AU659560B2

AU659560B2 - Air grain cleaner

Info

Publication number: AU659560B2
Application number: AU41457/93A
Authority: AU
Inventors: Greg Ryan
Original assignee: VORMAR Pty Ltd
Current assignee: VORMAR Pty Ltd
Priority date: 1992-08-25
Filing date: 1993-06-17
Publication date: 1995-05-18
Anticipated expiration: 2012-12-11
Also published as: AU4145793A

Description

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AUSTRALIA

PATENTS ACT 1990 P/00/011 Regulation 3.2 659560 COMPLETE SPECIFICATION FOR A STANDARD PATENT r rr

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Name of Applicant: Address of Applicant: Actual Inventor: Nominated Person: Address for Service: GREG RYAN MELARA ROAD MINGENEW W.A. 6522 GREG RYAN GERALDTON PLUMBING CO. PTY LTD ACN: 008 679 409 OCEAN STREET GERALDTON W.A, 6530 GRIFFITH HACK CO. Patent Trade Mark Attorneys of 256 Adelaide Terrace (6th Floor), Perth, Western Australia 6000, AUSTRALIA r r~r rrrr~

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Standard Complete Specification for the invention entitled: AIR GRAIN CLEANER Details of Parent Applications: 30115/92 filed December 11, 1992 The following Is a full description of this Invention, Including the best method of performing it known to me:- 'I W ;M;r n -2- AIR GRAIN CLEANER 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 20 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 impel -r similar to that used in water pumps and generates a relatively high pressure and low volume air stream. Another common tyre 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 unevenne-s 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.

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3 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.

The applicant has quite surprisingly discovered that the degree of separation and/or the capacity of grain cleaners can be improved by replacing the commonly used centrifugal fan with a propeller-type fan.

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 S.that a grain mixture introduced through the first inlet can oo fall by action of gravity into the chamber and, a second 20 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

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plurality of fan blades extending radially from an axis of t >: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 30 configuration for delivering said air stream from said fan to said second inlet; and, whereby, in use, said air stream blows any grain in said grain mixtu-e 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.

i .o .r i- T 4 Preferably said air stream equalising means is located between said fan and said second inlet.

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 first grain deflecting means for deflecting said grain mixture so as to fall in a direction toward said second inlet.

Preferably said first grain deflecting means comprises a plate disposed in a first 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 grain cleaner further comprises air deflecting means for deflecting said air stream to flow in a direction substantially opposite to that in which said mixture falls.

Preferably said air deflecting means comprises at least one plate disposed in a second inclined plane and locazed adjacent said second inlet.

Preferably said first and second inclined planes are substantially parallel.

Preferably said air grain cleaner further 2 comprises second air deflecting means located between said first and second inlets for preventing said air stream from flowing directly into said first inlet, said second air deflecting means being provided with a closed external surface which is shaped so as to substantially prevent the collection of any component of said grain mixture.

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 0" equalising means used in the air grain cleaner shown in Figure 1; and, Figure 3 is a side view of a second embodiment of the air grain cleaner.

As shown in Figure 1, an air grain cleaner comprises a chamber in the form of an air box 12 within which grain can be separated from a grain mixture and thereby cleaned. An inlet 14 is provided in a wall 16 in an upper part of the air box 12 for introducing the grain mixture into the air box 12. A second inlet 18 is formed in a side wall 20 of the air box 12 for admitting an air stream into the air chamber. A fan 22 for producing the air stream communicates with the inlet 18 via a U-shaped duct 24. An air pressure equaliser 26 for reducing the pressure gradient of the air stream across the inlet 18 is located in the duct 24 between the fan 22 and inlet 18.

The air box 12 is provided with an internal hopper 28 for feeding a supply of the grain mixture to the inlet 14. A grain deflecting plate 30 is fixed within the air chamber 20 12 adjacent and extending for the length of the inlet 14.

The plate 30 is also inclined in a plane toward the air inlet 18.

A plurality of air deflecting plates 32 extend horizontally across the air inlet 18 inside the air box 12.

The air deflecting plates 32 are inclined in a plane substantially parallel to that containing the grain deflector plate 30. Air entering the air box 12 from the inlet 18 is vented through a screen 34. The screen 34 forms a substantial portion of a side wall 36 of the air box 12 and forms a portion of the upper wall 38 of the air box from the side wall 36 to the hopper 28.

A second air deflector 40 is attached to the wall 16 inside the air box 12 between the first and second inlets 14, 18. The deflector 40 has a closed external surface 42 which is shaped to prevent the collection of any component of the grain mixture. For example, the air deflector 40 can take the form of an elongate strip of -6angle-iron having its free longitudinal edges connected with the wall 16.

A plurality of chutes 44 depend downwardly from a bottom wall 46 of the air box 12. Adjacent chutes 44 are separated by respective adjustable dividers 48 which extend in a generally upright manner from the bottom wall 46.

The fan 22 is a propeller-type fan provided with a number of blades 50 extending radially from a common drive shaft 52. The drive shaft 52 corresponds with the axis of rotation of the fan 22. The shaft 52 is supported along its length by spaced apart bearings 54. A pulley 56 is coaxially mounted on the shaft 52 between the bearings 54 for connection to a belt fan-drive motor (not shown).

The fan blades 50 are housed within a cowl 58 which is connected to the duct 24.

In order to assist in directing the air stream from the fan 22 to the air pressure equaliser 26, a number :i of curved blades 60 are disposed about the corners inside of the duct 24. An elongate viewing window 62 is provided 20 in the hopper 28 to allow visual indication as to the level of grain within the hopper. A rectangular window 64 is also provided in a front wall of the air box 12 to allow visual inspection of the cleaning of the grain.

Referring to Figure 2, it can be seen that the 25 air pressure equaliser 26 comprises a plurality of ducts 66 arranged in a matrix-like manner. Each duct 66 has a substantially constant cross-sectional area and the crosssectional area of each duct is substantially the same. The S" equaliser 26 is 35cm deep, 25cm long and 90cm across, with the cross-sectional area of each duct being 4cm square.

For convenience the air grain cleaner 10 is mounted on a trailer 68 to allow easy transportation.

The operation of the air grain cleaner 10 will now be described.

A supply of grain mixture is placed in hopper 28.

The hopper 28 feeds the grain mixture to the inlet 14 through which it enters the air box 12. The grain mixture i! ii I r 7 -7passing through the inlet 14 slides along the grain deflector plate 30 and falls by gravity in a generally parabolic path in a direction generally toward the inlet I s 18.

On rotation of the shaft 52, the fan 50 produces an air stream which flows through duct 24 being directed by curved blades 60 to the air pressure equaliser 26. The air stream is divided by and passes through the ducts 66 to the inlet 18. It has been empirically discovered that the air pressure equaliser 26 acts to reduce the pressure gradient across the air inlet 18. The air stream entering the air box 12 from the inlet 18 is deflected upwardly into the falling grain mixture by the air defectors 22. Air is prevented from blowing directly into the hopper 28 by the air deflector 40. Furthermore, grain sliding off the grain deflector 30 is prevented from collecting on the air deflector 40 due to the shape of its outer surface 42.

When the air stream contacts the falling grain mixture, it pushes the grain and other components of the o: 20 grain mixture different distances in the downstream direction due to their different weight and/or size as to separate the individual components of the grain mixture.

Each component then falls at a different location onto the bottom wall 46. The position of the dividers 48 can be adjusted so as to physically separate each component pile for ejection through respective chutes 44.

Figure 3 illustrates a second embodiment of the air grain cleaning apparatus in which like features are denoted by identical reference numbers. The most A 30 significant differences between the first and second embodiments are that the hopper 28 in a second embodiment is external to the air box 12 and the grain mixture inlet 14 is formed in upper wall 38. In all other respects the structure and functioning of the second embodiment is in essence identical to that describe above with reference to the first embodiment.

8 It will be apparent that embodiments of the invention enjoy numerous advantages over the prior art. It has been discovered that the use of the propeller fan 22 provides substantially greater volumes of air at low to medium pressure than centrifugal fans hitherto used in air grain cleaning devices. This feature by itself allows the capacity of the grain cleaner 10 to be significantly increased over the prior art grain cleaners. Moreover, prior art air cleaners can be readily converted to accord with embodiments of the invention by the replacement of an existing centrifugal fan with propeller like fan. In such arrangements, the air equaliser can take any conventional form, such as, for example baffle plates or air directing vanes. However, maximum benefit is obtained by use of the fan 22 in combination with an air equaliser similar to that shown in the present embodiments. Furthermore, the provision of the air pressure equaliser 26 reduces the pressure gradient which would otherwise exist across the inlet 18 and thereby provides a more even application of the air stream and thus more efficient cleaning of the grain. In addition, a problem in the prior art with grain collecting on an air deflector used for preventing air from an air box inlet being blown directly into the grain inlet has been elegantly solved by the provision of 25 the air deflector 40 having a closed surface 42.

Now that embodiments of the present invention have been described in detail, it will be apparent to those skilled in the relevant arts that numerous modifications S" and variations may be made without departing from the basic inventive concepts. For example, although the ducts 66 of the air pressure equaliser 26 as shown as having a square cross-section, they can of course be formed to have any cross-sectional shape, for example circular, triangular, hexagonal, etc. Also, individual ducts can be formed of a cross-sectional zrea which varies along the length of the duct. Similarly, the cross-sectional area of different ducts can also be made to be different. Furthermore, the 9 duct 24 can be formed of any shape including a straight cylinder. Alternatively, the duct 24 can be dispensed with altogether and the fan 22 connected directly to the air pressure equaliser 26. All such modifications and variations are considered 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.

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Claims

2. An air grain cleaner according to claim i, wherein each of said ducts are of constant cross-sectional t area.
3. An air grain cleaner according to claim 1 or 2, wherein the cross-sectional area of each duct is substantially the same.
4. An air grain cleaner according to any one of claims 1 to 3, further comprising a first grain deflecting means for deflecting said grain mixture so as to fall in a P Ir direction toward said second inlet. LI 13 i- i~li -i i -li- l~-ii iiiiii~l-- i 11 An air grain cleaner according claim 4, wherein said first grain deflecting means cormprises a plate disposed in a first 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.
6. An air grain cleaner according to any one of claims 1 to 5, further comprising air deflecting means for deflecting said air stream to flow in a direction substantially opposite to that in which said mixture falls.
7. An air grain cleaner according to claim 6, wherein said air deflecting means comprises at least ore plate disposed in a second inclined plane and located adjacent said second inlet.
8. An air grain cleaner according to claim 7, wherein said first and second inclined planes are substantially parallel.
9. An air grain cleaner according to any one of claims 1 to 8, further comprising a second air deflecting means located between said first and second, inlets for preventing said air stream from flowing directly into said first inlet, said second air deflecting means being provided with a closed external surface which is shaped so as to substantially prevent the collection of any component of said grain mixture.
10. An air grain cleaner substantially as herein described with reference to and as illustrated in the Saccompanying drawings. Dated this 10th day of March 1995. GREG RYAN By His Patent Attorneys: GRIFFITH HACK CO. Fellows Institute of Patent Attorneys of Australia. i, 3 i.I 0 d 1Bm F- iW I ABSTRACT The specification discloses an air grain cleaner comprising a chamber in the form of an air box 12 within which grain can be separated from a grain mixture and thereby cleaned. An inlet 14 is provided in a wall 16 in an upper part of the air box 12 for introducing the grain mixture into the air box. A second inlet 18 is formed in a side wall 20 of the air box 12 for admitting an air stream into the air chamber. A fan 22 for producing the air stream communicates with the inlet 18 via a U-shaped duct
24. An air pressure equaliser 26 for reducing the pressure gradient of the air stream across the inlet 18 is located in the duct 24 between the fan 22 and inlet 18. The air box 12 is provided with an internal hopper 28 for feeding a supply of grain mixture to the inlet 14. A grain deflecting plate 30 is fixed within the air chamber adjacent and extending for the length of the inlet 14. Plate 30 is also inclined in a plane toward the air inlet. A plurality of air deflecting plates 32 extending horizontally across the air inlet 18 inside the air box 12. Air entering the air box 12 from the inlet 18 is vented through a screen 34. When the air stream contacts the falling grain mixture, it pushes the grain and other components of the grain mixture different distances in the 25 downstream direction due to their different weight and/or size so as to separate the individual components of the grain mixture. i U.IB