Flume, and Method, For Supplying Vegetable Pieces

Abstract

A flume for supplying vegetable pieces in a supply of liquid, the flume extending between a flume inlet and a flume outlet, the flume comprising: a gulley section having an upstream inlet end at the flume inlet and a downstream outlet end, the gulley section having opposed sidewalls and a gulley floor therebetween, and a spreader section having opposed first and second lateral walls and a spreader floor therebetween, the spreader section having an upstream end connected to the downstream outlet end of the gulley section, the spreader section progressively increasing in width between the opposed first and second lateral walls in a downstream direction from the upstream end to a downstream end of the spreader section, wherein the opposed first and second lateral walls are each outwardly inclined away from a longitudinal axis of the spreader section by a respective angle α° for the first lateral wall and β° for the second lateral wall, in respective opposite directions, which extends from the upstream end of the spreader section to the downstream end of the spreader section, wherein the gulley section has a width of the gulley floor at the downstream outlet end of W1, the length of the spreader section between the upstream and downstream ends of the spreader section is N, and the dimensionless ratio N/W1 is within the range of from 2 to 15, and wherein the sum of α° and β° is from 10 to 25°.

Claims

1. A flume for supplying vegetable pieces in a supply of liquid, the flume extending between a flume inlet and a flume outlet, the flume comprising: a gulley section having an upstream inlet end at the flume inlet and a downstream outlet end, the gulley section having opposed sidewalls and a gulley floor therebetween, and a spreader section having opposed first and second lateral walls and a spreader floor therebetween, the spreader section having an upstream end connected to the downstream outlet end of the gulley section, the spreader section progressively increasing in width between the opposed first and second lateral walls in a downstream direction from the upstream end to a downstream end of the spreader section, wherein the opposed first and second lateral walls are each outwardly inclined away from a central longitudinal axis of the flume by a respective angle α° for the first lateral wall and β° for the second lateral wall, in respective opposite directions, which extends from the upstream end of the spreader section to the downstream end of the spreader section, wherein, at the downstream outlet end, the gulley section has a width of the gulley floor (W1), the spreader section between the upstream and downstream ends of the spreader section has a length (N), and a dimensionless ratio N/W1 is within a range of 2 to 15, and wherein a sum of α° and β° is from 10 to 25°.

2. The flume according to claim 1, wherein angle α° and β° are equal and the spreader section is symmetrical on opposite sides of the longitudinal axis.

3. (canceled)

4. (canceled)

5. The flume according to claim 1, wherein the opposed first and second lateral walls are linear and each first and second lateral wall diverges at a respective constant angle relative to the longitudinal axis.

6. The flume according to claim 1, wherein the opposed first and second lateral walls include a curved portion which connects to a respective sidewall of the gulley section, and the spreader section is trumpet-shaped in plan.

7. The flume according to claim 6, wherein (i) the respective opposed lateral walls each comprise an upstream continuously convexly curved transition section connected to a downstream linear section and the opposed lateral walls of the spreader section terminate in a linear-walled frustoconical end section; or (ii) the respective opposed lateral walls are each continuously convexly curved extending between the upstream and downstream ends of the spreader section; or (iii) the respective opposed lateral walls each have an inflected wall, and comprise an upstream continuously convexly curved transition section, an intermediate concavely curved intermediate section and a downstream section which is a convexly curved end section or a linear walled frustoconical end section.

8. The flume according to claim 1, wherein the downstream end of the spreader floor of the spreader section has a width (W2) which is a factor of from 2 to 8 greater than the width W1.

9. The flume according to claim 1, wherein the gulley section has a constant width of the gulley floor along the length thereof.

10. (canceled)

11. The flume according to claim 1, wherein the gulley section is downwardly inclined towards the spreader section at an angle to the horizontal of from 0.5 to 5 degrees.

12. The flume according to claim 1, wherein the spreader section is downwardly inclined towards the flume outlet at an angle to the horizontal of from 0.5 to 5 degrees.

13. (canceled)

14. The flume according to claim 1, wherein the spreader floor is free of any three-dimensional elements or three-dimensional surfaces extending upwardly therefrom.

15. (canceled)

16. The flume according to claim 1, wherein the opposed sidewalls of the gulley section and/or the opposed first and second lateral walls of the spreader section are inclined to the vertical, at an angle of up to 20°, in a direction upwardly and outwardly away from the longitudinal axis.

17. (canceled)

18. The flume according to claim 1, wherein the flume further comprises a discharge chute connected at an upstream end thereof to the downstream end of the spreader section, the discharge chute having opposed sidewalls and a discharge floor therebetween.

19. The flume according to claim 18, wherein the discharge chute is downwardly inclined at an angle to the horizontal which is greater than the angle to the horizontal of the spreader section, optionally wherein the discharge chute is downwardly inclined at an angle to the horizontal of from 2 to 10 degrees, or from 4 to 8 degrees, or about 5 degrees.

20. (canceled)

21. The flume according to claim 18, wherein the discharge floor is a planar surface and is free of any three-dimensional elements or three-dimensional surfaces extending upwardly therefrom.

22. A method of supplying vegetable pieces, the method comprising the steps of: (a) providing a flume according to claim 1; and (b) providing a supply of liquid containing the vegetable pieces into the gulley section of the flume thereby forming (i) a first flow of the vegetable pieces in the liquid from the upstream inlet end of the gulley section at the flume inlet to the downstream outlet end of the gulley section and thereafter (ii) a second flow, downstream of the first flow, of the vegetable pieces in the liquid from the downstream outlet end of the gulley section to the downstream end of the spreader section, wherein in the second flow, the vegetable pieces are spread across the width of the spreader section.

23. The method according to claim 22, wherein the vegetable pieces are potato slices for the manufacture of potato chips and the liquid is water.

24. The method according to claim 22, wherein in the gulley section the first flow has a velocity of from 0.6 to 1.4 meters/second, or from 0.6 to 1.0 meters/second.

25. The method according to claim 22, wherein at the downstream end of the spreader section the second flow has a velocity that is higher than the velocity of the first flow and is greater than 1.0 meters/second.

26. The method according to claim 22, wherein across a surface area of the spreader floor a minimum velocity of the second flow is at least 0.6 meters/second.

27. The method according to claim 22, wherein the vegetable pieces are supplied to a cooking apparatus, optionally a fryer, and wherein in step (a) the flume outlet is mounted to an input end of a conveyer for supplying the vegetable pieces to a cooking apparatus; and the method further comprises the steps of: (c) discharging the vegetable pieces in the liquid onto the conveyor from the flume outlet; and (d) conveying the vegetable pieces on the conveyor to the cooking apparatus, wherein the conveyor is permeable to liquid and the liquid is at least partially drained from the vegetable pieces on the conveyor.

28. (canceled)

Description

[0041] An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

[0042] FIGS. 1(a), 1(b) and 1(c) illustrate a modelled velocity distribution of some known flume designs;

[0043] FIG. 2 illustrates five different stall regimes for a known two-dimensional diffuser for gas flow;

[0044] FIG. 3 is a graph showing the known stall regimes for gas flow in a two-dimensional straight walled diffuser, as a function of the diffuser angle 2θ° and the non-dimensional length parameter N/W1;

[0045] FIG. 4 is a schematic plan view of a flume for supplying potato slices, prior to cooking, according to an embodiment of the present invention;

[0046] FIG. 5 is a schematic section on line A-A in FIG. 4;

[0047] FIG. 6 is a schematic section on line B-B in FIG. 4;

[0048] FIG. 7 is a graph showing the behaviour of a flume according to the present invention as a function of the flume angle (α+β°) and the non-dimensional length N/W1;

[0049] FIG. 8 is a graph showing the behaviour of a flume according to the present invention as a function of the flume angle (α+β°) and velocity of the carrier liquid in the gulley section;

[0050] FIG. 9 illustrates a modelled velocity distribution of a flume according to another embodiment of the present invention;

[0051] FIG. 10 illustrates the LCR potato slice distribution using the flume of FIG. 9;

[0052] FIG. 11 illustrates a modelled velocity distribution of a flume according to a further embodiment of the present invention; and

[0053] FIGS. 12a and 12b illustrate alternative trumpet-like designs for the spreader section of the flume according to further embodiments of the present invention.

[0054] An embodiment of an apparatus for supplying potato slices in water, prior to cooking of the potato slices by frying in oil to form potato chips, according to one aspect of the present invention is illustrated in FIGS. 4 to 6.

[0055] Referring to FIGS. 4 to 6, an apparatus, designated generally as 2, for separating supplying vegetable pieces in a supply of liquid, or example potato slices in a supply of water, comprises a flume 4. The potato slices typically have a thickness of 1 to 2.5 mm, more typically about 1.3 mm (51 thousandths of an inch). Potato slices for potato chip manufacture typically have a width varying from 40 to 120 mm, with a significant proportion being “medium size” slices within the 60 to 80 mm range.

[0056] The flume 4 extends between a flume inlet 6 and a flume outlet 8. Typically, the entire flume 4 has a length of from 10 to 15 metres. The flume comprises a gulley section 10 having an upstream inlet end 12 at the flume inlet 8 and a downstream outlet end 14. The gulley section 10 is typically linear, i.e. straight in plan view, but may alternatively have some curvature in plan view. The gulley section 10 is substantially U-shaped in cross-section and has opposed sidewalls 16, 18 and a gulley floor 20 therebetween. In the illustrated embodiment, the gulley section 10 has a constant width of the gulley floor 20 along the length thereof. Typically, the upstream inlet end 12 of the gulley section 10 has a width of the gulley floor 20 which is from 0.25 to 0.65 metres, for example from 0.4 to 0.55 metres.

[0057] In the illustrated embodiment, the gulley section 10 is downwardly inclined towards the downstream outlet end 14 at an angle to the horizontal of from 0.5 to 5 degrees, typically from 1 to 3 degrees, for example about 2 degrees.

[0058] In the illustrated embodiment, the opposed sidewalls 16, 18 of the gulley section 10 are inclined to the vertical at an angle of up to 20°, typically from 5 to 7°, in a direction upwardly and outwardly away from a central longitudinal axis L-L of the flume 4.

[0059] The flume 4 further comprises a spreader section 32 having opposed first and second lateral walls 34, 36 and a spreader floor 38 therebetween. The spreader section 32 has an upstream end 40 connected to the downstream outlet end 14 of the gulley section 10.

[0060] The spreader section 32 progressively increases in width between the opposed first and second lateral walls 34, 36 in a downstream direction from the upstream end 40 to a downstream end 42 of the spreader section 32. The opposed first and second lateral walls 34, 36 are each outwardly inclined away from the central longitudinal axis L-L of the flume 4 section by a respective angle α° for the first lateral wall 34 and β° for the second lateral wall 36, in respective opposite directions, the central longitudinal axis L-L extending from the upstream end 40 of the spreader section 32 to the downstream end 42 of the spreader section 32.

[0061] The opposed first and second lateral walls 34, 36 are linear. Each first and second lateral wall 34, 36 diverges at a respective constant angle, α° for the first lateral wall 34 and β° for the second lateral wall 36, relative to the central longitudinal axis L-L.

[0062] In the illustrated embodiment, the downstream end of the spreader floor 38 of the spreader section 32 has a width W2 which is a factor of from 2 to 8, or a factor of from 4 to 6, greater than the width W1 of the gulley floor 20 at the downstream outlet end 14 of the gulley section 10. Typically, the downstream end 42 of the spreader section 32 has a width of the spreader floor 38 which is from 1 to 2.5 metres.

[0063] In the illustrated embodiment, the spreader section 32 is downwardly inclined towards the flume outlet 8 at an angle to the horizontal of from 0.5 to 5 degrees, typically from 1 to 3 degrees, for example about 2 degrees.

[0064] In the illustrated embodiment, the spreader floor 38 is a planar surface, and is free of any three-dimensional elements or three-dimensional surfaces extending upwardly therefrom. Such a planar surface provides the advantage that slice build-up in the spreader section, which would cause both time and position based surging, is minimised, and typically avoided.

[0065] In the illustrated embodiment, the opposed first and second lateral walls 34, 36 of the spreader section 32 are inclined to the vertical at an angle of up to 20°, typically from 5 to 7°, in a direction upwardly and outwardly away from the central longitudinal axis L-L.

[0066] In accordance with the present invention, the gulley section 10 has a width of the gulley floor 20 at the downstream outlet end 14 of W 1, the length of the spreader section 32 between the upstream and downstream ends 40, 42 of the spreader section 32 is N, and the dimensionless ratio N/W1 is within the range of from 2 to 15, preferably within the range of from 6 to 13. Additionally, in accordance with the present invention the sum of α° and β° is from 10 to 25°, preferably from 14 to 24°, more preferably from 20 to 22°. Preferably, α° and β° are the same and the spreader section 32 is symmetrical on opposite sides of the central longitudinal axis L-L.

[0067] In the illustrated embodiment, the flume 4 further comprises a discharge chute 50 connected at an upstream end 52 thereof to the downstream end 42 of the spreader section 32. The discharge chute 50 has opposed sidewalls 54, 56 and a discharge floor 58 therebetween. The discharge chute 50 is typically downwardly inclined at an angle to the horizontal which is greater than the angle to the horizontal of the spreader section 32. For example, the discharge chute 50 may be downwardly inclined at an angle to the horizontal of from 2 to 10 degrees, optionally from 4 to 8 degrees, further optionally about 5 degrees. Typically, the discharge chute 50 has a constant width along the length thereof. Typically, the discharge floor 58 is a planar surface and is free of any three-dimensional elements or three-dimensional surfaces extending upwardly therefrom.

[0068] In the illustrated embodiment, the spreader section 32 supplies the spread vegetable pieces to the discharge chute 50 which then discharges the spread vegetable pieces onto a conveyor 60, which then conveys the vegetable pieces to a cooking apparatus 62 such as a fryer. Alternatively, the discharge chute 50 may discharge the spread vegetable pieces into a dip tank (not shown).

[0069] However, in alternative embodiments, the discharge chute 50 is omitted. The spreader section 32 may supply the spread vegetable pieces directly onto a conveyor 60, or into a dip tank, onto any other apparatus for further processing or treating the vegetable pieces.

[0070] An alternative embodiment of a flume according to the present invention having a spreader section with linear inclined opposed lateral walls is shown in FIG. 9.

[0071] In a further embodiment of a flume according to the present invention, as shown in FIG. 11 the flume has a “trumpet-like” design. In such a “trumpet-like” design instead of there being a sharp corner between the parallel sidewalls of the gulley section and the respective opposed lateral walls of the spreader section as shown in FIG. 4, downstream of the parallel sidewalls of the gulley section a curvature is provided to assist smoothing out of the flow from the gulley section to the spreader section. Accordingly, as shown in FIG. 11 the opposed first and second lateral walls 34, 36 include a curved portion 35, 37 which connects to a respective sidewall 16, 18 of the gulley section 10, and the spreader section 32 is trumpet-shaped in plan.

[0072] In the specific embodiment of FIG. 11, the “trumpet-like” design provides that the respective opposed lateral walls 34, 36 for the spreader section 32 may comprise an upstream smoothly and continuously convexly curved, with either a constant or varying radius of curvature, transition section 39, 41 connected to a downstream linear, i.e. straight, section 43, 45 and the opposed lateral walls 34, 36 of the spreader section 32 terminate in a linear-walled frustoconical end section 47.

[0073] Alternatively, as shown in FIG. 12a (which is not to scale for clarity of illustration) the respective opposed lateral walls 34, 36 for the spreader section 32 are smoothly and continuously convexly curved, with either a constant or varying radius of curvature in the “trumpet-like” design, extending between the upstream and downstream ends of the spreader section 32, which is connected to the gulley section 10.

[0074] In another embodiment of the “trumpet-like” design as shown in FIG. 12b (which is not to scale for clarity of illustration), the respective opposed lateral walls 34, 36 for the spreader section 32 have an inflected wall providing a “bell-like” shape, and may comprise an upstream smoothly and continuously convexly curved transition section 51, an intermediate concavely curved intermediate section 53 and a downstream convexly curved section 55. Each curved section may have either a constant or varying radius of curvature. The downstream section 55 may alternatively have linear, i.e. straight, walls and for a frustoconical end. The transition section 51 is connected to the gulley section 10.

[0075] In each embodiment of the “trumpet-like” design, the angles α° and β° on opposite sides of the longitudinal axis are defined between the longitudinal axis and a linear (i.e. straight) line extending from the upstream end of the spreader section 32 to the downstream end of the spreader section 32. The physical respective opposed lateral walls 34, 36 (in particular the base portion thereof) for the spreader section 32 of the “trumpet-like” design are substantially aligned with the linear lines defining the respective angles α° and β°, whereas for the linear walled design of FIGS. 4-6 and FIG. 9 the physical respective opposed lateral walls 34, 36 for the spreader section 32 are coincident with the linear lines defining the respective angles α° and β°.

[0076] In the “trumpet-like” design, the distance N is measured from the free downstream end of the spreader section 32 and the end of the linear walls 16, 18 defining the gulley section 10. The “trumpet-like” design provides a smoother transition between the gulley and spreader sections 10, 32, which can allow an increase in N, or an increase in the angles α° and β° for a given N, without compromising spreader performance in providing a uniform flow distribution of vegetable pieces across the width of the flume outlet.

[0077] The flume is employed in a method of supplying vegetable pieces in accordance with the present invention.

[0078] In the method, the flume as described above is provided.

[0079] A supply of liquid containing the vegetable pieces is fed into the gulley section 10 of the flume 4. In a preferred embodiment, the upstream inlet end 12 of the gulley section 10 is provided with the supply of liquid, e.g. water, containing a plurality of vegetable pieces, e.g. potato slices for the manufacture of potato chips, from the outlet of a potato slicer. Preferably, a constant flow of water containing potato slices enters the gulley section 10, and a corresponding constant flow of water containing potato slices exits the gulley section 10. The liquid flow velocity in the gulley section 10 preferably has a velocity of from 0.6 to 1.4 metres/second, for example from 0.6 to 1.0 metres/second.

[0080] A first flow F1 of the vegetable pieces in the liquid is formed, the first flow extending from the upstream inlet end 12 of the gulley section 10 at the flume inlet 6 to the downstream outlet end 14 of the gulley section 10.

[0081] Thereafter a second flow F2, downstream of the first flow F1, of the vegetable pieces in the liquid is formed, the second flow extending from the downstream outlet end 14 of the gulley section 10 to the downstream end 42 of the spreader section 32. In the second flow F2, the vegetable pieces are spread across the width of the spreader section 32.

[0082] At the downstream end 42 of the spreader section 32 the second flow F2 typically has a velocity that is higher than the velocity of the first flow F1 and is greater than 1.0 metres/second. The increase in velocity results from the downward inclination of the flume 4 and the spreader section 32.

[0083] Across a surface area of the spreader floor 38 a minimum velocity of the second flow F2 is at least 0.6 metres/second. Such a minimum velocity is higher than a typical stall velocity of vegetable slices in water, with the result that the flow of vegetable slices is spread substantially uniformly across the width of the spreader section 32 with a substantially uniform velocity profile of the second flow F2 across the width of the spreader section 32.

[0084] The discharge chute 50 exits onto the output conveyor 60, typically an endless belt conveyor, which is located below the discharge chute 50 and may be oriented along or at an angle to, even perpendicular to, the flow direction. The output conveyor 60 may be horizontal or inclined at a small angle, such as up to 10 degrees, to the horizontal. The output conveyor 60 typically has a translational velocity of from 0.1 to 0.8 m/s, optionally 0.2 to 0.5 m/s.

[0085] The output conveyor 60 is mounted above a water recovery tank 62. The output conveyor 60 is water permeable, for example comprising an endless belt composed of metal mesh, such as stainless steel mesh. The water can drain off the potato slices and then can drip through the mesh into the recovery tank 62 for subsequent re-use, optionally after clean-up such as filtering.

[0086] The vegetable pieces are supplied by the conveyor 60 to a cooking apparatus 64, optionally a fryer. Accordingly, the flume outlet 8 discharges the vegetable pieces in the liquid onto the conveyor 60. The conveyor 60 conveys the vegetable pieces to the cooking apparatus 64. The conveyor 60 is permeable to liquid and the liquid is at least partially drained from the vegetable pieces on the conveyor 60, so that minimum free water on the vegetable pieces is introduced into the cooking apparatus 64.

[0087] In a modified embodiment of the present invention, the flume may be incorporated into a multi-tier flume assembly. In such an assembly, an upper flume is disposed above a lower flume, and the upper and lower flumes each output onto a respective conveyor, for conveying the pieces to a cooking apparatus, which may be a common cooking apparatus or respective cooking apparatus, or into a common dip tank, or respective dip tanks. The upper and lower flumes may be fed by the output from a common slicer had, which output has been split to provide upper and lower flows, or may be fed by respective slicer heads.

[0088] Although the embodiment of the present invention is described with respect to potato slices, any shaped pieces of any vegetables may be spread by the apparatus and method of the invention; for example sweet potato pieces for forming sweet potato French fries. Furthermore, although the embodiment of the present invention is described with respect to spreading the vegetable pieces prior to cooking, the spread vegetable pieces may be otherwise treated; for example seasoned prior to packaging. Still further, although the vegetable pieces are flowed along the flume using water as a carrier medium, which water may contain additives such as antioxidants, preservatives, etc., any other liquid medium may be employed as the carrier medium; for example a medium comprising or consisting of cooking oil such as sunflower oil.

[0089] The various aspects of the present invention will now be described in greater detail with reference to the following non-limiting Examples.

Example 1

[0090] Various flume structures were modelled to represent the behaviour of the flume with regard to LCR solid product distribution across the width of the flume using a liquid carrier. The results are shown in FIG. 7 which is a graph showing the behaviour of a flume according to the present invention as a function of the flume angle (α+β°) and the non-dimensional length N/W1.

[0091] Based on the experimental modelling, it was found that if the flume angle (α+β°) is above 25°, this can result in jetting of the supply of solid products in the carrier liquid, with the undesirable result that a narrow jet of the solid products in the carrier liquid can be located along only a small proportion of the width of the flume. The LCR distribution is accordingly poor and unpredictable. The jet can spontaneously and randomly dynamically migrate across the width of the flume.

[0092] Furthermore, it was found that if the flume angle (α+β°) is below 10°, there is minimal spreading of the supply of solid products in the carrier liquid, with the undesirable result that the flume is excessively long, or the output width is excessively narrow, for incorporation into a commercial food production facility, in particular a potato chip fryer production line. Furthermore, with such a long flume the flow velocity is reduced along the length of the flume, and can fall below a minimum suspension velocity. This means that solid products in the carrier liquid can stall and build up a static body of products upstream of the flume outlet. Such a flume geometry also cannot be effectively retrofitted into any existing potato chip fryer production line.

[0093] It was further found that if the non-dimensional length N/W1 is above 15, then the spreading section of the flume is too long. As explained above, excessive length of the spreading section can cause stalling at low velocity and cannot readily be installed in a potato chip fryer production line. Furthermore, minimising the width of the gulley section can cause excessively high velocities, causing jetting, which is undesirable as explained above.

[0094] It was still further found that if the non-dimensional length N/W1 is below 2, then there is minimal spreading of the supply of solid products in the carrier liquid, which is undesirable as explained above.

[0095] The flume structures were also modelled to provide experimental data shown in FIG. 8 which is a graph showing the behaviour of a flume according to the present invention as a function of the flume angle (α+β°) and velocity of the carrier liquid in the gulley section.

[0096] As for FIG. 7, FIG. 8 shows that, based on the experimental modelling, it was found that if the flume angle (α+β°) is above 25°, this can result in jetting of the supply of solid products in the carrier liquid, and if the flume angle (α+β°) is below 10°, there is minimal spreading of the supply of solid products in the carrier liquid.

[0097] Furthermore, FIG. 8 shows that it was found that if the velocity of the carrier liquid in the gulley section is below 0.6 metres/second, then the solid products are not sufficiently suspended in the carrier liquid. It was also found that if the velocity of the carrier liquid in the gulley section is above 1.4 metres/second, this can result in jetting of the supply of solid products in the carrier liquid.

[0098] These experimental data, although based on modelling, show that in the flume the dimensionless ratio N/W1 should be within the range of from 2 to 15, and the sum of α° and β° should be from 10 to 25° to achieve the desired uniform LCR spreading of the products across the flume outlet, and that preferably in the gulley section the liquid carrier flow has a velocity of from 0.6 to 1.4 metres/second.

Example 2

[0099] A flume having the structure shown in FIG. 9 (which is not drawn to scale) was provided. This flume had a dimensionless ratio N/W1 of about 6.43, and the sum of α° and β° was 21°. The gulley section and the spreader section, i.e. fishtail ramp, were each downwardly inclined in the flow direction at an angle to the horizontal of 2 degrees.

[0100] It may be see that the LCR distribution modelled in FIG. 9 was substantially uniform.

[0101] When the physical flume was used to spread potato slices in a flow of water, with a water velocity in the gulley section of from 1 to 1.2 metres/second, the LCR slice distribution shown in FIG. 10 was achieved. The LCR slice distribution is expressed as % of slices per lane, the width of the output end of the flume having been notionally divided into nine consecutive lanes. This data was achieved by physically measuring slices in each respective lane over a statistically significant time period. This LCR slice distribution result is substantially uniform and is within a statistically acceptable range about a target slice distribution.

Example 3

[0102] A flume having the structure shown in FIG. 11 (which is not drawn to scale) was provided. This flume had a dimensionless ratio N/W1 of about 8.4, and the sum of α° and β° was 20°. The gulley section and the spreader section, i.e. fishtail ramp, were each downwardly inclined in the flow direction at an angle to the horizontal of 2 degrees. In this Example, rather than having linear inclined opposed lateral walls of the spreader section as shown in FIG. 9, the flume has a “trumpet-like” design, as described above. In the illustrated “trumpet-like” design instead of there being a sharp corner between the parallel sidewalls of the gulley section and the respective opposed lateral walls of the spreader section as shown in FIG. 9, the parallel sidewalls of the gulley section and the respective opposed lateral walls for the spreader section are connected by a smoothly curved intermediate section and the inclined opposed lateral walls of the spreader section are continuously and smoothly curved with a large radius of curvature and terminate in a linear-walled frustoconical end section. The angle between the linear line extending between the upstream and downstream ends of the spreader section and the longitudinal axis on opposite sides of the longitudinal axis defines a respective opposite equal angle α° and β°. The distance N is measured from the free downstream end of the linear-walled frustoconical end section and the end of the linear walls defining the gulley section.

[0103] It may be see that the LCR distribution modelled in FIG. 11 was substantially uniform.

[0104] Various other modifications to the illustrated embodiment will be apparent to those skilled in the art and are intended to be within the scope of the present invention as defined by the appended claims.