GB2570442A

GB2570442A - Washing and sorting vegetables

Info

Publication number: GB2570442A
Application number: GB1800301.2A
Authority: GB
Inventors: Paul Williams Keston
Original assignee: BARFOOTS OF BOTLEY Ltd
Current assignee: BARFOOTS OF BOTLEY Ltd
Priority date: 2018-01-09
Filing date: 2018-01-09
Publication date: 2019-07-31
Anticipated expiration: 2038-01-09
Also published as: GB201800301D0; GB2570442B

Abstract

A process line for washing and sorting harvested vegetables such as green beans B comprises in sequence a washing station for washing the vegetables, a drying station 32 for drying the vegetables, a sorting station 42 for removing small vegetables and vegetable pieces and passing sizeable vegetables, and an inspection station 51 downstream of the other stations for optically inspecting sizeable vegetables including means for removing individual vegetables not complying with inspection standards. The line may include an infeed elevator 2 at the washing station end, a blowing station 6 for blowing leaves from the vegetables, a manual inspection station (56, fig. 7) downstream of the inspection station, and a bagging and weighing station (see figure 8). The washing station may comprise first stage and second stage washing stations 13, 20. The drying station may comprise fans (33, fig. 5) and/or an air-knives (34, fig. 5) for blowing moisture from the vegetables. The sorting station 42 may comprise a vibrational sorter having gaps sized to allow small vegetables and pieces to fall through. The optical inspection station 51 may comprise cameras 53 for optically detecting defects and air nozzles 58, 59 for removing defective vegetables (see figure 7).

Description

WASHING AND SORTING VEGETABLES

The present invention relates to a process line for washing and sorting harvested vegetables, in particular, but not exclusively green beans.

It is known to sort for defects vegetables, including green beans, before their packaging. Generally this has been done on a labour intensive, manual processing line.

It is also known to harvest beans mechanically, in order to render harvesting less labour intensive. Mechanical harvesting introduces the need for further processing steps prior to packaging, in particular washing, since beans growing close to the ground can be dirty from soil splashed up by rain. Also, mechanical harvesting involves whole plant harvesting, introducing the need for sorting to remove undersized beans.

The object of the present invention is to provide an at least partially automated process line for washing and sorting vegetables, in particular but not only green beans.

According to the invention there is provided a process line for washing and sorting harvested vegetables, the line comprising in sequence:

• a washing station for washing harvested vegetables;

• a drying station for drying washed vegetables;

• a station for removing small vegetables and vegetable pieces and passing sizeable vegetables and • a station for optically inspecting sizeable vegetables including means for removing individual vegetables not complying with inspection standards.

Conveniently an elevator is provided for discharging the vegetables into the process line at an elevated position at a washing station end of the line.

Preferably the line includes a preliminary blowing station for blowing leaves from the harvested vegetables. In the preferred embodiment, the blowing station comprises a chute having means feeding for vegetables in at a top to fall down the chute and a suction device for sucking air up to separate leaves from the vegetables.

Preferably the washing station comprises a first stage washer having:

• an upwardly-open, conical vessel filled with water in use, • water paddles for moving the vegetables around and outwards in the vessel, • an upper, tangential discharge for the vegetables over a weir for regulating water depth in the vessel and • a lower, central discharge for extraneous material washed from the vegetables, conveniently with a discharge to a leaf exit from the blowing station.

Conveniently a chute is provided down which the vegetables are delivered from the conical separator.

Preferably the washing station comprises a second stage washer having:

• a conveyor for the vegetables, • means for vibrating the vegetables on the conveyor, · wash-jet nozzles for washing the vegetables on the conveyor and • an inclined vibratory grating for draining water from the grating.

Preferably, the grating is formed with elongate slits oriented in the direction of feed of the vegetables, the slits being narrow in comparison with their length.

Preferably the drying station comprises • at least one perforate conveyor and • fans for blowing or sucking vegetable-drying air through the conveyor.

In the preferred embodiment, for augmenting the effect of the fans in blowing moisture from the vegetables at least one air knife is provided.

Conveniently the small vegetable and vegetable piece removal station comprise a series of vibratory conveyor elements having gaps therebetween unable to be bridged by small vegetables which fall through the gaps.

Preferably, the conveyor elements have vegetable alignment grooves to align narrow vegetables with their direction of travel, whereby it is short vegetables that are sorted out.

Preferably the optical inspection station includes • a conveyor operable at a speed to separate individual vegetables for their individual inspection, • a processor programmed to recognise vegetable defects, • means for illuminating vegetables, • detectors for detecting illuminated vegetables and • removers for removing vegetables having optical defects.

Conveniently the removers are air nozzles having solenoid valves opened to release jets of compressed air in response to defect detection.

In the preferred embodiment, the inspection station is programmed to detect two types of defect and is provided with two sets of removers and two conveyors for the respectively different defect type removed vegetables.

Further in the preferred embodiment, a short manual inspection station is provided downstream of the optical inspection station.

The vegetables can be weighed out and packed, preferably in bags, downstream of the manual inspection station. However, there can be an incompatibility in the speed of operation of the washing and sorting line and our preferred weighing and bagger, which is a form fill weigher. In the preferred embodiment, the latter is provided separately with a buffer of crated vegetables in between it and the process line.

To help understanding of the invention, a specific embodiment thereof will now be described by way of example and with reference to the accompanying drawings, in which:

Figure 1 is a plan view of a green bean processing line in accordance with the 5 invention;

Figure 2 is a side view of a bean and leaf separator at the upstream end of the processing line of Figure 1;

Figure 3 is a side view of first and second bean washing stations of the processing line of Figure 1;

Figure 4 is a plan view of the first and second washing stations of Figure 3;

Figure 5 is a side view of a bean drying elevator of the processing line of Figure 1;

Figure 6 is a plan view of bean drying elevator and a small bean removal ramp of the processing line of Figure 1, with a scrap side view of a slot in the ramp;

Figure 7 is a side view of an optical inspection and defective bean removal station of the processing line of Figure 1; and

Figure 8 is a side view of an off-line bean weigher and bagger.

Referring first to Figures 1 & 2 of the drawings, the green bean processing line

1 thereshown has an infeed elevator 2 for beans B deposited onto it from crates 3, emptied into a hopper 4 at the lower end of the elevator. This lifts the beans to a horizontal vibratory feed 5, with flexible mounts 51 and a vibrator 52, which feeds them into a leaf separator 6. This has an upright, columnar chamber 7 down which the beans B fall.

A fan 8 blows air up the chamber, separating leaves L stripped of the bean plants with the beans from the beans B as such. The leaves are blown over an edge 9 and onto a conveyor 10 for removing them from the separator. The fan draws air from the top of the chamber over the edge, drawing the leaves with it, and past the 30 conveyor. The air is blown out of the fan and into the bottom of the chamber. The beans B as such are too heavy to be lifted by the airflow and fall out via a chute 11.

From the chute 11, the beans fall onto a second elevator 12, which feeds them into a first stage washer 13. This has an invert-conical body 14 with centrally mounted paddles 15, which together with directed nozzles 16, circulate water around in the body, in the manner of a cyclone separator. A tangential outlet 17 is provided for beans to leave the body 14.

The beans are deposited into the cyclone close to its centre. The paddles 15 are driven (by a non-shown drive) to cause the beans, which float, to move progressively outwards. They pass the nozzles 16 from which water is pumped and dirt on them is dislodged. Extraneous material such as stones in soil stuck to the beans falls from them as they circulate in the washer. The dirt is drawn out of the bottom of the washer tank by a conveyor 15. A weir 18 is provided at the end of the outlet. Water pumped to the nozzles causes and overflow over the weir. The beans are carried over the weir.

They drop onto a chute 19 provided for passing the beans on to a second washer 20. The chute has a grid 21 for collecting the water from the weir and passing it via a pump 22 back to the nozzles 16. The second washer 20 comprises a conveyor 23, which is vibrationally mounted, i.e. resiliently mounted and provided with a vibrator 24. Waterjet nozzles 25 are provided for spraying the beans as they move along the conveyor. They are transferred onto a vibrationally mounted grating 26. This has slits 27, which are 15mm long and 1,2mm wide, and is slightly inclined. The dimensions avoid hang up of the beans as they slide along the grating. The grating allows most of the sprayed on cleaning water to drain away.

From the grating, the beans fall onto a mesh elevator 31 provided in a drying tunnel 32. This has six fans 33 for drawing air through the beans to dry them. In addition, air knives 34 are provided, one between the fans. The air knives are concentrated, substantially planar air streams at higher velocity than air from the fans, provided for blowing water from the beans as opposed to evaporating it from them.

A further conveyor 41 takes the beans from the top of the drying tunnel to a vibrational sorter 42. This has a series of five grooved plates 43. The grooves 44 are of a cross-section to receive beans. They slope down for bean travel. At the upper ends of the plates, ridges 45 forming the grooves are provided with fins 46, which are higher at their downstream end, to align the beans with the grooves. The plates have transverse gaps 47 between them, sized to allow short and broken beans to fall through. Whole single beans and a small proportion joined together as pairs or more by their stems reach the end of the vibratory sorter. They are free of leaf picked by a harvester, clean and dry. They reach this state without human intervention, save loading onto the infeed elevator 2.

The next station is an optical scanner 51. It has a conveyor 52 running much faster than the speed at which the beans advance onto it from the sorter 42. The speed is not such as to carry the beans through the scanner one at a time, but is sufficient to enable them to be individually scanned, by cameras 53 coupled to a processor 54, usually with others alongside. A typical speed is lOm/s. This enables optical sorting and projection of good beans over a reject chute 55 onto an outfeed conveyor 56. The scanner has bright lights 57 for the cameras 53. The processor 54 is programmed to recognise certain types of defects in beans: in particular (1) disease and other blemishes and ¢2) connection of multiple beans still connected by their stalks.

Over the reject chute, two lines 58,59 of servo operated air-jet nozzles are provided under control of the processor 54. If a particular bean is detected to have a type (1) blemish defect, a jet of air is blown at it as it passes over a first half 551 of the reject chute. If beans are detected to have a type (2) still-connected-together defect a jet of air is blown at them as they pass over a second half 552 of the reject chute. Respective conveyors 571,572 are provided for disposal or further processing of the reject beans.

The outfeed conveyor 56 provides an opportunity for manual inspection of the beans prior to crating for off-line packaging.

The offline packaging station has an infeed conveyor 61, an elevator 62, a form fill weigher 63, a flow wrap bagger 64, a transfer conveyor 65, an individual bag weigher 66 with feed-back control to the weigher and a conveyor (not shown) from which the bags of beans are packed for despatch. To spread the beans between individual weighing receptacles, a steeper cone 67 is provided centrally of a main distribution cone 68.

1701 18

CLAIMS:

Claims

CLAIMS:

1. A process line for washing and sorting harvested vegetables, the line comprising in sequence:

• a washing station for washing harvested vegetables;

5 · a drying station for drying washed vegetables;

10

2. A process line as claimed in claim 1, including an elevator for discharging the vegetables into the process line at an elevated position at a washing station end of the line.

3. A process line as claimed in claim 1 or claim 2, including a preliminary blowing station for blowing leaves from the harvested vegetables.

15

4. A process line as claimed in claim 3, wherein the preliminary the blowing station includes a chute having means feeding for vegetables in at a top to fall down the chute and a suction device for sucking air up to separate leaves from the vegetables.

5. A process line as claimed in any preceding claim, wherein the washing station comprises a first stage washer having:

20 · an upwardly-open, conical separating vessel filled with water in use, • water paddles for moving the vegetables around and outwards in the vessel, • an upper, tangential discharge for the vegetables over a weir for regulating water depth in the vessel and • a lower, central discharge for extraneous material washed from the vegetables,

25 conveniently with a discharge to a leaf exit from the blowing station.

6. A process line as claimed in claim 5, including a chute down which the vegetables are delivered from the conical separator.

7. A process line as claimed in claim 5 or claim 6, wherein the washing station further comprises a second stage washer having:

30 · a conveyor for the vegetables, • means for vibrating the vegetables on the conveyor, • wash-jet nozzles for washing the vegetables on the conveyor and • an inclined vibratory grating for draining water from the grating.

1701 18

8. A process line as claimed in claim 7, wherein the grating is formed with elongate slits oriented in the direction of feed of the vegetables, the slits being narrow in comparison with their length.

9. A process line as claimed in any preceding claim, wherein the drying station

5 comprises:

• at least one perforate conveyor and • fans for blowing or sucking vegetable-drying air through the conveyor.

10. A process line as claimed in claim 9, including at least one air knife for augmenting the effect of the fans in blowing moisture from the vegetables.

10

11. A process line as claimed in any preceding claim, wherein the small vegetable and vegetable piece removal station comprise a series of vibratory conveyor elements having gaps therebetween unable to be bridged by small vegetables which fall through the gaps.

12. A process line as claimed in claim 11, wherein the conveyor elements have

15 vegetable alignment grooves to align narrow vegetables with their direction of travel, whereby it is short vegetables that are sorted out.

13. A process line as claimed in any preceding claim, wherein the optical inspection station includes:

• a conveyor operable at a speed to separate individual vegetables for their

20 individual inspection, • a processor programmed to recognise vegetable defects, • means for illuminating vegetables, • detectors for detecting illuminated vegetables and • removers for removing vegetables having optical defects.

25

14. A process line as claimed in claim 11, wherein the removers are air nozzles having solenoid valves opened to release jets of compressed air in response to defect detection.

15. A process line as claimed in claim 13 or claim 4, wherein, the inspection station is programmed to detect two types of defect and is provided with two sets of removers

30 and two conveyors for the respectively different defect type removed vegetables.

16. A process line as claimed in any preceding claim, including a short manual inspection station downstream of the optical inspection station.

17. A process line as claimed in any preceding claim, including a bagging and weighing station.

18. A process line as claimed in claim 17, wherein the weighing station includes a form fill weigher.

5

19. A process line as claimed in claim 17 or claim 18, including a buffer of crated vegetables upstream of the bagging and weighing station.

5 19. A process line as claimed in claim 17 or claim 18, including a buffer of crated vegetables upstream of the bagging and weighing station.

Amendments to the claims have been filed as follows • · • · ·· • · ->

♦ *· *

CLAIMS:

a washing station for washing harvested vegetables;

a drying station for drying washed vegetables;

a station for removing small vegetables and vegetable pieces and passing sizeable vegetables and a station for optically inspecting sizeable vegetables including means for removing individual vegetables not complying with inspection standards being downstream of the other stations.

an upwardly-open, conical separating vessel filled with water in use, water paddles for moving the vegetables around and outwards in the vessel, an upper, tangential discharge for the vegetables over a weir for regulating water depth in the vessel and a lower, central discharge for extraneous material washed from the vegetables, conveniently with a discharge to a leaf exit from the blowing station.

• a conveyor for the vegetables, • means for vibrating the vegetables on the conveyor, • wash-jet nozzles for washing the vegetables on the conveyor and • · · • · · « « · ······ • · ··· A • · • •«ft • v · · *·

4«·· • 4 *··» ♦ •♦••λ- • an inclined vibratory grating for draining water from the grating.

5

9. A process line as claimed in any preceding claim, wherein the drying station comprises:

10. A process line as claimed in claim 9, including at least one air knife for

10 augmenting the effect of the fans in blowing moisture from the vegetables.

15

12. A process line as claimed in claim 11, wherein the conveyor elements have vegetable alignment grooves to align narrow vegetables with their direction of travel, whereby it is short vegetables that are sorted out.

20 · a conveyor operable at a speed to separate individual vegetables for their individual inspection, • a processor programmed to recognise vegetable defects, • means for illuminating vegetables, • detectors for detecting illuminated vegetables and

25 · removers for removing vegetables having optical defects.

15. A process line as claimed in claim 13 or claim 4, wherein, the inspection station is 30 programmed to detect two types of defect and is provided with two sets of removers and two conveyors for the respectively different defect type removed vegetables.

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