WO2011009461A2

WO2011009461A2 - Vertical plate freezer

Info

Publication number: WO2011009461A2
Application number: PCT/DK2010/050182
Authority: WO
Inventors: Christian BRØCHNER POULSEN
Original assignee: Carnitech Aps
Priority date: 2009-07-22
Filing date: 2010-07-09
Publication date: 2011-01-27
Also published as: WO2011009461A3

Abstract

Vertical plate freezer of the type comprising a substantially horizontal and flat bottom plate ( 10 ), a plurality of vertical freezing plates ( 12 ), and side limiting means creating a number of stations or freezing chambers, where means are provided for supplying a cryonic fluid to the freezing plates ( 12 ) and the bottom plate ( 10 ), and further that means are provided for moving the bottom or the freezing plates vertically relative to each other, and where means are provided for supplying a hot medium to either the bottom and/or the freezing plates, and emptying means ( 20 ) are provided for removing frozen blocks horizontally along the bottom plate.

Description

Vertical plate freezer

Field of the Invention

The present invention relates to a vertical plate freezer as well as a method for using a vertical plate freezer according to the invention. Background of the Invention

In the art vertical plate freezers are commonly used for a number of purposes, but in particular used when freezing fish and other seafood products.

These types of freezers are often used onboard fishing vessels or in fish treating facto- ries. When used onboard fishing vessels usually substantially complete fish are arranged in the freezing chambers in order to achieve an as fast as possible freezing process in order to keep the product as fresh as possible.

In the chambers in the vertical freezers the products are frozen into so-called blocks. How these are created will be explained below.

After the blocks have attained the desired core temperature the freezer must be emptied and the blocks transported for storage onboard the ship. These processes must be optimized as much as possible in order to use the freezing capacity to a premium in that space particularly on board a ship is very limited, and as such the freezer must be utilized to its maximum.

Object of the Invention

The present invention is particularly directed to a vertical plate freezer which facilitates easy and fast emptying of the freezer such that this part of the process which has until now been the most time-consuming process may be reduced substantially.

A vertical plate freezer is typically constructed by having a substantially flat bottom plate on which bottom plate a number of freezing plates are arranged vertically. Along the side edges of the bottom plate and the freezing plates are arranged side members such that the bottom plate, two adjacent freezing plates and the side limitations create a hollow space which will be referred to as a station. The products to be frozen are placed in the station after which a cryonic liquid is circulated in die freezing plates whereby the products will be frozen. When the products are frozen they need to be removed from the freezer, and this may be carried out in a number of different manners. The traditional way is to elevate the bottom such that the frozen products which will hereinafter be referred to as blocks are lifted free from the freezing plates and may then be removed for example by hand. This process has also been automated by providing a small crane which will be superposed the blocks and lift the blocks from the bottom and unto for example a conveyor or a packaging station.

A further example of automation is illustrated in WO 2007/067062 wherein the blocks are frozen as described above, and when the desired core temperature has been reached, the bottom is elevated thereby exposing the frozen products, the blocks. In this position the blocks are free from the freezing plates and only resting on the bot- torn plate. In this position a robotic arm is superposed the blocks, and by gripping means grips the frozen block and removes it to a desired position.

Although this method has alleviated at least part of the manual labour involved in emptying the freezer, the process is still very limited in mat the robotic arm may only remove one or two blocks at a time and takes up a substantial amount of space and still only operates at a relatively slow pace.

It is therefore an object of the present invention to provide a freezer of the type described above which facilitates and improves the emptying process of the vertical plate freezer.

Description of the Invention

The invention addresses this by providing a vertical plate freezer of the type comprising a substantially horizontal and flat bottom plate, a plurality of vertical freezing plates, and side limiting means, wherein means are provided for supplying a cryonic fluid to the freezing plates and the bottom plate, and further that means are provided for moving the bottom or the freezing plates vertically relative to each other, and that means are provided for supplying a hot medium to either the bottom and/or the freezing plates, and emptying means are provided for removing frozen blocks horizontally along the bottom plate. By supplying a hot medium to either the bottom and/or the freezing plates the surface layer of the frozen block will thaw slightly thereby create a phase change in the ice such that water will be present. The water will seep downwards and between the bot- torn and the blocks a very thin water layer will be present. This water layer reduces the friction such that the frozen blocks substantially without friction against the bottom plate may be slid across the bottom plate into a position where the blocks may be removed from the freezer. The further feature of moving the bottom relative to the freezing plates, for example by lowering the bottom, provides a freezer solution where the bottom plate may be one substantially flat homogenous surface such that the blocks may slide very easily on top of this surface. Alternatively, by removing/elevating the freezing plates the same situation will occur, namely that the bottom is substantially free from any obsta- cles and by providing the substantially frictionless contact between the frozen blocks and the bottom, the blocks may be slid along the bottom to the appropriate discharge position.

In a further advantageous embodiment the means for removing the frozen blocks hori- zontally along the bottom plate comprise mechanical means engaging each block for pushing it along the bottom substantially equidistant in relation to adjacent blocks.

As there is substantially no friction between the frozen blocks and the bottom, the mechanical means may easily engage and push the blocks along the bottom. By fur- thermore maintaining the same distance between the blocks, for example a distance corresponding to the space occupied by the freezing plates, which at this point have been removed, the blocks will be delivered to a discharge position as single blocks. This may facilitate further handling of the blocks. In a still further advantageous embodiment an example of the mechanical means is illustrated where the mechanical means are in the shape of a plurality of fins arranged on an endless belt which belt is arranged alongside the bottom, such that as the freezing plates and side limiting means are removed the fins are interposed in the space left by the removed freezing plates between two adjacent blocks, after which the belt is rotated, whereby the fins push the blocks along the bottom. When the side limiting means and the freezing plates have been removed as already described above, the frozen blocks will be standing on the substantially flat bottom only separated by a very thin liquid layer. In this stage the mechanical means having a plurality of fins arranged on endless belts may be brought into a position where the fins will insert themselves between the frozen blocks, and by rotating the endless belt and thereby also the fins, the fins will push the blocks along the bottom.

It may be advantageous to arrange mechanical means on both sides of the bottom, such that a more controlled and homogenous propulsion of the blocks due to the insertion of the fins will be obtained.

In an alternative embodiment the mechanical means are in the shape of a plurality of fins arranged on a reciprocating rod arranged alongside the bottom, where the fins may fold against a biasing means in one direction of the rod but not in the other direction, such that as the freezing plates and side limiting means are removed the fins are interposed in the space left by the removed freezing plates between two adjacent blocks, after which the reciprocating rod is activated, whereby the fins in a first direction of movement of the rod push the blocks forward along the bottom and in a second opposite direction fold and are moved out of the space between two adjacent blocks, and when the reciprocating movement is reversed such that the movement is in the first direction, the fins will be inserted in another space between two adjacent blocks and move the blocks along the bottom. This mechanism works by inserting the fins in the space between two frozen blocks previously occupied by the freezing plates. As the fins are biased in one direction and able to fold against the bias, the fins will be urged to stand out perpendicular to the rod such that as the rod reciprocates, i.e. moves in a first direction, the fins will push the blocks forward corresponding to the length of the reciprocating movement. As the reciprocating movement changes direction and thereafter goes in the opposite direction, the fins will fold and thereby retract themselves from their engagement with the blocks and the space left between the blocks.

As the reciprocating movement switchs back to movement in the first direction, the fins, due to the biasing means, will be forced to insert themselves into the space be- tween two frozen blocks previously occupied by the freezing plates. In this manner a number of blocks corresponding to the number of fins will be moved in a stepwise fashion in the first direction of the reciprocating movement.

In a further alternative embodiment the mechanical means are in the shape of a plural- ity of flanges equidistantly arranged on and extending from a reciprocating rod arranged alongside the bottom, where the flanges are provided with high friction means in a distal end away from the rod, such that as the freezing plates and side limiting means are removed the high friction means are brought into contact with a side of a frozen block, after which the reciprocating rod is activated, whereby the flanges in a first direction of movement of the rod engage and push the blocks forward along the bottom and in a second opposite direction disengage the blocks, and when the reciprocating movement is reversed such that the movement is in the first direction, the high friction means engage another block and moves the blocks along the bottom. In this embodiment the mechanical means instead of being arranged in a free space between two adjacent blocks will engage the side edges of the blocks by high friction means, for example a claw structure or the like, and engage the blocks in a manner such that as the reciprocating rod moves back and forth as already described above the blocks will also move forward in a stepwise fashion due to their engagement with the high friction means arranged at the distal end of the flanges. At the end of the movement in the first direction the high friction means will disengage the blocks which will thereafter be left standing on the bottom plate until another frictional means arranged at a distal end of a flange engage the side edge of the block and push it further along the bottom plate.

In a still further advantageous embodiment the means provided for supplying a hot medium optionally to the bottom and/or the freezing plates are in the shape of a hot gas or liquid circulated in the bottom and/or freezing plates or electrical heating means arranged in the bottom and/or freezing plates, where the means are capable of raising the temperature in the surface layer of the blocks in order to thaw water present in the surface layer of said blocks.

The source of heating should be sufficient in order to thaw the surface layer of the frozen block in order to create the water film on which the blocks will slide on the bottom plate. Typically a hot gas will be used, but also the provision of electrical means, especially when dividers are provided as will be discussed below, may be advantageous either alone or in combination. In a still further advantageous embodiment dividers are provided where said dividers are suitable to be arranged between and in contact with two adjacent freezing plates and the bottom, thereby dividing the stations into two or more sections. The divider serves to divide a block in two, three or more sections which will make it easier to handle, especially if manual handling is required further down the line. The dividers may or may not comprise means for freezing and/or heating, but mainly serve to divide the station into two or more sections.

In a further advantageous embodiment the dividers are provided as integrated parts of the freezing plates, where a full divider may be arranged on each freezing plate, or where a part of a divider is integrated in one freezing plate and the other part of the divider is integrated in the adjacent freezing plate, and where heating means are provided in the divider or part of divider,

In order to minimize the manual labour involved in operating the freezer, the dividers may be integrated in the freezing plates such that an entire divider may be arranged vertically and perpendicularly to the large surface of a freezing plate on one side of said freezing plate such that when arranging the freezing plates on the bottom, the divider integrated in one freezing plate will join the adjacent freezing plate on the side of the freezing plate where there is not integrated divider. Alternatively, each freezing plate may comprise parts of a divider arranged on both flat sides of the freezing plates such that as the freezing plates are arranged on the bottom in the correct position, the two parts of the dividers will engage and create a full divider.

In this connection it may also be advantageous to provide heating in the dividers as the heating will make the frozen block disengage from the freezing plates and the dividers as the water falls.

The invention is also directed at a method of using a vertical plate freezer as discussed above. The method comprises the following steps which are carried out in sequence: a) the plurality of vertical freezing plates are arranged vertically and equidistant on and in contact with the bottom plate;

b) the side limiting means are arranged along the bottom side edges and the vertical freezing plates side edges, thereby creating a plurality of stations;

c) the stations are filled with the material to be frozen into blocks;

d) a cryonic fluid is supplied to the freezing plates and/or the bottom plate and circulated until the desired temperature has been reached in the now frozen blocks;

e) the cryonic flow is reversed and instead a hot gas, ϋquid or fluid is circulated for a short time in the freezing plates and the bottom plate until water in the surface layer of the blocks is liquid again;

f) the bottom plate is lowered or the vertical freezing plates and the side limiting means are elevated, leaving the frozen blocks free standing on the bottom plate;

g) the emptying means are activated, sliding the blocks off the bottom plate;

h) the bottom plate is elevated into contact with the vertical freezing plates and the side limiting means or the vertical freezing plates and the side limiting means are lowered into contact with the bottom plate.

Further advantageous method steps are set out in the further dependent method claims.

Description of the Drawing

The invention will now be explained with reference to the accompanying drawing wherein

Figs. 1-3 shows plane views of a first embodiment of a freezer according to the invention as seen from various views, Fig. 4 and 5 shows alternative emptying means,

Fig. 6a) and b) shows details of freezing plates with dividers.

Fig. 7 shows plane view of another embodiment of a freezer according to the invention— seen from the side,

Fig. 8 shows a plane view of the freezer cf. Fig. 7 - seen from above,

Fig. 9 shows a plane view of a further embodiment of a freezer according to the invention, and Fig. 10 shows a perspective view of the freezer shown in Fig. 9.

Figs. 1 -3 illustrate a preferred embodiment of a vertical freezer according to the in- vention. The shown vertical plate freezer comprising a bottom 10, freezing plates 12 and side limitation means (not shown). Between adjacent freezing plates 12 is created a station 14 which station is filled with the product to be frozen, for example fresh fish. In Fig. 1 the freezer is in the process of freezing the product in the stations 14. In this embodiment the freezing plates 12 as well as the bottom 10 are in an elevated position meaning that as the freezing cycle is completed the bottom 10 may be lowered relative to the freezing plates 12 as illustrated with reference to Fig. 2.

As the freezing cycle is completed, the cryonic liquid which is circulated in the interior of the freezing plates 12 and the bottom 10 is replaced by a heated gas such that a surface layer of water is created against all freezing surfaces 10, 12. In this manner it is possible to lower the bottom 10 as illustrated in Fig. 2 such that the freezing blocks 12 will remain in position but the bottom 10 together with the frozen blocks 16 are lowered into the position as illustrated in Fig. 2. In this position the blocks 16 are free standing on top of the bottom 10. Due to the liquid layer created by heating of the bottom 10 and the freezing plates 12 for a short period of time, there is substantially no friction between the bottom 10 and the underside of the blocks 16, such that the blocks 16 may slide easily on the top surface of the bottom 10.

In this position emptying means 20 only partly illustrated in Fig. 2 are moved into engagement with the blocks 16. In this embodiment the emptying means 20 are in the shape of an endless conveyor belt 22 on which conveyor belt 22 a number of fins 24 are equidistantly arranged substantially corresponding to the position of the freezing plates 12. By inserting the fins 24 in the space 26 left between the blocks 16 by the freezing plates 12 and rotating the endless conveyor belt 22 the fins will engage the blocks 16 and push them towards the left as indicated by the arrow 28. In this manner the blocks 16 will be moved onto an emptying conveyor 30 provided at one end of the vertical freezer whereby the blocks 16' may be transported for further processing in the direction indicated in Fig. 3 with reference to the arrow 32. In the embodiment of the invention illustrated with reference to Figs. 1-3, the bottom is lowered relative to the freezing plates but in other freezer constructions it may be possible to elevate the freezing plates into a position as illustrated with reference to Fig. 2. For any of these two embodiments the operation and method of using the vertϊ- cal freezer according to the invention will be substantially the same.

As should be evident from the above explanation the feature of providing heating in the bottom 10 and the freezing plates 12 for a short period in order to create a water layer especially between the bottom 10 and the frozen blocks 16 is essential to the invention. This water layer reduces the friction to nearly nil, and as such it becomes very easy to slide even heavy blocks 16, which by way of example have the following size (height x width x thickness - 1070 x 530 x 100 mm), along the substantially fiat bottom 10 in a direction as indicated by the arrow 28 to the emptying conveyor 30. Consequently the need for manual operations or even heavy lifting as is the case with prior art systems is completely avoided, and the freezer may be quickly and reliably emptied with a minimum of effort.

In Fig. 4 is illustrated an alternative embodiment of the emptying means. In this embodiment the emptying means 20 comprises two reciprocating rods 32, 34. The rods 32, 34 are adapted to be arranged alongside the bottom 10 at a certain distance above the bottom 10 in order to engage the frozen blocks 16 by inserting flanges 36 in the space 26 left by the freezing plates 12. The reciprocating rods 32, 34 are arranged in bearings 38 and driven by two cylinders 40. In order to bring the flanges 36 into and out of engagement the rods 32, 34 may be turned as indicated by the arrows 42. As the reciprocating rods are moving in a first direction indicated by the arrow 44 corresponding to moving the blocks 16 towards the emptying conveyor 30 indicated with the arrow 28 in Fig. 2, the flanges 36 are arranged substantially horizontally inside the space 26 between two adjacent freezing blocks. Before the reciprocating rods change directions to the opposite direction indicated by the arrow 44 the cylinder 46 is activated whereby the rods 32, 34 are turned as indicated by the arrows 42 whereby the flanges 36 are brought into a more or less vertical position free of engagement with the blocks and the space 26. The reciprocating movement thereafter brings the flanges back in direction opposite the indication by the arrow 44 whereby the flanges 36 upon activation of the cylinder 46 once more will be brought into a space 26 further back from the emptying conveyor 30. In this manner the flanges 36 will be brought into and out of engagement with the frozen blocks and thereby move them in single file towards the emptying conveyor.

In Fig. 5 is illustrated yet another embodiment of the emptying mechanism where a reciprocating rod 32', 34' are provided with flanges 50 which flanges at a distal end remote from the fastening of the flanges 50 to the reciprocating rods 32', 34' are provided with high friction means 52, for example spikes or the like. The high friction means 52 are suitable to engage the side surface 54 of a frozen block 16 such that prior to movement of the rods 32', 34' the high friction means 52 are inserted in a side surface 54 of a frozen block 16. Then the reciprocating rod 32', 34'is brought to move in a first direction indicated by the arrow 44 whereby the blocks 16 will move in the same direction towards the emptying conveyor 30 (not shown). At the end of the stroke of the reciprocating rods 32', 34' the reciprocating rods 32', 34' will be turned as indicated by the arrow 42' whereby the high friction means 52 will come free of engagement with the frozen block 16. At this point the reciprocating rods 32', 34' will move oppositely to the direction indicated by the arrow 44 and be positioned outside a new frozen block 16 after which the high friction means 52 by rotation of the rod 32', 34' as indicated by the arrow 42' will be brought into engagement with a new block to be moved forward in the same manner as described above etc.

In some instances it is desirable to create half blocks by inserting dividers 60 separating a block 16 into two half blocks. At the same time as the freezing plates 12 are re- moved, the dividers 60 are also removed. Before the emptying means 20 in any of the illustrated embodiments are activated, the half blocks are lightly pushed together such that the emptying means 20 will move two half blocks as one single block as already described above. The embodiment described with reference to Fig. 4 may also be without the turning motion but where the fins 36 are mounted in a hinge-like manner, such that they may fold about a vertical axis. Furthermore, biasing means are provided such that as the reciprocating means are reversed, the fins 36 will fold towards a position parallel to the reciprocating rods 32, 34, but due to the action of the biasing means they will be urged into a position as illustrated with reference to Fig. 4. Therefore, as a consequence, as the next freeze base 26 is in front of a fin 36, the fins 36 will insert themselves into the space between two adjacent blocks 16, 60. With respect to the embodiment illustrated with reference to Figs. 1 , 2 and 3 tests have indicated that the same result may be achieved with endless conveyor belts without the fins 24 but substantially flat conveyor belts in that the friction between the conveyor belts and the side surfaces of the blocks 16 may be sufficient in order to move the blocks 16 towards the emptying conveyor 30.

In order to ensure a complete emptying of the freezer a beam may be arranged between the two conveyor belts 22 in order to ensure the emptying should any friction connection between a block and a conveyor belt be missing. In Figs. 6 a) and b) are illustrated in a schematic form a top view of two stations including dividers.

In Fig. 6a the freezing plates 12 are both provided with part of a divider 61 , 62. Together the divider parts 61 , 62 constitute a full divider 60. The divider parts 61 , 62 are integral with the freezing plates 12, and as such when the freezing plates are removed, the parts of the dividers 61 , 62 are removed together with the freezing plates 12.

In the embodiment illustrated with reference to Fig. 6b the divider 60 is welded as indicated by the welding seam 63 to the freezing plate 12' such that in a vertical plate freezer every other freezing plate 12' will be equipped with a divider 60.

In order to facilitate the removal of the freezing plates from the frozen blocks, the dividers 60, 61. 62 may be provided with heating means in the same manner as the freezing plates 12.

Figs. 7 and 8 show another embodiment of a vertical freezer according to the invention - where the bottom plate 10 is shown in its lowermost position that is emptying position below the freezer unit 12, 14. The frozen blocks 16 are moved towards the right hand side in the direction of a transverse roller conveyor 64 conveying the blocks to a storage or possible a packing station. The moving of the frozen blocks 16 towards the roller conveyor 64 is carried out by pushing means 66 operated by means of two threaded rods 68 - and at right the end of the freezer the frozen blocks 16 are one by one swung down on to the roller conveyor 64 by means of swingable arranged forks 70.

Figs. 9 and 10 show a further embodiment of a vertical freezer according to the invention by which the emptying means comprises two endless chain conveyors 72 arranged at opposite sides of the frozen blocks 16 in order to moved the frozen blocks successively to the left hand side towards a transverse belt conveyor 74 serving the conveying of the frozen blocks to a storage or packing station.

The chain link of said endless chain conveyor may be provided with projection means adapted to engage with the sides of the frozen blocks 16 and furthermore said endless chain conveyors 72 at each side of the freezer may advantageously be provided with an engagement system adapted to serve for safe abutment of the chain links against the opposite sides of the frozen blocks 16. Such engagement means could comprise a system for forcing said endless chain conveyors 72 towards the side of the frozen blocks 16 for engaging them in order to establish said successive movement of the frozen blocks 16 towards said transverse belt conveyor 74.

In practice the heating cycle shall be carried out for approximately two minutes which is enough to loosen the blocks from the elements of the freezer and create the water film necessary in order to slide the blocks effortlessly on top of the bottom 10. It is foreseen that a plurality of vertical plate freezers according to the invention may be arranged extending substantially perpendicularly from a central emptying conveyor such that as the blocks by any of the means described above are transported from the vertical plate freezer onto the emptying conveyor, a central emptying conveyor may convey frozen blocks from a plurality of freezers.

Finally it should be mentioned that the emptying of the freezer may be obtained in a quite easy manner by just slightly tilting the bottom 10 in order to let the frozen blocks 16 slide by themselves towards the emptying end of the freezer - of course by elevating the far end of the bottom 10 - as seen from the emptying end of the freezer.

Claims

1. Vertical plate freezer of the type comprising a substantially horizontal and flat bottom plate, a plurality of vertical freezing plates, and side limiting means, characterised in that means are provided for supplying a cryonic fluid to the freezing plates and the bottom plate, and further that means are provided for moving the bottom or the freezing plates vertically relative to each other, and that means are provided for supplying a hot medium to either the bottom and/or the freezing plates, and emptying means are provided for removing frozen blocks horizontally along the bottom plate.

2. Vertical plate freezer according to claim 1 wherein the means for removing the frozen blocks horizontally along the bottom plate comprises mechanical means engaging each block for pushing it along the bottom substantially equidistant in relation to adjacent blocks.

3. Vertical plate freezer according to claim 2 wherein the mechanical means is in the shape of a plurality of fins arranged on an endless belt which belt is arranged alongside the bottom, such that as the freezing plates and side limiting means are removed the fins are interposed in the space left by the removed freezing plates between two adjacent blocks, after which the belt is rotated, whereby the fins push the blocks along the bottom.

4. Vertical plate freezer according to claim 2 wherein the mechanical means is in the shape of a plurality of fins arranged on a reciprocating rod arranged alongside the bot- torn, where the fins may fold against a biasing means in one direction of the rod but not in the other direction, such that as the freezing plates and side limiting means are removed the fins are interposed in the space left by the removed freezing plates between two adjacent blocks, after which the reciprocating rod is activated, whereby the fins in a first direction of movement of the rod push the blocks forward along the bot- torn and in a second opposite direction fold and are moved out of the space between two adjacent blocks, and when the reciprocating movement is reversed such that the movement is in the first direction, the fins will be inserted in another space between two adjacent blocks and move the blocks along the bottom.

5. Vertical plate freezer according to claim 2 wherein the mechanical means is in the shape of a plurality of flanges equidistantly arranged on and extending from a reciprocating rod arranged alongside the bottom, where the flanges are provided with high friction means in a distal end away from the rod, such that as the freezing plates and side limiting means are removed the high friction means are brought into contact with a side of a frozen block, after which the reciprocating rod is activated, whereby the flanges in a first direction of movement of the rod engage and push the blocks forward along the bottom and in a second opposite direction disengage the blocks, and when the reciprocating movement is reversed such that the movement is in the first direc- tion, the high friction means engages another block and moves the blocks along the bottom.

6. Vertical plate freezer according to claim 1 wherein the means provided for supplying a hot medium optionally to the bottom and/or the freezing plates are in the shape of a hot gas or liquid circulated in the bottom and/or freezing plates or electrical heating means arranged in the bottom and/or freezing plates, where the means are capable of raising the temperature in the surface layer of the blocks in order to thaw water present in the surface layer of said blocks.

7. Vertical plate freezer according to claim 1 wherein dividers are provided, where said dividers are suitable to be arranged between and in contact with two adjacent freezing plates and the bottom, thereby dividing the stations into two or more sections.

8. Vertical plate freezer according to claim 7 wherein the dividers are provided as in- tegrated parts of the freezing plates, where a full divider may be arranged on each freezing plate, or where a part of a divider is integrated in one freezing plate and the other part of the divider is integrated in the adjacent freezing plate, and where heating means are provided in the divider or part of divider.

9. Method of using a vertical plate freezer according to claim 1 wherein the following steps are carried out:

a) the plurality of vertical freezing plates are arranged vertically and equidistant on and in contact with the bottom plate;

b) the side limiting means are arranged along the bottom side edges and the vertical freezing plates side edges, thereby creating a plurality of stations; c) said stations are filled with the material to be frozen into blocks;

e) said cryonic flow is reversed and instead a hot gas, liquid or fluid is circulated for a short time in the freezing plates and the bottom plate until water in the surface layer of the blocks is liquid again;

f) said bottom plate is lowered or the vertical freezing plates and the side limiting means are elevated, leaving the frozen blocks free standing on the bottom plate;

g) said emptying means are activated, sliding the blocks off the bottom plate;

h) said bottom plate is elevated into contact with the vertical freezing plates and the side limiting means or the vertical freezing plates and the side limiting means are lowered into contact with the bottom plate.

10. Method according to claim 9 wherein between step b) and c) one or more dividers are arranged perpendicular to two adjacent freezing plates, dividing the station in two, three or more sections, and where the means for emptying the freezer, initially pushes the separate part blocks together, before the blocks are slid of the bottom plate.

1 ] . Method according to claim 9 or 10 wherein the frozen blocks are sliding on the thawed water along the bottom, and where the blocks at the end of the bottom plate are transferred to a conveyor.