US2368881A

US2368881A - Tube cooler

Info

Publication number: US2368881A
Application number: US457890A
Authority: US
Inventors: William J Roberts; Jr Samuel W Traylor
Original assignee: Traylor Engineering & Manufacturing Co
Current assignee: Traylor Engineering & Manufacturing Co
Priority date: 1942-09-10
Filing date: 1942-09-10
Publication date: 1945-02-06
Anticipated expiration: 1962-02-06

Description

Feb. 6, 1945.

TUBE COOLER Filed Spt. 10, 1942 2 Sheets-Sheet l gr WWW! wwgwg m? Q nzzmmaazerzs j Mu zy! I :2

a N 0 o 0 0 Feb. 6, 1945.

W. J. ROBERTS ETAL TUBE COOLER Filed Sept. 10, 1942 2 Sheets-Sheet 2 wzzzmmzzazekzs Patented Feb. 6, 1945 j Allentown,

-Pa., assignors to Traylor Engineering- & Manufacturing 00., AllentotviLPa a col- 1 Claim.

This invention relates to tube coolers of the general type in which the material to becooled is passed in separate streams through a series of relatively tl'iimwalled, heat-conductive mufile tubes mounted for rotation about a common axis inclined slightly out of horizontal while a cooling medium, such as air or water, or both, is

directed into, contact with the external surfaces of the tubes for cooling the material passing therethroug h. Such type of. apparatus is especially suitable forthe cooling of materials, such as lime, that hasa tendency to react with the air or the moisture in the air and which for that reason desirably should not be exposed to the atmosphere, and particularly When in a heated" condition.

An important object of the present invention is to provide in'a tube cooler of the above character means to accelerate the cooling of the material during its passage through the tubes. This object is accomplished accordingto the invention by providing means for drenching the tubes with cooling water as they rotate through a portion of their circular path of travel, the cooling,action being further aided by evaporation of the moisture from the surface of the tubes as they move through another portion of their path of travel.

In the preferred form of the invention means are provided for applying the cooling Water tothe tubes in the form of a spray, or sprays, lo-

cated below the cooler and so arranged as to discharge upon the bottom circumferential surfaces of the tubes as the tubes rotate through their lowermost arc of travel, whereby the Water is efiectively applied upon the hottest portions of the tubes, namely those portions which at the moment are overlain by beds of material inside the tubes.

Another object of the invention is to provide in a. tube cooler of the above character means for bringing the material into moreflintimate contact with the cooling surfaces of the tubes. Under ordinary operating conditions in the case of tube coolers, the material tends to slide along the tubes in fixed masses so that portions of the material contained inside these in'asses do not come into contact with the cooling surfaces of the tubes and. hence a longer time is required for cooling the material. To overcome this objeotion, the invention contemplates the provision of diaphragms extending lengthwise within the tubes and partitioning the tubes into a number of segmental'compartments' for dividing the mass Ofi materialtraveling through the tubes poration of Delaware I Application Slitbhibir 10, 1942.881121] N0. 457,890

into streams of relatively small Volume and for spreading the material out in the'form of shallow layers, thus insuring that all portions of the material are brought into direct and effective contact with the cooling surfaces of the tubes.

Another function of the diaphragins is to shower the material from one diaphragmto another during rotation of the cooler, whereby a continuous stirring up and turning over of the material is achieved, resulting in the complete aeration and repeated exposure of all the particles to' the cooling surfaces of the'tubes. The

'diaphra'gms are preferably made of metal and arranged in heat-conductive relationto the circumferential walls of the tubes in order to increase the lieat transfer surface of the tubes and to conduct heatfrom the material on the inside of the tubes to the water-cooled walls of the tubes. I

Otherobjects and advantages will be apparent from the following detailed description of a preferred embodiment of theinvention, reference being had to the annexed drawings in which: i Figure 1 is a longitudinal cross-sectional view of a rotary, water-cooled tube cooler;

Figure 2 is a transverse cross-sectional view through the cooler taken on the line- 2 2 of Fig. l;

Figure 3 is a transverse cross-Sectional view through one of the mufiie tubes of the cooler, showing the arrangement of one of the diaphragm units therein;

Figure 4 is a contracted plan view of a diaphragm unit; and

a series of circularly arranged muflle tubes 1 of relatively thin walled heat-resistant steel extend generally horizontally but at a slight down- Wardinclination between a front header plate 2 and a 'rear header plate 3.

through these header plates and to the front header plate 2 is secured a dome-shaped cover member 4 havinga hollow trunnion 5 projecting coaxially outward therefrom. This trunnion is supported on rollers forming bearings Emoufited on top of aconcrete block 1. Similarly; at the opposite, lower end of the cooler a dome-shaped rear cover member 8 is secured to the header plate 3, and this cover member is formed with a eoaxially-oisposed hollow trunnion 9 supported in a saddle bearing l 0 mounted on top- Of a} doll- 'crete'blo'clt I' l. ammo-bearing t2 encircling The tubes o en l4 encircling the rear header plate 3 and later as three in number but which may be more or less than this, as desired. These spray pipes are arranged parallel to each other and to the tubes,

- and at one end are connected by a header pipe ally abutting and fastened to the rear cover member 8. For feeding the hot material to be cooled into the cooler there is provided at the forward end of the apparatus a water-cooled spout l5 leading ofi at a downward inclination from the bottom of a hopper l6 which desirably is located below the discharge end of a rotary kiln (not shown) for receiving material, for example lime, spilling from the kiln,

The spout extends through the hollow trunnion 5 so as to empty into the compartment provided by the dome-shaped cover member 4 forwardly of the front header plate 2. A closure ring I? encircling the spout and snugly fitting within the open end of the hollow trunnion 5 seals this inlet compartment against the outside atmosphere. I

At the discharge end of the cooler a conicalshaped deflector piece it! projects centrall'y rearward from the rear header plate 3 and partially through the hollow trunnion 9. A series of radi ally disposed vanes 19 occupying the outlet compartment provided by the cover member 8 and rotatable with the cover member, intercept and lift the material issuing from the discharge ends of the mufile tubes and cause it to spill down the surface of the deflector piece and out through the hollow trunnion 9. A discharge casing 20 surrounding the open end of the hollow trunnion 9 includes a chute 2| through which the cooled material escapes from the casing -for example, onto a conveyor (not shown) by which it is carried to a place of storage. A weighted flap valve 22 closes the clearance in the chute passageway above the material therein.

Contained Within and extending throughout a portion of the length of the mufile tubes I are diaphragm units 23. These diaphragm units, as best illustrated in Figs. 3 and 4, each comprises a pair of elongated metal plates 23a bent at approximately right angles and welded together at their corners, as indicated at 24, to define four radially-disposed diaphragms or wings 25 directed approximately at right angles to each other and dividing the tubes into quadrant- ;shaped compartments. The diaphragms are provided with relatively large escape openings 26, the openings of adjacent diaphragms being offset in a direction lengthwise of the cooler; The

I outer longitudinal edges of the diaphragms are adapted to slidably engage and foot upon the inside circumference of the tubes so as to be manually insertible and removable from the tubes.

For retaining the diaphragm units in place, they may be tack-welded to the tubesas indicated at 2'1. The diaphragm units may be made up of several sections assembled end-to-end as indi- 30. Opposite ends of header pipe are capped while one end of header pipe ZSis closed and its other end is connected by a conduit 29a to a source of water supply for furnishing Water to the spray pipes under pressure. The

header pipes

29 and 30 are bent into arcs concentric with the arcuate path of travel of the muiile tubes in completing their down swing and beginning their upswing during the rotation of the cooler, the location of the spray pipes relative to the tubes being indicated in Fig. 2. The spray pipes are perforated to provide longitudinal rows of orifices cated in Fig. 4, and for this purpose tongues 21a project from the'end of one sectionand are designed to slip over the opposed end of a contiguous section. v

Running lengthwise of and located a short distance below the cooler. are a plurality of spray pipes 28, shown in the present instance (Fig. 5)

3| from which cooling water is discharged in directions such as to impinge upon the'bottom circumferential surfaces of the muffle tubes (see Fig. 2) as the latter sweep through their lowermost. are of travel and subject these tubes to a bath of cooling water.

Arranged below the, cooler and extending throughout the length of the spray pipe 28 is a sump 32 into which the water delivered by the spray pipes may drain, and an outlet pipe 33 is suitably provided for removing water from the sump. A shield 34'is secured to the circumferential portion of the header plate 3 at the rear end of the cooler and this shield is cupped so as to direct into the sump 32the water draining down the muffle tubes. A cover 35 closes a manhole in the front-header plate 2 but this cover may be unbolted from the header plate to afford access to the interior of the ring of tubes.

The operation of the rotary tube cooler just described is as follows: The rotation of the apparatushaving been started, the material to be cooled is fed by the spout 5 into the inlet compartment provided by the cover plate 4 at the forward elevated end of thecooler where it flows into the open ends of the rnufile tubes l and under the combined action of gravity and agitation due to rotation ofthe cooler passes downwardly within the tubes, After traversing the tubes for a portion of their length, the mass of material encounters the diaphragm units 23 and is split up by these diaphragms into four separate shallow streams each passing into one of the segmental compartments formed by the diaphragms with the circumferential walls of the tubes. During rotation of the cooler the material is showered from one compartment to another by way of the openings 26in the diaphragms, mixing and tumbling the material about and exposing all parts of it to the cooling surface of the tubes, including thelarge surface presented bythe diaphragms which are in heat-conductive contact with'the walls of the tubes.

Throughout the travel of the material through the muflie tubes I it is indirectly cooled by the spray pipes 28 during a period in the rotation ing along the inside of the tubes. As the tubes in their rotation move .out'of the range of the water sprays and complete their circular path of travel, evaporation ofmoisture from the outside of the tubes takes place, thus accelerating the cooling action. And because this evaporative effect vis-important for the most efficient operation of the cooler, the mufiie tubes l are preferably left uncovered and exposed to the atmosphere in order to promote the free circulation of air into contact with the tubes.

The metal diaphragms not only serve to cascade the material during its downward passage through the tubes, but also function as heatconducting plates for transferring the heat from the material within the segmental compartments to the walls of the tubes. As will be seen from Fig. 2, not only are the circumferential closing walls of three segmental compartments of each tube subjected to the direct action of the water sprays as the tubes swing through their lowermost are of travel, but the diaphragms by reason of their snug engagement with the walls of the tubes are indirectly but eil'ectively cooled by the sprays and in this manner substantially contribute to the cooling of the material not onl by increasing the cooling area of the tubes but. by providing for a more rapid dissipation of heat from the material. Furthermore, because the openings 26 in the diaphragms are staggered relative to each other in a lengthwise direction, the material flowing through the openings in one diaphragm is intercepted by the succeeding diaphragm, 7 thus interrupting the travel of the material between the segmental compartments and causing the material to pause and move a short distance lengthwise along each diaphragm before escaping onto the next diaphragm. This insures a suitable interval of contact between the material and the diaphragms and enhances the cooling effect.

As the cooled material issues from the ends of the muflle tubes,-it is directed by the deflector piece l8 out through the hollow trunnion 9 and thence into the discharge casing 20. From the discharge casing the material is led ofi by way .a torch-or the like and the diaphragm units with drawn longitudinally from the tubes. Then :new units may be slid into the tubes and tackwelded into place.

While it is within the scope of the present in vention to utilize air as the cooling medium for the tubes, greatly superior results are attained by employing a liquid coolant, such as water, by reason of its ability to rapidly absorb and carry err heat from the tubes as Well as to increase the cooling efiect by evaporative action. Also instead of bathingthe tubes by means of a spray, the tubes may periodically dip within a tank of cooling liquid, although this is not desirable because it imposes lateral stresses upon the tubes which might result in damage thereto. I

The diaphragms may be made of heat-resistant steel or other suitable metal or alloy which possesses durability and good heat-conducting properties.

It will be understood that the invention may take other forms than that described above, which is to be regarded as exemplary rather than as restrictive of the invention, with departing from the spirit of the invention as defined in the following claim:

We claim:

A rotary tube cooler comprising a series of laterally spaced-apart muflie tubes supported in circular arrangement about an axis of rotation which is sufficiently inclined to the horizontal to enable granular material to be cooled to gravitate through the tubes when the cooler is rotated, heat-conductive diaphragm units extending longitudinally and fixed within said tubes 'for dividing the stream of material flowing down a tube into smaller streams and for imparting agitation thereto, each of said diaphragm units including wall portions meeting at the center of its associated tube and said wall WILLIAM J. ROBERTS. SAMUEL W. TRAYLOR, Jr.