CA1146743A - Anti-pollution rotary-sweep grain drier - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
An improved grain drying apparatus of the type having a bin with a perforated floor through which hot air is blown upward for grain drying purposes, and a rotary sweep assembly employing a wet grain distributing auger on its lag side and a dried grain re-trieving auger on its lead side. One improvement includes an inclin-ed elongate plate forming an overflow dam which extends along the floor on the lead side of the retrieving auger and which is connected to the sweep assembly for rotation therewith so as to build up the thick-ness of dried grain on the floor ahead of the retrieving auger to in-crease the resistance of the dried grain to the upward flow of hot air on the lead side such that a greater proportion of hot air will flow upwardly through the floor on the lag side through the wet grain being deposited thereon. Additional features include provision for connect-ing the suction system of the apparatus to the wet lag side of the bin as well as to a central well into which the retrieving auger deposits dried grain for removal from the bin, and a system for recycling air suctioned from the bin through an external cyclone dust separator back into a plenum chamber under the perforated floor.

Description

CROSS REFERENCES TO RELATED APPLICATIONS
_ This application is a ~ivision of my previously filed co-pending application bearing the same title, Serial Number 324,548 filed March 30, 1979.
BACKGROUND OF THE INVENTION
Field of ~lhe Inventiorl This invention relates to the art of drying wet grain, con-tinuously or batchwise, and to the air pollution problem it creates.
Description Of The Prior Art The Francis U. S. patent #3,449,840 and Lambert, Jr. U.S.
patents #3,755,917 and #4,085,520 all disclose a grain drying appara-tus of the continuous (or batchl rotary sweep type and are all owned by a common assignee, the Clayton & Lambert Manufac-turing Company of Buckner, Kentucky 40010. As a continuous drier, the lag side of the sweep continuously deposits wet grain as it ro-tates, say counter-clockwise (CCW), over a circular perforated floor, to form a circular layer of grain extending clockwise (CW) on the floor from the wet lag side of the sweep to the lead side thereof. This circular layer of grain dries pro~ressively from the wet lag side to the dry lead side of the sweep as hot air is blown upwardly through the layer. As it dries, its thickness decreases; hence, its dry end is much thinner than its wet end. The dry lead side of the swPep continuously re-trieves dried grain from the adjacent dry end of the circular layer.
The moist or wet hot air, flowing from the entire layer, is contamin-ated with fugitive dust. It is discharged from the bin into the am-bient atmosphere, thereby polluting the atmospherP.
SU~ARY OF THE INVENTION

. ~
Objects Of The Invention 29 The principal objects of the present invention are: to 3~ ' reduce the loss of heat passing through the dry grain and flowing into the suction system on the dry lead side of the sweep; to in-crease the recovery of fugitive dus-t created within the confines of the sweep as a whole; to reduce the emission of fugitive dust into the ambient atmosphere; and to improve the general design.
Statement Of The Invention _ . .
The aforesaid Lambert, Jr. U. S. patent #4,085,520, which adds said anti-pollution system -to the prior art grain driers, includes a suction canopy chamber embracing -the fugitive dust created along the lead side of -the sweep and a duct system leading to a high efficiency cyclone separator for separating and recovering that dust and dis-charging the clean air into the ambient atmosphere.
I have come to appreciate that, s.ince the depth of the dry end portion of the grain layer decreases more or less progressively as it approaches the point of retrieval, there is, in said Lambert anti-pollution system, a progressive increase in the amount of unused hot air flowing from that progressively thinner layer of grain; hence, I propose to provide the lead side of the sweep with an overflow dam, which compels the grain in the dry end portion of the layer to build up to and remain at a desired thickness and then overflow into the dry grain retrieving or removal means. In this way, the resistance of the dry end portion of the layer to the flow of hot air is increas-ed over what it would otherwise be with a consequent decrease in the amount and temperature of the hot air discharging from that portion and flowing into the suction system.
Moreover, I have found that fugitive dust is also created on the wet lag side of the sweep by the incoming wet grain as it falls toward the floor and that much of this wet-side dust, together with 29 the dust created by the outgoing dry grain discharging into the cen-ter well, can be sucked through the suction canopy chamber into theanti-pollution duct system and thus prevented from escaping through the bin atmosphere to the outside ambient atmosphere.
Furthermore, in accordance with my invention, the clean air, discharging from the outlet of the high efEiciency cyclone used in the anti-pollution system, may be directed back into the grain drying bin under its perforated floor so that the dust and heat content are once again subject to recapture. Preferably, the cyclone outlet air is re-cycled into the bin through one of its air heaters. Finally, I im-prove the design, par-ticularly the inner end support of the rotary sweep.
sRIEF DESCRIPTION OF THE DRAWINGS
The invention is illustrated in the accompanying drawing wherein:
Fig. 1 is a top plan vie~ of a grain bin installation embody-ing the present invention;
Fig. 2 is a partly broken side e~evation of Fig. l;
Fig. 3 is a somewhat schematic top plan view showing the po-sitional relationship of important rotary sweep parts betw~en the ou-t-er wall of the bin an~ the vertical axis thereof;
Fig. 4 is a section taken along line 4-4 of Fig. 3 to show the left or lag and right or lead sides of the sweep;
Fig. 5 is a partly broken vertical section taken along line ; 5-5 of Fig. 4;
Fig. 6 is a perspective view of the parti-cylindrical cap covering the outermost part of the top of the center cylinder;
Fig. 7 is a fragmentary perspective view of the innermost end of the canopy;
29 - Fig, 8 is a horizontal section through the upper part of the 7~3 center cylinder, this view, which looks downward, omits the funnel-mouthed grain inlet conduit and the inner ends of the upper and lower grain-handling augers;
Fig. 9 is an enlarged section along line 9-9 of Fig. 2 with the rotary sweep swung 90 CCW from its position in Fig. 2; and Fig. 10 is a vertically exploded view of the center support means and grain trough.
DESCRIPTION OF THE PREFERRED EMBODIMENT
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The structure illustrated comprises: a Lambert-type of anti-~`~ 10 pollution grain drying apparatus; and my improvement.
;
; The Lambert Apparatus The Lambert apparatus illustrated, which includes a grain drier of the type disclosed in the Francis and Lambert U.S. patents #3,449,840 and #3,775,917, and which also includes the Lambert anti-pollution apparatus of said U.S. patent #4,085,520, conventionally comprises: a grain bin; grain drying means; wet grain feed means;
dry grain discharge means; a rotary sweep; sweep drive means; sweep support means; and Lambert's anticpollution means.
Grain Bin The grain bin 10 has a bottom plenum chamber 11 under a per-forated partition or floor 12 separating the plenum chamber 11 from an upper drying chamber 13, havlng one or more wall openings ~not shown) for discharging the hot moisture-laden air into the ambient atmosphere. The top of the grain bin is covered by a conical roof 14.
Grain Drying ~eans ~; The graln drying means simply comprises a "hot air" blower 16 mounted to blow atmospheric air through a heater (not shown) into 29 the bottom plenum chamber 11 to establish a continuous flow of hot dr~ing air from the bottom plenum chamber successively through the floor 12, a grain layer on the floor 12, the drying chamber 13 and one or more air discharge openings in the bin wall.
Wet Grain Feed Means . . _ The wet grain feed means includes: an inlet conduit 18, feed-ing grain -to and downwardly -through the center of the conical roof 14; a conical wet grain hopper 19, mounted on the interior bin walls to receive the incoming wet grain; and a funnel-mouthed conduit 20 centrally positioned not only to receive wet grain from the bottom of conical hopper 19 but also to feed that grain downwardly along the a~is of the bin into the lag side of the rotary sweep. The ver-tical conduit terminates at its lower end in a horizontal sleeve 21 having an inner closed end and an outwardly projecting outer end.
Dry Grain Dlscharge Means The dry grain discharge means comprises: a stationary trough 22 having an open top positloned adjacent the level of a centrally disposed opening in the bin floor, straight end walls and V-slanted side walls which terminate in a rounded or semi-cylindrical bottom wall 23; and a conveyor auger or screw 24 extending radially along 20 the rounded bottom 23 of trough 22 and through a conveyor pipe 25 projecting, from an opening in one end wall of the trough, successive-ly through the plenum chamber 11 and an outer wall of the bin to a desired discharge area outside of the bln.
Rotary Sweep The rotary sweep 27 comprises: a rotary cylinder 28 concen-tric to the vertical axis of the sweep 27 and vertically arranged, at the floor level of the bin, to open downwardly into said V-shaped trough 22 with which it cooperates to form a vertical center well 29;
29 a wet grain distributing conveyor 30 arranged on the lag side of the /

7~3 sweep with its inner end housed in sleeve 21; a dry grain retrieving conveyor 31 arranged on -the lead side thereof with its inner end hous-ed in choke sleeve 31~; a horiæontally elongate vertical partition wall 32 projec-ting radially from the rotary cylinder 28 to separate the lag side of tile sweep from the lead side thereof, and having hori-: zontally oEfset upper and lower vertically straight portions and a rearwardly declining or slanted vertical mid-portion separating the upper lag-side wet grain distributing conveyor 30 from the lower under-lying lead-side dry grain retrieving conveyor 31; and a radially-elon-gate leveling wall 33, on the lag side of the lag conveyor 30. The cyl-inder 28 is slotted on its auger side, its slot edges flanged and its slot closed by a shallow U-shaped channel 28A, through which the aug-. ers pass.
Rotary sweeps may be arranged to rotate horizontally in .~ sweep fashi`on in either direction. For the sake of clarity, the sweep llustrated will be referred to throughout this application as moving counter~clockwise tCCW)- It rece.ives an incoming stream of wet grain from the.we.t grain ~eed means through co~duit 20, 21 and drops it on the floor where it piles. up, its lag side conveyor 30 distributes that pi:le of grain radi`ally over the floor, its leveling wall 33 scrapes the distributed grain to maintain the wet end of the circular layer at a desired thickness, and its lead side conveyor 31 ~oves the dry end of the circular layer inwardly to the center well 29 where it drops into trough 22 of the dry grain discharge means.
A suitable seal 34 is interposed between the round bottom of rotary cylinder 28 and a round hole in a plate placed on the top of the stationary trough 22 to facilitate relative rotation therebetween.
The seal 34 doesn't transmit weight.

~ ~a,~7~3 Drive Means The drive means requires only one outside electric motor 36 to drive the dry grain discharge and retrieving augers 24 and 31, the wet grain distributing auger 30 and the rotary sweep 27. To drive the dry grain discharge auger 24, motor 36 is connected to the outer end thereof. To drive the re-trieving auger 31, the inner end of the bot-tom grain discharge auger 24 is connected to the retrieving auger 31 through a vertically spaced pair of intermediate and terminal gear boxes 37 and 38 in the center well. As seen in Fig. 5, the intermed-iate gear box 37 is located in the upper half of stationary trough 22while the terminal gear box 38 is located in the lower half of rotary cylinder 28. To drive the distributing auger 30, the terminal gear box 38 is connected by chain 39 to the receiving end of the shaft of auger 30. As seen in Fig. 8, the rotary sweep 27 terminal gear box 38 is connected through chain 40 and tracking shaft 41 to a tracking gear 42 which, when rotated, tracks along stationary ring gear 43 carrying the outer end of the sweep with it.
Rotary Sweep Support ~eans - -- - ---- ---The rotary sweep is supported at its outer and inner ends.
The outer end of the sweep is conventionally supported from rollers on the lower flanges of the stationary ring gear 43 and, since this type of support is in the form of a widely known and used outer roller-bracket assembly, it is no-t deemed necessary to illustrate or describe it.
The inner end of the Lambert rotary sweep was supported largely by an end-to-end ver-tical post arrangement, including a sta-tionary lower center post and an upper rotatable post, wherein the center weight was transmitted downwardly through the floor level by 29 a power transmitting shaft. My arrangement, which will be subsequent-7~3 ly described, supports and transmits all of the center weiyht uponand through structural members.
The ~nti-Pollu-tion 2~eans .
The La~bert anti-pollution means, which is in the Eorm of a suction system for removing and capturing airborne dust coming from the grain in the vicinity of the lead side of the sweep, comprises:
a suction chamber 45 arranged on the front side of the partition wall 32 to extend over and above the lead side of the sweep, this suction chamber being co~posed of a canopy 46 forming the roof of the chamber and a depending curtain 47 extending from the periphery of the canopy's opposite end and front walls downwardly into contact with the under-lying grain so as to form the vertical end walls and the front wall of the suction chamb.er, a pair of orbital conduits 48; a hollow donut casing 49, stationary cQnduit means 50, blower 51; and an outside dust separator 52.
The orbital con~uits 48 connect outlets in the roof of the suction chamber canopy 46 to the interior of the donut casing 49 through an inlet in the casing's bottom wall, which is rotationally mounted on the casing's stationary side walls. The stationary con-duit means 50 connects the interior of the donut casing 49, throughan opening in a stationary wall thereof, to a blower 51 which suctions air from the suction chamber 45 successively through orbital conduits 48, donut casing 49 and the approaching portion of the conduit means 50. and then blows that air through dust separator 52 where the dust is separated from the air and the cleaned air discharged either to atmosphere or in accordance with my invention.
My Improvement I propose: to improve the support means; to provide an over-29 flow dam, which is useful in the grain drying apparatus whether or not 79~3 it is equipped with anti-pollution means; and to improve the anti-pollution means.
Improved Support_~leans My support means comprises: a lower stationary int,egrated support assembly; and an upper rotary integrated support assembly.
The lower assenlbly includes: a pair of trough supportiny base brackets 55, one on each slanted outer side of -the trough 22 to bridcJe the vertical space between that side oE the bot-tom of the bin;
a cross-brac]cet 56 arranged transversely within and mounted on the inner slanted Eaces of the walls of the trough adjacent the upper ends o~ the vertical brackets 55; a pair of horizontally-spaced up-right brackets 57 mounted Oll cross-bracket 56, one located on each side of the vertical axis of the grain bin adjacent opposite sides of intermediate gear box 37; and an axis-concentric top plate 58 on the upper end of upright brackets 57, wllich terminate in the vicinity of the floor level. These s-tationary parts 55-58 and trough 22 are all rigidly connected together and remain stationary at all -times.
The upper rotary assembly, which rests rotationally on the top plate 58, includes: a base plate 60 resting on, and in rotational face-to-face relation to, said top plate 58; an integrated three-sided vertical casing having two opposed side walls 61, 62 located at and connected to the opposite sides of terminal gear box 38; and a third or bight wall 63 extending transversely from one side wall 61 to the other side wall 62 and integrated with both. The side walls extend the full vertical length of cylinder 28. The bight wall 63 projects beyond the upper end of the cylinder 28.
The side walls 61, 62 incline for a short distance outward-ly upward from the top or the terminal gear box 38 to widen the space 29 therebetween sufficiently to receive the incoming wet feed sleeve 21 7~3 wnich houses the inner end portion of the distributing auger 31 within rotary cylinder 28. The side walls 61, 62 con-tinue straight upwardly along opposite sides of the upper distributing auger 30 and terminate at or near the top of rotary cylinder 28. sight wall 63 is in the form of a straigh-t plate vertically arranged within the cylin-der 28 between the bin axis and the distributing auger 30 and track-ing shaf-t 41 dri~e chains 39, 40. It ex-tends upwardly beyond the top of rotary cylinder 28 sufEiciently to receive and support the inner end of the tracking shaft 41 and terminates near the bottom level of the funnel-mouth of the wet grain receivlng conduit 20.
The inner end of dry auger 31 is supported by the housing of terminal gear box 38. The inner end of wet auger 30 is supported on the bight wall 63 of the integrated casing 61-63. Likewise, the inner end of the tracking shaft 41 is supported on the upper end por-tion of the bight wall 63. Thus the weight of the apparatus at the inner ends of wet and dry augers 30, 31 and of track shaft 41 is transmitted through-the integrated casing 61-63, and associated struc-tural parts, directly to base plates 60 of the upper assembly 60-63, thence to the top plate 58 of the lower assembly 55-58.
The ilmermost roof truss 65 of the canopy rests upon the upper end of the side walls of the integrated casing 61-63. The ro-tary cylinder 28 i5 supported on casing 61-63 by means including a T-bracket 66 connecting two points on the inner wall of the cylinder :; to the casing through the cross bar of bracket 66 and a 3rd point ~: of the cylinder to the casing through the stem of bracket 66~ The casing also supports the funnel-mouthed conduit 20, its sleeve 21 and - air-locking choke sleeve 31A of retrieving auger 31. The roof of canopy 46 covers a small portion of the open top of rotary cylinder 29 28. The remainder of the open top of cylinder 28 is covered by a parti-cylindrical cap 68, i.e. a partial band-shaped or ring-shaped cap, having a closed top and an open bottom. The -top of cap 68 is on a level sliyhtly above -the uppermost level of canopy 46. Suit-able walls (not shown) close any vertical openings resulting from this difference in levels.
OverElow Darn In accordance with a particular feature of my invention, an overflow dam is arranged on but near the lead side of the lead auger 31 so that, as the rotary sweep 27 sweeps forwardly, it piles up the dry grain in front of it until the dry grain layer thickness exceeds the vertical height of the dam whereupon the dry grain begins to overflow the dam.
The dam is in the form of an elongate metal plate 70 which is slightly longer than the horizontal space between the bin wall ~ and the outer end of the air-loc~ing sleeve 31A of dry auger 31. The : pla-te 70 is supported from the lead side of partition wall 32 by two or more horizontally spaced vertical bars 71 and from the truss system of the canopy 46 by two or more slanted bars 72 which may be lengthen-ed or shortened by turnbuckles 73 or other suitable adjustable means.
The overflow-feature is useful in continuous batch driers of the type illustrated with or without any anti-pollution means.
: Improved Anti-Pollution Means The anti-pollution me~ns is improved, in accordance with my invention, by extending the canopy 46 rearwardly over the lag side of the rotary sweep so as to extend over -the lag space 75, which ex-tends on all sides of lag auger 30 between partition wall 32 and ].eveling wall 33. The lag space 75 communicates with the space ex-tending under the canopy 46 between the roof trusses of the canopy 29 46. As a consequence, space 75 is also subject to the suction exert-~4~7~3 ed through orbital conduits 48 connec-ting the suction chamber 45 to the donut casing 49.
Again, in accordance with my invention, the suction chamber 45 is extended to the center well 29 of rotary cylin~er 28. Suction from the orbital conduits 48 Causes air to flow from the center well

2~ oE the rotary cylinder 28 upwardly into and obliquely through the suction space 76 lying under the canopy 46 between the innermost truss 65 and the adjacent canopy-supporting member of i-ts truss system.
My invention contemplates either the conventional discharge of the cleaned air from the high efficiency cyclone separator 52 di-rectly into the ambient atmosphere or the unconventional discharge of that air bac]c into the plenum chamber 11 so that its dust and heat contents are once again subject to recapture. The cyclone air outlet is recycled into -the plenum chamber 11 through outlet pipe 78, which, preferably, is connected to the intake of one of the hot air blowers 16.
sOth the partition wall 32 and the leveling board 33 are conventionally provided with yieldable sealing means (not shown) which scrape the wall of the bin.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

A grain drying apparatus comprising:
A. a grain drying bin having a perforated floor through which hot air is blown upwardly for drying purposes;
B. a rotary sweep mounted in the bin for sweep movement over the floor, said sweep having distributing means on its lag side for distributing wet grain over the floor and radially-extending retrieving means on its lead side for removing dried grain from the floor;
C. means for feeding wet grain to said distributing means;
D. means for receiving dried grain from said retrieving means and conveying said dried grain outside of the bin;
E. a partition wall connected to a central portion of said rotary sweep and extending radially outward therefrom for movement over said floor with the movement of said rotary sweep, said wall extending between said distributing and retrieving means to sepa-rate the lag side from the lead side of said sweep; and F. means for building up the thickness of the dry grain on the lead side of the retrieving means including a rigid plate at least partially suspended from an upper portion of said wall and dis-posed in front and on the lead side of said retrieving means, said plate radially extending parallel to said retrieving means between said central portion and a sidewall of said bin, said plate being inclined with respect to a vertical plane through said bin such that its upper edge is relatively closer to said retrieving means than its lower edge, said lower edge being spaced above said floor to form a horizontally extending gap therebetween.

The apparatus of Claim 1 further comprising means for adjusting the height of the lower edge of said thickness building means above said perforated floor to vary the width of said gap.

The apparatus of Claim 2 wherein said height-adjusting means comprises an adjustable turnbuckle connected between an upper portion of said sweep and a lower edge portion of said plate, said partition wall extending upward in said bin between said distributing and retrieving means, an upper edge portion of said plate being pivotally attached to said partition wall, whereby adjustment of said turnbuckle lifts and lowers the lower edge portion of said plate to vary the width of said gap.

The apparatus of Claim 1 wherein said distributing means is parallel with and spaced vertically above said retrieving means, said partition wall having horizontally offset upper and lower ver-tically extending portions and a slanted mid-portion connected be-tween said horizontally offset upper and lower portions and extend-ing through the space between said distributing and retrieving means, said plate being at least partially suspended from said offset upper portion of said wall.

The apparatus of Claim 3 wherein said upper portion of said sweep to which said turnbuckle is connected is a suction chamber canopy.

A grain drying apparatus comprising:
A. a grain drying bin having a perforated floor through which hot air is blown upwardly for drying purposes;
B. a rotary sweep mounted in the bin for sweep movement over the floor, said sweep having distributing means on its lag side distributing wet grain over the floor and radially-extending retrieving means on its lead side for removing dried grain from the floor;
C. means for feeding wet grain to said distributing means;
D. means for receiving dried grain from said retrieving means and conveying said dried grain outside of the bin; and E. means for building up the thickness of the dry grain on the lead side of the retrieving means, said thickness building means having a bottom edge spaced above said perforated floor to form a gap therebetween.

The apparatus of claim 6 wherein said thickness building means includes a dam mounted on the sweep adjacent the lead side of the retrieving means.

The apparatus of Claim 6 further comprising means for adjusting the height of the bottom edge of said thickness building means above said perforated floor to vary the width of said gap.