GB2383964A

GB2383964A - Apparatus for separating components of differing density

Info

Publication number: GB2383964A
Application number: GB0125718A
Authority: GB
Inventors: David Ian Haith
Original assignee: Tickhill Engineering Co Ltd
Current assignee: Tickhill Engineering Co Ltd
Priority date: 2001-10-26
Filing date: 2001-10-26
Publication date: 2003-07-16
Also published as: GB0125718D0

Abstract

Apparatus for separating components of differing density (e.g. potatoes and stones), comprises a liquid containing separation chamber 12. A liquid inlet (18, figure 2) is situated near the base of the chamber such that liquid flows into the chamber, upward through the chamber and over the top of two weirs 20a, 20b at the top. Preferably a baffle (52, fig. 2) is situated close to the inlet to improve the flow characteristics of the liquid. Desired lighter weighted products flow over the weirs and into a single channel 22 which leads them to an apertured conveyor belt 28 which acts to de-water the product. The undesired product sinks to the bottom of the separating container and is removed via a second conveyor belt 40.

Description

Title: Apparatus for separating debris and produce Description of Invention The present invention relates to an apparatus for separating debris and produce, particularly, but not exclusively, for separating stones from root vegetables and the like.

When produce, such as potatoes or other root vegetable, are harvested using a harvesting machine, debris such as stones are picked up by the machine along with the produce. The stones may be manually separated from the potatoes, for example by a person picking stones out as the debris/produce mixture is passed by on a conveyor, and separation can be achieved whilst causing minimum damage to the produce. This process is, however, time consuming and costly.

It is therefore known to use an automatic destoning machines in which a mixture of produce and stones are placed in a tank of water, and a paddle rotating in the top of the tank maintains the produce at the top of the tank whilst the stones fall to the bottom. This type of machine has the disadvantage that the paddle can damage the produce.

Another type of automatic destoning machine is disclosed in UK patent GB1299723, in which water is pumped down a chute into a tank, and into the top of the tank adjacent to the chute. A mixture of produce and stones is placed on the chute and is washed down the chute into the tank by the water flowing down the chute. By virtue of the flow of water into the tank, the stones sink to the bottom of the tank, and the produce is washed out of the tank onto a perforated discharge chute. The capacity of this machine is limited, however, and therefore it is not efficient for separating large volumes of produce and stones.

An aim of the present invention is to provide a new and improved apparatus for separating debris and produce. Such an apparatus may separate the two quickly, be cost effective, and cause relatively little damage to the produce.

According to a first aspect of the invention we provide an apparatus for separating debris and produce comprising a container adapted for receiving a mixture of produce and debris, pumping means adapted to pump liquid into the container such that the liquid, on being pumped into the container, is caused to flow in a manner to create an upsurge which causes produce to collect in an upper portion of the liquid within the container and debris to collect in a lower portion of the liquid within the container.

Preferably the container further comprises an inlet aperture through which liquid is pumped into the container, the inlet aperture being located in a base portion of the container.

Preferably, the container comprises at least one weir over which produce and liquid may flow, and the apparatus comprises a produce collection means which is adapted to collect produce flowing from the container over the or each weir. In this case, the container may comprise two weirs, and the produce collection means may comprise a single channel portion adapted to collect produce and liquid flowing from the container over both weirs.

The produce collection means may further comprise a de-watering means whereby liquid, which passes with produce over the or each weir, is separated from the produce. Such a de-watering means may further comprise a conveyor with a belt onto which liquid and produce are directed after passing over the or each weir, the belt having a plurality of apertures, through which fluid, but not produce, may pass.

Preferably the apparatus further comprises a debris collection means adapted to collect debris from the lower portion of the liquid within the container and remove debris from the container. Such a debris collection

means may further comprise a conveyor which extends from the container such that debris collecting in the lower portion the liquid within the container may fall onto the conveyor and be transported out of the container, the debris collection conveyor being inclined at an angle to the horizontal such that debris falling onto the conveyor is transported vertically upwardly and horizontally away from the container.

Preferably the container is provided with a baffle means which deflects flow of liquid being pumped into the container, and assists in creating the upsurge of liquid within the container. The baffle means may be generally cuboidal. Alternatively, the baffle means may be generally conical.

Preferably the baffle means is located generally vertically above the inlet aperture.

The apparatus may be adapted to separate root vegetables, such as potatoes, from debris such as stones or rocks.

According to a second aspect of the invention we provide a method of separating produce from debris the method comprising placing a mixture of produce and debris in a container, pumping liquid into the container in such a manner as to produce an upsurge of liquid within the container, collecting produce from an upper portion of the liquid within the container, and collecting debris from a lower portion of the liquid within the container.

The invention will now be described with reference to the accompanying drawings in which, FIGURE I shows a perspective view of a debris/produce separation apparatus according to the invention, and FIGURE 2 shows a section through the apparatus for separating debris and produce of Figure 1.

Referring now to the drawings, there is shown an apparatus 10 for separating debris and produce which is typically used for separating stones from root vegetables such as potatoes and the like. The apparatus 10 comprises

a container 12, and pumping means 14 whereby a liquid 16, typically water, may be pumped into the container 12.

The container 12 is open-topped, has four walls 13a, 13b, 13c, 13d, a top portion 12a, and a base portion 12b, the top portion 12a having a greater cross- sectional area than the base portion 12b, and an intermediate portion 12c which tapers between the top portion 12a and the base portion 12b. In this example the four walls 13a, 13b, 13c, 13d form a generally square-shaped cross-section, but the container 12 need not have this configuration. The four walls 13a, 13b, 13c, 13d may be arranged to form a cross-section in the shape of any other four-sided polygon, for example, one of the walls 13a may have a smaller area than its opposite wall 13c, and therefore the cross-section of the container 12 may taper toward the smaller wall 13a. Alternatively, the container 12 may have fewer or more than four walls 13a, 13b, 13c, 13d or may have one or more curvilinear sides. For example, the container 12 maybe conical.

An inlet aperture 18 is provided in the base portion 12b of the container 12, and the pumping means 14 is connected to the inlet aperture 18 such that liquid may be pumped into the container 12 via the inlet aperture 18.

The walls 13a, 13b, 13c, 13d of the container 12 have a top edge, and the top edge of one of the container walls 13a includes two portions which are substantially lower than the remaining portions of the wall 13a. Thus the container is provided with two weirs 20a and 20b over which liquid and produce from the container may flow. It is not necessary to provide two weirs, it is possible to provide only one weir, for example by providing one wall 13a with a top edge that is lower along its entire length than the top edges of the remaining walls 13b, 13c, 13d, but is has been found that such an apparatus does not work as well with high volumes of produce and debris mixture as the embodiment herein described. If desired more than two weirs may be provided.

The container 12 further includes two barrier means 60, each of which comprises an elongate metal sheet arranged with a longitudinal axis generally

parallel to the surface of the liquid within the container 12, a bottom portion of the barrier means 60 being positioned below the liquid surface, and a top portion above the liquid surface. The two barrier means 60 each extend from a portion of the walls 13b and 13d adjacent to the weirs 20a and 20b respectively to the wall 13c opposite the weirs 20a, 20b.

Extending from the container 12 is a produce discharge chute 22, which has two side walls 24a, 24b and a base 26 which form a channel-shaped crosssection. In this example first end 22a of the chute 22 is connected to the wall 13a of the container 12 at or adjacent to the two weirs 20a, 20b, although it will be appreciated that the first end 22a of the chute 22 may be connected to the wall 13a of the container 12 below the two weirs 20a, 20b. The chute 22 tapers towards a second end 22b, and is inclined at an angle to the horizontal, such that the first end 22a is higher than the second end 22b. Thus produce and liquid flowing over either of the two weirs 20a, 20b flows onto the produce discharge chute 22 at the first end 22a and down the chute to the second end 22b.

The second end 22b of the produce discharge chute 22 is located generally vertically above a produce discharge conveyor 28 which is adapted receive produce from the chute 22 and transport is away from the apparatus 10, for example for loading into a sack 58 or other container. In this case, the produce discharge conveyor 28 is arranged such that, in use, it moves the produce in a direction generally normal to the direction of liquid and produce flow in the produce discharge chute 22.

The produce discharge conveyor 28 is provided with a plate 39 which is attached, by means of bolts in this example, to a side of the conveyor 28 opposite the second end 22b of the produce discharge chute 22. The plate 39 is arranged generally vertically with a longitudinal axis parallel to the direction of travel of the conveyor, and thus prevents any produce being washed down the

produce discharge chute 22 from overshooting and missing the produce discharge conveyor 28.

The produce discharge conveyor 28 has a belt 30 which, in this example, comprises an array of spaced apart, generally parallel rods 30a, the rods 30a extending across the width of the conveyor each having a longitudinal axis arranged generally normal to the direction of travel of the belt 30.

By virtue of the array of rods 30a, the conveyor belt 30 acts as a de- watering means. The rods 30a are spaced such that when liquid and produce fall from the produce discharge chute 22 onto the conveyor belt 30, the produce is retained on the belt 30, but the liquid passes through the spaces between the rods 30a, and into a used liquid receptacle 34. The used liquid receptacle 34, may simply direct used liquid into a conventional drainage system, but in this case the receptacle 34 is connected to the pumping means 14 by means of a pipe 36, such that the used liquid may be pumped from the used liquid receptacle 34 and into the container 12 to be re-used.

A debris removal conveyor 40 extends from the base portion 12b of the container 12, a first end 40a of the debris removal conveyor being located adjacent to a lowermost wall 41 of the base portion 12b of the container 12, through a debris removal aperture 42 provided in the base portion 12b of the container 12 and away from the container 12. The conveyor 40 extends at an angle of around 45 to the horizontal such that a second end 40b is located vertically above the top portion 12a of the container 12.

In order to prevent the liquid held in the container 12 from flowing out of the container 12 through the debris removal aperture 42, a conveyor casing 48 is provided which extends from the wall 13b surrounding the aperture 42 and encase the conveyor 40. The conveyor casing 48 does not encase the second end 40b of the conveyor 40, but terminates at a position on the conveyor which is vertically above the surface level of the liquid 16 in the container 12.

Thus the casing 48 retains the liquid within the container 12.

The debris removal conveyor 40 includes a belt 44 which is provided with an array of spaced, mutually parallel, elongate, debris collection members 46, each of which is orientated with a longitudinal axis generally normal to the direction of travel of the conveyor 40. The debris collection members 46 act as barriers to assist in ensuring debris 50 falling onto the first end 40a of the conveyor 40 is transported to the second end 40b without rolling back towards the first end 40a. Furthermore, the lowermost wall 41 of the base portion 12b of the container 12 is curved such that when the debris removal conveyor is in operation, the each debris collection members 46 scrapes along the lowermost wall 41 and collects debris which has fallen onto the lowermost portion of the base portion 12b of the container 12.

A baffle means 52 is suspended in the intermediate portion 12c of the container 12 vertically above the first end 40a of the debris collection conveyor 40, and adjacent to the base portion 12b of the container 12, from a first elongate support element 54. The first elongate support element 54 is arranged generally vertically in the container 12 and is in turn supported by a second elongate support element 56 which extends generally horizontally from the top edge of one container wall 13b to the top edge of the opposite container wall 13d.

The baffle means 52 in this example is generally cuboidal, and is connected to the first support element 54 at one comer of the cube 52. The baffle means 52 need not, however, be cuboidal. It may, in an alternative embodiment, be formed in the shape of a cone or a pyramid, or any other appropriate shape.

The first support element 54 is telescopic, and its length may be adjusted by loosening an adjustment screw means 54a, so that the baffle means may be positioned at an optimum location in relation to the inlet aperture 18 to achieve maximum separation performance. When the first support element 54 is set at

the desired length the adjustment screw means 54a is tightened, to maintain the length of the first support element 54 at the desired length.

There is provided a generally horizontal loading conveyor 32 which has a first end 32a and a second end 32b, the second end 32b being located generally vertically above the container 12. Produce and the associated debris is, in use, loaded onto the first end 32a of the loading conveyor 32 and transported to the second end 32b of the conveyor from where it falls into the liquid filled container 12. In this example, a second loading conveyor 38 is provided in order to transport produce and associated debris from a loading position close to the ground onto the loading conveyor 32.

The debris/produce separating apparatus 10 may be operated as follows.

A mixture of debris and produce, for example, a mixture of stones and potatoes as is typically obtained when harvesting potatoes using a mechanical potato harvester, is loaded onto the second loading conveyor which is operated to transport the mixture onto the first end 32a of the first loading conveyor 32.

The first loading conveyor 32 is operated to transport the produce and debris mixture from the first end 32a of the conveyor 32 to the second end 32b, from where it falls into the container 12.

Liquid, typically water, is continually pumped by the pumping means 14 into the container 12 via the inlet aperture 18, such that the liquid level reaches the weirs 20a, 20b and liquid flows down the produce discharge chute 22. On being pumped into the container 12 through the inlet aperture 18, liquid flows around the baffle means 52 into the intermediate portion 12c of container 12, and the baffle means 52 assists in creating an upsurge of liquid within the container 12 throughout substantially all of the liquid within the container 12.

On falling into the container 12, the relatively buoyant produce is urged by the upsurge of liquid towards an upper portion of the liquid in the container from where it may pass over either of the weirs 20a, 20b and onto the produce discharge chute 22. The barrier means 60 prevent produce from accumulating

along the side walls 13c, 13d of the container, where the produce could be retained rather than passing over the weirs 20a, 20b. The debris is denser than the produce and the upsurge of liquid is not sufficient to overcome the gravitational forces acting on the debris, and the debris sinks to a lower portion of the liquid in the container 12.

The produce is washed over the weirs 20a, 20b and down the produce discharge chute 22 with overflow liquid, and falls onto the produce discharge conveyor 28. The overflow liquid drains through the apertures between the rods 30a of the conveyor belt 30 and into the used liquid receptacle 34. The produce discharge conveyor 28 may be operated to transport the produce into a receptacle such as a sack 58.

The debris collection conveyor 40 is operated to catch the sinking debris using the collection members 46, and to transport the debris to the second end 40b of the conveyor 40. A further receptacle may be provided vertically below the second end 40b of the conveyor to collect debris falling from the conveyor 40.

The invention thus provided for quick and inexpensive separation of debris and produce, whilst causing minimal damage to the produce.

In the present specification"comprises"means"includes or consists of" and"comprising"means"including or consisting of.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. An apparatus for separating debris and produce comprising a container adapted for receiving a mixture of produce and debris, pumping means adapted to pump liquid into the container such that the liquid, on being pumped into the container, is caused to flow in a manner to create an upsurge which causes produce to collect in an upper portion of the liquid within the container and debris to collect in a lower portion of the liquid within the container.

2. An apparatus as claimed in claim 1, wherein the container further comprises an inlet aperture through which liquid is pumped into the container, the inlet aperture being located in a base portion of the container.

3. An apparatus as claimed in claim 1 or 2, wherein the container comprises at least one weir over which produce and liquid may flow, and the apparatus comprises a produce collection means to collect produce flowing from the container over the or each weir.

4. An apparatus as claimed in claim 3, wherein the container comprises two weirs, and the produce collection means comprises a single channel portion adapted to collect produce and liquid flowing from the container over both weirs.

5. An apparatus as claimed in claim 3 or 4, wherein the produce collection means comprises a de-watering means whereby liquid, which passes with produce over the or each weir, is separated from the produce.

6. An apparatus as claimed in claim 5, wherein the de-watering means comprises a conveyor with a belt onto which liquid and produce are directed

after passing over the or each weir, the belt having a plurality of apertures through which fluid but not produce may pass.

7. An apparatus as claimed in any one of the preceding claims, comprising a debris collection means adapted to collect debris from the lower portion of the liquid within the container and remove debris from the container.

8. An apparatus as claimed in claim 7, wherein the debris collection means comprises a conveyor which extends from the container such that debris collecting in the lower portion of the liquid within the container may fall onto the conveyor and be transported out of the container.

9. An apparatus as claimed in claim 8, wherein the debris collection conveyor is inclined at an angle to the horizontal such that debris falling onto the conveyor is transported vertically upwardly and horizontally away from the container.

10. An apparatus as claimed in any one of the preceding claims, wherein the container is provided with a baffle means which deflects flow of liquid being pumped into the container, and assists in creating the upsurge of liquid within the container.

11. An apparatus as claimed in claim 10, wherein the baffle means is generally cuboidal.

12. An apparatus as claimed in claim 10, wherein the baffle means is generally conical.

13. An apparatus as claimed in any one of claims 10,11 or 12 where dependant on claim 2, wherein the baffle means is located generally vertically above the inlet aperture.

14. An apparatus as claimed in any one of the preceding claims, wherein the produce comprises root vegetables and the debris comprises stones or rocks.

15. An apparatus for separating debris and produce substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

16. A method of separating produce from debris the method comprising placing a mixture of produce and debris in a container, pumping liquid into the container in such a manner as to produce an upsurge of liquid within the container, collecting produce from an upper portion of the liquid within the container, and collecting debris from a lower portion of the liquid within the container.

17. A method of separating produce from debris substantially as hereinbefore described with reference to the accompanying drawings.

18. Any novel feature or novel combination of features as hereinbefore described with reference to and/or as shown in the accompanying drawings.