Title of Invention

"AIR GRAIN CLEANER"

Abstract

An air grain cleaner 10 comprising a chamber in the form of an air box 12 within which grain can be separated from a grain mixture and thereby cleaned. The air grain cleaner has an internal grain hopper 14 which is provided with a manually operable valve 18 in an inlet 20 in a wall in an upper part of the air box 12 for introducing the grain mixture into the air box. A second inlet 22 is formed in a side wall 24 of the air box 12 for admitting an air stream into the air chamber. A fan 26 for producing the air stream communicates with the inlet 22 via a conduit 28. An air pressure equaliser 30 for reducing the pressure gradient of the air stream across the inlet 22 is located in the conduit 28 adjacent the inlet 22. A grain deflecting plate 32 is fixed within the air chamber 12 beneath inlet 20. Plate 30 is also inclined toward the air inlet 20. A plurality of air deflecting plates 34 arranged in a stack are inclined toward the grain inlet 20 to deflect the air stream to the grain. When the air stream contacts the falling grain mixture, it pushes the grain and other components of the grain mixture different distances in the downstream direction due to their different weight and/or size so as to separate the individual components of the grain mixture.

Full Text

The present invention relates to an air grain cleaner. Air grain cleaners are commonly used for separating grain from intermixed unwanted foreign bodies such as, for example, chaff or grass seeds. Throughout this specification the term "grain" is used in a general sense to denote grain or other particulate vegetables or fruit derived from agriculture, including for example cereals such as wheat, oats, corn, barley, maize, rape seed or lupins etc; peas and beans. In addition, the term "grain mixture is used in a general sense to denote a wanted grain, for example wheat, intermixed with unwanted foreign bodies which may include other types of grain, for example barley. Typically, air grain cleaners operate by blowing a stream of air across the path of a free falling stream of grain mixture. Due to their different weight and/or size, each component of the grain mixture is blown different distances in the direction of flow of the air stream thereby resulting in separation of the components. The separate components form corresponding piles which can later be collected. In prior art air grain cleaners the air stream is produced almost exclusively by centrifugal fans of various configurations. One type of centrifugal fan commonly used has an impeller similar to that used in water pumps and generates a relatively high pressure and low volume air stream. Another common type of centrifugal fan has an impeller similar to that of a paddle wheel and provides a very low pressure but high volume air stream. While the centrifugal fans allow adequate grain cleaning, the air flow dynamics of air grain cleaners using such fans are not entirely satisfactory. The major deficiencies in such air grain cleaners are unevenness of air pressure across the air stream cleaning the grain and less than optimum balance between air pressure and air volume in the air stream. These features affect the cleaning efficiency both in terms of the degree of separation of the individual components of the grain mixture and the rate of cleaning (or capacity) of the air grain cleaner. It is an object of the present invention to attempt to alleviate at least one of the above deficiencies in the prior art. According to the present invention there is provided an air grain cleaner when used for separating grain from a grain mixture comprising: a chamber within which said grain can be separated from said grain mixture, said chamber including a first inlet disposed in an upper part of the chamber so that a grain mixture introduced through the first: inlet can fall by action of gravity into the chamber and, a second inlet for admitting an air stream into the chamber, said air stream directed toward said grain mixture as it falls into the chamber; a propeller-like fan in communication with said second inlet for producing said air stream and including a plurality of fan blades extending radially from an axis of rotation of said fan; an air stream equalising means for reducing the pressure gradient of said air stream across said second inlet, said air stream equalising means comprises a plurality of ducts arranged in a matrix-like configuration for delivering said air stream from said fan to said second inlet; and one or more air deflecting plates arranged in a stack located near but spaced from said second inlet, said plates being disposed in mutually parallel and inclined planes whereby, in use, said air stream blows any grain in said grain mixture a different distance in the downstream direction of the air stream from other components of said grain mixture to separate and thereby clean said grain from said other components of the grain mixture, and any grain which lands on anyone of said plates can slide down that plate by action of gravity to fall through the space between that plate and the second inlet into said chamber. Preferably said air stream equalising means is located between said fan and said second inlet. Preferably said air stream equalising means comprises a plurality of duals arranged in a matrix. Preferably each of said ducts are of constant cross-sectional area. Preferably the cross-sectional area of each duct is substantially the same. Preferably said air grain cleaner further comprises a conduit facilitating said communication between the propeller-like fan and said second inlet, said conduit including a dividing plate extending along a longitudinal central plane of at least a portion of the length of the conduit. Preferably said air grain cleaner further comprises an elongate shroud in which said propeller-like fan is housed, and having one end located adjacent said conduit, said fan being disposed near said one end. Preferably said air grain cleaner further comprises grain deflecting means for deflecting said grain mixture so as to fall in a direction toward said second inlet. Preferably said grain deflecting means comprises a plate disposed in an inclined plane and located adjacent said first inlet so that said grain mixture, after passing through said first inlet, falls onto and slides down said plate. Preferably said air deflecting plates are arranged for deflecting said air stream to flow in a direction substantially opposite to that in which said mixture falls. Preferably said inclined plane is substantially parallel to the planes containing said air deflecting plates. Preferably said air grain cleaner further comprises opposite and substantially symmetrically profiled side walls, said opposite side walls having respective first portions which are uniformly spaced apart by a first distance and respective second portions which are uniformly spaced apart by a second distance being greater than said first distance, and one or more movable grain dividers for dividing a lower part of said chamber into a plurality of grain collection areas and disposed between said respective second portions, opposite sides of each grain divider extending laterally beyond adjacent first portions of said side walls. Embodiments of the present invention will now be described by way of example only, with reference to the accompanying drawings in which: Figure 1 is a side view of the air grain cleaner; Figure 2 is a perspective view of an air pressure equalising means used in the air grain cleaner shown in Figure 1; Figure 3 is an enlarged side view of an air deflecting plate arrangement incorporated in the air grain cleaner; and, Figure 4 is a partial end view of the air grain cleaner1 showing a grain divider. As shown in Figure 1, an air grain cleaner 10 comprises a chamber in the form of an air box 12 within which grain can be separated from a grain mixture. The separation of grain from the grain mixture effectively cleans the grain. The grain cleaner 10 includes an internal hopper 14 for feeding a grain mixture into the air box 12. Grain is fed into the hopper 14 via external means (not shown). Grain stored within the internal hopper 14 can be fed into the air box 12 via a manually operable valve 18 disposed in a grain inlet 20 to the air box 12. An air inlet 22 is formed in the lower part of a side wall 24 of air box 12 for admitting an air stream into the air box. Fan 26 for producing the air stream communicates with the inlet 22 via a conduit 28. An air pressure equaliser 30 for reducing the pressure gradient of the air stream across the inlet 22 is located in the conduit 28 between the fan 26 and inlet 22. More specifically the air pressure equaliser 30 is located in the conduit 28 adjacent the air inlet 22. An inclined grain deflecting plate 32 is disposed beneath the inlet 20 so as to direct grain which leaves said hopper 14 to fall in the general direction toward the air inlet 22. Also, a plurality of air deflecting plates 34 arranged in a stack are located near but spaced from the air inlet 22. The air deflecting plates 34 are disposed in mutually parallel and inclined planes. In this embodiment, the air deflecting plates 34 are substantially parallel with the grain deflecting plate 32. Because the air deflecting plates 34 are spaced from the air inlet 22, any grain 36 which may land on the plates 34 will slide down respective plate and fall through the gap between the plate and the air inlet under a further lower plate 38 and into the air box 12 (refer Figure 3). This substantially prevents grain from inadvertently passing through the air equaliser 30 and depositing at the bottom of the conduit 28. Air entering the air box is vented through a screen 38. The screen 38 forms a substantial portion of side wall 40 of the air box 12. A viewing window 42 is also formed in wall 44 of the air box so as to allow viewing of the air grain cleaner in operation. A plurality of chutes 46 depend downwardly from a bottom wall 48 of the air box 12. Respective grain dividers 50 are located between adjacent ones of the chutes 46. Referring to Figure 4, it can be seen that each grain divider 50 includes a manually operable handle 52 for pivoting the grain divider plate 50. Wall 44 of the air box 12 and opposite wall 54 are of symmetrical profile. Walls 44 and 54 include first portions 44" and 54" and adjacent second portions 44" and 54". The wall portions 44" and 54" are flared outwardly in respect to wall portions 44' and 54'. That is, the distance between wall portions 44" and 54" is greater than that between wall portions 44'and 54'. The grain deflecting plates 50 are disposed between the wall portions 44" and 54" and have their opposite sides 56 and 58 extending laterally beyond wall portions 44' and 54'. As a result of this, grain which may slide along or fall down wall portions 44' and 54' is unlikely to become wedged or otherwise caught between the opposite sides 56, 58 of the grain deflecting plates and the interior of wall portions 44" and 54". Referring again to Figure 1, it can be seen that the grain dividers 50 divide the bottom wall 48 of the air chamber 12 into three separate grain collection areas 62, 64 and 66. Depending on the weight of each grain in the grain mixture, the grains will be blown across the air box 12 different distances and fall in one of the three grain areas 62, 64 and 66 for later dumping through one of the chutes 46. Referring to Figure 2, it can be seen that the air pressure equaliser 30 comprises a plurality of ducts 68 arranged in a matrix-like manner. Each duct 68 has a substantially constant cross-sectional area and the cross-sectional area of each duct is substantially the same. In one embodiment, the equaliser 30 may have a depth of 35 cm, a length of 25 cm and be 90 cm across, with the cross-sectional area of each duct being 4 cm square. An air stream director 70 in the form of a plate is installed centrally along the conduit 28 to assist in eliminating swirling air turbulence associated with the fan 26. The rotation of the fan 26 swirls air in one direction creating a build-up on one side. The air director 70 assists in eliminating this. An end of the conduit 28 distant the air inlet 22 is provided with an elongate shroud 72 for creating a substantially even air flow on the suction side of the fan 26. The air grain cleaner 10 is conveniently mounted on a trailer 74 so that it may be transported readily from place to place. The fan 26 is driven by motor or power take-off (not shown). The operation of the air grain cleaner 10 will now be described. A supply of grain is fed into the internal hopper 14. By turning the valve 18-grain mixture flows through inlet 20 into the air box 12 and initially impacts on grain deflecting plate 32. This causes the grain mixture to travel in a parabolic path in a general direction toward the air inlet 22. Assuming that the fan 26 is being rotated an air stream flows through the conduit 28 toward the air pressure equaliser 30. The air stream is then divided by and passes through the ducts 68 and then through the air inlet 22. It has been empirically discovered that the air pressure equaliser 28 acts to reduce the pressure gradient across the air inlet 22. The air stream entering the air box 12 from the inlet 22 is deflected upwardly toward the falling grain mixture by the air deflectors 34. Grain which may land on the air deflector plates 34 will, as described above, slide down those plates and fall through a space between the plates in the air inlet 22 into the air box 12. This avoids the build-up of grain in the conduit 28. When the air stream contacts the falling grain mixture, it pushes the grain and other components of the mixture different distances in a downstream direction due to their different weight and/or size so as to separate individual components of the mixture. Each component then falls in a different one of grain collection areas 62, 64 and 66. The position of the grain dividers 50 can be adjusted by manipulation of the handles 52 to vary the size of the respective grain collection areas 62, 64 and 66. Now that an embodiment of the present invention has been described in detail, it will be apparent to those skilled in the relevant arts that numerous modifications and variations may be made without departing from the basic inventive concepts. For example, although the ducts 68 of air pressure equaliser 30 are shown as having a square cross-section, they can be made of any other cross-sectional shape, for example, circular, triangular, hexagonal, etc. Also, individual ducts can be formed of a cross-sectional area which varies along the length of the duct. Similarly, the cross-sectional area of different ducts can also be made different. All such modifications and variations are deemed to be within the scope of the present invention, the nature of which is to be determined from the foregoing description and the appended claims. WE CLAIM: 1. An air grain cleaner when used for separating grain from a grain mixture comprising; a chamber within which said grain can be separated from said grain mixture, said chamber including a first inlet disposed in an upper part of the chamber so that a grain mixture introduced through the first inlet can fall by action of gravity into the chamber and, a second inlet for admitting an air stream into the chamber, said air stream directed toward said grain mixture as it falls into the chamber; a propeller-like fan in communication with said second inlet for producing said air stream and including a plurality of fan blades extending radially from an axis of rotation of said fan; an air stream equalising means for reducing the pressure gradient of said air stream across said second inlet, said air stream equalising means comprises a plurality of ducts arranged in a matrix-like configuration for delivering said air stream from said fan to said second inlet; and one or more air deflecting plates arranged in a stack located near but spaced from said second inlet, said plates being disposed in mutually parallel and inclined planes whereby, in use, said air stream blows any grain in said grain mixture a different distance in the downstream direction of the air stream from other components of said grain mixture to separate and thereby clean said grain from said other components of the grain mixture, and any grain which lands on anyone of said plates can slide down that plate by action of gravity to fall through the space between that plate and the second inlet into said chamber. 2. An air grain cleaner as claimed in claim 1, further comprising opposite and substantially symmetrically profiled side walls, said opposite side walls having respective first portions which are uniformly spaced apart by a first distance and respective second portions which are uniformly spaced apart by a second distance being greater than said first distance, and one or more movable grain dividers for dividing a lower part of said chamber into a plurality of grain collection areas and disposed between said respective second portions, opposite sides of each grain divider extending laterally beyond adjacent first portions of said side walls. 3. An air grain cleaner as claimed in claim 2, wherein said air stream equalising means is located between said fan and said second inlet. 4. An air grain cleaner as claimed in claim 3, wherein said air stream equalising means comprises a plurality of duals arranged in a matrix. 5. An air grain cleaner as claimed in claim 4, wherein each of said ducts are of constant cross-sectional area. 6. An air grain cleaner as claimed in claim 5, wherein the cross-sectional area of each duct is substantially the same. 7. An air grain cleaner as claimed in claim 2, further comprising a conduit facilitating said communication between the propeller-like fan and said second inlet, said conduit including a dividing plate extending along a longitudinal central plane of at least a portion of the length of the conduit. 8. An air grain cleaner as claimed in claim 7, wherein an elongate shroud in which said propeller-like fan is housed, and having one end located adjacent said conduit, said fan being disposed near said one end. 9. An air grain cleaner as claimed in claim 8, wherein said air grain cleaner further comprises grain deflecting means for deflecting said grain mixture so as to fall in a direction toward said second inlet. 10. An air grain cleaner as claimed in claim 9, wherein said grain deflecting means comprises a plate disposed in an inclined plane and located adjacent said first inlet so that said grain mixture, after passing through said first inlet, falls onto and slides down said plate. 11. An air grain cleaner as claimed in claim 10, wherein said air deflecting plates are arranged for deflecting said air stream to flow in a direction substantially opposite to that in which said mixture falls. 12. An air grain cleaner as claimed in claim 11, wherein said inclined plane is substantially parallel to the planes containing said air deflecting plates.

Documents:

501-del-1997-abstract.pdf

501-del-1997-claims.pdf

501-del-1997-correspondence-others.pdf

501-del-1997-correspondence-po.pdf

501-del-1997-description (complete).pdf

501-del-1997-drawings.pdf

501-del-1997-form-1.pdf

501-del-1997-form-13.pdf

501-del-1997-form-19.pdf

501-del-1997-form-2.pdf

501-del-1997-form-3.pdf

501-del-1997-form-4.pdf

501-del-1997-form-6.pdf

501-del-1997-gpa.pdf