GB2095102A - Improved vegetable washing apparatus - Google Patents

Abstract

Apparatus for separating tangled vegetables comprising a water reservoir (12) across which the vegetables are floated, a tray or screen (60) to prevent the vegetables from sinking and an air bubble generator at the bottom of the reservoir from which large bubbles of air are to frequently issue. The latter are produced by filling pivoting cups (46) with air from below and allowing the cups to suddenly pivot and release the accumulated air as a large bubble. The cups are freely rotatable and shaped so that the collecting air causes a turning movement due to the flotation effect which causes the cup to tilt upwardly to release the air. <IMAGE>

Description

SPECIFICATION Improved vegetable washing apparatus Field of Invention This invention concerns vegetable handling apparatus and in particular a preliminary washing stage in which tangled lumps of vegetables are dispersed to allow vegetable to be individually withdrawn for future processing.

Background to the Invention It is known to handle harvested damage-prone bulky leafy vegetable crops such as leeks and celery after harvesting in bushel boxes which allows for easy access to units when tipped onto a conveyor for subsequent washing and handling. When such vegetables are loaded into larger containers or bulk carts they remain in a large mass even when conveyed off into water reception which avoids damage. To handle and wash the crop they have to be separated into a single layer. It is an object of the present invention to provide apparatus for separating large lumps of tangled vegetables so as to present the vegetables in a more convenient manner for subsequent washing and handling.

It is an object of the present invention to provide an improved device for separating tangled vegetables which causes little or no damage to the crop. This assists in the washing process and in the removing of stones and earth from the harvested crop and presents them in a single layer unloading converyor.

The Invention According to the present invention means for separating lumps of tangled vegetables comprises a reservoir of water into which the vegetables are introduced at one end and removed from the other in which screen means is provided at a position intermediately top and bottom of the reservoir to prevent vegetables from sinking to the bottom to allow fluid to pass in an upward direction therethrough and second means is provided for introducing air into the reservoir to form large bubbles or air which rise through the screen to disturb the water, thus agitating the tangled vegetables floating in the upper regions of the reservoir.

It has been found by experiment that this form of agitation assists in the breaking up of clumps of vegetables and causes little or no damage to the crop.

The air may be introduced by means of air jets and nozzles supplied with air continuously or intermittently. However, this approach is only successful if a very large volume of air is available and the nozzles are of large cross-sectional area.

According to a preferred aspect of the invention the nozzles are of much reduced size and the air is supplied continuously into the reservoir through the nozzles and above each nozzle is located a temporary air reservoir in which a pocket of air is collected and released in the form of a large bubble. Each reservoir may comprise a container having a closed top and an open base which is located over each nozzle and is rotated at intervals so that the air can escape from the upper end as a large bubble to produce the turbulence and agitation required.

The mechanism for causing the intermediate reservoirs to tilt or rotate may be a drive means acting through a shaft to which the intermediate air reservoirs are attached.

Alternatively and preferably, each reservoir is in the form of a cup eccentrically mounted for pivoting movement about a generally horizontal axis having a position of equilibrium in which the open end of the cap faces downwards, the arrangement being such that the air bubble which collects within the cup when it occupies its position of stable equilibrium eventually produces sufficient lift to cause the cup to rotate and tilt until the air trapped therein can be released through the open end of the cup.

Such an arrangement needs no motive power since the departure of air from the cup is matched with an inrush of water so that the previous lift caused by the presence of air pockets is lost and the cup reverts to its normal position of equilibrium ready to receive further air issuing from the nozzle over which it is located so as to form a further air bubble therein and allow the process to repeat.

Conveniently the said first means comprises a wire mesh or apertured tray or other form of screen through which water and air can pass in one direction, but in which the apertures are too small for vegetables, but are sufficiently large to allow stones and the like to drop therethrough.

The invention will now be described by way of example with reference to the accompanying drawings in which: Fig. 1 is a side view and cross section of a celery washing installation embodying the invention, Fig. 2 is a plan view of the reservoir section of the installation which contains the invention, Fig. 3 is an end view of the installation in the direction of the arrow III in Fig. 1, Fig. 4 is a side view of one of the pivoting cups or buckets for creating the air bubbles and Fig. 5 is an end view of the bucket in the direction of arrow V in Fig. 4.

Detailed Description of Drawings Referring to Fig. 1, a harvested crop is tipped in the direction of the arrow 10 into a receiving tank 12 which is filled with water up to a level 14. The general movement of water within the tank is in the direction of the arrow 16 at least in the surface region of the water and a take-off conveyor generally designated 1 8 picks up vegetables which tend to float near the surface of the water and removes these in the direction of the arrow 20 onto a transversely extending discharge conveyor 22 for removing the washed vegetables in known manner.

Mounted in a framework 24 above the take-off conveyor 1 8 are one or more spray bars of a water deluging unit for directing water in a cascade in the direction of arrow 26 onto the crop as it moves up the conveyor 1 8. No detail of the water deluge is given since such devices are well known to those skilled in the art and any convenient crop washer may be used.

The invention is directed to the breaking up of the clumps of tangled vegetables which are found to occur in any crop which has been harvested and then carted in a bulk carrying vehicle or trailer.

The act of tipping the vegetables into the water reservoir will obviously break up some of the clumps but in general large clumps are still found to remain particularly in the case of celery.

In accordance with the present invention these clumps are broken up by intermittently causing large bubbles of air to be released in the lower regions of the reservoir, the rising bubbles serving to break up the tangled mass of vegetables in the upper regions of the reservoir.

To this end a plurality of buckets are mounted about pivoting axles in the lower region of the reservoir. One full bucket is shown in Fig. 4 and 5 of the drawings. Each bucket includes an open end 28 and a curved opposite end 30 with two parallel plane sides 32 and 34 through which extends a tubular bearing 36. The latter is freely rotatable on a shaft (not shown). A common shaft is provided for a line of such buckets.

The position of the tubular bearing 36 within each bucket is selected so that if air collects in the upper closed end of the bucket so as to form an air pocket such as 38 (see Fig. 4) the turning moment about the axis of pivoting is such as to cause the bucket to rotate anticlockwise as viewed in Fig. 4 thus causing the open end 28 to be raised. If the air bubble is allowed to carry on increasing in size, the turning moment becomes greater and greater as the bucket rotates and finally the bubble of air within the bucket can escape around the edge 40 and can move in a generally upward direction towards the surface of the reservoir where the disturbance caused by the exploding bubble of air is found to be sufficient to break up clumped and tangled vegetables.

In order to control the time taken for each bucket to fill with air and tilt, weights can be bolted or otherwise secured onto the front face 42 by using a mounting bracket such as 44. By increasing the weights, so a great quantity of air must be trapped under the bucket before it will displace and release the air pocket. The larger the bubble, the greater the disturbance effect in the surface of the reservoirs On the other hand, it will take longer for the bucket to fill and therefore there will be fewer such bubbles released.

Ideally no two buckets rotate and release air simultaneously so that there is always a regular but randomly occurring release of air bubbles so as to cause a good disturbance in the reservoir.

Referring to Figs. 1 and 2, it will be seen that two lines of such pivoting kits are provided designated by reference numerals 46 and 48 respectively.

The two common pivoting axles of the lines of buckets are supported by means of uprights such as 50 and 52 and stops such as 54 and 56 are provided to prevent the buckets from rotating too far in the clockwise direction after discharging a pocket of air.

The upright struts 50 and 52 are themselves carried on a sub-frame 58.

Above the lines of buckets 46 and 48 is located a screen 60 of wire mesh the aperture size of which is sufficient to allow stones to pass in a downward direction although being too small to allow vegetables to pass therethrough and being of a sufficient regular pitch as not to interfere with the passage of air and water in upward direction.

As viewed in Fig. 3 the baffles 62, 64 etc., can be seen which serve to direct the water from the spray bars at the correct angle onto the crop on the conveyor 18.

Mounted outboard of the transverse take-off conveyor is a motor 66 and gearbox 68 for driving through pulleys 70 and 72 the line of pulleys 74 are mounted around which the conveyor belts extend. When the motor is operated the belt is moved in the direction of the arrow 20 in Fig. 1.

A sensing device in the form of an infra red sensor and light source at 76 in Fig. 1 serves to produce a signal when there is no crop waiting to be discharged.

Although reference has been made to the discharge conveyor 22 as being a transversely extending conveyor it is to be understood that the main conveyor 1 8 may be extended all the way around the path shown and no transverse conveyor provided so that vegetables are delivered in the direction of the arrow 78 into a weighting skip or other container or onto another conveyor.

Air is supplied via three conduits 80, 82 and 84 from an air manifold into the manifolds serving to supply air to the underwater jets below the buckets 46 and 48.

Water is supplied to the interior of the reservoir through a water inlet 88 and can be drained from the reservoir through a. drain outlet 90 which is normally closed.

One further sensing device is provided namely an ultrasonic beam or equivalent below the water level which is directed across the width of the tank. A typical position for the beam is designated by reference numeral 92.

Operation of the Equipment (1) A tilted cart conveyor is started manually and this initiation causes the cart conveyor slats to move forward by a preset increment of approximately 100 cm (the increment being variable by adjustment) and to then stop. This movement should deposit celery into the reservoir.

The conveyor drive speed if 2.9 metres per minute so that 100 m travel takes approximately 2 seconds.

(2) Water flow will induce the celery to flow along the length of the tank towards the dewatering conveyor 1 8 and in doing so the first sticks of celery to pass the ultrasonic beam will interrupt the latter and generate an electrical signal. As soon as the ultrasonic beam is interrupted the cart conveyor is stopped.

(3) When all of the celery in the tank has moved past the ultrasonic beam position and the beam in consequence becomes uninterrupted again, a second signal is generated and a control signal given to the cart conveyor drive to move its preset increment approximately 100 mm of travel to unload a further quantity of celery. The sequence continues in this way until the cart is emptied.

(4) If the ultrasonic beam has not been interrupted by a celery flow after a pre-set period of time (variable by adjustment) and introduced by means of a time delay facility (not shown) a further increment of conveyor travel is initiated to load more celery into the tank. If, after a further period of time delay (typically the same as the first) the ultrasonic beam has again not been interrupted, the conveyor drive is initiated to run continuously until the beam is interrupted by celery flow. This ensures that a load stuck in the tilted cart is eventually released into the reservoir.

(5) The de-watering conveyor is arranged to have two speeds of operation. A first slow normal speed operates all the time the infra red beam 76 is uninterrupted thereby indicating a lack of celery at the discharge end of the conveyor. However, interruption of the infra red beam is arranged to initiate a higher speed of operation of the conveyor albeit for a controlled period of time so as to bring more celery to the feed point with the minimum delay. As soon as the infra red beam is interrupted by the presence of celery the drive reverts to its normal slow running speed of typically 7 to 8 cm per minute.

The advantage of the invention is that: (a) the use of air bubbles to break up the tangled vegetables introduces little or no damage to the vegetables and, (b) by using the inverted pivoting buckets so a relatively continuous and low volume of air can be supplied to the other sides of the buckets which then trap the building up pocket of air until the latter creates sufficient lift to cause the buckets to tilt completely and release the pocket of air as previously described.

Claims (6)

1. Apparatus for separating lumps of tangled vegetables comprising a reservoir of water into which the vegetables are introduced at one end and removed from the other in which screen means is provided at a position intermediately top and bottom of the reservoir to prevent vegetables from sinking to the bottom to allow fluid to pass in an upward direction therethrough and second means is provided for introducing air into the reservoir to form large bubbles of air which rise through the screen and disturb the water, thus agitating the tangled vegetables floating in the upper regions of the reservoir.

2. Apparatus as claimed in claim 1 in which the air is introduced by means of air jets and nozzles supplied with air continuously or intermittently.

3. Apparatus as claimed in claim 1 in which the air is supplied through nozzles of reduced size and the air is supplied continuously to the reservoir through the nozzles and above each nozzle is located a temporary air reservoir in which a pocket of air is collected and from which the air is released in the form of a large bubble.

4. Apparatus as claimed in claim 3, in which each reservoir comprises a container having a closed top and an open base which is located over each nozzle, and is rotated or tilted at intervals so that the air can escape from the upper end as a large bubble to produce the turbulence and agitation required.

5. Apparatus as claimed in claim 3 or 4 in which the mechanism for causing the intermediate reservoirs to tilt or rotate is a drive means acting through a shaft to which the intermediate air reservoirs are attached.

6. Apparatus for separating lumps of tangled vegetables constructed, arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.

6. Apparatus as claimed in claim 3 or 4 in which each reservoir is in the form of a cup eccentrically mounted for pivoting movement about a generally horizontal axis having a position of equilibrium in which the open end of the cup faces downwards, the arrangement being such that the air bubble which collects within the cup when it occupies its position of stable equilibrium eventually produces sufficient lift to cause the cup to rotate and tilt until the air trapped therein can be released through the open end of the cup.

7. Apparatus as claimed in any of claims 1 to 6 in which the said first means comprises a wire mesh or apertured tray or other form of screen through which water and air can pass in one direction, but in which the apertures are too small for vegetables, but are sufficiently large to allow stones and the like to drop therethrough.

8. Apparatus for separating lumps of tangled vegetables constructed arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.

New claims of amendments to claims filed on 16 March 1982.

Superseded claims 1-8.

New or amended claims:

1. Apparatus for separating lumps of tangled vegetables, comprising a reservoir of water into which the vegetables are introduced at one end and removed from the other end, in which screen means is provided at a position intermediate the top and bottom of the reservoir to prevent vegetables from sinking to the bottom and to allow fluid to pass in an upward direction therethrough, and second means is provided for introducing air into the reservoir to form large bubbles of air which rise through the screen and disturb the water, thus agitating the tangled vegetables floating in the upper regions of the reservoir, wherein second means include nozzles and the air is supplied to the reservoir through the nozzles and above each nozzle is located a temporary air reservoir in which a pocket of air is collected and from which the air is released in the form of a large bubble, and wherein each temporary air reservoir comprises a container having a closed top and an open base which is located over each nozzle, each container being rotated or tilted at intervals so that the air can escape from the upper end as a large bubble to produce the turbulence and agitation required.

2. Apparatus as claimed in claim 1, in which the air is introduced into the first-mentioned reservoir continuously.

3. Apparatus as claimed in claim 1 or 2 and including a mechanism for causing the temporary air reservoirs to tilt or rotate, the mechanism having a drive means acting through a shaft to which the temporary air reservoirs are attached.

4. Apparatus as claimed in claim 1 or 2, in which each temporary air reservoir is in the form of a cup eccentrically mounted for pivoting movement about a generally horizontal axis having a position of equilibrium in which the open end of the cup faces downwards, the arrangement being such that the air bubble which collects within the cup when it occupies its position of stable equilibrium eventually produces sufficient lift to cause the cup to rotate and tilt until the air trapped therein can be released through the open end of the cup.

5. Apparatus as claimed in any of claims 1 to 4, in which the said first means comprises a wire mesh or apertured tray or other form of screen through which water and air can pass in one direction, but in which the apertures are too small for vegetables, but are sufficiently large to allow stones and the like to drop therethrough.