 5a defining the forward air-cooled chamber I8, and a rear section 5b dening the l water-cooled chamber Ita. The forward section, because it must support the weight of the front end of the cooler, is composed of comparatively thick metal plate, reinforced by a circumferential strap 4I which distributes the pressure transmitted through the riding ring 9 over a Vwide circumferential area of the drum section.` The rear section 5b is made of relatively light metal plate to reduce the weight of the cooler since this drum section is not called upon to withstand heavy stresses and serves principally as ahousingfor `the water spray.

' For affording convenient access to the interior of the cooler, the front header plate 6 isprovided with a centrally formed manhole adapted to be closed when the cooler is in operation by a cover 6b detachably bolted to the header plate. Similarly, the partition plate I5 is centrally provided with a manhole normally closed by a cover a..

The material leaving the cooler through the hollow trunnion I l escapes through a chute 42 into the lower end of a vertical bucketeconveyor 43, indicated schematically in Fig. 1, feeding to a sacking station where the material may be directly placed in bags, or the elevator may deliver the material to a hopper from which it is subsequently withdrawn for sacking.

In the operation of the cooler just described, the hot material coming fro-m the rotary kiln K is fed through the spout 23 into the materialreceiving compartment 22 at the forward end of 75 enters the chamber the drum. From the compartment 22 the material during rotation'of the cooler flows down the inclined surface ofthe front closure member 2I-into the inlet ends of the mufe tubes T. Under the combined inuence of gravity and the agitation produced by rotation of the cooler, the material passes slowly through the mule tubes, Iinally issuing from the ends of the tubes and spilling down the inclined surface of the de` fleeting member 29 and assisted by the lifting blades 30, out through the hollow trunnion II.

During the period of travel of the material through the forward chamber I 6 of the cooling drum, the heat transmitted through the walls of the munie tubes is carried oi by the air which, by means of a fan of small capacity connected to pipe 2U leading 01T from the casing I9, is drawn into the chamber through inlet ports I'I and deiiected across the tubes by the baille ring I8. The highly heated material thus initially undergoes a gradual cooling and the air entering the casing I9 is heated to a high temperature by reason of its passage into contact with the munie tubes so that this air desirably may be used in junction with coal-red kilns, for drying and preheating the fuel in advance of its delivery to the burner.

The material after traversing the chamber i6 IBa where the tubes are eX- posed to a water spray from the axial-extending spray pipe 3|. The spray pipe rotates with the drum and directs jets of water in various directions against the muiile tubes, (see Fig. 4) so that the tubes are showered with water throughout their entire period of rotation and the material therein is rapidly cooled. The water falling into the drum ows out through the drain slots 3S into the basin 39 located below the drum. and this heated water may be pumped to other parts of the plant .for use in boilers or other appropriate apparatus, or the water may be cooled for recirculation through the cooler.

The water-cooling of the tubes is so efficient that the material is required to travel only a relatively short distance before its temperature is lowered sufciently to allow it to be sacked without danger of injuring the sacks. Furthermore,

vantageous.

Because of the rapid cooling of the material in the spray chamber I 6a the cooler may be substantially shorter than heretofore when the cooling was done entirely by air, thus providing a more compact and lighter structure requiring substantially less power for its operation. Furthermore, by constructing the forward end of the drum for air cooling, suicient heated air is reclaimed fromv the cooler to meet the normal needs of the plant. At the same time. the initial air-cooling of the tubes to lower the temperature of the material to a point where water may be safely applied to the tubes without danger of cracking or 'deforming them, is another advantageous feature of the cooler.

The cooler of our invention may take other forms than that described above, In Figs. 6, '7 and 8 is shown a rotarytube cooler that is wholly water-cooled.

This form of cooler comprises a front header plate 5D-anda rear header plate 55a and a series of spaced-apart, circularly-arranged mufile tubes 5l extending between and opening through the header plates. These tubes are welded to both header plates. A dome-shaped closure member 52 having a hollow trunnion 52a-extending axially outward therefrom is welded to the front header plate so as to provide a material-receiving compartment at the forward end of the cooler. An inclined spout 53 communicating at its upper end with a hopper 54 extends through thehollow trunnion 52a and delivers material to be cooled into the material-receiving compartment. A closure member 55 `is bolted to the rear header plate 55a located at the opposite end of the cooler, and this rear closure member is formed with a hollow trunnion 55a extending axially outward therefrom.k A bell-shaped deiiecting member 55 secured to the rear header plate serves to direct the material issuing from the ends of the tubes out through the hollow trunnion 55a and into a chute 56 (see Fig. 8) leading to an elevator or other point of discharge. Radial blades 51 upon the interior of the closure member 55 assist in the evacuation of material from the cooler.

The hollow trunnion 52a is circumferentially tted with a tire which rests upon rollers, one of which is indicated at 5S, mounted on foundation Bl. The hollow trunnion 55a at the rear of the cooler is supported in a journal bearing 5i! suitably mounted on the foundation 52. cooler is supported at a downward inclination from its forward end toward its rear end and thus produces the gravitational travel of material through the muiile tubes. A thrust-bearing 62a (Fig. 8) encircling the hollow trunnion 55a takes the end thrust of the cooler. A ring gear 53 is secured to the circumference of the rear header plate 55a, and this ring gear is adapted to be connected through suitable gearing (not shown) to a motor or other source of power for rotating the apparatus on its trunnions.

A spray pipe 53 extends axially of the apparatus and is formed with rows of orices 64 directed in different radial directions for discharging jets of water upon the mufle tubes during rotation of the cooler. The forward end 53 is closed and rests in a socket 55 secured to the front header plate 5l), while the opposite end of the pipe extends axially through the rear header plate 55a and the deiiecting member 58 to the exterior of the apparatus where it is connected through a swivel coupling G5 with a source of water supply. The spray pipe by reason of its tight i'lt within the deflecting member is caused to turn with the cooler.

A plurality of disks 61 are associated with the muie tubes at spaced distances throughout their length to rigidify and strengthen the tube assem bly, and these disks are centrally provided with manholes normally closed by covers 68 but adapted to be opened by sliding the covers along the spray pipe 63. The front header plate 50 is likewise centrally provided with a manhole closed by a cover 59 detachably bolted to the header plate. As best shown in Fig. 1, the clearance about the feed spout 53 where it extends through the open end of the hollow trunnion 52 is sealed by a ring 10 having snug circumferential 'bearing with the interior of the trunnion. The ring is provided with a central opening for passing the feed spout 53, and the spout carries a hollow plug 1l adapted to close the clearance around the spout. Because the feed spout is heated to a high tem- The of the spray pipe y perature by the hot material passing therethrough, we provide a water jacket 12 surroundingthe feed passage. Cooling water is caused to circulate through the jacket from an intakepipe -13 leading from a source of water supply and passing through the wall of the jacket. The outlet of pipe'13 is located adjacent the discharge end of the spout, whereby the end of the spout confined within the material-receiving compartment and therefore most liable to overheating is subjected to the maximum cooling effect of the water as it initially enters the jacket. After circulating through the jacket the water is removed through an oitake pipe 14 leading to a suitable point of discharge.

The muiile tubes are enclosed by a stationary arched housing 15, which may be of sheet metal, this housing extending 'throughout the major length of the tubes. The housing at its ends has inturned terminal flanges 15al lying close tothe circular'path of rotation of the tubes. A shield 15 attached to the rear header plate so as to turn therewith flares toward the forward end of the cooler and closes the space between the housing and the rear closure member 55.

A stationary water spray pipe 11 extends lengthwise of the housing above the mule tubes and discharges downwardly through a multitude of orifices 11a. upon the tubes. The spray pipe 11 extends between the front and rear anges 15a of the housing, and one end of this pipe projects externally of the cooler and is suitably connected to a source of water supply. Below the cooler and constituting the bottom of the housing is a shallow basin 18 adapted to receive the water delivered by the spray pipes 63 and 11 upon the tubes. The heated water accumulating in this basin may be drawn off and either used in other parts of the plant or cooled for recirculation through the cooler. A pivoted gravity-closed gate 18a is provided in the chute 5B, this gate being adapted to be maintained open by the passage of material through the chute but being held closed by a weighted arm 19 for preventing access of air to the tubes.

The cooler just described corresponds generally to the cooler of Figs. 1 through 5, except that the tubes are entirely water-cooled (instead of being partially air-cooled) and the housing enclosing the tubes, instead of rotating with the tubes as in the case of the drum 5 of the cooler of Figs. 1 through 5, is stationarily mounted. The material coming from the kiln is delivered through the water-jacketed feed spout 53 into the material-receiving compartment formed by the front closure member 52 from which it enters the mufe tubes 5l. During rotation of the cooler by means of a suitable source of power operatively connected to the ring gear 63, the material gradually passes through the tubes which are cooled by the water discharged thereon from the spray pipes 63 and 11. The material issuing from the tubes at the lower end of the cooler is directed by the deflecting member 55 and the lifting blades 51 through the follow trunnion 55a and out through the chute 53.

While we have disclosed a water-cooled feed spout only in connection with the embodiment of Figs. 6 and 8, it is to be understood that such a type of water-cooled spout may be used with the cooler of Figs. 1 through 5.

It will be apparent that the invention is capable of being embodied in forms other than those described above without departing from the spirit of our invention as dened in the following claims.

We claim:

1. A tube cooler comprising a substantially horizontally-disposed housing, a series of heatconductive muflle tubes extending longitudinally through the housing, means for unitarily rotating said tubes, means for introducing material to be cooled into the tubes at one end of the housing, said tubes being of longitudinal sectional construction, and the sections of said tubes being of diierent diameters telescopically and slidably interltted adjacent their opposed ends, and means upon the housing for supporting the tubes adjacent their ends and intermediate their lengths at a point adjacent the telescopically interiitting sections thereof.

2. A cooler comprising a series of circularly arranged munie tubes supported as a unit about a generally horizontal axis of rotation, means for supplying hot material to the tube series at one end thereof for passage therethrough, a drum portion surrounding a portion of the length of said tubes adjacent said end and including headers provided with openings in which the tubes are received, said drum portion being provided with spaced air inlet and outlet openings, means in con- 5 nection with the outlet openings for leading heated air to a point of use, and water-cooling means for the tube portions which are outside of said drum portion, the header which is remote from said end forming a closed partition between the air heating zone and the water-cooling zone.

3. A cooler Vcomprising a drum including a peripheral wall and front and rear haders and arranged for rotation about a generally horizontal axis, a series of muille tubes circularly arranged about said axis and extending between and through said headers, an intermediate header through which said tubes pass and which forms a closed partition separating the drum interior into front and rear compartments, said front compartment being provided with spaced air inlet and outlet openings, means in connection with the outlet openings for leading heated air to a point of use, and Water spraying means in said rear compartment for the Water cooling of the tube portions which are in said rear compartment, said rear compartment having escape means for the cooling Water.

ROBERTS. WALKER. FRED A. MERTZ. R. R. SHAFTER.

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