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(11) | EP 1 524 481 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Device for freezing products and method applying such device |
| (57) Device for freezing products, characterised in that it at least consists of two plates
(2-3; 2-2) in between which the product (12) to be frozen can be provided, whereby
these plates (2-3; 2-2) are erected such that they can be rotated, such that the distance
between the plates, at right angles to the plates, changes during the rotation. |
[0001] The present invention concerns a device for freezing products, as well as a method whereby such a device is applied.
[0002] The invention in particular concerns a device for freezing products, especially food, supplied in bulk, either or not prepacked.
[0003] Such devices are already known which make use of freezing plates which are vertically immersed at a certain distance from each other in a container with product to be frozen and which are slightly heated after the freezing in order to detach the blocks of frozen product from the freezing plates, such that the freezing plates can be lifted from the container.
[0004] A disadvantage of such known devices is that heating the freezing plates and cooling them again for subsequent use requires relatively much time and energy.
[0005] Another disadvantage is that extra provisions are required which make it possible to heat the freezing plates.
[0006] Another disadvantage is that, by heating the freezing plates, also the frozen product is locally heated at the contact surface with the freezing plates and, as a consequence, is locally defrosted, which has a negative effect on the storage life of the frozen product, especially in the case of food.
[0007] Devices with horizontal freezing plates are also known situated at a distance on top of one another and in between which the product to be frozen is provided. After the freezing, the freezing plates are in this case lifted one by one and pulled loose from the frozen product, such that the blocks with frozen product created in between the freezing plates can be removed one by one for further storage or processing.
[0008] A disadvantage of the latter type of known freezing devices is that the process for detaching the blocks is complex and time-consuming.
[0009] Another disadvantage is that powerful and expensive equipment is required for pulling the freezing plates loose from the frozen product.
[0010] The present invention aims a device in general for freezing products which is very efficient to use and which makes it possible to freeze a product in a simple and fast manner.
[0011] Moreover, it aims a device which, according to a preferred embodiment, can be made such that the above-mentioned and other disadvantages are remedied in that no extra heating elements or extra heavy appliances are required for detaching the frozen product.
[0012] To this end, the invention concerns a device for freezing products which at least consists of two plates in between which the product to be frozen can be provided, whereby these plates are erected such that they can be rotated and whereby, by rotating them, the distance between the plates is altered.
[0013] The product to be frozen is provided between the aforesaid plates when these plates are in a first position, after which the plates are moved closer together by rotating them into a second position, as a result of which the product is so to say clamped between the plates.
[0014] In this position of the plates, the product is frozen and the plates are then rotated into their first position again, as a result of which the frozen product is automatically detached from the plates, since the plates are moved further away from each other during the rotation on the one hand, and since the plates also shift in relation to each other as a result of the rotation, thus creating shearing forces which promote the detachment of the frozen product.
[0015] An advantage of such a freezing device according to the invention is that the frozen product can be detached in a very fast and simple manner by means of a simple revolving movement of the plates, whereby only a restricted force is required for this movement, partly thanks to the creation of the aforesaid shearing forces, such that no heavy means are required either in this case to develop said force.
[0016] Another advantage is that in most applications, no extra heating means are required either for detaching the frozen product. Normally, such heating means will not be provided. This does not exclude, however, that a combination of the rotatable plates with heating means is possible according to a variant.
[0017] Although the plates with the product to be frozen can be provided in a cold-storage room for freezing the product, at least one of the above-mentioned plates, and preferably both plates, are preferably made as freezing plates, such that the product makes contact with the freezing plates on two sides, as a result of which the freezing will be more efficient.
[0018] The freezing device according to the invention can be applied on an industrial scale with a large throughput, by providing a series of freezing plates in between which the product to be frozen can be applied and which can be rotated together between a first and a second position, whereby the freezing plates lie closer together in this second position than in the first position.
[0019] The invention also concerns a method for freezing products whereby a device according to the invention is applied and whereby the product to be frozen is provided between two plates; the plates are rotated such that the product is clamped in between them; the product is frozen; the plates are rotated back, such that these plates move further away from each other; and the frozen product is finally removed from between the plates.
[0020] In order to better explain the characteristics of the invention, the following preferred embodiments of a device according to the invention for freezing products are described as an example only without being limitative in any way, with reference to the accompanying drawings, in which:
figure 1 schematically represents a device for freezing products according to the invention;
figure 2 is a view according to arrow F2 in figure 1;
figures 3 and 4 represent the device according to figure 1, but for two other positions;
figure 5 represents a practical embodiment of a device according to the invention;
figure 6 represents the device according to figure 5, but in another position;
figure 7 represents a section according to line VII-VII F7 in figure 5;
figure 8 represents a section according to line VIII-VIII in figure 7;
figure 9 represents a variant of a device according to figure 5;
figure 10 represents the device according to figure 9 in another position;
figure 11 represents another variant of a device according to the invention;
figure 12 represents a section according to line XII-XII in figure 11 to a larger scale;
figure 13 represents another variant of a device according to the invention;
figure 14 represents the device from figure 12 in another position;
figure 15 represents a section according to line XV-XV in figure 14.
[0021] Figures 1 to 4 represent a device according to the invention in a very schematic manner which mainly consists of a frame 1 and two plates, 2 and 3 respectively, which are preferably parallel to each other and which are provided on one edge 4 such that they can rotate around parallel, in this case horizontal shafts, which in this case are formed of pens 5 fixed to the frame 1 and which mesh in flanges 6 provided on the aforesaid edge 4 of the plates 2-3.
[0022] In the given example, the top plate 2 is a freezing plate in which a cooling circuit which is not represented in the figures is integrated in the known manner whose inlet 7 and outlet 8 are connected to a cooling device 11 known as such which is only represented here in a schematic manner, by means of a coil 9, 10 respectively.
[0024] When the freezing process starts, as represented in figure 1, the plates 2-3 are put in a first position whereby the vertical distance between the parallel plates 2-3 is maximal and equal to the indicated distance A and whereby, in the given example, this first position corresponds to the horizontal position of the plates 2-3.
[0025] In this position, the product 12 to be frozen is provided between the plates 2-3 in any manner whatsoever, for example by injecting the product 12 between the plates 2-3 or by shifting the product 12 in bulk or packed between the plates 2-3.
[0026] As soon as the product 12 has been provided between the plates 2-3, as represented in figure 3, the plates 2-3 are rotated into a second position, whereby the distance between the plates 2-3 has been decreased to a distance B which is smaller than the distance A corresponding to the first position and whereby, in the given example, this second position corresponds to a slanting position of the plates 2-3.
[0027] As the plates 2-3 are moved closer together during the rotation, the product 12 to be frozen will be clamped between the plates 2-3, such that a close contact is created between the product 12 to be frozen and the plates 2-3.
[0028] The plates 2-3 are kept in this second position for a certain while, such that the product 12 to be frozen, thanks to the close contact with the freezing plate 2 and the circulation of the cooling medium of the cooling device in the freezing plate 2, is gradually cooled up to the core until the required temperature is reached.
[0029] As soon as the product has been sufficiently frozen, the plates 2-3, as represented in figure 4, are rotated back into their first position, preferably simultaneously, as a result of which the frozen product 12 is automatically and without much effort detached from the plates 2-3 as the plates 2-3, during the rotation, are removed from each other over a distance A minus B as a result of which they are pulled loose from the frozen product 12 on the one hand, and as the plates 2-3 shift parallel in relation to each other over a distance C on the other hand, such that shearing forces are created between the frozen product 12 and the plates 2-3 which promote the detachment of the frozen product 12.
[0030] It is clear that both plates 2-3 can also be made as freezing plates, as a result of which the freezing can be accelerated since the product 12 makes contact with a freezing plate at the top as well as at the bottom.
[0031] Another possibility is that none of both plates 2-3 is made as a freezing plate, whereby the frame 1 and the plates 2-3 are in this case provided in a freezing chamber guaranteeing the required cooling.
[0032] It is also clear that the plates 2-3 must not necessarily be parallel, nor that they must necessarily rotate around a horizontal shaft, but that use can also be made for example of vertical plates which can be rotated between two positions around a vertical shaft.
[0034] This device in this case mainly consists of a frame 1 and a series of plates 2, in particular freezing plates, which are preferably parallel to each other and which are each provided on an edge 4 such that they can rotate along a horizontal shaft, for example by means of pens 5 which are fixed at equal distances D from each other to the frame 1 and which are bearing-mounted in flanges 6 provided on the aforesaid edge 4 of each of the plates 2.
[0035] The plates 2 are connected to each other at their edge 13 situated opposite to the edge 4, in this case by means of two vertical struts 14 onto which pens 15 are fixed, preferably at regular distances D from each other, whereby these pens 15 are bearing-mounted in flanges 16 provided at the aforesaid edge 13 on the plates 2.
[0036] The aforesaid struts 14 are each coupled in a hinged manner at their top ends to a bar 18 of a hydraulic or pneumatic cylinder 19 by means of a pivot 17, whose body 20 is mounted to the frame 1 in a rotatable manner. To this end, the body is provided with two horizontal coaxial shafts 21 mounted in bearings 22 on the frame 1.
[0037] Guides 23 made of plastic or the like are provided at the top side of the plates 2 on the aforesaid opposite edges 4 and 13.
[0038] A cooling circuit which is not represented in the figures is integrated in the plates 2, whose inlet 7 and outlet 8 are connected by means of coils 9-10 respectively to a common inlet collect 24 for all plates 2 and a common outlet collector 25 for the cooling medium originating from a cooling device onto which these collectors are connected.
[0040] The working of the freezing device is very simple and analogous to that of the device discussed above.
[0041] The plates 2 are put in a horizontal position by means of the cylinder 19, as represented in figure 5, after which the product to be frozen is provided in the spaces between the plates 2 and the guides 23 on the edges of the plates 2 in any way whatsoever.
[0042] Next, the plates 2, as represented in figure 6, are rotated upward by withdrawing the bars 18 from the cylinders 19, such that the struts 14 and thus also the edges 13 of the plates 2 are lifted.
[0043] In this position, the product 12, of which only three portions are represented in figures 5 and 6 for clarity's sake, is frozen.
[0044] It is clear that most plates 2 hereby provide for a double cooling action, namely the cooling of the product lying on the plate on the one hand, and the cooling of the product lying against it on the bottom side on the other hand.
[0045] When the product 12 has been frozen, the cylinder bars 18 are pushed out of the cylinders 19 again, until the plates 2 are in their horizontal position again, as a result of which the plates 2 are moved away from each other and the frozen product 12 is detached from the plates 2.
[0046] The blocks of frozen product 12 can then be pushed one after the other out of the device, parallel to the guides 23, and they can be collected for further processing in a suitable manner on the back side of the device.
[0047] It is clear that the aforesaid struts 14 can also be made in the form of a cable or of links which are hinge-mounted between two adjacent plates 2 or the like.
[0048] On either side of the device can also be provided intermediate connecting struts 14A which are hinge-mounted to the plates 2. Thus is prevented that the plates 2 force themselves apart while the product is being pressed on.
[0049] It should be noted that the plates can be fixed such in one or several of their hinge points that they can move more or less freely, for example as the pens 5 and/or 15 mesh in groove-shaped holes. This makes the whole work more smoothly, among others as deviations due to temperature differences, tolerance differences and the like can have no influence then on the smooth operation.
[0050] It is also clear that the cylinder 19 can be replaced by any other drive whatsoever which makes it possible to make the plates 2 rotate.
[0051] Figures 9 and 10 represent a variant of a device according to the invention whereby this device is in this case provided, with suitable containers 27 in the shape of shallow trays whose height is almost equal to the minimum distance B between the plates 2 when they are in the freezing position, as represented in figure 10, on the one hand, and the width is almost equal to the distance between the guides 23 on the other hand.
[0052] The containers 27 are provided with an outward directed collar 28 on their top side edges with which the containers rest on the guides 23.
[0053] The working of this device is identical to that of the preceding embodiment, with this difference that the product 12 to be frozen is first loaded in the containers 27, and that the containers 27 loaded with the product 12 are then pushed on the plates 2 in the device.
[0054] In order to prevent that the loaded containers 27 would be too heavy, the length of the containers can be selected such that two or more of such containers 27 rest on a single plate 2 one after the other.
[0055] In this case, after the freezing, the containers 27 with frozen product 12 can be removed on the back side of the device by pushing in new containers with fresh product 12 to be frozen on the front side of the device between the plates 2.
[0056] Figures 11 and 12 represent a variant of a device for freezing products according to the invention, whereby several single devices, as mentioned above, are placed one after the other in a production line 29 and whereby also two such production lines 29 are provided next to each other in order to increase the throughput of the freezing device as a whole.
[0057] At the beginning of each production line 29 is provided a filling station 30 in which fresh product 12 to be frozen is loaded in containers 27, and a conveyor belt 31 runs as of this filling station 30 under the single devices of the production line 29 concerned.
[0058] On the front side of each single device is erected an automatic loading device 32 which is provided with a carriage 33 which can be moved up and down in which several containers 27 can be put on top of each other and onto which is provided a cylinder 34 which can push the containers 27 from the carriage 33 into the single device concerned, while an automatic unloading device 35 is provided on the backside of each single device concerned, which is also equipped with a carriage 36 which can be moved up and down in which several containers 27 can be taken from the device concerned and placed on top of each other.
[0059] The containers 27 which have been loaded in the filling station 30 are led to the successive freezing devices by the conveyor belt 31, where they are picked up by the automatic loading devices 32 and are successively pushed between the plates 2 of the freezing devices concerned, as a result of which the containers 27 with already frozen product 12 will be pushed out on the backside of the devices, and where these containers 27 with frozen product 12 are collected by the automatic unloading devices 35 and are loaded on the conveyor belt 31 to be carried off to the end of the production line 29 concerned for further processing.
[0060] Figures 13 to 15 represent another variant of a device according to the invention whereby a device 37 is centrally provided between two single freezing devices erected next to each other, which consists of a carriage 38 which is provided such that it can be shifted on a central guide 39 extending in the longitudinal direction of the plates 2, whereby this carriage 38 is provided with carriers on either side which can work in conjunction with the containers 27.
[0061] In the given example, the carriers consist of laterally protruding pens 40 which can work in conjunction with cams 41 provided on the collar 28 of the containers 27. It is clear, however, that other forms of carrier mechanisms can be applied. The special cams 41 are not really necessary either, as the carriers can also push directly against the containers themselves according to a variant.
[0062] When the product 12 has been frozen in one or in both single freezing devices, the plates 2 of the freezing device concerned are rotated into the horizontal position, and the carriage 38 of the device 37 is moved from the front to the back, as a result of which the pens 40 stop against the cams 41 of the containers 27 which have been put in a horizontal position; as a result of which these containers 27 are pushed out of the freezing device.
[0063] Thus, the containers 27 can be pushed out of the device one after the other. The carrier can also mesh directly behind the last container 27, such that this container is pushed to the outlet simultaneously with all the containers situated in front of it. The carriers can also be useful while loading.
1. Device for freezing products, characterised in that it at least consists of two plates (2-3; 2-2) in between which the product (12) to
be frozen can be provided, whereby these plates (2-3; 2-2) are erected such that they
can be rotated, such that the distance between the plates, at right angles to the
plates, changes during the rotation.
2. Device according to claim 1, characterised in that it comprises a series of rotatable plates (2), whereby product to be frozen is each
time provided between two successive plates (2).
3. Device according to claim 1 or 2, characterised in that at least one plate (2) is a freezing plate.
4. Device according to any of the preceding claims, characterised in that all the plates (2) are freezing plates.
5. Device according to any of the preceding claims, characterised in that the plates (2) are parallel.
6. Device according to any of the preceding claims, characterised in that the plates (2) can be rotated around parallel shafts.
7. Device according to any of the preceding claims, characterised in that all the plates (2) are connected to a drive.
8. Device according to claim 7, characterised in that the plates (2) are connected to a common drive by means of at least one strut (14),
bar or the like which is hinge-mounted to each plate (2).
9. Device according to claim 8, characterised in that the common drive is formed of a cylinder.
10. Device according to any of the preceding claims, characterised in that the plates (2) are provided with guides (23) on two edges (4-13) situated opposite
to each other.
11. Device according to any of the preceding claims, characterised in that it is provided with containers (27) for the product to be frozen whose height is
almost equal to the distance (B) between two plates (2) when they are in the freezing
position.
12. Device according to claims 10 and 11, characterised in that the containers (27) are provided with a collar (28) extending above the guides.
13. Device according to claim 11 or 12, characterised in that, next to the device for freezing products, is provided a device (37) which consists
of a carriage (38), whereby this carriage (38) is provided with carriers which can
work in conjunction with the containers (27) for loading and/or unloading them.
14. Device according to any of the preceding claims, characterised in that it is provided with an automatic loading device (32) and/or with an automatic unloading
device (35) for the containers (27).
15. Device according to any of the preceding claims, characterised in that it is provided with a conveyor belt (31) running under the freezing device from where
the products to be frozen are brought in the device, whereby the products coming out
of the device are also carried off via the same conveyor belt (31).
16. Method for freezing products whereby a device according to the invention is applied
according to one or several of the preceding claims, characterised in that the product (12) to be frozen is provided between two plates (2-3); these plates
(2-3) are rotated such that the product to be frozen is clamped in between them; the
product (12) is frozen; the plates (2-3) are rotated back, whereby these plates move
further away from each other; and the frozen product (12) is finally removed from
between the plates (2-3).