AU627943B2 - Grain analyser - Google Patents

Description

627943 COMMONWEALTH OF AUSTRALIA Patents Act 1952 Name of Applicant(s): Address of Applicant(s): Actual Inventor(s): Address for Service: 0 r. 4 4 0 Of 4 444 SCREEN MANAGEMENT CONSULTANTS PTY.

LTD.

88 BRICKYARD ROAD, GEEBUNG, QUEENSLAND, 4034, AUSTRALIA GREGORY ELDRIDGE G.R. CULLEN COMPANY, Patent Trade Mark Attorneys, 79 Eagle Street, Brisbane, Qld. 4000, Australia.

4400 aoo G 0 I r i 4444 4040~ COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED:

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-l GRAIN ANALYSER The following statement is a full description of the invention including the best.method of.performing it known to us: r_ i -I I 2 THIS INVENTION relates to apparatus for analysing harvested grain samples in order to determine the quality and quantity of the whole grain therein. The apparatus can also be used for the bulk separation of millable grain from harvested grain.

Previously, analysis of harvested grain was performed manually with the use of a sizer comprising a circular sieve having 2mm long slots. A predetermined quantity of grain was placed on the sieve and shaken thirtytwo times in the direction of the slots. The dockages and undersized grain were thereby separated out leaving the millable grain which was then weighed to determine the percentage of whole grain in the sample.

a4 Such manual analysis was subject to a number of deficiencies. The main deficiencies were the errors due to the differing amounts of shaking by different persons, oOt.O resulting in differing separations; and the tendency for the So screen to "blind out" after fifteen or so shakes. (Blinding out is where the slots become blocked by grain).

In order to overcome the deficiencies of such 0 0 manual analysis, a semi-automatic analysing apparatus having a cylindrically driven sc',-en was proposed and is the subject of Australian Patent No. 569598. Analysis was performed by feeding a known sample of grain into one end of the cylindrical sc-een while rotating it at a constant predetermined speed in a horizontal plane. The grain sample L t- n*rpas~ was carried along the cylindrical screen by means of a scroll formed integrally with its internal surface, and whole grain issued at the outlet end while the dockages passed through the screen openings to be collected beneath the screen.

Such an apparatus was, however, found in practice to give results not much better than the old manual analysis.

There were several reasons for this. main reasons were firstly that the screen was made from pressed sheet metal having lengthwise openings orientated at right-angles to the direction of grain movement through the cylindrical screen.

Because of this design and since grain does not roll end-on, S accurate separation of undersized fractions did not occur.

Secondly, the scroll formed on the iin'de nf the cylindrical screen resulted in particle turbulence with no optimal screen surface velocity. The efficiency of separation was therefore grossly impaired. Thirdly, the combination of screen design and scroll gave rise to "pegging" clogging) of the 0 screen with consequent impaired accuracy in the analysis and the need to continually dismantle the apparatus for cleaning.

Similar problems are found in apparatus used for the large scale separation of millable grain from harvested grain since such apparatus is basically just a scaled up version of the analyser.

It is therefore an object of the present invention to provide an automatic grain analyser and bulk grain separator which obviate or at least minimise the L aforementioned disadvantages of the existing analysers and separators.

Accordingly, the present invention provides a grain separator comprising a cylindrical screen mounted for rotation about its longitudinal axis in a substantially horizontal plane, and a plurality of fixed slotted discs arranged in parallel alignment within the cylindrical screen, said cylindrical. screen having its cylindrical wall formed from a plurality of lengthwise extending strands of roll or wedge wire; the construction and arrangement being such that .o upon introduction of a grain and dockage mixture into the *4 '4a cylindrical screen through one end wall thereof during rotation of the screen, the mixture is moved along towards an outlet at the other end of the screen and during such carriage the undersized grain and dockages pass through the cylindrical screen wall and the whole grain passes right o along the cylindrical screen and through the outlet.

S.Preferably, the grain separator also includes one bo or more anti-pegging rollers located along an outer longitudinal section of the cylindrical screen. Such a roller or rollers may suitably include a multiplicity of sprockets which are adapted to fit within the sieve openings for the purpose of dislodging any grain, dockages or detritis which happens to become wedged therein.

The roller may take the form of a single cylinder which extends the entire length of the cylindrical screen, or i may comprise a plurality of smaller cylinders optionally supported on a common axle. The roller or rollers may be freely idling, in which case they are driven by the cylindrical screen, or may be rotated on a common axle through a separate drive means. Preferably, the roller or rollers are freely supported within an open sided trough arranged along a side of the cylindrical screen and are kept in place under their own weight.

The rollers are suitably fabricated from plastics material such as polyurethane.

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The cylindrical screen is preferably formed from Sroll wire or wedge wire strands which are welded onto circular metal bands which define the size and shape of the d cylinder. Alternatively, the cylindrical screen may be formed by rolling a flat sheet of roll or wedge wire mesh into a cylinder and welding it together along adjacent edges.

i A typical size cylindrical screen for use in i analysing grain is one which is manually transportable and i can be located on a bench top for ease of operation.

However, large scale separation of bulk grain is also envisaged and to this end the apparatus will generally be free standing and may include a cylindrical screen up to II several meters in length and of commensurate diameter.

The spacings between the adjacent strands of roll or wedge wire are dimensioned to permit undersized grain and dockages to pass through but to be too small to allow useful r_ 6 whole grain to pass through. Suitable spacings are approximately 2mm.

When wedge wire profiled strands are used in the construction of the screen, they are most usefully arranged with the taper pointing outwardly away from the interior of the cylinder. Such an arrangement will minimise the likelihood of any blinding of the screen and will facilitate cleaning thereof.

The preferred material for use in the fabrication of the cylindrical screen is stainless steel because of its durability and strength, however high density plastics 0 40 material, galvanized iron, or like rigid self-supporting workable material could equally well be used.

i The slotted discs may take the form of substantially flat circular plates with aligned slots, however for the facilitation of construction and location K 0 within the cylindrical screen, they are preferably in the form of slotted annuli which extend around, and are supported by, an inner tube which is located concentrically within the cylindrical screen. Each annulus is connected to an adjacent annulus by means of a deflector plate adjacent to the slots of both annuli. The function of the deflector plates is to transfer the grain from the region bounded by two discs to the adjacent region bounded by one of these discs and another disc, and so on from one end of the cylindrical screen to the other.

r_ Iil~-U- -pll IIII ~ICI~ The inner tube on which the slotted discs are supported will generally have an end wall at the inlet end with a suitably dimensioned opening to permit the grain and dockage mixture to be fed into the interior of the inner tube. An opening in the inner tube permits the mixture to pass into the first annular region bounded by the end of the inner tube and the first annular disc. Ideally, the slotted disc arrangement is dimensioned so as to be a snug fit within the cylindrical screen, and to therefore rotate with the screen. The number of slotted discs will be determined by S the desired rotational speed of the cylindrical screen to 4 0 achieve maximum separation of the particular type of grain to S be separated and/or analysed, as the case may be, in minimal S time. For instance, for wheat grain analysis per se, a particularly suitable revolution has been found to be in the order of 12 rpm. For maximum separation in a convenient time frame, it has been found that twelve discs is particularly suitable for such a purpose.

4 a 0 6Preferably, the slotted discs and inner tube are 4004 constructed from stainless steel but high density plastics material such as polyurethane and other materials such as galvanized iron can be used.

The cylindrical screen may be supported in a frame which preferably includes an inlet chute for directing the grain and dockage mixture through the inlet opening in the end wall of the screen; an electric motor with suitable 1 pulley or like drive linkages for rotating the cylindrical screen; an outlet chute for directing the useful whole grain to a suitable collector; and, an optional dockage and undersized grain collecting tray beneath the cylindrical screen.

Such a grain separator/analyser overcomes all the shortcomings of the prior art grain analyser previously mentioned. Because the slots in the cylindrical sieve point in the direction of movement of grain through the sieve, accurate separation with minimal pegging occurs. Any pegging °0 which may arise can be overcome by the use of the antipegging ii h roller or rollers. Additionally, the use of discs to 44 transfer the grain and dockage mixture through the cylindrical screen, overcomes the problem of particle turbulence and gives optimal screen surface velocity for the mixture. The efficiency of separation is therefore 4 maximized.

,4 Preferred embodiments of the invention will now be described with reference to the accompanying drawings, in 1 4 which:- Fig. 1 is a perspective end on view of a bench top separator according to the present invention with the internal discs removed for clarity; Fig. 2 is a top plan view of the support framework for the separator depicted in Fig. 1; Fig. 3 is a side-on view of the cylindrical sieve r_ c i depicted in Fig. 1; Fig. 4 is a side-on perspective of a slotted disc arrangement for use in the separator of Fig. 1; Fig. 5 is an end-on sectional view of the cylindrical screen and slotted disc arrangement depicted in Figs. 3 and 4; and Fig. 6 is a top-sectional view of the arrangement depicted in Fig. Referring to Fig. 1, the apparatus depicted comprises a cylindrical screen 10 supported for horizontal rotation upon a frame 11 adapted for location on a bench top.

The cylindrical screen is supported upon free rolling wheels journalled to the sides of the frame, as can be seen in Fig. 2, and is rotated by a drive belt 12 which extends around the circumference of the screen. The drive b-it is connected by way of a drive wheel 13 and appropriate linkages oto the drive shaft of an electric motor 14. The capacity of the motor and the gearing is selected to rotate the cylindrical screen at the rate which gives maximum separation in a minimum time frame.

The support frame depicted in Fig. 2 also includes an inlet chute 20 for the grain mixture to be introduced into 4 I one end of the cylindrical screen, an outlet chute 21 for directing the useful whole grain out of the cylindrical screen; and a waste collector chute 22 directly beneath the screen for directing the dockages and undersized grain to a

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collecting container placed beneath the screen.

Upstanding walls 23, 24 are provided on each side of the lower section of the cylindrical screen support apparatus to assist in the channeling of the waste material to the waste collector chute 22 and also to provide a trough shaped support 25 for a plurality of anti-pegging rollers 26.

These anti-pegging rollers have sprockets 27 which are dimensioned to fit between the openings 28 in the cylindrical screen. The rollers comprise solid polyurethane mouldings of length compatible with the distance between adjacent bands 29 a of the cylindrical screen.

S The detail of the cylindrical screen can be most clearly seen in Fig. 3. The screen is fabricated from a mriltiplicity of stainless steel roll wire strands 30 welded to stainless steel bands 29 which extend on the exterior surface of the screen. The inlet end of the cylindrical screen (see Fig. 1) has an end wall 32 with an axial opening 33 through which the inlet chute 20 of the support frame extends. There is no wall on the outlet end of the screen.

Slotted discs 40 are snugly fitted to the inside of the cylindrical screen 10 and these are depicted in detail in Figs. 4,5 and 6. The slotted discs are arranged in parallel °O alignment so as to extend from one end of the screen to the other. They are supported by an inner tube 41 and are in the form of annuli. Each disc 40 has a cut out section 45 at which section a deflector plate 42 is. located for the purpose of deflecting the grain mixture from one region 43 to an adjacent region 44 of the screen upon rotation of the screen and discs. In this manner the grain mixture is transferred toward the outlet end.

In operation, a raw grain mixture is fed through the inlet chute 20 and drops into the first region 43 between the end wall of the cylindrical screen and the first slotted disc. Rotation of the cylindrical screen at a predetermined constant speed carries the grain mixture into the adjacent region 44 by virtue of contact with deflector plate (see arrows in Fig. 6).

As rotation continues, undersized grain and dockages in the outermost region of the screen, pass through the openings 28 in the screen and fall beneath the screen for collection by way of the waste collecto: chute 22. Continued rotation brings more dockages and undersized grain to the oO outermost region of the screen for separation as it passes S along the screen. By the time the grain has reached the cutlet chute 21, it comprises only whole grain of the desired 20 size.

oo4o o Any grain or dockages which happen to be caught in the openings 28 during rotation of the cylindrical screen, S" are dislodged inwardly when an anti-pegging roller comes into contact therewith. The sprockets on the anti-pegging rollers are designed so as to neatly fit between the openings 28 as the cylindrical screen rotates and by virtue of the rotation OIL- 12 of the cylindrical sieve, they rotate in a counter direction to the sieve. The anti-pegging rollers rotate under their own weight by contact with the rotating cylindrical screen.

The grain separator/analyser may be operated in a batch-wise or continuous manner and may be scaled up in size for the handling of bulk grain.

Whilst the above has been given by way of illustrative example of the invention, many modifications and variations may be made thereto by persons skilled in the art without departing from the broad scope and ambit of the S invention as herein set forth in the following claims.

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Claims (8)

1. A grain separator comprising a cylindrical screen mounted for rotation about its longitudinal axis in a substantially horizontal plane, and a plurality of fixed slotted discs arranged in parallel alignment within the cylindrical screen, said cylindrical srreen having its i cylindrical wall formed from a plurality of lengthwise extending strands of roll or wedge wire; the construction and arrangement being such that upon introduction of a grain and dockage mixture into the cylindrical screen through one end Swall thereof during rotation of the screen, the mixture is moved along towards an outlet at the other end of the screen and during such carriage the undersized grain and dockages I pass through the cylindrical screen wall and the whole grain j passes right along the cylindrical screen and througl the i outlet. o

2. A grain separator as claimed in claim 1 and including a plurality of anti-pegging rollers located along an outer longitudinal section of the cylindrical screen. PIQOj

3. A grain separator as claimed in claim 2, wherein P44404 4 4 the rollers are supported for free rotation within an open sided trcough arranged to one side of the cylindrical screen.

4. A grain separator as claimed in any one of claims 1-3, wherein the roll or wedge wire bands are welded onto circular metal bands which define the size and shape of the cylindrical screen.

OIL-- 0 I i 14 A grain separator as claimed in any one of the preceding claims in which the cylindrical screen is manufactured from wedge wire and the taper on the wedge decreases in the direction away from the interior of the screen.

6. A grain separator as claimed in any one of the preceding claims, wherein the discs are in the form of slotted annuli which extend around, and are supported by, an inner tube which is located concentrically within the cylindrical screen, and each annulus is connected to an adjacent annulus by means of a deflector plate adjacent to the slots of both annuli.

7. A grain separator as claimed in any one of the preceding claims and including an inlet chute for directing a grain and dockage mixture through the inlet opening in the end wall of the screen.

8. A grain separator substantially as herein described with reference to the accompanying drawings. DATED this 24th day of October 1990 SCREEN MANAGEMENT CONSULTANTS PTY. LTD. By their Patent Attorneys CULLEN CO. 0 00 Lr0 0 0 0n 0 0* 0 0 01 -1 A