CLIAMS:
1. Device (1) for sparse feeding of bulk materials such as cereal grains, in particular rice, to a processing and/or analysing machine (2) comprising in flow direction of the bulk material
- means (3) for branching a partial flow (P) of bulk material off a main flow (M) of bulk material and
- means for conveying (4) the branched-off partial flow (P) to the processing and/or analysing machine (2),
characterized in that the means for branching off (3) and the means for conveying (4) are arranged such that a heap of branched-off bulk material is formable at the transition between the means for branching off (3) and the means for conveying (4).

2. Device according to claim 1, characterized in that the means for branching off (3) and the means for conveying (4) are arranged such that the flow direction of the partial flow (P) is changeable at the transition between the means for branching off (3) and the means for conveying (4) in order to facilitate the natural flow of materials for unbiased sampling.

3. Device according to claim 1 or 2, characterized in that the means for branching off (3) and the means for conveying (4) are arranged such that a gap is formed at the transition between the means for branching off (3) and the means for conveying (4).

4. Device according to one of the preceding claims, characterized in that the means for branching off (3) comprise a baffle.

5. Device according to claim 4, characterized in that the baffle (3) is essentially u-shaped in a direction substantially perpendicular to the flow direction of the partial flow (P).

6. Device according to one of the claims 4 or 5, characterized in that the position of the baffle (3), in particular a deflection angle, is adjustable.

7. Device according to one of the preceding claims, characterized in that the means for conveying (4) comprise a deflector plate.

8. Device according to claim 7, characterized in that the deflector plate (4) is a chute which allows spreading of single bulk material particles over the width of the chute, thus achieving the desired single layer distribution with non-touching particles.

9. Device according to claim 7 or 8, characterized in that the position of the deflector plate (4), in particular a deflection angle, is adjustable.

10. Device according to one of the claims 7 to 9, characterized in that a width of the gap between the means for branching off (3) and the deflector plate (4) is adjustable.

11. Device according to one of the preceding claims, characterized in that it further comprise a hinged mixing plate (5) for deflecting the main flow (M) towards the means for branching off (3).

12. Method for sparse feeding of bulk materials such as cereal grains, in particular rice, to a processing and/or analysing machine (2), preferably with a device (1) according to one of the preceding claims, comprising the step of
- branching-off a partial flow (P) of bulk material from a main flow (M) of bulk material to achieve a single layer distribution with non-touching particles,
and further
- conveying the partial flow to the processing and/or analysing machine (2),
characterized in that the partial flow is heaped between the step of branching-off and the step of conveying.

13. Method according to claim 12, characterized in that the flow direction of the partial flow (P) is changed between the step of branching-off and the step of conveying.

14. Method according to one of the claims 12 or 13, characterized in that, the partial flow (P) is re-added to the main flow (M) after having been processed in the processing and/or analysing machine (2).

15. Method according to one of the claims 12 to 14, characterized in that after the step of branching off, the partial flow (P) is conveyed only by means of gravity to the processing and/or analysing machine (2) for unbiased sampling.
,TagSPECI:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
(See section 10, rule 13)

“Device and Method for sparse feeding of bulk materials to a processing and/or analysing machine”

By
Buhler (India) Pvt. Ltd.,
13-D, KIADB Industrial Area,Attibele – 562107
Bangalore District, India

The following specification particularly describes the invention and the manner in which it is to be performed.

The invention relates to a device and a method for sparse feeding of bulk materials such as cereals grains, in particular rice, to a processing and/or analysing machine according to the preamble of the independent claims.

According to the prior art bulk material is branched off continuously or as a bulk from a main flow of bulk material and further processed. In particular when the branched-off partial flow has to be conveyed to an optical analysing machine, e.g. for determining the amount of broken grains, it is important that the partial flow or at least the grains flowing through the analysing machine are in a single layer and distributed such that a minimum amount of the grains and preferably no grains are contacting each other.

Known devices and methods use a vibrating tray feeder for obtaining the desired single layer and grain distribution. A vibrating tray feeder is however expansive, energy consuming and mechanically complicated. In addition it is more adequate for high capacity processes.

It is therefore aim of the present invention to provide a device and a method as cited above which solve the problems of the prior art and in particular can provide a reliable and cost saving solution which is appropriate also for low throughput processes, while still offering the capacity of unbiased sampling.

The problem is solved with a device according to the independent claim.

The device for sparse feeding of bulk materials such as cereal grains, in particular rice, to a processing and/or analysing machine comprises in flow direction of the bulk material means for branching a partial flow of bulk material off a main flow of bulk material and means for conveying the branched-off partial flow to the processing and/or analysing machine.

The bulk material is normally conveyed in a main conduit, from which the means for branching off divert. Preferably, the means for branching off are constructed such as between 1% and 4% of the main flow is diverted, i.e. with a main flow between 3,75 tons per hour (t/h) and 10 t/h a partial flow between 100 kg/h and 150 kg/h of bulk material is diverted.

According to the invention the means for branching off and the means for conveying are arranged such that a heap of branched off bulk material is formable at the transition between the means for branching off and the means for conveying. Single particles of the bulk materials, e.g. single grains and grain fragments, are then released from the heap of bulk materials formed at the transition between the means for branching off and the means for conveying, thus creating a sparse flow of bulk material with a single layer, which then flows to the processing and/or analysing machine arranged downstream of the means for conveying. Preferably, the flow of the partial flow of bulk material is achieved only by means of gravity.

Preferably, the means for branching off and the means for conveying are arranged such that the flow direction of the partial flow is changeable at the transition between the means for branching off and the means for conveying.

By “flow direction” of the partial flow or main flow respectively it is meant within the meaning of the present invention the average direction of the bulk material along the means for branching off and the means for conveying respectively in the case of the partial flow and the average direction in a main conduit in the case of the main flow. Of course, the direction of single bulk material particles can differ from the flow direction of the partial flow or main flow, e.g. single particles bouncing after colliding with each other.

A change in flow direction is a simple constructive way for creating a heap of bulk material at the transition between the means for branching off and the means for conveying.

The means for branching off and the means for conveying are preferably arranged such that a gap is formed at the transition between the means for branching off and the means for conveying.

A gap arrangement is particularly preferable when the flow direction of the partial flow is changeable. In this case the gap constitutes a transition region between the means for branching off and the means for conveying where a heap can be formed without directly obstructing the partial flow on the means for branching off.
Preferably the means for branching off comprise a baffle.

A baffle represents an easy and simple constructive solution for branching off the bulk material of the main flow flowing i.e. through a main conduit.

More preferably, the baffle is essentially u-shaped in a direction substantially perpendicular to the flow direction of the partial flow.

Such a u-shaped baffle is a reliable way for branching off the partial flow from the main flow. In particular, the u-shaped baffle has a flat sliding surface with protruding side walls. The width of the sliding surface is preferably between 20mm and 30mm. As an alternative, a baffle with a radius of curvature between 10mm and 15mm can be used. Preferably, the baffle is made of steel or stainless steel, in particular with a surface roughness resulting in a friction coefficient between the baffle and the bulk material between 0, 18 and 0, 22. It is clear from the above that the u-profile does not necessarily have to be with a constant radius. It can therefore have a changing radius, i.e. having a sliding surface with a big radius of curvature and curved side walls with a smaller radius of curvature. Furthermore, other materials with the same characteristics cited above may be used for the baffle.

Preferably, the position of the baffle, in particular a deflection angle, is adjustable. Positioning the baffle is convenient depending on different factors, such as the bulk material being conveyed, the flow rate of the bulk material, the particle dimension(s) of the bulk material etc. The preferred angle range for the baffle is less than 40 degrees with respect to the flow direction of the main flow. It is clear that the baffle may be equipped with means for changing the position of the baffle during operation, in particular combined with sensors for an open-loop or closed loop control system.

The means for conveying preferably comprise a deflector plate.

A deflector plate is an easy and simple constructive solution for distributing single bulk material particles released from the heap.

The deflector plate is preferably a chute.

A chute with a flat profile allows spreading of single bulk material particles over the width of the chute, thus achieving the desired single layer distribution with non-touching particles.

Preferably, the position of the deflector plate, in particular a deflection angle, is adjustable.

As for the baffle, positioning the deflector plate is convenient depending on different factors, such as the bulk material being conveyed, the flow rate of the bulk material, the particle dimension(s) of the bulk material etc. The preferred angle range for the deflector plate is less than 40 degrees with respect to the flow direction of the main flow. As for the baffle, the deflector plate is preferably made of steel or stainless steel, in particular with a surface roughness resulting in a friction coefficient between the deflector plate and the bulk material between 0, 18 and 0, 22. Other materials with the same characteristics cited above may be also used for the deflector plate.

It is clear that the deflector plate may be equipped with means for changing the position of the deflector plate during operation, in particular combined with sensors for an open-loop or closed-loop control system.

Preferably, a width of the gap between the means for branching off and the deflector plate is adjustable.

The distance between the means for branching off and the means for conveying is an important factor for the creation of the heap and therefore for the sparse feeding of the processing and/or analysing machine. Preferably, the gap width is between 4 and 13mm, more preferably between 6mm and 11mm, measured perpendicular to the surface of the means for conveying. In particular, the gap width is slightly larger than the size of a single particle of the bulk material, e.g. a grain of rice, allowing only single particles through the gap and thus increasing the heap formation at the transition between means for branching off and means for conveying.

It should be noted that in the case where a gap is present, the formation of the heap also reduces the hitting of the bulk material particles against the means for conveying, thus reducing wear of the latter.

Preferably the device further comprises a hinged mixing plate for deflecting the main flow towards the means for branching off.

The hinged mixing plate is in particular arranged inside a main conduit for the bulk material and can be positioned such that a desired amount of the main flow is deflected and thus branched off as a partial flow for further processing and/or analysing.

The hitting of the mixing plate also causes thoroughly mixing of the bulk material. Further, the position of the mixing plate can be adapted to different factors such as a flow rate or type of the bulk material, the shape and arrangement of the means for branching off and the means for conveying.

The invention further relates to a method for sparse feeding of bulk materials such as cereal grains, in particular rice, to a processing and/or analysing machine.

The method according to the present invention is preferably performed with a device as described above. Advantages cited with regard to the above cited device also apply to the method according to the present invention.

The method according to the present invention comprises the step of branching-off a partial flow of bulk material from a main flow of bulk material and further conveying the partial flow to the processing and/or analysing machine.
The problem is solved in the method according to the present invention in that the partial flow is heaped between the step of branching-off and the step of conveying.
Preferably, the flow direction of the partial flow is changed between the step of branching-off and the step of conveying.

Preferably, the partial flow is re-added to the main flow after having been processes in the processing and/or analysing machine.

This is particularly preferred when the machine is an analysing machine and the bulk material should be further processed.

Preferably, after the step of branching off, the partial flow is conveyed only by means of gravity to the processing and/or analysing machine.

With such a method step and a proper arrangement of the device parts, a easy and cheap construction without the need for moving pieces such as conveyors, vibrators, etc. can be achieved.

The invention will be now described by means of a preferred embodiment of the invention and by means of the figures. It is shown in:

Fig. 1 A schematical arrangement of a preferred embodiment of the present invention.
Fig. 2 a cross section of the channel of figure 1.

Figure 1 shows schematically a preferred arrangement of the device 1. Bulk material is flowing in a main conduit 6 and is schematically represented by the arrow M, which also depicts the flow direction of the main flow M. The flow rate of the bulk material is the main flow M is approximately 10 t/h.

In the main conduit 6 there is arranged, in flow direction of the bulk material, a first mixing plate 7 and a second mixing plate 5. Bulk material flowing through the main conduit 6 is therefore thoroughly mixed when hitting the first and the second mixing plates 7 and 5 respectively.

In the main conduit there is provided an opening 8, out of which a u-shaped channel 3 branches off. Bulk material flowing through the main conduit 6 is deflected by the mixing plate 5, which is hinged and can therefore be adjusted such that a given amount of approximately 150 kg/h of bulk material is branched off the main flow M, and directed toward the channel 3.

The cross section of the channel 3 in a plane perpendicular to the partial flow P is shown schematically in figure 2. The channel 3 has flat sliding surface 10 with perpendicular side walls 11 and is made of steel. A width X of the channel 3 is 25mm.

A partial flow P of the bulk material then flows due to gravity towards a chute 4 in a directed depicted by the arrow P. An angle a between the channel 3 and the main conduit 6 measured as an angle between the main flow M and the partial flow P is 300.

The channel 3 and the chute 4 are arranged such that a gap is provided between and such that the flow direction of the partial flow P is changed. A gap width G measured perpendicular to the chute 4 is chosen depending on the size of the particles of the bulk material and is slightly larger than the mean size of a single particle, in this case 8 mm.

An angle ß between the chute 4 and the main conduit 6 measured as an angle between the main flow M and the (changed) partial flow P (depicted as P’ in figure 1) is 300.

The bulk material hits the chute 4, whereby a heap of bulk material is formed. Depending on different factors such as the inclination of the channel 3 and/or the chute 4, the material and thus the friction between the bulk material and the channel 3 and/or the chute 4, the bulk material characteristics itself etc. singe particles of bulk material of the heap are released and spread over the width of the chute 4.

The single particles then flow by means of gravity through an optical device 2, in this case a CCD-camera, where different characteristics of the bulk material such as size, volume, colour, etc. may be determined, and then further through an opening 9 provided in the wall of the main conduit 6, where the partial flow P is re-added to the main flow of bulk material for further processing. The optical device 2 has a measurement window with a square size of 125mm X 125mm. A bulk material path length X’ between the heap and the beginning of the measurement window in flow direction P’, measured between an intersection point of a virtual extension of the channel 3 and the chute4 and the beginning of the measurement window, is approximately 10 cm.

Claims

1. Device (1) for sparse feeding of bulk materials such as cereal grains, in particular rice, to a processing and/or analysing machine (2) comprising in flow direction of the bulk material
- means (3) for branching a partial flow (P) of bulk material off a main flow (M) of bulk material and
- means for conveying (4) the branched-off partial flow (P) to the processing and/or analysing machine (2),
characterized in that the means for branching off (3) and the means for conveying (4) are arranged such that a heap of branched-off bulk material is formable at the transition between the means for branching off (3) and the means for conveying (4).

2. Device according to claim 1, characterized in that the means for branching off (3) and the means for conveying (4) are arranged such that the flow direction of the partial flow (P) is changeable at the transition between the means for branching off (3) and the means for conveying (4) in order to facilitate the natural flow of materials for unbiased sampling.

3. Device according to claim 1 or 2, characterized in that the means for branching off (3) and the means for conveying (4) are arranged such that a gap is formed at the transition between the means for branching off (3) and the means for conveying (4).

4. Device according to one of the preceding claims, characterized in that the means for branching off (3) comprise a baffle.

5. Device according to claim 4, characterized in that the baffle (3) is essentially u-shaped in a direction substantially perpendicular to the flow direction of the partial flow (P).

6. Device according to one of the claims 4 or 5, characterized in that the position of the baffle (3), in particular a deflection angle, is adjustable.

7. Device according to one of the preceding claims, characterized in that the means for conveying (4) comprise a deflector plate.

8. Device according to claim 7, characterized in that the deflector plate (4) is a chute which allows spreading of single bulk material particles over the width of the chute, thus achieving the desired single layer distribution with non-touching particles.

9. Device according to claim 7 or 8, characterized in that the position of the deflector plate (4), in particular a deflection angle, is adjustable.

10. Device according to one of the claims 7 to 9, characterized in that a width of the gap between the means for branching off (3) and the deflector plate (4) is adjustable.

11. Device according to one of the preceding claims, characterized in that it further comprise a hinged mixing plate (5) for deflecting the main flow (M) towards the means for branching off (3).

12. Method for sparse feeding of bulk materials such as cereal grains, in particular rice, to a processing and/or analysing machine (2), preferably with a device (1) according to one of the preceding claims, comprising the step of
- branching-off a partial flow (P) of bulk material from a main flow (M) of bulk material to achieve a single layer distribution with non-touching particles,
and further
- conveying the partial flow to the processing and/or analysing machine (2),
characterized in that the partial flow is heaped between the step of branching-off and the step of conveying.

13. Method according to claim 12, characterized in that the flow direction of the partial flow (P) is changed between the step of branching-off and the step of conveying.

14. Method according to one of the claims 12 or 13, characterized in that, the partial flow (P) is re-added to the main flow (M) after having been processed in the processing and/or analysing machine (2).

15. Method according to one of the claims 12 to 14, characterized in that after the step of branching off, the partial flow (P) is conveyed only by means of gravity to the processing and/or analysing machine (2) for unbiased sampling.

Abstract
Device (1) and method for sparse feeding of bulk materials such as cereal grains, in particular rice to a processing and/or analysing machine (2) comprising in flow direction of the bulk material means (3) for branching a partial flow (P) of bulk material off a main flow (M) of bulk material and means for conveying (4) the branched-off partial flow (P) to the processing and/or analysing machine (2), whereby the means for branching off (3) and the means for conveying (4) are arranged such that a heap of branched-off bulk material is formable at the transition between the means for branching off (3) and the means for conveying (4).
Figure 1