US3449840A - Continuous grain drying apparatus - Google Patents

Description

June 17, 1969 J- H. FRANCIS CONTINUOUS GRAIN DRYING APPARATUS Sheet Filed Oct 18, 1967 RYING CHAMBER l4 PLENUM ll INVENTOR.

JAMES H. FRANCIS FIGI ATTORNEY June 17, 1969 J. H. FRANCIS CONTINUOUS GRAIN DRYING APPARATUS Sheet Filed Oct. 18, 1967 N OI INVENTOR.

JAMES H. FRANCIS ATTORNEY June 17, 1969 J. H. FRANCIS CONTINUOUS GRAIN DRYING APPARATUS Sheet 3 of4 Filed Oct. 18. 1967 INVENTOR.

JAMES H. FRANCIS AT TO R N E Y June 17,1969 J. H. FRANCIS 3,449,840

CONTINUOUS GRAIN DRYING APPARATUS Filed Oct. 18, 1967 Sheet 4 of 4 4 s? 41 AZ QLP/ FIG. 4

WET GRAIN IN INVENTOR. JAMES' H. FRANCIS ATTORNEY United States Patent CONTINUOUS GRAIN DRYING APPARATUS James H. Francis, Louisville, Ky., assignor to Clayton and Lambert Manufacturing Company, Buckner, Ky., a

corporation of Delaware Filed Oct. 18, 1967, Ser. No. 676,126 Int. Cl. F26b 15/02 US. Cl. 34-187 9 Claims ABSTRACT OF THE DISCLOSURE A radially-extending grain handler is mounted in a grain drying bin for rotary sweep movement about the vertical axis of a centrally-open disc-like floor which is perforated to accommodate the upward passage of a drying gas therethrough. As the handler sweeps rotationally forward, it operates, on its lag side, through one auger, to feed a stream of incoming wet grain to said floor and, on its lead side, through another auger, to retrieve and remove dry grain from said floor. The grain feeding auger receives an incoming stream of wet grain at its inner end adjacent the central opening of the floor and directs that stream horizontally outward along a radially-extending overflow dam on its lag side in a manner causing the dam to overflow rearwardly along its length and thereby deposit, during each rotation of the handler, a radially wide band or layer of wet grain progressively extending circularly about said vertical axis of the bin. The grain retrieving auger has a radially-extending grain scoop on its lead side which, during each rotation of the handler, progressively scoops up the circular layer of grain deposited during the preceding rotation while the feed auger contemporaneously deposits at new circular layer of wet grain.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to grain drying apparatus of the continuous type. More particularly, the invention is concerned with an apparatus for receiving wet grain in a continuous stream, progressively drying that grain and then discharging the dried grain in a continuous stream.

Description of the prior art The Ellis US. Patent No. 3,309,782 points out: (1) that is is desirable to harvest and dry ripe grain promptly; and (2) that such grains are usually dried either (a) by a batch-drying method, wherein small quantities of grain are placed and dried in a drier and then removed for storage, or, (b) by an in-storage drying method, wherein large quantities of grain are placed in the storage bin and slowly dried. Continuous grain driers are shown in the Ullgren and Denison et al US. Patents No. 1,779,571 and No. 3,256,615 wherein a stream of wet grain is continuously fed to the axial center of a drying bin and then I subjected to a drying action as the layer is progressively forced to move over that surface along a path extending from the center of the surface spirally outward to a peripheral discharge opening.

SUMMARY OF THE INVENTION Objects of the invention ice heated (or unheated) air supply unit for forcing drying air upwardly from the plenum chamber successively through the perforated floor, the stored grain and the roof of the bin; and to provide one which, in use, maintains a continuous stream of grain flowing into and out of the drier while providing, within the drier, from the time the stream enters the drier as wet grain to the time it leaves the drier as dry grain, operating conditions which facilitate the uniform drying of the grain over a substantial range of grain flow rates.

Statement 0] the invention All of the important objects of the present invention can be achieved in a grain drier constructed in accordance with my preferred embodiment wherein a radiallyextending grain handler, having grain feeding and retrieving augers, is installed in a grain drying bin, of the conventional perforated floor type, for rotary sweep movement about the vertical axis of the bin. The feeding auger provides, on the lag side of the handler, a radially extending overflow dam for feeding grain along its radial length at a controlled rate and thereby depositing on the floor, during each revolution, the wet lead end of desired layer of grain. The retrieving auger provides, on the lead side of the handler, a radially extending means for picking or scooping up grain along its radial length and thereby removing from the floor, during each revolution, the dry lag end of that layer of grain which was deposited during the preceding revolution.

With this arrangement, the rate of grain feed can be coordinated to the speed of the relative movement to provide a uniform layer of desired thickness while the drying action can be coordinated with the speed, thickness and length of this layer to reduce the grain to a desired and uniform degree of dryness.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in the accompanying drawings wherein:

FIG. 1 is a partly broken perspective view of a grain drying installation constructed in accordance with the present invention;

FIGS. 2 and 3 are enlarged fragmentary views showing the lag side and lead side, respectively, of the grain handler shown in FIG. 1;

FIG. 4 is a vertical section corresponding to one taken along line 44 of FIG. 2;

FIG. 5 is a partly broken side elevation showing the inner end of the grain handler as seen in FIG. 3; and

FIG. 6 is a schematic illustration of a modified form of drier.

DESCRIPTION OF THE PREFERRED FIGS. 1-5 EMBODIMENT The preferred embodiment illustrated in FIGS. 1-5 may be described as comprising four more or less conventional elements together with one element, which is constructed in accordance with the present invention, these five elements being as follows: A. a perforated-floor type of grain bin; B. grain drying means; C. means for conducting incoming wet grain; D. means for conducting outgoing dry grain; and E. static layer-forming means.

The grain bin The conventional perforated-floor type of cylindrical metal bin 10 illustrated in FIG. 1 has: a bottom plenum chamber 11; an elevated perforated floor 12 containing a central opening concentric to the vertical axis of the bin 10; a drying chamber 14 above the floor; and a conical roof 15 covering the drying chamber 14 and containing a central opening to accommodate the inflow of Wet grain and the outflow of spent moisture-laden air.

Grain drying means Any suitable means for drying the grain may be employed. In the arrangement shown, a blower 18 is conventionally mounted to blow heated or unheated air into the bottom plenum chamber 11 and, in so doing, maintain a continuous flow of drying air from the plenum chamber upwardly successively through the floor 12, any grain layer on the floor, the drying chamber 14 and the central air-outlet opening in the roof 15.

Needless to say, the central opening of the floor 12 is blocked off from plenum 11 in any conventionally suitable way (which is later described) to prevent the flow of drying air from the plenum chamber 11 to the drying chamber 14.

Means for conducting incoming wet grain The conveying or conducting means for the incoming wet grain comprises: a hopper 20 into which the incoming wet grain may be dumped; a conveyor screw 21 driven by motor 22; a horizontal conveyer pipe 23; an upright side wall pipe 24; and a slanted roof pipe 25, which contains a conveyer screw driven by motor 27 and which is arranged to discharge wet grain downwardly into and along the vertical axis of bin through down-pipe 28. This brings the incoming wet feed into and drops it down along the vertical axis of bin 10.

Means for conducting outgoing dried grain The conveying or conducting means for the outgoing dried grain comprises: an upwardly open stationary hopper 30 which is positioned on the under side of the central opening of the floor 12 (to receive dry grain which falls along the vertical axis at that point) and arranged to block the flow of drying air upwardly through the central floor opening; and a horizontal pipe 31, which contains conveyer screw 32 driven by motor 33 and which is arranged to discharge dry grain downwardly into outlet pipe 34.

Static layer-forming means The static layer-forming means, which is interposed between the conducting means for incoming wet grain and the outgoing dry grain, operates to form and maintain a relatively stationary static layer of grain within the grain bin 10. This static layer, which has a lead end, lag end and a given or predetermined length therebetween, essentially includes three (3) elements comprising: 1) means for forming the lead end of said layer on said surface, including means for feeding grain to the perforated surface of the floor 12 at the lead end of said static layer, said grain feeding means preferably but not necessarily including an accumulator for leveling out variations in the rate of flow of the incoming wet grain; (2) means for contemporaneously removing the lag end of said static layer of dry grain from said surface; and (3) means for creating relative movement, between said surface and said conducting means at the opposite ends of said static layer, and for contraining that relative movement in a direction such as to lengthen the static layer at the lead end and shorten it at the lag end.

The accumulator and the aforesaid three (3) essential elements may be best described as comprising: an accumulator; a grain handler; handler mounting means; and a handler drive means.

The accumulator The accumulator 38 of the feed means is in the form of a large vertical open-ended cylinder, also designated 38, positioned along the axis of the grain bin 10 to receive the incoming wet grain from the top outlet pipe 34 and hold back any excess wet grain while feeding a continuous stream of wet grain from its bottom opening at a desired rate into the grain handler. In place of the accumulator, the flow of incoming grain may be suitably metered during its passage between hopper 20 and down pipe 28 at the center of the roof 15.

The grain handler The grain handler 40 comprises: a horizontally elongate frame 41 composed of spaced longitudinal and transverse frame members suitably secured together; a horizontally elongate screw conveyer or feed auger 42 of the overflow type, which is mounted on the frame to extend longitudinally along the frame, which is provided at its inner end with a funnel 43 for channeling the incoming feed to the feed auger 42 and which is arranged to provide, on the lag side of the handler, a radially-extending overflow darn 44 which, by lag-side overflow action along its radial extent, deposits grain on the floor to form the wet progressively advancing lead-end of a desired layer of grain; a horizontally elongate screw conveyer or re trieving auger 45, which is mounted on the frame to extend longitudinally along the frame and which is provided along its length, with a parallel scoop-apron 46 positioned alongside the retrieving auger 45 to provide two things, namely, 1st, a radially-wide forwardly-extending lead-side scoop, which scoops up the dry grain from the floor at all points along the radial width of the scoop, and which directs that grain rearwardly to the retrieving auger 45, and, 2nd, an apron which is located behind the retrieving auger 45 and which cooperates therewith to force the scooped up dry grain to flow inwardly along the auger toward the center opening 13 of the floor 12. The inner end of the retrieving auger 45 extends inwardly through the cylindrical wall of a rotating baffle 47, which forms a part of the frame of the grain handler 40. The auger 45 discharges the retrieved grain within the confines of the rotating baflie 47 where the grain falls into the open hopper 30 of the outgoing grain conducting means.

Handler mounting means The grain handler 40 is mounted at its opposite ends for rotary sweep movement about the vertical axis of the grain bin 10. The inner end mounting means comprises: a stationary upright (preferably hollow) post 50 centered on the long axis of the hin with its lower end fixed to the base 51 of the bin; a collector ring having a stationary part .(not shown) fixedly mounted on the upper end of the post 50 and a cup-like rotary part 52 inverted over and rotationally mounted on the stationary part of the collector ring; a rotary sleeve 53 mounted to depend from and rotate with the rotary part 52 of the collector ring. The inner end of the handler frame 41 is rigidly secured to the sleeve 53. Thus the handler 40 is rotationally supported on the collector ring center post 50 through the rotary collector-ring part 52 and its depending sleeve 53.

The means for rotationally supporting the outer end of the grain handler 40 comprises: a stationary traction ring 56, of the type conventionally having an endless series of spaced sprocket wheel openings 57, mounted on the wall of the bin 10 through spaced brackets 58; and a pair of transversely spaced wheels 59 carried by the outer end of the handler frame 41 in position to ride upon the lower flange of the traction ring 56 and thereby suspend the outer end of the handler rotationally therefrom.

Handler drive means The handler drive means comprises: a main drive unit;

and means for driving the handler and both of its augers from that unit.

ing the traction ring 56 with the main drive unit in a manner such as to rotate the handler 40 when the main drive unit is energized. This drive train includes: a reduction gear-driven belt 66 at the inner end of the handler; a belt-driven radial shaft 67 rotationally mounted on the handler frame 41; a shaft-driven belt 68 located at the outer end of the radial shaft 66; a belt-driven gear mechanism 69 (not shown) but housed in a gear box, which is also designated by the numeral 69; and a gear-driven sprocket 70 which is mounted to engage in the openings 57.01? traction ring 56 and thereby track along that ring when rotated, so as to pull the outer end of the handler 40 with it. Alternatively, the handler may be driven by connecting sprocket 70 to a suitable variable speed driven motor mounted on the handler frame at its outer end.

The auger drive means on the handler 40 comprises: a direct connection 72 between the reduction gear mechanism 64 at the upper end of gear box 64 and the shaft of the feeding auger 42; and another direct connection 75 between the rotary end of reduction gear mechanism 64 and the shaft of the retrieving auger 45.

Operatiom In operation, the main drive unit is energized to impart rotary sweep movement to the grain handler 40 and to the drive the grain-feeding and grain-retrieving augers 42 and 45. At the same time, the motors 22 and 27 of the conveying or conducting means for the wet grain are energized so that grain fed into the wet grain hopper 20 will pass as a continuous stream through the conducting means 20-27 for Wet grain and be discharged into the upper end of the accumulator 38 of the static layerforming means.

A continuous stream of Wet grain will flow from the accumulator 38 through the receiving hopper or funnel 43 into the inner end of the feed auger or conveyer 42, which forces the grain to flow radially outward along the conveyer and causes it to overflow dam 44 of the conveyer and thereby fall upon the floor 12 where it forms the lead end of the 1st static layer of grain. During the 1st revolution of the handler, we assume that the drying fan 18 is not operated; hence, near the end of the 1st revolution, a static layer of wet grain will extend circularly from the feeding auger 42 at the lead end of the 1st static layer clockwise to the retrieving auger 45 at the lag end of the static layer.

At the end of the 1st and the beginning of the 2nd revolution, the operation of the drying fan 18 and associated drying equipment may be instituted to direct a stream of heated or unheated drying air, as the case may be, upwardly through the perforations of the floor, the static layer and the wet air outlet of the bin. During the 2nd revolution, the scoop or retrieving auger 45 on the the lead side of the handler will remove Wet grain from the lag end of the first static circular layer while the feeding auger 42 on the lag side of the handler will contemporaneously form the lead end of the second circular layer as a continuation of the first circular layer.

As the 1st circular layer is scooped up by the scoop apron 46, it is forced to move inwardly along that apron by the screw of the retrieving auger 45, the inner end of which passes through the rotating baflle 47 to discharge the grain downwardly into the upwardly-open hopper 30 on the underside of the floor 12 at its central opening. This particular layer of grain may be recycled through the bin in any suitable fashion since it is largely composed of wet grain. At the end of the 2nd revolution, the scoop or retrieving auger will be located at the lag end of the 2nd static layer but, since this end is now dry, regular operation may be instituted with the scoop auger 45 on the lead side of the handler removing the dry grain constituting the lag end of the 2nd circular layer and with the feed auger 42 on the lag side of the handler contemporaneously forming the wet lead end of the third circular static layer, etc.

FIG. 6 modification In FIG. 6, a continuous stream of wet grain is fed onto one end of the upper run of a horizontally elongate endless perforated belt 81, having a feed end and a discharge end. The belt 81 is rotationally supported on drums 82, 83 and rotated to move the upper run 80 toward the discharge end. As a result, the static layer 84, formed on the upper run, is progressively carried by that run toward the discharge end and thus correspondingly lengthened until it reaches the discharge end.

The flow of grain may now be continued as before, the flow of drying air instituted, and the discharged grain recycled until the discharge of suitably dry grain begins. On the other hand, when the upper run 80 is covered by a full length layer of grain, the How of drying air may be instituted and the flow of grain stopped until all of the grain 'on the upper run 80 is suitably dry. Again, that part of the upper run, which is not covered by the first layer, may be blocked off to restrict the flow of drying air to the covered part, the blockage being removed when a full length of drying grain is first achieved and the discharge of dry grain begins or is about to begin.

Finally, the flow of drying air may be instituted at the very beginning of the flow of incoming grain and the flow of incoming grain regulated to provide a progressively thickening layer, beginning with a thin layer of low gas-flow resistance and ultimately ending with a layer of desired thickness. For example, a perforated floor provides a resistance to air flow approximating the resistance of a 6" layer of grain. Consequently, if a 1" layer of grain is initially formed on the floor 12, the resistance which it affords to the air flow will be 7 units as against the 6 units afforded by the uncovered portion of the floor; hence, an adequate drying rate can be maintained in that grain despite the fact that the entire floor is not covered. Furthermore, this 1" thickness can be progressively increased at a desired rate beginning before, during or after the completion of the first circular layer. At the tail end of the operation, the thickness of the last layer can be progressively reduced to insure adequate drying.

In any such event, drying air, drawn from a suitable source of supply, is forced into the space between the upper and lower runs of the belt 81 and thence forced upwardly successively through the upper run 80 of the belt 81 and static layer 84. By appropriately co-ordinating the rate of wet grain flow to the speed of the belt, a grain layer of a desired and uniform thickness can be built up and maintained on the belt. By co-ordinating the drying action (the volume, velocity, temperature and moisture content of the drying air) to the speed, thickness and length of the static grain layer, the incoming wet grain can be reduced to a desired and uniform degree of dryness by the time it reaches the discharge end of the belt where it will be directed into any suitable receiver or dry grain conveying means.

The present invention has many advantages. First it can be readily installed in existing cylindrical drying bin installations. This enables the farmer to use existing equipment and thus effect important economies. Another important advantage is that, after all of the grain has been dried, it my be returned to and stored in bin 10 to be removed as needed through the bottom auger 31-32. In this connection, the handler 40 may be operated until it lays the last circular layer. Thereupon it can be removed and the last layer dried entirely by the heat stored in the bin or by a continuing use of the drying apparatus. With the last layer in a suitably dry condition, the previously dried grain may now be fed back into the bin and stored. This again enables the farmer to effect important economles.

Having described my invention, 1 claim 1. An improvement in a grain drying apparatus of the type having a grain-supporting circular surface, which is stationarily mounted within a housing to extend circu- (A) said grain moving means comprises a pair of adjacent elongate grain handlers of the rotary sweep larly about a vertical axis and perforated to accommodate a stream of grain-drying gas flowing upwardly therethrough, comprising:

(A) a pair of grain moving means for continuously maintaining, on said stationary surface, a relatively type mounted to extend radially over said surface and arranged for rotation about said vertical axis, each handler having mechanism for moving grain stationary static layer of grain having a radial width radially along its length from a receiving point to and a predetermined circular length between ends, a discharging point, said pair of means including (1) one rotary sweep grain handler including (1) one for forming one end of said layer on said (a) a frame, and

surface by feeding incoming grain to and de- (b) a radially-extending grain feeder mountpositing it across said surface along a line cored on said frame to receive incoming grain responding to the radial width of said one end in the vicinity of said axis to direct the of said static layer, and flow of said grain radially outward and to (2) the other for removing the other end of said discharge said outwardly flowing grain layer from said surface by contemporaneously 5 along its length to form a radially wide removing grain from said surface along a line layer of grain on said surfa 011 the lag corresponding to the radial width of said other side of said rotary feeder, end of said static layer, (2) the other rotary sweep grain handler including (3) one of said pair being in the form of an elon- (a) a frame, and

gate grain-handler of the rotary sweep type a a radially-extending grain retriever mounted to extend radially over said surface mounted on said frame to pick up grain and arranged for rotation about said vertical forming the radial width of the lag end of axis, said handler having mechanism for mov- Said l y r, to flow Said Picked p grain ing grain radially along it length f a reradially inward and to discharge said inceiving point to a discharging point; and wardly flowing grain in the vicinity of said (B) means for rotating said grain moving means horiaxis.

zontally over said surface in a direction tending to Th apparatus of claim 6 wherein: lengthen the static layer at said one end and shorten Said grain feeder is in t f rm f an auger conit at aid other end. veyer having an overflow darn over which the dis- 2. The apparatus of claim 1 wherein: C a g g grain flows; and (A) said grain handler includes (B) said grain retriever is in the form of a radially- (1) a frame d extending auger having a radially-wide scoop along (2) a radially extending grain feeder of the roits length to P p Said graintary sweep type mounted on id fra to 8. The improvement of claim 7 in combination with: ceive incoming grain in the vicinity of said axis, means p viding said perforated grain-supporting to direct the flow of said grain radially outward surface; and and to discharge said outwardly flowing grain means for drying grain along the length of a Static along its length to form a radially wide layer layer of grain 011 a d a of grain on id surface at h l i f id 9. The improvement of claim 7 in combination with: rotary f d 40 (A) an upright cylindrical bin providing said per- 3, Th apparatus f l i 2 h i forated grain-supporting surface and a plenum cham- (A) said grain feeder is in the form of an auger conher under Said Surface; and

veyer having an overflow dam over which the dis- (B) means for flowing a drying gas from Said Plenumv charging grain fi chamber upwardly through said surface. 4. The apparatus of claim 1 wherein: (A) said grain handler includes References Cited a i f n t d UNITED STATES PATENTS a ra 1a y-ex en mg grain retriever of the q y Sweep type mounted on said frame to gig; 34 173 XR pick up grain forming the radial width of the lag 2,132,984 10/1938 ch end of said layer to flow said picked up grain 3,256,615 am-ay 34-173 XR 6/1966 Dennison 34-68 radially inward and to discharge said inwardly flowing grain in the vicinity of said axis.

5. The apparatus of claim 4 wherein:

(A) said grain retriever is in the form of a radiallyextending auger having a radially-wide scoop along its length to pick up said grain.

'6. The apparatus of claim 1 wherein:

FREDERICK L. MATTESON, JR., Primary Examiner.

HARRY B. RAMEY, Assistant Examiner.

US. Cl. X.R.

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