GB2244437A

GB2244437A - Juice sample extraction press

Info

Publication number: GB2244437A
Application number: GB9012362A
Authority: GB
Inventors: Patrick Boughey
Original assignee: COCKSEDGE ENG Ltd
Current assignee: COCKSEDGE ENG Ltd
Priority date: 1990-06-02
Filing date: 1990-06-02
Publication date: 1991-12-04
Also published as: GB9012362D0

Abstract

A sample of fruit or vegetable pulp is delivered by slide 22 into chamber 28, falls on to filter paper 34 and is pressed by a descending piston 30 so that the juice filters through into a cup 38. When a certain pressure is reached, the piston stops and a filter support screen 36 moves into chamber 52, where it is cleaned by an air blast, and the cup 38 is moved away to enable the juice sample to be analysed. The piston then descends further to eject the filter paper 34 and residual pulp into waste bin 20. Filter holder 44 moves to the right to collect another filter paper from dispenser 58, then holder 44 and screen 36 return to positions shown, and a new cup 38 is delivered to receive the next sample. Slide 22 may be fed continuously with sugar beet pulp from a saw 10, and the apparatus operates continuously to prepare a succession of juice samples. <IMAGE>

Description

Juice Sample Extraction System This invention relates generally to a juice sample extraction system and in particular to a method of and apparatus for extracting juice from a sample of vegetable or fruit pulp, more especially but not exclusively a sample of sugar beet pulp generally known as brei.

Currently, in a sugar beet juice sampling system, after production of a brei sample by use of a sample saw, juice from the brei sample is obtained by first mixing the brei with a reactive additive and then filtering the reacted mixture. This method of extracting the juice from the sample is slow, laborious and relatively expensive, and can give rise to problems of cross contamination between one sample and another which are not readily overcome.

It is an object of this invention to provide an improved method of and apparatus for extracting juice from a sample of vegetable or fruit pulp, more especially a sample of sugar beet brei.

According to one aspect of the present invention, there is provided a method cf extracting juice from a sample of vegetable or fruit pulp, according to which the pulp sample is delivered beneath the piston of a cylinder/piston assembly, the piston is caused to descend to squeeze the pulp against a filter element, juice emergent through the filter element is collected and removed, descent of the piston is continued to eject the filter element and pulp residue thereon, the piston is raised and the filter element is replace~ to be ready for extraction cf juice from the next pulp sample.

According to another aspect of the invention, there is provided apparatus for extracting juice from a sample of vegetable or fruit pulp, comprising a generally vertical cylinder/piston assembly, means for delivering a pulp sample beneath the piston, means supporting a filter element in the path of descent of the piston, means for operating the cylinder/piston assembly, whereby the piston is caused to descend to squeeze the pulp sample against the filter element, means for collecting and removing juice emergent through the filter element, the operating means then causing the descent of the piston to be continued to eject the filter element and pulp residue carried thereby, a collector for spent filter element and pulp residue, and means enabling replacement of the filter element after the piston has been raised by the operating means.

Preferably, the filter element, e.g. filter paper or card, is supported by a screen element, e.g. of suitable perforation. The screen element is preferably carried by a laterally movable slide, for example ram driven, so as to be retractable out of the path of the piston before said piSton contines its descent tc eeot the filter element.

A cleaning unit, conveniently one effecting cleaning by means cf an aIr blast, is provided for the p'rpose of effecting cleaning of the screen element in its retracted position. After cleaning, and after the piston has again been raised, the slide is movable to restore the cleaned screen element to its operative position. Cleaning of the screen element is important to minimise risk of cross contamination.

A second laterally movable slide, w'nich also m~s- be ran driven, is preferably provided to support the filter element over an aperture in said slide, the descending piston passing through this aperture to eject the spent filter element. After the piston has again been raised, the second slide may be withdrawn to enable a fresh filter element to be deposited in position by a filter element dispenser, the second slide then being moved back to position the fresh filter element in its operative position.

At a suitable point in the cycle, a further cleaning means, again preferably effecting cleaning by means of an air blast, may be operated to clean the bottom face of the piston, again for the purpose of minimising risk of cross contamination.

Descent of the piston may be in part controlled responsively to increase of pressure on the piston face. Thus, as the pulp is squeezed, this pressure increases, and the descent of the piston may be temporarily halted when a preset but possibly adjustable pressure has been attained. While the piston is stopped, the collected juice is removed, thereafter to be evaluated in a juice analyser, and the screen element is withdrawn. The further descent of the piston is then initiated. The whole cycle of operations is preferably automatically controlled and carried out repetitively, the jie fror successive pulp samples being collected in cups which are so conveyed by a conveyor operating in synchronism with the cycle that successive cups are positioned beneath the cylinder/pistor, assembly each to receive the juice from one pulp sample.Between passage of two successive cups beneath the cxlinder/piston assembly, the spent filter element and associated pulp residue is ejected into a waste bin.

In a preferred arre-gement, the pulp sample is fed into the cylinder/piston assembly through an opening in the upper part of the side wall of the cylinder, beneath the fully raised piston, by means of a cylindrically walled pulp delivery member which is laterally movable back and forth by means of a ram. A fixed floor member supports the pulp within the cylindrical wall to the side of the piston cylinder. As the pulp delivery member enters laterally into the piston cylinder, the pulp sample is released to fall on to the filter element and, having fully entered the piston cylinder, the pulp delivery member is then withdrawn to enable the piston to start its descent.In its laterally withdrawn position above the floor member, the pulp delivery member is top loaded with pulp emergent from the exit of a high speed saw, of a known conventional kind, which operates to produce the pulp from a cleaned sample of the fruit or vegetable, e.g. sugar beet, under test.

A still further cleaning means, again of the air blast type for example, may operate to clean the pulp delivery member at a suitable point in each operating cycle.

The frequency of repetition of the operating cycles is increased by re-loading the ir delivery member vith the next pulp sample while the cylinder/pistor, assembly is operating ir. cor...e~ With extraction ci juice from the previous pulp sample.

At the bottom end of the cylinder/piston assembly, a spring loaded and releasable sealing ring is preferably provided for the purpose of preventing escape of pulp and/or juice between the bottom of the cylinder and the filter element during squeezing. One or more thrust members, operated by a miniature ram as part of the operating cycle, may act t press the sealing ring tightly into position during squeezing, and release said ring to facilitate ejection of the spent filter element and movement of the filter element and filter screen slides. Avoidance of escape of pulp and/or juice is also important to avoid cross contamination between samples.

Further features of the invention will be apparent from the following description of a preferred arrangement of apparatus for extracting juice from a sample of brei, making reference to the accompanying drawings, in which: Figure 1 is a pictorial view of the apparatus; Figure 2 shows the apparatus in elevational cross-section; and Figures 3a to 3f are views showing the apparatus at different stages in its operating cycle.

Referring te Figure 1, the discharge of a sample of brei produced by a high speed saw discharging through saw discharge guard 10 is received into a collector 12. From the collector 12 the brel sample passes to a compressor 14, wherein the sample is squeezed against a filter, the juice from the sample being collected in a cup positioned beneath the outlet from the filter by a cup positioner 16, the cups bin fed to and away from the positioner by a cup feed conveyor 18.

Subsequently, the spent filters and pulp residue are ejected from the compressor 14 into a waste bin 20. Other references applied in Figure 1 will be clear from the following more detailed description of the apparatus, making reference to Figure 2.

The collector 12 into which the brei sample from the saw discharge guard 10 is received comprises a cylindrical pulp delivery member 22 laterally movable back and forth by a pneumatic ram cylinder 24. On the forward stroke of the ram, the pulp delivery member is displaced laterally over a floor member 26 thence to enter through a lateral opening in the upper part of the compressor 14, which comprises a vertical cylinder 28 through which a piston 30 can be caused to descend and lift by means of a pneumatic or mechanical compressor drive 32.

When the pulp delivery member 22 laterally enters into the upper part of the cylinder 28, the brei sample drops down through the cylinder on to a filter card 34 supported above a filter screen 36 of suitable perforation.

The pulp delivery member 22 having been withdrawn, the piston 30 can then be driven downwardly to compress the pulp against the filter 34, squeezing the juice through the filter 34 and filter screen 36 into the cup 38 whicn has been positioned by the cup positioner 16. During the squeezing operation, a spring loaded sealing ring 4G is pressed tightly against the filter 34 around the bottom end of the cylinder by a small pneumatic thruster 42, thereby to prevent leakage of pulp and/or juice.

The filter 34 and the filter screen 36 are carried by respective slides 44, 46 laterally movable by respective pneumatic ram cylinders 48, 50.

The descent of the piston 30 is stopped when sensing means (not shown) detects the application cf pre-set and possibly adjustable pressure by the piston. The filter screen 36 is then withdrawn on its slide 46, tc the left as shown in Figure 2.

In its withdrawn position, filter screen 36 is cleaned within cleaning chamber 52 by an air blast delivered by a valve controlled air cleaner 54. The cleaner discharge funnel, indicated at 56 in Figure 2, may be led into the waste bin 20, as indicated at 57 in Figure 1.

The piston 30 is then caused to resume its downward stroke, passing through an aperture in the filter slide 44 to eject the spent filter 34 and pulp residue carried thereby into the waste bin 20. The piston is then raised to the top of the cylinder to allow withdrawal of filter slide 44, to the right as shown in Figure 2. A fresh filter is deposited from filter card dispenser 58 over the aperture in the withdrawn filter slide 44.

The lateral slides 44, 46 are moved back to locate the fresh filter and the cleaned filter screen in their operative positions in the path of the descent of the piston 30.

During the pulp squeezing operation, the pulp delivery member 22 has been reloaded and is ready to deliver a fresh brei sample into the cylinder.

The clete operating cycle is electro-pneurraticallv controlled so that the afore-described operations take place automatically in the required sequence. Reference 60 in Figure 1 denotes a casing carrying the electropneumatic controls.

The cleaning of the filter screen 36 is necessary to avoid cross contamination between one brei sample and another.

The juice obtained from each sample is conveyor fed te an analysing system, in particular to determine sugar content, and a reliably accurate analysis is not achievable unless contamination of one sample by another is avoided.

Additionally, therefore, although not shown, an air cleaning means is provided to clean the bottom face of the piston 30 at a suitable point in the operating cycle.

Still further air cleaning means may be provided to clean the pulp delivery member between cycles.

Figures 3a to 3f illustrate different stages in the automatic operating cycle of the apparatus.

Figure 3a shows the starting condition, the pulp delivery member 22 being loaded ready to deliver a brel sample into the cylinder 28 beneath the fully raised piston 30. A clean filter card and cleaned filter screen are in position at the bottom of the cylinder, and a cup 38 is in position to collect the juice.

In Figure 3b, the brei sample has been delivered into the cylinder, the pulp delivery member 22 being at the inner end of its stroke, within the upper part of the cylinder 2.

In Figure 3c, the pulp delivery ear 22 has been witdrawn, and the piston 30 has descended te compress the pulp and squeeze uOe ntc the cup 38.

In Figure 3d, the filled cup 38 is being moved away, and the filter screen 36 has been laterally withdrawn for cleai.

In Figure 3e, the descent of the piston has continued to eject the spent filter and pulp residue into the waste bin 20.

In Figure 3f, the filter card slide 44 has been withdraw to enable replacement of the filter, after the piston 30 has been lifted. The cleaned filter screen has been returned to its operative position. From the condition shown in Figure 3f, return of the filter slide to position the fresh filter in its operative position returns the apparatus to the condition shown in Figure 3a.

Various modifications of the afore-described and illustrated method and apparatus are possible within the scope of the invention hereinbefore defined.

Claims

1. A method of extracting juice from a sample of vegetable or fruit pulp, according to which the pulp sample is delivered beneath the piston of a cylinder/piston assembly, the piston is caused to descend to squeeze the pulp against a filter element, juice emergent through the filter element is collected and removed, descent of the piston is continued to eject the filter element and pulp residue thereon, the piston is raised and the filter element is replaced to be ready for extraction of juice from the next pulp sample.

2. A method according to claim 1, in which, as the pulp is squeezed, pressure on the piston face increases and the descent of the piston is halted when a preset pressure is attained, whereafter the collected juice is removed and a filter-supporting screen element withdrawn before descent of the piston is recommenced to eject the filter element.

3. A method according to claim 1 or claim 2, in which the juice from successive pulp samples is collected in cups conveyed by a conveyor operating in synchronism with the movement of the piston so that successive cups are positioned beneath the cylinder/piston assembly each to receive the juice from one pulp sample.

4. Apparatus for extracting juice from a sample of vegetable or fruit pulp, comprising a generally vertical cylinder/piston assembly, means for delivering a pulp sample beneath the piston, means supporting a filter element in the path of descent of the piston, means for operating the cylincer/pistor. assembly, whereby the p piston is caused to descend to squeeze the pulp sample against the filter element, means for collecting and removing juice emergent through the filter element, the operating means then causing the descent of the piston to be continued to eject the filter element and pulp residue carried thereby, a collector for spent filter element and pulp residue, and means enabling replacement of the filter element after the piston has been raised by the operating means.

5. Apparatus according to claim 4, in which the filter element is supported by a screen element.

6. Apparatus according to claim 5, in which the screen element is supported by a laterally movable slide so as to be retractable out of the path of the piston before said piston continues its descent to eject the filter element.

7. Apparatus according to claim 6, including an air blast cleaning unit for cleaning the screen element in its retracted position.

8. Apparatus according to claim 6 or claim 7, in which a second laterally movable slide is provided to support the filter element over an aperture in said slide, the descending piston passing through this aperture to eject the spent filter element.

9. Apparatus according to claim 8, in which, after the piston has again been raised, the second slide may be withdrawn to enable a fresh filter element to be deposited in position by a filter element dispenser, the second slide then being moved back to position the fresh filter element in its operative position.

10. Apparatus according to any of claims 4 to 9, in which, at a selected point in the cycle of operation of the piston, an air blast cleaning means is operable to clean the bottom face of the piston.

11. Apparatus according to any of claims 4 to 10, in which the pulp sample is fed into the cylinder/piston assembly through an opening in the upper part of the side wall of the cylinder, beneath the fully raised piston, by means of a cylindrically walled pulp delivery member which is laterally movable back and forth by means of a ram.

12. Apparatus according to claim 11, in which a fixed floor supports the pulp within the cylindrical wall to the side of the piston cylinder and, as the pulp delivery member enters laterally into the piston cylinder, the pulp sample is released to fall on to the filter element and, having fully entered the piston cylinder, the pulp delivery member is then withdrawn to enable the piston to start its descent, whilst in the laterally withdrawn position above the floor member, the pulp delivery member is top loaded with pulp emergent from the exit of a high speed saw.

13. Apparatus according to claim 12, in which an air blast cleaning means is operable to clean the pulp delivery member at a selected point in its cycle of operation.

14. Apparatus according to claim 11 or claim 12 or claim 13, in which, at the bottom end of the cylinder/piston assembly, a spring loaded and releasable sealing ring is provided for the purpose of preventing escape of pulp and/or juice between the bottom of the cylinder and the filter element during squeezing.

15. Apparatus according to claim 14, in which one or more thrust members, operated by a miniature ram, act to press the sealing ring tightly into position during squeezing, and release said ring to facilitate ejection of the spent filter element and movement of the filter element and filter screen slides.

16. A method of juice extraction substantially as hereinbefore described.

17. Apparatus for juice extraction substantially as hereinbefore described with reference to the accompanying drawings.