Grain cleaner

[57] ABSTRACT

A grain cleaner including, in series, feeder chutes, an inlet manifold, vibrating apparatus, an outlet manifold and vertically extending outlet chutes. The feeder chutes are designed to have a specific minimum crosssectional area ratio and they serve as conduits between grain elevators or scalpers and the inlet manifolds. The inlet manifold includes both an opening at the top for receiving a mixture of grain and foreign matter and side walls converging downwardly toward outlets. The outlets are located at one side of the inlet manifold near the lower end, each one being constructed to feed a stream of the mixture to one of a plurality of superposed screening decks. The mixture flowing through the outlets may be individually regulated by gates disposed therein to give uniform flows to each deck. Each deck includes a screen superposed over a nan. Whole grains are retained above the screen; tines, consisting of foreign matter, broken grains, and undersized grains, fall through the pores of the screen onto the pan. A vibrator is operatively assembled to shake the box and its contents at an acceleration of at least 3.4 times that of gravity and to exert a throw on the fines which is adequate to cause them to strike the underside of the screen and dislodge any material blinding any of the openings. The outlet manifold includes two outlets from each deck. One outlet is disposed to receive the grain which is retained on the screen. The other outlet is disposed to receive the fines on the pan. A passage in the outlet manifold adjoins each of the outlets and baffles are provided therein to horizontally deflect the grain or fines into different vertically extending outlet chutes. Below the outlet manifold, the outlet chutes are structured to laterally deflect the grain in one direction and the fines in another direction whereby all the grain will empty into a single duct and the fines will empty into another single duct.

Claims, 7 Drawing Figures

Patented Sept. 5, 1972

3,688,902

Sheets-Sheet i

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LOUIS E. HUBACH

BY &amp; MuUtoUa*d

ATTORNEYS

Patented Sept. 5, 1972

3,688,902

Sheets-Sheet 2

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ATTORNEYS

Patented Sept. 5, 1972

3,688,902

Sheets-Sheet 3

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ATTORNEYS

Patented Sept 5, 1972

3,688,902

Sheets-Sheet 4

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GRAIN AND \ FINES ⁽ELEVATOR {

SCALPER

INLET MANI FOLD '2 15

FIG. 6

OVERFLOW

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GRAIN X CLEANER 47 OUTLET MANIFOLD

FINES 60

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’Ί·Γ“

GRAIN 58

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FIG. 7

LOUIS

FINES

INVENTOR. E. HUBACH

VERTICAL CHUTES

ACCEPTABLE GRAIN

ACCEPTABLE GRAIN ri—

FINES

<img file="US3688902A_D0009.tif" />

BY &amp; MuUvdlattd

ATTORNEYS

3,688,902

GRAIN CLEANER

This is a continuation-in-part of my co-pending application, Ser. No. 795,260 filed Jan. 30,1969, entitled GRAIN CLEANER.

BACKGROUND OF THE INVENTION

A conventional grain cleaning device includes a chute for feeding a mixture of grain and fines to a shaker box. Within the shaker box in the mixture flow path, a series of spaced openings of equal size provide for gravitational division of the mixture into a plurality of equal streams. The intent is to provide a uniform feed of material to each of a plurality of screening decks disposed in the box. Each of the decks includes a screen with a pan disposed thereunder. The screen is provided with appropriately sized openings to retain the whole grains above the screen and allow the fines to fall onto the pan.

Near the end of each and disposed thereon is a baffle. The baffle directs the grain to one side of the screen where it is discharged to a vertically extending chute. A similar baffle on the pan deflects the fines to the other side into a second vertically extending chute.

The first problem encountered in the sequence of flow outlined above is to provide both a constant pressure head of grain and a head which is great enough to get maximum gravitational flow of grain into the separators.

The second problem is the proper division of the flows of material to the screening decks to prevent choking of one screen and starving of another. Unfortunately, the plurality of spaced openings is inadequate to equally divide the grain-fines mixture. Grain will not spread evenly on a flat surface in a short distance; see U. S. Pat. No. 2,908,391 for an example of the prior art.

The instant invention has solved the uniform feed problem by providing an inlet or feeding manifold which has a uniform pressure head of grain applied to the various inlets to the screens and adjustable gates in each screen inlet to insure the uniform feeding of each screen.

The next problem in the sequence is the screen itself. Often the fines will be very close to the size of the whole grain and will pass partially through the screen openings and remain lodged therein. This is called “blinding” of the screen and prior art devices require frequent shutdowns to disassemble the screen and clean it by air blasts or other means.

It has been discovered that where the shaker apparatus has an acceleration of at least 3.4 times that of gravity applied thereto, a spacing of about 1 inch between the screen and pan and with a vertical throw of the material on the pan which is adequate to strike the underside of the screen, the blinding is almost totally eliminated because the material on the underside of the screen will tend to dislodge the materials blinding the pores. This improvement greatly increases the longevity of operation as compared to conventional machines because there is no need for periodic shutdowns to clean the screens.

The next problem in the line of flow is the baffles disposed within the shaker box. As may be imagined, providing the baffles both above and below the screen tends to reduce its effective area. The baffles in the prior art usually extend at an angle of approximately 45° and this lost screen space is shown to be an unnecessary waste by this invention. It was conceived that a separately assembled baffle structure in an outlet manifold on the end of each deck would be a proper solution to this problem. Thus, no part of the screen is blocked off from its prime function. As a result, the total screen would be usable for separating grain from fines and the previously discussed solution to the blinding problem would insure throughout the screen rather than only part of the screen. Therefore, an outlet manifold has been provided at the end of the box with two openings for each deck, one for the fines and the other for the whole grain. Baffles are provided therein for deflecting the grain into a plurality of vertically extending chutes and the fines similarly are deflected into an appropriate plane for discharge into other vertically extending chutes.

When the first experimental machines were placed in operation the surfaces of the pans were painted. In some instances the separated fines falling through the screen tended to build up and remain within the machine. Thus, the discovery was made that fines acquire a charge of static electricity during the separating operation. This is particularly true in dry, cold weather. Apparently, the paint acts as a dielectric and prevents the discharge of the fines through contact with the metal pan. As a result of this discovery, it is recommended that the pans be unpainted. Experience has shown that static electricity ceases to be a problem where there is direct contact between the fines and the bare metal pan.

BRIEF DESCRIPTION OF THE INVENTION

Feeder chutes serving as conduits for grain and foreign matter lead from a scalper structure or an elevator to the open tops of inlet manifolds. There are two distinct sections of the feeder chutes, the spouting section and the bulk storage section. The bulk storage section is controlled in volume by an overflow chute opening near its top. To maintain a constant head there should be some flow through the overflow chute at all times.

The upper elevation of the bulk storage section is often dictated by the building which houses the unit. The spouting sections are branch conduits extending from the bulk storage section to the open upper mouths of the inlet manifolds. Obviously, to obtain gravity feed the spouting must be inclined to an angle greater than the angle of repose of the grain. Additionally, and unobviously, for maximizing feed rate the cross-sectional area of the bulk storage section above the spouting sections should be at least about twice the total cross-sectional area of the spouting.

Each inlet manifold is attached by suitable structure to a box containing a plurality of screening decks. A single vibrator is provided for the two shaker boxes with one box above and one box below for structural balance. A plurality of outlets from the manifold are provided facing the shaker box screening apparatus and disposed in each outlet is an adjustable gate for regulating the flow of material therethrough, thereby providing a means for insuring controlled flows of the mixture to each of the screening decks.

3,688,902

The multi-deck screens housed in the box are inclined at the optimum angle for conveying grain and adequately separating the mixture. The screens are vibrated by a shaking or vibrating means which is regulated to vibrate the box with an acceleration of at least 3.4 times that of gravity, and greater where the spacing between the pan and screen is greater than one inch.

Each screening deck includes a pan with a superposed screen. The screen openings are of a size to allow foreign matter, broken grains and undersized grains to pass therethrough and be deposited on the pan. It is intended that whole grains remain above the screen. The vibrating apparatus imparts to the separated material on the pan a vertical throw adequate to have the materia] strike the underside of the screen and dislodge any materials which may tend to be deposited in the openings of the screen and blind the screening operation.

At the outlet end of the box is an outlet manifold. The outlet manifold has a plurality of openings at its inlet end to receive the material from the screening decks. There are two inlets in the manifold for each deck, one to receive the whole grains from above the screen and one to receive the fines from between the screen and the pan. The flow paths are of decreasing downstream cross-section within the outlet manifold; thus, to maintain proper movement the outlet manifold is inclined at a greater angle than the screening deck. Provided within the outlet manifold are a plurality of baffles for deflecting the grains and the fines horizontally in opposite directions whereby the grain and fines from each of the screens or pans, respectively, will exit from the outlet manifold into one of a plurality of separate vertically extending chutes. Material exiting ³⁵from the outlet manifold will fall into an outlet chute and acquire a momentum due to gravity. A suitable distance below the outlet manifold in each outlet chute is an angularly extending deflector. The grain and fines are laterally deflected by these deflectors in opposite directions, each into a single, larger duct.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of the combination of this invention including a feeding chute, an inlet manifold, a vibrating screen housing, a discharge manifold and a plurality of vertically extending outlet chutes;

FIG. 2 is a perspective view of the feeding manifold, partially section, showing the adjustable outlet openings;

FIG. 3 is a fragmentary elevational view, partially in section, of the box and the decks of separators therein;

FIG. 4 is an exploded view of the elements of the outlet manifold showing the baffles for deflecting the separated grain and fines;

FIG. 5 is a fragmentary plan view of the screening area and the outlet manifold, partially in section;

FIG. 6 is a diagrammatic view of the flow path of the grain and fines; and

FIG. 7 is an elevational view of the vertically extending outlet chutes.

PREFERRED EMBODIMENT

This invention is related to a multi-deck grain cleaner or separator in general, and in particular to separators for com and soybeans. It includes a chute 10 comprising a bulk storage section 9 and a plurality of spouting sections 11 for feeding mixtures of grain and fines to feeding manifolds or hoppers 12 and 13, which ⁵ in turn feed a vibrating apparatus 15. Substantially identical upper and lower shaker boxes or housings 14 and 16 respectively, are secured together in spaced relationship by rigid side members 17. Disposed between the boxes is a vibrator 18 for shaking or vibrat⁰ ing the structure. The particular machine for vibrating is not a novel part of this invention and any conventional vibrating mechanism may be employed, provided it will give the required acceleration to the boxes as will ₁₅ be explained subsequently. At the outlet end of each of the shaker boxes is an outlet manifold 20 which guides the separated material to a plurality of outlet chutes indicated generally at 22.

It was discovered that there is a direct relationship 2o between the resulting feed rates to the boxes 14 and 16 and the ratio of the cross-sectional area of the bulk storage section 9 to the combined cross-sectional area of the spouting sections 11. The general size and shape of the inlet manifolds 12 and 13, shaker boxes 14 and 25 16, etc. have become standarized and thus the shape, size and volume of the spouting sections 11 have also become standardized. The same is not true for the bulk storage sections 9. Each grain elevator will have its own unique adjacent building and because of this a different ³⁰ bulk storage section must be designed for each individual building. The result of designing several feeder chutes 10 led to the discovery that the separator 15 can adequately separate the grain as fast as it can be fed. Thus, it was decided that the feeder chute 10 should be increased in height and volume to increase the grain head and thereby the flow rate. Since the shape, size and volume of the spouting sections are limited by other factors, the portion expanded was the bulk ₄₀ storage section 9. Surprisingly, a physical constant was discovered. As expected, as the height and cross-sectional area of section 9 increased the grain flow rate increased but only to a certain limit. It was thought (inaccurately) that the effective “head” and flow rate would 45 be affected most by the relative elevation of the upper level of the grain, but some buildings forced the design of short squat storage sections. Thus, it was discovered that the flow rate increased in proportion to the ratio of the cross-sectional area of storage section 9 to that of 50 spouting 11. However, it was further discovered that only when the ratio exceeds about 2 is there substantial increase in flow rate. This optimum ratio discovered allows quick and easy design of inlet chutes which provide an optimum flow rate within a given building. Un³³ less the cross-section area ratio is above about 2, increased heights in the bulk storage section 9 will have little affect on flow rate.

As the boxes 14 and 16 are substantially identical, only one will be described. The mixture of grain and ⁰ fines is fed into the feeding manifold 12 through an inlet opening 24 at the top thereof. The bottom wall 26 of the inlet manifold 12 is disposed adjacent the bottom edge of the shaker box 14.

At the side of the inlet manifold 12, juxtaposed to the housing 14, are a plurality of outlets 28. One outlet 28 is provided and aligned to feed each of a plurality of screening decks 27 secured in the housing 14. The out3,688,902 lets 28 are disposed just above the screen 29 of each of the screening decks 27 and to insure a controlled or uniform feed of grain and foreign matter to each of said screening decks, gates 30 are provided within each outlet. These gates 30 may be individually adjusted to prevent the choking of one screening deck and the starving of another or they may be locked together for group adjustment, as desired. Each gate 30 is pivoted at 32 about an axis at one side edge extending perpendicular to the direction of grain flow. It is understood that other adjustable flow regulation means than pivotable gates 30 might be employed successfully.

As best seen in FIG. 2, the edge of each gate 30, remote from the pivot axis, is tapered to a sharp edge 33. The sharp edge facilitates the flow of grain past the gates and provides a definite dividing line between flow paths. Also, when separating com, the sharp edge will sever any corn husks which may be in the stream, thereby preventing clogging.

In order to properly adjust the gates for continual uniform feed, there must be a constant pressure head of grain applied to the gates. As a result of this fact, an internal rear wall 34 is provided within the feeder chute 10. Just above the internal rear wall 34 is an overflow opening 36 which feeds an overflow chute 38. The continual grain separation process includes feeding the grain-fines mixture into the feeder chute 10 faster than it flows into the mouths or inlet openings 24 of the hopper 12 and at a faster rate than the rate of exit from the outlets 28. Thus, at all times there may be some material overflowing the feeder chute 10 through the overflow opening 36 and into the overflow chute 38, where it will be returned to the feeder chute 10 or to storage bins (not shown).

Resilient mountings 40 at each corner of the shaker boxes serve to support the separator above a substrate 41. Such mountings have been found convenient for preventing the transfer of vibrations from the separator to the supporting structure.

Each of the decks 27 includes a screen 29 fixed in position above a pan 46. Appropriate sealing devices 47 are provided along the edges of the screen and the pan to prevent intermingling of the separated materials. The screen, per se, may be woven wire, a perforated sheet metal piece or some woven cloth, depending upon the particular kind of separation desired. The word “screen is intended to include any type of apparatus such as this, which is involved in a separating operation.

As is conventional, the screening decks 27 are encompassed in shaker boxes 14 and 16 and are caused to vibrate by the vibrator 18. This agitates the grain and fines on the screen 29 and the fines tend to pass through the screen openings and be deposited on the pan 46. Moreover, in this invention, the vibrator 18 is regulated to impart an acceleration to the boxes 14 and 16 of at least 3.4 times that of gravity and the pan 46 and screen 29 are so spaced and regulated with the vibrator 18 that a vertical throw is imparted to the fines which is adequate to cause them to strike the underside of the screen 29 and dislodge any materials in the openings which might tend to blind the screen. The spacing of the screen 29 and the pan 46, the rotational velocity of the vibrator 18, etc. may be experimentally determined for any particular sizes of grain, as necessary6

With com and soybeans and an acceleration of 3.4 g. the pan-screen spacing should be about one inch. These are minimum values, the spacing should never be less than one inch because on the upward throw the fines will pass up through the screen and not be adequately separated. The minimum acceleration is about 3.4 g. but with a one inch spacing an acceleration of about 4.0 g. is preferred because it moves the grain through the machine faster. Increased pan-screen spacing requires a higher acceleration and vice versa.

In addition, the optimum angle of inclination for the screening decks 27 should be determined. This was determined to be in the range 15° - 20°. With many of the ordinary grains, the deck should incline at about 17°. When the grain and fines arrive at the outlet end of the screening deck 27, it is anticipated that substantially all of the fines will have been separated from the whole grains when the optimum angle is used.

Each deck has two outlets to the outlet manifold 20. An upper outlet 48 is disposed immediately above the screen 29 for the grain. A lower outlet 50 is provided between the screen 29 and the pan 46 for receiving the separated fines.

Two passages are provided in the outlet manifold for each deck, one is a grain passage 52 and the other is a fines passage 54. Disposed in each passage are a plurality of baffles 56 which deflect the grain and fines horizontally in different directions. The outlet passages and baffles are uniformly disposed from deck to deck, whereby the deflections tend to direct the grain toward a passage of smaller cross-sectional area downstream and eventually to a plurality of vertically extending outlet chutes 58 for receiving the separated cleaned grain and a plurality of different outlet chutes 60 for receiving the fines which have been separated from the grain. Thus, the elements making up vertically alternate passages are in register.

It will be noted that the angle of inclination of passages 52 and 54 is greater than the angle of inclination of the screening decks. The decreasing cross-sectional area of the outlet manifold passages causes a greater frictional force which must be overcome. It was found that where the passages 52 and 54 are inclined at an angle about 5° greater than the screening decks, the grain and fines will move freely through the outlet manifold 20 and into the outlet chute 22. In the instant application the inclination of the outlet manifold should be in the range 20° - 25° with 22° being preferred.

In each of the chutes 58 and 60, below the outlet manifold 20, is an angularly inclined deflector 62. The deflectors in the grain chutes are inclined in one direction with the deflectors in the fines chutes inclined in another direction. This structure allows all the grain chutes 58 to empty into a single larger chute 64. Similarly, a single chute 66 accommodates the discharge of all the fines chutes 60. The single enlarged grain chute 64 may extend to storage bins or elsewhere, as desired.

In operation, the vibrator 18 is actuated, preferably giving the two boxes 14 and 16 an acceleration of at least 3.4 g. A mixture of fines and grain is continuously fed to the manifolds 12 and 13 through the feeder chute 10. As the mixture flows into the manifolds, the outlets 28 therefrom are adjusted to feed uniform streams of the mixture to each of a plurality of super3,688,902 posed screening decks 27. As the screening decks 27 are rigidly fixed within the boxes, they also receive an acceleration of approximately 3.4 g. The grain and foreign matter on the decks are agitated by the vibrating of the screens and the fines, including the foreign matter, broken grains and undersized grains, will fall through the screen opening onto a pan 46 located beneath the screen. Grain is retained above the screen 29 because the openings are specifically structured smaller than a normal sized grain of the particular type being separated.

As the grain passes along the screen toward the outlet of the box, certain of the grains which are very close in size to the openings through the screen may be lodged or trapped. To overcome this, correlation between the vertical throw of the vibrating apparatus and the acceleration is regulated to toss the fines on the pan 46 upward to strike anything which may be blinding any of the openings and adequate momentum is imparted to the fines to dislodge anything which may be tending to blind the screen. In the preferred embodiment an eccentric rotating at about 1,115 rpm and having a diameter of about three-sixteenths inches will provide the necessary momentum. Passing on through the box, the separated grains exit into a passage in an outlet manifold which is immediately above a similar passage which receives the separated fines.

The exits from the box take the separated materials into an outlet manifold which is made up of a plurality of superposed passages for receiving the grain and fines. Within each passageway through the outlet manifold are a plurality of baffles for deflecting material in a horizontal direction. The grain will be deflected 35 to one side, the fines to the other side and the grain and fines will separately exit from the outlet manifold into one of a plurality of vertically extending chutes. The fines will exit into certain chutes and the grain will exit into certain other chutes.

Gravity will carry the material in the chutes downward to deflecting apparatus within each chute. The grain will be deflected laterally to one side and the fines laterally to the other side. Each of the grain chutes merges into a larger single grain chute for receiving all of the grain and a similar chute receives all of the discharge from the fines chutes. The grain in its single chute and the fines in its single chute may be conducted to appropriate disposal or storage apparatus as desired.

For ease of description, the principles of the invention have been set forth in connection with but a single illustrated embodiment. It is not intended that the illustrated embodiment nor the terminology employed in describing it be limiting inasmuch as variations in this 55 embodiment may be made by those of ordinary skill in the art without departing from the spirit of the invention. Rather, it is desired that the invention be restricted only by the scope of the appended claims.