US2431799A

US2431799A - Cooler having overlapping replaceable grates

Info

Publication number: US2431799A
Application number: US627325A
Authority: US
Inventors: Joseph B Gaffney
Original assignee: Fuller Co
Current assignee: Fuller Co
Priority date: 1945-11-08
Filing date: 1945-11-08
Publication date: 1947-12-02
Anticipated expiration: 1964-12-02
Also published as: DE952785C; DK77564C; GB611296A; FR925589A; ES181429A1

Description

Dec. 2, 1947. J. a. GAFFNEY CQOLER HAVING OVERLAPPING REPLAGEABLE GRATES Filed Nov. 8, 1945 2 Sheets-Sheet l Hf. v. 9. f.

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2 sheets-sheet 2 Dec. 2, 1947. l J. B. GAFFNEY COOLER HAVING OVERLAPPING REPLACEABLE GRATES Filed Nov. 8 1945 Patented Dec. 2, 1947 COOLER HAVING OVERLAPPING REPLACE- ABLE GRATES Joseph B. Gaffney, Hokendauqua, Pa., assignor to Fuller Company, Catasauqua, Pa., a corporation of Delaware Application November 8, 1945, Serial No. 627,325

15 Claims.

This invention relates to material cooling and more particularly to the rapid air quenching of Portland cement clinker, ore nodules, and lime in varied particle size as issuing from rotary kilns in which the material is burned.

The apparatus of the invention is an improvement upon that of United States Patent No. 2,137,158, granted November 15, 1938, to which reference may be had for a complete statement of the general problem of cooling Portland cement clinker.

The principal cooling elements in the patented structure comprise a series of overlapping, horizontal grates, with xed grates alternating with laterally movable reciprocating grates. The moving grates serve to agitate the bed continuously and to cause the individual particles of material being cooled to be rolled and overturned as they advance toward the discharge port at the lower end of the grate assembly. formed by the leading edges of the grates is preferably relatively flat and well within the angle of repose of the material so that incoming particles will not roll freely down over the grates, a slope of about 12 degrees being usually provided.

Each grate is provided with a multiplicity of vertical air ports, which are alternately covered and uncovered, as the moving grates are reciprocated, and air is forced through these ports.

upwardly through the clinker bed. The fixed and moving grates are also vertically spaced, usually about one-quarter of an inch.' to provide a horizontal air passage through which air is forced continuously at substantially right angles to the flow through the ports and generally in the direction of advance of the material.

Immediately upon dropping through the chute from the kiln and entering the cooling chamber, the material particles are subjected to blasts of cold air, and as they are continuously agitated and overturned as they advance from grate to grate, the cold blasts cf air impinging upon the particles from two directions provide for abrupt and uniform cooling.

The space in the cooling chamber below the grates forms a wind-box supplied by a fan having the capacity to deliver a volume of air at least equal to the kiln requirement of secondary air for combustion and at sufficient pressure, usually about 5 inches of water, to overcome the resistance of the grates and the material stream. The wind-box is preferably provided with transverse baffles forming compartments which may be separately supplied with air in varying quantities so that the necessary volume of air can be forced The slope through and between the grates at and adjacent to the entrance to the chamber to reduce the temperature of the material abruptly.

In apparatus of the prior art and incorporating the invention of the above patent, it was found that frequently operation of the apparatus would have to be shut down to replace grates which were cracked or broken. This usually involved shutting down of the kiln also in order to cool the interior of the cooler sufliciently to permit workmen to enter the interior to makethe necessary replacements. The grates of the prior art apparatus were constructed of solid one-piece cast iron or steel rigidly attached to the supporting frames at their ends. In operation of the apparatus, the upper surfaces of the grates are subjected to extremely high temperatures, while at the same time, the lower side is cooled by the air from the wind-box, thus causing relative expansions to develop, which very often resulted in a crack or break. It has been suggested to water cool the grates in an effort to more uniformly distribute the heat. Such additional apparatus as` is required 4to Water cool the grates is diicult to operate and, in those installations where such water cooling has been installed, it has failed to prevent the failure of the grates when cooling high temperature material.

The present invention is, accordingly, directed to the provision of a simple grate structure including a light-Weight grate which may be used without artificial cooling in a cooler of the type referred to, the grate of the invention being so constructed that it will withstand wide temperature differences on either side thereof without development of stresses sufficient to break or otherwise injure it and which may be replaced with the minimum of effort. The grate structure comprises a plurality of skeletal supports in the form of horizontal vertically spaced spider web members, each member adapted to support a plurality of thin grate sections detachably connected from the under and cool side, thus permitting replacement or adjustment without having to lower the temperature in the cooler.

For a better understanding of the invention, reference may be had to the drawings which are to be taken as illustrative and not as limiting. Fig. 1 is a fragmentary elevation in section oi the apparatus, with some of the conventional parts only partially shown. Fig. 2 is a front elevation of a movable grate structure with parts in sections for purpose of illustration. Fig. 3

Vfixed grates 2l and movable grates 22.

is a iront elevation of a stationary grate structure with parts in section lor purpose of illustration. Fig. 4 is a plan view of a grate with several of the grate plates removed for the purpose of clarity. Fig. 5 is a vertical sectional view of one form of the grate structure. Fig. 6 is a vertical sectional view of another form of the grate structure.

A conventional rotary kiln Ill is normally closed and sealed by a refractory-lined hood II, having a relatively large circular opening I2 communicating with an arch-shaped refractory lined bustle I3. Bustle I3 is somewhat longer than is usual and is provided with an open botton I4 registering with a passage I5 opening into cooling chamber I6.

Hot material as discharged from kiln I9 falls through narrow chute I1 which is displaced transversely toward the rising side of kiln l0. The bottom of chute I1 is closed by shelf I8 which is air-cooled by means of radiating fins I9. After the material particles have accumulated on shelf I8. and have formed a natural angle of repose, the descending particles which follow are distributed bythe pile previously formed and pass through entrance 20 of the cooling chamber I6 in which they form an inclined bed resting upon the upper portion of the grate assembly.

The grate assembly and the means for operating it are described in detail in the patent to Douglass No. 2,137,158 and comprises alternately Fixed grates 2i are rigidly secured to a stationary frame comprising inclined channels 23 secured by upright supports 24 and 25 to lower frame members 26 which rest on ledges 21. Suitable transverse bracing is provided as at 28. Movable grates 22 are mounted on a moving frame comprising inclined side members 29 suitably braced and carrying uprights 32 to which movable grates 22 are secured. Members 29 are movably mounted on

axles

33 and 34.

The desired reciprocating motion of the movable frame may be conveniently accomplished by two spaced. eccentrics comprising eccentric rods 44 pivotally connected to a horizontal shaft 45 secured to the movable frame members 29. Rods 44 pass through slots in the rear wall of chamber IIB and terminate in straps 48 surrounding the eccentric discs 49. A common crankshaft mounts sprocket wheel 50 driven through chain 5I by a when treating material having a tendency to cascade down the inclined surface.

Grate supports 53 as shown in Figures 2-4 are identical for both4 movable and stationary grates. Grate supports 53 for the movable grates are rigidly attached to inclined side members 29 in any desired manner such as bolts 54 and grate supports 53 for the stationary grates are rigidly supported from inclined side members in the form of channels 23 by means of brackets 55. The supports 53 comprise transverse members 56 and 51 having .stiiening members 58 therebetween. Fingers 59 extend forwardly of transverse member 56 and the entire spider assembly may be cast as one integral piece if desired. Raised pads 60 are provided at the ends of each lingerA 59 and also spaced along members 56 and 51 for the purpose of supporting the grates .with

`a minimum of contact with the support for a purpose to be later explained.

` Each grate comprises a plurality of thin plates 6I having openings 62 therein through which the cooling air from the wind-box enters the material bed. Forward lips $2' cast integral with each of the plates 6I are adapted to extend downwardly over the fingers 59 to provide a smooth vertical edge. A pair of hook-like members 63 which may be cast integral with the plates extend downwardly from their bottom side, and

variable speed motor and speed reducer indicated edge of the fixed grate above it, thereby avoiding 'A passage of fine clinker between the grates. It will be understood that the rate of travel of the bed, and consequently its thickness can be varied by changing the speed of the motor 52.

The fixed and movable grates are substantially similar, and may be constructed of iron or steel depending upon the abrasiveness of the material to be treated. Two forms of grate shapes are shown in Figures 5 and 6 which may be used interchangeably depending upon the characteristics of the material to be treated, the form shown in Fig. 6 having a. forward raised lip which may be installed for proper operation of the apparatus ho'ok bolts 64 having T-shaped heads adapted to engage over and to be received by the hook-like members 63 extend through suitable openings in the transverse member 56 and by means of nuts 65 the grate plates may be readily attached to the support.

From the foregoing it will be clear that the grates in their assembled form comprise a plurality of individual thin grate plates having a minimum of contact with the grate support. With such structure, the cooling air from the wind-box in its passage upwardly through the grates sweeps practically the entire under-surface of each grate plate, thus affording a maximum of heat transfer resulting in a more or less uniform temperature in the plate. In use of apparatus of this type, a wide range of temperatures may be encountered in any horizontal section of the material bed undergoing cooling temperature, and great advantage results from the use of the grate of the present invention having sectional supporting plates where each plate may have limited movement for expansion and contraction, thus eliminating undue stresses which apparatus heretofore used frequently resulted in cracks or breaks. y v

With apparatus of the present invention, in the event of a break in one or more of the grate plates, it is possible to remove the individual plate, in which case the nuts on the T-bolt are backed up and the T-bolt pushed forward until its cross-head drops free of the hook 63. The broken grate then is pushed out of place and the new grate placed in position from the forward side by a repairman entering the cooling chamber, if it is not too hot, or, if the cooling chamber is too hot for that purpose, by lowering the new grate on a wire toits approximate position, after which a repairman underneath the cooling chamber pulls it into proper position, tips the T-bolt up so that the cross-head engages over which lowers the possibility of cracking or`breaking to a minimum, and the adaptability of replacement without substantial loss of time causes the new grate lto be highly effective for its intended purpose.

I claim:

1. -An apparatus for the rapid cooling of heated material comprising a series of spaced over-lapping grates, including fixed grates alternating with movable grates, the upper surface of the grates serving to support a bed of material particles, members at the longitudinal side edges of the series of grates extending longitudinally of the direction in which the series of grates extend, means to impart reciprocating movement to the movable grates to agitate and advance a bed of material thereon, at least some of said grates comprising elongated grate plate supporting means extending transversely of the direction in which the series of grates extend and connected at their ends to said members, and at least one grate plate detachably secured to said gratesupporting means.

2. An apparatus for the rapid cooling of heated material as set forth in claim 1 in which a plurality of grate plates slightly' spaced from one another are detachably secured along the grateplate-supporting means.

3. An apparatus for the rapid cooling of heated ture and a plurality .of grate plates having air channels extending therethrough are detachably secured to the skeletal supporting structure.

5. An apparatus for the rapid cooling of heated material as set forth in claim 1 in which the grate-plate-supporting means has relatively small, raised, grate-plate-supporting surfaces spaced from one another both transversely and longitudinally of the direction in which the series of grates extend for supporting the grate plates.

6. An apparatus for the rapid cooling of heated material as set forth in claim 1 in which the grate-plate-supporting means includes spaced members and said spaced members are provided with relatively small, raised, grateplatesupport ing surfaces spaced from one another both transverselyY and longitudinally of the direction in which the series of grates extend for supporting the grate plates.

7. An apparatus for the rapid cooling of heated material as set forth in claim 1 in which the grate-plate-supporting means includes spaced members and fingers extending transversely from one of said spaced members, and,said spaced members and the ngers are provided with relatively small, raised, grate-plate-supporting surfaces spaced from one another both transversely and longitudinally of the direction in-which the series of grates extend for supporting the grate plates. i

8. An apparatus for the rapid cooling of heated material as set forth in claim 1 in which the grate-plate-supporting means is of a skeletal structure and comprises spaced members, and in which a, plurality of grate plates slightly spaced from one another are detachably supported on said spaced members.

. the bolt of which extends through an grate-plate-supporting means is of a skeletal structure and includes a plurality of spaced members and the grate plates are detachably secured to said spaced members by bolt and nut means, the bolt of which extends through an-opening in the grate-plate-supporting means structure.

11. An apparatus for the rapid cooling of heated material as set forth in'claim 1 in which the detachable securing means includes an extension yon said grate plate, a bolt having the head thereof engaging said extension and the shank thereof extending through an opening in the grate-plate-supporting means, and a nut on the distal end of the shank of the bolt which passes through the grate-plate-supporting means.

l2. VAn apparatus for the rapid cooling of heated material as set forth in claim 11 in which the grate-plate-supporting means is of a skeletal structure and comprises spaced members to which the grate plate is secured.

13. An apparatus for the rapid cooling of heated material comprising a series of spaced over-lapping grates, including fixed grates alternating with movable grates. the upper surfaces of the grates serving to support a bed of material particles, means to impart reciprocating movement to the movable grates to agitata and advance a bed of material thereon, at least some of said grates comprising a supporting structure, at least one grate plate having a pair of hook-like members extending therefrom, a T-bolt having the head thereof engaging said hook-.like members and the shank thereof extending through an, opening in said supporting structure and a nut on' the distal end of said shank, whereby the grate plate is detachably secured to said `supporting structure. i

14. An apparatus for the rapid i cooling of heated material as set forth in claim 13 infwhich the supporting structure is of a skeletal nature.

15. An apparatus for the rapid cooling of heated material as set forth in claim 1 in which the detachable securing means includes an extension on said grate plate, a hook bolt having the hook portion thereof extending over and engaging said extension, and the shank thereof extending through an opening in the grate-plate-supporting means, and a nut on the distal end of the shank of the bolt which extends through the supporting means.

JOSEPH B. GAFFNEY.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Bennett Jan. l2. 1932