WO2014057250A1

WO2014057250A1 - A retorting apparatus

Info

Publication number: WO2014057250A1
Application number: PCT/GB2013/052604
Authority: WO
Inventors: David Lambert
Original assignee: Continuous Retorts Limited
Priority date: 2012-10-11
Filing date: 2013-10-07
Publication date: 2014-04-17
Also published as: GB201218259D0

Abstract

Load and unload apparatuses (40, 42) for transferring a product in or out of a retort (20) or the like is disclosed. Said apparatus comprises a tubular cassette having pockets along the length of the cassette to retain product during passage of the cassette through a retort. The pockets (126) open to the exterior of the cassette (104) to enable product to be inserted into the pocket (126). A retaining means (124) is positioned around the outside of the cassette (104) and is rotatable about the axis thereof, and relative to the cassette (104), to prevent removal of product from a pocket (126) the rotation being driven by rotation means. The retaining means (124) comprises one or more apertures (123) to selectively enable release or insertion of product from or into a pocket (126) as the retaining means rotates relative to the cassette (104).

Description

A Retorting Apparatus

Field of the Invention

The present invention relates to an apparatus to sterilise food product contained within a packaging material, and especially to a means of loading product into and unloading product from the apparatus as well as controlling the angular position of product relative to the horizontal plane during heat processing.

Background to the Invention

The continuous heat processing of products in packaging that has poor heat resistance is addressed in patent application EP08 736874. The significant energy recovery and elimination of cooling water in heat processing in the continuous retort described in patent application EP08 736874 is described in patent application EP09 785174.

To gain the maximum benefit from the apparatus described in these two patent applications the product needs to be loaded and unloaded at high speed in a fully automatic manner to maximise the unit cost savings and minimise damage to the product and apparatus itself.

Certain products also require rotation during heat processing to be stopped at predetermined angular positions relative to the horizontal plane.

There is now described a system that enables product to be automatically loaded into the retorting apparatus and unloaded from the retorting apparatus at high speed (above 50 packs per minute, typically 400 packs per minute and as high as 1,200 packs per minute) as well as providing means whereby the rotation of the product to be stopped at predetermined positions if required by the specific thermal process. Summary of the Invention

According to the invention, there is provided a load/unload apparatus for transferring a product in or out of a retort or the like, said apparatus comprising a means to insert and remove product from a cylindrical cassette or equivalent product carrier of the retort, said cassette having pockets along its length to retain product during passage of the cassette through a retort, the cassette being capable of rotation around its longitudinal axis , the apparatus including stopping means to allow such rotation to be stopped at required angular positions, said pockets opening to the exterior cylindrical surface of the cassette to enable product to be inserted into and removed from the pockets; the stopping means being capable of arresting angular rotation at least in as many angular positions as are represented by the rows of pockets; an indexing means to sequentially allow successive batches, rows or groups of product to be inserted into the pockets or removed from the pockets as required; a retaining means positioned around the outside of the cassette and rotatable about the axis of, and relative to the cassette to secure the product within the pockets, the rotation relative to the cylindrical cassette being driven by rotation means during loading or unloading, but allowing the retaining means and cassette to remain rotationally static in relation to each other during transfers or thermal processing in order to retain the product within the cassette once loaded; the retaining means comprising one or more apertures to selectively enable release or insertion of product from or into a pocket as the cassette rotates in relation to the retaining means.

The retaining means enables product to be retained after loading and passage of product through the apparatus but to allow rapid loading into and unloading from the apparatus, of batches, rows or groups of product to give a semi-continuous process.

Preferably, the stopping means comprises a ratchet pawl and escapement mechanism. Further preferably, the ratchet pawl and escapement mechanism is operated either by flow of water or mechanical means during thermal processing. Preferably the rotation of the retaining means is indexed to bring the apertures into release or loading position for sequential batches. Further preferably the retaining means rotates a half index in relation to the cassette to bring the apertures out of alignment with the pockets to retain product within a pocket.

Conveniently apertures extend the length of the retaining means to allow loading or unloading of a row or multiple rows of product from the cassette. Further conveniently, the apertures are arranged each to allow pairwise loading/unloading with a locally increased wall thickness at the apertures in order to increase the strength of the retaining means.

Optionally, the apparatus includes locking means to lock the retaining means in particular rotational alignment with the cassette or alignment with the apparatus itself. Further optionally, the locking means comprises a locking pawl engaging a castellated locking ring on the cassette.

Conveniently rotation of the locking ring is achieved by geared wheels or friction drives. The rotation of the cassette can be achieved by the means described in Patent Application EP09 785174.

Advantageously, the apparatus includes mechanical means to transfer product to and from the cassette. Further advantageously, the mechanical means comprises suction transfer cups or cam-operated actuators.

Brief Description of the Drawings

The invention is now described with reference to and as illustrated by the accompanying drawings which show by way of example only, two embodiments of a retorting apparatus and loading means. In the drawings:

Figure 1 is a perspective view of one type of apparatus in accordance with the invention with the loading and unloading unit (100);

Figure 2 is a further perspective view of the apparatus of Figure 1 with the unprocessed product infeed and processed product outfeed;

Figures 3a, 3b show respectively the load unload unit with rows of unprocessed product being loaded into a cassette in position 1 (Fig.2) and the cassette (104) in the unloading position where product from rows 106 and 107 are dropping onto the product outfeed conveyor;

Figure 4 shows in closer detail the in-feed of the load unload apparatus;

Figure 5 is a perspective view of a first embodiment of a complete torpedo showing its longitudinal axis;

Figure 6 is a close-up view of a cassette showing the product carrying pockets;

Figure 7 illustrates a sectional cutaway of the load/unload unit at its midsection;

Figure 8 illustrates shows an alternative type of apparatus using the same type of torpedoes and cassettes and showing the direction of transfer of the torpedoes during thermal processing with the in-feed (40) and out-feed (42) of product in separate units;

Figure 9 is a perspective view of a second embodiment of a complete torpedo;

Figure 10 is an expanded view of the end of a torpedo; and

Figure 11 is a further expanded view of the end of a torpedo.

Detailed Description of the Invention

Further to patent applications EP08 736874 and EP09 785174 there are now described two apparatuses and methods to automatically load unprocessed product in packs such as plastic containers, plastic pouches, glass jars or tin cans, into the product carrying Cassettes which are contained in the Torpedoes that move through the retorting apparatus as described in these two pieces of prior art during heat processing, during which time the rotation of the product carrying Cassettes can be arrested in predetermined angular positions by the apparatus , and then automatically unload the processed product to permit the Cassettes to be re-used in the system continuously.

In the first type of self-contained apparatus known as a Load/Unload Unit (LULU) the empty Cassette-carrying Torpedoes are filled with unprocessed product at position 1 (see Figure 2) by inserting paired rows of unprocessed product sliding horizontally from the in-feed section via two paired rows of insert apertures (105) into the two paired rows of tubular holders.

Once the paired rows are filled with unprocessed product the cassette is rotated around the torpedo/cassette's common longitudinal axis by the means described in the prior art to the next loading position and the process of insertion of unprocessed product restarts. Product in the filled pockets that have rotated past the horizontal plane are restrained from sliding out of said pockets by a cylindrical restraining collar (not shown). Once all product carrying holders are full the unprocessed product is locked in position by a half index rotation of the restraining collar and the internal magazine of the LULU which carries the torpedo/cassette combinations is rotated about the longitudinal axis of the LULU such that the filled torpedo moves angularly from position 1 to position 2 wherein it is preheated. An empty torpedo cassette combination has at the same time been moved angularly from position 14 to position 1 where it, in turn is filled with unprocessed product.

The filled torpedo cassette combination is then moved from position 2 through all subsequent sequential positions of heating in the heating or come-up tubes (linearly through tubes 2, 3 & 4), sterilisation in the Main Retort Chamber (MRC) (angularly rotated through positions 5, 6, 7, 8 & 9), cooling in the cooling tubes (linearly through tubes 10 & 11 and LULU cooling position 12) then angularly rotated to position 13 where the torpedo is further cooled and then made ready for angular rotation to position 14 and unloading.

In position 14 the cassette is unlocked and the processed product from the exposed paired rows (106) is transferred vertically from the product carrying holders exiting via the insertion apertures onto a conveying means aligned with the longitudinal axis of the LULU shown as Product Outfeed above. The cassette is then rotated angularly about its longitudinal axis to present a second set of paired rows of processed product for unloading. The process continues until all the processed product has been removed from the cassette/torpedo combination and has been transferred out of the LULU.

The torpedo carrying magazine of the LULU then rotates again angularly about the longitudinal axis of the LULU such that the empty cassette/torpedo moves from position 14 to position 1 where it is filled with unprocessed product as described above.

The product carrying torpedoes of the retorting apparatus are large cylinders, typically weighing up to 1.2 tonnes and carrying up to 2,500 packs (depending on product size) within cylindrical Cassettes. The product is arranged within said Cassettes around the central longitudinal axis of the torpedo (117) in product carrying 'cassettes', either as radial arrays or lateral arrays or any other combination required for the processing of the product in question.

During heat processing the product may be required to be rotated and periodically stopped as described in the prior art. However, this rotation is also preferably arrestable in predetermined angular positions and the Cassette to torpedo rotation needs to be stopped by the same mechanical or other means that is used herein for the rotational indexing during loading.

These torpedoes then need to be emptied of processed product and then refilled with unprocessed product at high speed, reliably and consistently without damaging the packs or product to enable the product-carrying torpedoes to be rapidly returned to the heat processing environment within relatively short cycle times (being made up of multiple cycles of between 2 and 5 minutes each).

There are many factors and conditions of this process which are addressed by the invention described herein:

1. unprocessed product must not be capable of being mixed up with processed product and so two distinct product flows, spaced some distance apart, are necessary. Additionally the heat transfer medium to be used, whether for heating or cooling, such as water, air or steam, or any combination of the three, should not be intermixed in any way that could cross-contaminate the medium that will be in direct contact with the processed product with another flow of medium that has been in direct contact with unprocessed product.

2. Product needs to be dried before it leaves the retorting apparatus and this needs to be done within the LULU. It is therefore important that dried product is not rewetted by even sterile water, and certainly not potentially contaminated water.

3. The LULU rotates the torpedoes about the longitudinal axis of the LULU within the LULU' s magazine (although not necessarily the product-carrying cassettes within the torpedoes which may need to be kept horizontal throughout processing) in such a way that they leave and then re-enter the processing tubes with the correct angular orientation/displacement as defined by the torpedo carrying magazine of the MRC. For example a 5-tube MRC will require a 5-tube LULU to ensure the 72 degrees of angular displacement between the come up, or heating tubes and the cooling tubes. 4. For products requiring relatively long heating or cooling cycles it may be necessary to start heating as well as finishing off cooling within the LULU and so the required fluids connections as well as tube sealing systems are capable of being operated in synchronisation with the LULU.

5. Torpedoes and cassettes will need to be removed from the retorting apparatus for planned preventative maintenance as well as for possible product size changes. The removal and re-introduction of torpedoes (116) is best done from the LULU as it is an unpressurised machine.

6. Some form of washing of torpedo carrying tubes is needed within the LULU to minimise the possibility of cross-contamination from tubes that carried unprocessed product before they are transferred into the retort apparatus and before they then have to accept processed product carrying torpedoes returning from the apparatus.

7. Some form of 'buffering' of both unprocessed product arriving at the retort apparatus from the product container filling lines as well as the output of processed product from the retort apparatus to the end of line packing operations is needed to convert the continuous stream into intermittent streams at the retort in-feed and convert the intermittent streams from the retort into a continuous stream at the out-feed.

8. A means of product rejection can be incorporated into the design of the LULU to segregate torpedoes of product that may contain leaking or broken packs that have been detected by the retorting apparatus or elsewhere.

With reference to the accompanying drawings, a cylindrical body, the load/unload unit (LULU) 100 contains a torpedo-carrying magazine 101 rotatably mounted about the common longitudinal axes 103 of 100 and 101. A number of torpedo-carrying tubes 102 are arranged about this axis 103 and are mounted within the magazine 101 to alternately accept torpedoes from the retorting apparatus in alignment with the cooling tube 11 of that apparatus and then angularly rotate the magazine 101 about this axis 103 to pass through a number of intermediate positions which are also axially arrayed around that axis 103 to carry out cooling, drying, unloading, loading and eventually allow transfer to the heating tube 3, or "come-up" of that apparatus by ensuring that the longitudinal axis of each tube 102 in the magazine 101 aligns with the longitudinal axis of the come up tube 3. In position 1 product carrying tubes, holders or pockets 106 are mounted within a cassette 104 in either a radial array or other desirable configuration such that product can be inserted from the outside of the cassette in the direction 107. The cassette is then rotated about its own longitudinal axis 105 within torpedo tube 102 to the next loading position which allows alignment of the in-feed product 108 to be inserted into the pockets 105 in either a pair of adjacent rows or such other configuration as is desirable.

Once all product holders are filled with product to be processed, the unprocessed product is locked into the cassette by means of a locking collar or equivalent device to stop the product leaving the pocket or holder during processing and the magazine 101 is rotated about the axis 103 such that the n number tubes mounted in the magazine align again with the next n number of operational positions. By way of example, if there are 5 tubes in the MRC of the retorting apparatus then there will be a corresponding 5 tube positions in the LULU 100 and magazine, and the magazine in that instance will rotate 72 degrees to become aligned.

In the above example the torpedo in tube position 1 rotates counter clockwise to position 2. If water is chosen as the heat transfer means, preheated water can either start to fill the tube in position 1 during product loading or, alternatively, filling and preheating can start in position 2. No overpressure is applied during filling and preheating in the LULU 100.

Once the LULU magazine has stopped in the position 2, this places the longitudinal axis of tube 2 in alignment with the longitudinal axis of come up tube 3. The torpedo in tube 2 can be transferred into tube 3 as soon as the rotary knife gate valve (RKGV) 111 has fully opened. Once the torpedo is locked in position within tube 3 the RKGV 111 can close and over pressure and further heating can take place within tube 3 and subsequent tubes as described in the above patent applications. It will be recognised that other valves known in the art can also be utilised.

Incorporated within the transfer of the torpedo from tube 2 to tube 3 is the washing of the inside of the LULU tube in position 2 with warm sterile water so that this tube can be used to accept processed product when in its next position.

Processed product which has been partially cooled with applied over-pressure in tubes 10 and 11, can be similarly transferred into LULU tube position 12 as soon as the pressure in tube 11 has been reduced to ambient, the longitudinal axes of tube 11 and tube 12 are aligned and RKGV 112 has opened. As stated above, the torpedo with its corresponding cassette full of processed product will now be entering a tube that previously had water in contact with unprocessed product but which has subsequently been drained and cleaned with sterile water.

Other means of transferring torpedoes can also be used provided effective cleaning takes place at this point in the process.

A pipework manifold 114 allows the injection of heating fluids into the preheating position 2 of the LULU 100 and manifolds 115 allow the injection of cooling fluids into the cooling positions 12 & 13 of the LULU 100.

The torpedoes are sealed within the rotating tubes which comprise the LULU manifold which enables them to be selectively heated or cooled. In positions 1 and 14 the tubes are opened to allow loading and unloading respectively.

Tubes in positions 2 and 12 are also sealed with their respective come up or cooling tubes 3 and 11 after the LULU magazine has rotated such that the longitudinal axes of 2 and 3, and 11 and 12 are respectively aligned such that the longitudinal linear transfers of torpedoes can take place from 2 to 3 and 11 to 12.

The sealing of these two sets of apertures allows the transfer to be effected by hydraulic displacement of the heat-transfer fluids as described in the above-cited applications.

After torpedoes are transferred, the LULU magazine rotates counter-clockwise until the next series of longitudinal alignments are complete. Torpedoes in positions 12 and 13 are successively cooled by cold water or other fluid or gaseous means and immediately prior to the subsequent rotary transfer of the magazine to position 14 the cooling medium is drained from position 13 to permit the unloading of processed product in position 14.

Conveniently, the processed product contained within the cassette/torpedo in position 13 can be rotated rapidly about its longitudinal axis 105 during the draining of the tube in position 13 to remove excess water by centrifugal action. This is particularly beneficial for plastic pouches where water can be retained within the folded gusset at the base of the pouch.

Unloading in position 14 is achieved by opening a longitudinal slot 116 in the torpedo carrying tube aligned with the longitudinal axis of the tube and torpedo 105 and then unlocking the processed product within the product-carrying cassette 104 within position 14 to allow a pair of longitudinally spaced processed products (106) to be displaced downwards by gravity or other mechanical means. Once the first processed products have been removed from the cassette 104 the cassette 104 is rotated by geared or other means to bring a second pair of longitudinally spaced processed products to be removed. This sequence continues until the cassette 104 within the torpedo in position 14 is empty of processed product. The LULU magazine then rotates again in a counter clockwise sense ready for subsequent loading with unprocessed products in position 1.

Processed product which has been removed from the cassette and torpedo in position 14 is transferred longitudinally out of the LULU 100 by conveyor or other means in the direction shown.

Conveniently, product being removed in this manner can pass through a drying system at the discharge end of the LULU 100 marked 'Out-feed'.

In the second type of apparatus as shown in Fig.8 separate individual loading and unloading units are utilised. The empty Cassette-carrying Torpedoes in position 1 are filled sequentially by matching the angular position of the cassette with the discharging of rows of unprocessed product from a cross feed accumulator conveyor 40 which runs in as semi-continuous manner which in turn is fed from the product in-feed conveyor 41 which runs continuously. Product is transferred from the cross feed conveyor 40 into the open slots within the Cassette of the torpedo in position 1 by gravity or by directly actuated mechanical means such as suction transfer cups or cam operated actuators as required for the particular product type.

The cross feed accumulator conveyor is sized to allow the continuous stream of product arriving from conveyor 41 to become an intermittent supply of product which permits the torpedoes to be filled rapidly, thereby emptying the cross feed accumulator conveyor 40 at a faster speed than the product is supplied to it.

Once the torpedo 30 has been filled from the cross feed conveyor the torpedo 30 is transferred laterally to position 2 and is replaced in position by the next torpedo 30 to be filled. During the transfer operation the unprocessed product that is continuously arriving on conveyor 41 is allowed to build up on the cross feed accumulator conveyor 40 ready for higher speed discharge to the next torpedo 30 once it arrives in position.

The filled torpedo 30 in position 2 is loaded into the first chamber of the pair of pre-heating chambers by any suitable mechanical means which then moves laterally by suitable mechanical means to allow the next torpedo 30 to be loaded into the second chamber of this pair.

Once 2 torpedoes have been loaded into the pre-heating chambers at position 2 the pair of chambers is moved transversely from position 2B to 2A (of Figure 8) where seals between the pair of pre-heating chambers and the pair of heating (come-up) chambers are inflated and the pair of pre-heating chambers are flooded with water at between 60 and 80 degrees °C (depending on process requirements) and at ambient pressure.

Once the pairs of chambers at position 2 A are full the torpedoes 30 are transferred laterally to position 3 by mechanical means or by the use of hydraulic pressure as described in the above- cited prior art.

The pair of chambers in position 2A are then drained and the seals are deflated to allow the pair of chambers to move transversely back to position 2B ready to accept a further 2 torpedoes containing unprocessed product.

The torpedoes are then heat processed as described in the above-cited prior art before being discharged into the pair of final cooling and drying chambers in position 4 which has been sealed to the pair of cooling chambers by inflatable or other sealing means and pre-filled with cooling water at between 80 and 5 degrees °C (depending on product processing requirements) and ambient pressure. This pair of final cooling chambers in then drained and centrifugal (spin) drying is carried out before the seals are deflated allowing the pair of chambers at position 4C to be transferred transversely to position 4D.

The 2 torpedoes 30 at position 4D are then transferred laterally to position 5, one at a time, where they are actuated by mechanical means to rotationally sequentially discharge rows of processed product onto the cross feed conveyor 42 by gravity or any other suitable mechanical means such as suction cups or cam operated actuators. The cross feed conveyor 42 is sized to allow the processed product to be discharged at a higher speed than the processed product is leaving the system on the out-feed conveyor 43 such that the gap in the discharge of processed product when a first torpedo has finished its processed product discharge and the next torpedo begins its discharge cycle is accommodated by the 'buffer' of processed product on the cross feed conveyor 42.

The empty torpedo is then moved laterally from position 5 to position 6, in the main retort chamber 20 by any suitable mechanical means. At position 5 there are 3 possible outcomes for the empty torpedo. It can either be moved laterally to position 1 for charging with unprocessed product as described above. Or it can be removed for inspection via positions 7 and 8 by any suitable mechanical means in the event that incomplete discharge of product, or any other defect during processing has been detected. Or it can be removed to be replaced with another empty torpedo configured with a cassette of a different type during product sized change operations.

In Fig.9 product is loaded and unloaded by gravity or other mechanical means via apertures 123 in the outer locking ring 124 of the cassette assembly such that the aperture is rotated to align successive product carrying 'pockets' with these apertures through which the product 125 is mechanically deposited or simply allowed to drop into position by gravity alone.

In Fig. 10 a half pitch rotation of the locking collar closes the aperture once the loading of product has been completed. The rotation of the locking collar in relation to the cylindrical cassette is achieved by geared wheels, friction drives or any other suitable means. Common to both systems are the product carrying cylindrical cassettes which are contained within 'torpedoes' . These torpedoes carry the cassettes through the retort for thermal processing as well as through the loading and unloading units as well as providing closely managed cassette rotation about the joint longitudinal axes of the torpedo and cassette.

The closely managed rotation is vital for effective heat transfer, as well as for sequential indexing of the cassette during product loading and unloading operations. Whilst the prior art describes means to stop rotation during heat processing, the angular position at which the Cassette stops rotation cannot be accurately pre-determined. Additionally, any out of balance forces, such as in a half filled cassette, could cause the Cassette to either overrun its stop position, or rotate backwards away from it in an uncontrolled manner. The torpedoes used in both systems comprise two end caps which are mounted at each end of the cassettes and which provide rotational movement of the cassette relative to the end caps, see Fig. 9. Rotation of the product carrying Cassette is provided by means of hydraulic action on turbines or by any other suitable mechanical means as described in the prior art.

It is advantageous for the rotation to be started and stopped at precisely defined angular positions relative to the horizontal plane of the system and this cannot be accurately achieved by the means described in the prior art. In the present invention this is achieved by such mechanical means as pawls 120 actuated by indexing brake valves or other suitable mechanical means, referring to Figure 10, acting on castellated crown wheels 121, friction clutches, ratchets, escapements, or other mechanical brakes or clutches.

As the indexing brake valve shown in Fig. 10 can be located within one of the water inlet manifold pipes as described in the prior art it can be actuated by the flow of heat processing water and thereby provides an automatic indexing device as it immediately stops the rotation of the Cassette as soon as the water flow reduces below a threshold level in the inlet pipe. In this way the water powered Cassette rotation as described in the prior art can become a rotational indexing device with no further modifications. The apparatus can include an additional cylindrical collar which can be rotated to change the size of the product carrying pockets.

The same indexing brake valve can be mechanically actuated in the loading or unloading units where there is no water used.

Claims

1. A combined load/unload apparatus (100), or individual load unit (40) and unload unit (42) for transferring a product in or out of a retort (20) or the like, said apparatus comprising means of accepting a tubular torpedo incorporating a cassette (104) having pockets along its length to retain product during passage of the cassette through a retort, said pockets (105, 106) opening radially or laterally to the outer cylindrical surface of the cassette (104) to enable product to be inserted into the pockets 105 or removed from pockets (106); a retaining means (124) positioned around the outside of the cassette (104) and rotatable about the axis thereof, and relative to the cassette (104) as well as in relation to the torpedo and apparatus to prevent removal of product from a pockets (105, 106, 126) the rotation of the cassette and the retaining means each being driven by independent rotation means; the retaining means (124) comprising one or more apertures (123) to selectively enable release or insertion of product (125) from or into pockets (105, 106, 126) as the retaining means rotates in relation to the cassette.

2. An apparatus according to Claim 1, wherein the rotation of the retaining means is indexed to bring the apertures into release or loading position for sequential batches.

3. An apparatus according to Claim 2, wherein the retaining means rotates a half index in relation to the cassette to bring the apertures out of alignment with the pockets to retain product within a pocket.

4. An apparatus according to any preceding claim, wherein apertures extend the length of the retaining means to allow loading or unloading of a row of product from the cassette.

5. An apparatus according to Claim 4, wherein the thickness of the wall of the restraining means in the vicinity of the apertures is increased to increase the strength of the retaining means at this location.

6. An apparatus according to any preceding claim, wherein the apparatus includes locking means to lock the retaining means in particular rotational alignment with the cassette.

7. An apparatus according to any preceding claim, wherein the apparatus includes locking means to lock the retaining means in particular rotational alignment with the torpedo.

8. An apparatus according to any preceding claim, wherein the apparatus includes locking means to lock the retaining means in particular rotational alignment with the apparatus.

9. An apparatus according to Claim 6, wherein the locking means comprises a locking pawl or ratchet device engaging a castellated locking ring or escapement on the cassette.

10. An apparatus according to Claim 9, wherein the locking pawl or ratchet is operated by water flow acting on a brake valve.

11. An apparatus according to Claim 9, wherein the locking pawl or ratchet is operated by any mechanical means during heat processing, loading or unloading operations.

12. An apparatus according to any preceding claim, wherein rotation of the locking ring is achieved by geared wheels or friction drives.

13. An apparatus according to any preceding claim, wherein the apparatus includes mechanical means to transfer product to and from the cassette.

14. An apparatus according to Claim 9, wherein the mechanical means comprises suction transfer cups or cam-operated actuators.

15. An apparatus according to any preceding claim, wherein the apparatus includes an additional cylindrical collar which can be rotated to change the size of the product carrying pockets.

16. An apparatus substantially as herein described with reference to and as illustrated in the accompanying drawings.