EP0936427A1 - Device for cooling a fixed cooled plate and means for moving articles on the mentioned plate - Google Patents

Abstract

The cooling bed is designed to freeze an article (1a) which passes over a fixed cooling bed (2) having an article feed end (3) and an article exit end (4). The articles to be frozen rest directly on the surface of the cooling bed (2) during their passage over it. Toothed rollers (5a), which are regularly spaced along the bed are provided to move the articles over the bed (2). The rotational speed of the rollers (5a) is controlled by a unit (8a) and the roller separating distances can be adjusted.

Description

The invention relates to the field of cooling installations. We will note which is understood in the present description by the term "cooling", lowering the temperature of a product below its initial temperature up to a temperature which may or may not be negative. Such a term covers in particular the deep-freezing and freezing, i.e. cooling products to negative temperatures as known to those skilled in the art, used in particular in the food industry.

More specifically, the invention relates to a cooling device including a cooled hearth allowing articles to be cooled very quickly.

• "croûter" les produits alimentaires, c'est-à-dire refroidir seulement une ou plusieurs de leurs faces extérieures afin de faciliter leur surgélation ou leur congélation ultérieure ;
• surgeler ou congeler les produits c'est-à-dire les refroidir à coeur.

The invention finds its application in particular for:

• "crusting" the food products, that is to say cooling only one or more of their outer faces in order to facilitate their freezing or their subsequent freezing;
• freeze or freeze the products, i.e. cool them to the core.

In crusting plants known from the state of the art, only one surface layer of at least one side of the product is sufficiently cooled to freeze its shape and thus facilitate its deep freezing or subsequent freezing, i.e. its cooling to the core, avoiding it from sticking to the support on which it transits during this operation.

We know in the prior art crusting facilities comprising a conveyor belt on which the products to be crusted pass through inside a chamber and onto which a refrigerant gas is sprayed. Such an installation is in particular described in American patent US-A-5,509,278 (Kiczek).

Such a technique has the disadvantage of requiring the use of a gas refrigerant, which induces significant implementation costs and makes it more complex the installations implementing it.

We also know in the prior art a crusting installation in which the products to be crusted pass on a thin conveyor film of material plastic sliding in contact with a cooled floor in which a low coolant temperature is recycled in a closed circuit. Upon contact with the conveyor film, the underside of the product begins to freeze on a certain thick (crust) and shape of the product is thus frozen. Thanks to such crusting of the underside of the product, it is then rigid enough to be easily and quickly frozen or frozen. This type of installation is described in particular in French patent FR2693877.

This type of crusting installation has the disadvantage of implementing a plastic film between the refrigerated support and the product to be crusted and therefore to involve a loss of the frigories actually transmitted to it. The crust must therefore be in contact with the conveyor film for a longer time than if it were in direct contact with the cooled floor.

For deep-freezing or freezing itself, the products to be deep-frozen or freeze, preferably previously crusted, pass through a tunnel deep-freezing or freezing where they are put in contact with a fluid or a support refrigerated. Many types of tunnel are known in the state of the art deep freezing and / or freezing.

By way of example, mention may be made of the tunnels in which the products to be cooled circulate in an enclosure, cooled by cooling circuits, and provided with an endless helical belt, as described in the French patent FR2693877 cited above. Such a technique involves the need to cool the entire enclosure without directly cooling the endless belt. This type of tunnel therefore implements an endless carpet which scrolls in a refrigerated atmosphere but which does not constitute a directly cooled sole. The time required for cooling at the heart of the product is therefore longer.

In another type of installation, the products to be cooled pass through a bath coolant. Thus, in the technique described in American patent US-A-4,361,016 (Multack), the products to be refrigerated pass through ice water. The products to be cooled are transported by a flexible conveyor belt made of plastic and moved by rotating cylinders. This conveyor belt is provided spacers, integrated into the conveyor belt, to prevent products to cool to stick to each other. The technique described in US patent US-A-5,509,277 (Kieczek) also implements a passage of the products to be refrigerated in a cooling bath.

These techniques have the disadvantage of involving the passage of the product to freeze in a liquid, which prevents their use for a certain number of products.

In the technique described in US patent US-A-4,534,183 (Hashimoto), the products to be frozen pass through a steel conveyor, the lower surface is continuously cooled by spraying a coolant stored under the conveyor, a bag refrigerated by a liquid and delimited by a flexible sheet which conforms to the shape of the products being also provided above the products for cooling the upper side thereof.

US patent US-A-4,555,914 (Kanto) describes a similar technique according to which the products to be cooled are transported in a refrigerated enclosure in being wedged between the belts of two synchronized conveyors, namely a conveyor lower and an upper conveyor, each of the conveyor belts being cooled by contact with a coolant.

These techniques have the drawback of requiring complex installations to be carried out.

The objective of the present invention is to propose a technique allowing the delivery of a product to be cooled by direct contact with a cooled hearth, that is to say involving neither the use of a plastic conveyor film, nor the passage of product in coolant.

Another object of the present invention is to present such a technique which can be easily implemented in installations that are not very complex to produce.

Another object of the present invention is to describe such a technique which allows very rapid cooling of the products.

These various objectives are achieved thanks to the invention which relates to a device for cooling an article or articles comprising at least one fixed cooled hearth having at least one feed end at which said item (s) to be cooled are supplied and at least one end outlet at which the cooled item (s) are removed, the at least one articles resting directly on said cooled sole when they pass over it, said device being characterized in that it has means designed to allow the movement of said articles on said fixed cooled floor from said end supply to said discharge end.

The invention therefore provides cooling of articles on a cooled hearth fixed offering the advantage of involving direct contact between this cooled hearth and said articles and therefore a short cooling time thereof. Thanks to the means designed to allow movement of said articles on said fixed cooled floor from said feed end to said discharge end, the articles are moved to this sole without loss of frigories.

The invention can be implemented on any type of sole cooled by a internal cooling circuit thanks to a cooling fluid. This sole could possibly be tilted but according to a preferred variant of the invention this cooled sole is horizontal.

It will also be noted that the floor of the installation according to the invention may be flat or profiled. We can thus choose to make a profiled sole to adapt to the shape and / or size of the items.

According to a preferred variant, said means designed to allow the movement of said articles on said fixed cooled floor from said end supply to said discharge end include a plurality of pushers mobile.

In addition to such a variant or according to another variant, these means include a plurality of movable elements towing said articles.

Such towing elements are advantageously constituted by at least two rollers mounted mobile in rotation on themselves and preferably arranged essentially transversely to the direction of scrolling of the article or articles on the sole. In this case the mobility of the towing elements will be constituted by the rotation of the rolls on themselves.

We can consider other ways to organize the mobility of said pushers and / or said towing elements, in particular by mechanical and / or hydraulic means. Said pushers and / or said mobile towing elements may be mounted on at least one endless chain provided on at least one side of said fixed cooled sole.

According to a variant, said pushers and / or said mobile towing elements are mounted on two endless chains provided on either side of said cooled floor, the displacement speeds of the two endless chains being identical. Such a solution could in particular be envisaged for sole having a large width.

Also according to a preferred variant of the invention, said pushers and / or said towing elements are regularly spaced from each other.

Also according to an advantageous variant of the invention, said pushers and / or said towing elements are removably mounted. Such a characteristic will allow facilitate the cleaning of these pushers and / or of these towing elements as well as that of the cooled sole. It will also make it possible to vary the number of pushers and / or of traction elements used depending on the size and shape of the articles to be cooled.

Pushers and / or mobile mounted towing elements may also present a shape and a variable size according to the applications. However, according to a interesting variant, said pushers are constituted by bars positioned essentially perpendicular to said longitudinal axis of said cooled hearth.

Also according to a variant, when said pushers and / or said elements mobile tractors are mounted on two endless chains provided on either side of said cooled sole, said pushers and / or said movable towing elements are mounted in staggered rows.

Advantageously, the device according to the invention is also provided with means for adjusting the running speed of the pushers and / or of said elements mobile tractors on said fixed cooled sole or means for adjusting the speed of rotation of the rollers when said towing elements comprise such rollers. The device may also include means for adjusting the distance separating said rollers from said sole.

Finally, also advantageously, said fixed sole is provided with a coating surface favoring the sliding of said articles.

• la figure 1 représente une vue schématique en perspective d'un premier mode de réalisation d'un dispositif selon l'invention ;
• la figure 2 représente une vue supérieure d'un second mode de réalisation d'un dispositif selon l'invention ;
• la figure 3 représente une vue en perspective d'un troisième mode de réalisation d'un dispositif selon l'invention.

The invention, as well as the various advantages which it presents, will be more easily understood thanks to the description which follows of three nonlimiting embodiments of the latter with reference to the drawings in which:

• Figure 1 shows a schematic perspective view of a first embodiment of a device according to the invention;
• FIG. 2 represents a top view of a second embodiment of a device according to the invention;
• FIG. 3 represents a perspective view of a third embodiment of a device according to the invention.

With reference to FIG. 1, the first embodiment of the device according to the invention is intended for crusting food items, that is to say for cooling their lower face. Note that in the embodiment shown, the items in question have a circular shape but obviously this shape may differ.
The device shown comprises a horizontal fixed cooled sole 2. In a conventional manner, this sole is cooled by an internal cooling circuit (not shown) in which an adequate cooling fluid circulates.

This fixed horizontal cooled sole 2 has a shape essentially parallelepiped, with a feed end 3 at which the articles to be cooled are brought in and a discharge end 4 at which the cooled items are removed. Note that the device shown may be preceded of all types of means for supplying articles to be cooled, placed upstream of the supply end 3. Similarly, this device can be followed by any type of device for evacuating cooled articles provided downstream from the evacuation end 4.

Note also that in the embodiment shown, the sole cooled is mounted on a set of feet 7 but that it can also, in other embodiments, be supported by other means.

In accordance with the present invention, the device shown is provided with pushers 5 mounted movable and moving in a direction parallel to the axis longitudinal of the refrigerated floor 2. These movable lifters consist of bars positioned essentially perpendicular to the longitudinal axis of the floor fixed horizontal cooled.

In order to organize the movement of the mobile pushers 5, these are mounted on an endless chain 6 placed on one side of the cooled floor 2.

This endless chain cooperates with two drums 9a and 9b provided at each end of the device, the drum 9a being provided at the discharge end 4 and the drum 9b being provided at the feed end 3 thereof. One of these drums is rotated by a motor (not shown).

The movement of the mobile pushers 5 on the horizontal fixed cooled floor 2 allows to drive the items to be crusted from the feed end 3 to the discharge end 4. During this passage, the prolonged contact of these articles with the cooled sole provides the desired effect, i.e. freezing the product on a certain thickness of its underside. During this transfer, the articles slide on the cooled sole.

Depending on the nature and size of the items to be crusted, it may be necessary to transit these on the cooled sole 2 at a time t plus at less long. To this end, the device shown comprises means 8 making it possible to vary the running speed of the pushers 5 on the cooled floor 2.

Note also that the movable pushers 5 are mounted on the chain without end 6 removably. In this way, it is very easy to detach them from this chain for cleaning them and for cleaning the refrigerated floor. Such a characteristic also allows to vary the number of mobile pushers 5 mounted on the chain endless 6 and so adapt the device to different shapes and sizes of items to crust.

According to the embodiment of Figure 2, the device shown comprises also a fixed horizontal cooled sole 2 as well as movable pushers 5. In this embodiment, the mobility of the pushers 5 is ensured by two chains endless 6 provided on each side of the cooled hearth 2. Like the mode of embodiment shown in Figure 1, these endless chains 6a, 6b cooperate with drums provided at the ends of the hearth and have an identical running speed. In this embodiment, the mobile pushers 5 mounted on the chains 6a and 6b are installed in staggered rows on the floor 2. Such a characteristic makes it possible to distribute the pushing efforts of the articles on two chains and no longer on one. Note that in other embodiments, the pushers 5 may each cooperate with the two endless chains provided on each side of the chilled bottom.

By allowing direct contact of the items to be crusted with the cooled sole, the crusting can be done in a much shorter time t than in state-of-the-art crusting plants, such as in particular those described in French patent FR2693 677. In addition, the present invention makes it possible to facilitate the time management t necessary to obtain optimized crusting by varying simply the speed of movement of the mobile pushers. Such a characteristic presents a big advantage compared to the crusting installations implementing the scrolling of a plastic film whose scrolling speed is sometimes difficult to manage.

With reference to FIG. 3, a third embodiment of the invention is shown in perspective.

According to this third embodiment, the device shown comprises a fixed cooled sole 2 and a plurality of towing elements constituted by rollers 5a provided above and at an adjustable distance therefrom. In Figure 3, only two rollers are shown, but it will be understood that several rollers spaced apart others at a substantially constant distance are provided.

These rollers are mounted mobile in rotation on themselves as symbolized by the arrows A carried at one of their ends. They are mainly intended perpendicular to the direction of movement of a foodstuff (“article”) 1a on sole 2, direction symbolized by arrow B. (Note that the rollers do not move not in the direction of arrow B). In the context of this embodiment, said article consists of a layer of pre-cooled mash, and therefore compact, in a single block which will be cut into portions later. However, the device shown could of course also be used with any type of individual item.

It will also be noted that said rollers are removable and easy to maintain. These movable rollers 5a have a toothed outer surface. The rotation of rollers 5a makes it possible to tow the foodstuff 1a onto the fixed cooled floor.

Finally, it will be noted that said rollers are connected to means 8C for adjusting their speed of rotation.
The embodiments of the invention described here are not intended to reduce the scope thereof. Many modifications can therefore be made without departing from its scope. In particular, it will be noted that the mobile pushers may have a shape different from that indicated. They can also be positioned in a different way with respect to the floor (V-shaped arrangement, inclined arrangement with respect to the scroll axis, etc.). It will also be noted that the installation according to the invention may include means making it possible to crust and / or freeze the upper face of the products, for example by ventilation of cold air through evaporators.

Claims (10)

Device for cooling at least one article (1a) comprising at least at least one fixed cooled floor (2) having at least one feed end (3) at which said item (s) (1a) to be cooled are brought in and at least a discharge end (4) at which the cooled item (s) (1a) are evacuated, characterized in that said articles rest directly on said sole cooled (2) when they pass over it and in that it has means designed to allow the movement of said articles on said fixed cooled floor (2) from said supply end (3) to said discharge end (4), said means including a plurality of movable elements towing (5a) said articles. Device according to claim 1 characterized in that said elements tractants (5a) are regularly spaced from each other. Device according to either of Claims 1 and 2, characterized in that that said cooled sole (2) is horizontal. Device according to either of Claims 1 and 2, characterized in that that said cooled sole (2) is inclined. Device according to any one of Claims 1 to 4, characterized in that said towing elements (5a) are removably mounted. Device according to any one of Claims 1 to 5, characterized in that said towing elements (5a) consist of at least two toothed rollers mounted in rotation. Device according to claim 6 characterized in that it comprises means for adjustment (8a) of the speed of rotation of said rollers (5a). Device according to one of claims 6 or 7 characterized in that it comprises means for adjusting the distance separating said rollers (5a) from said sole (2). Device according to any one of Claims 1 to 8, characterized in that said fixed sole (2) is provided with a surface coating promoting the sliding of the item (s) (1a). Device according to any one of Claims 6 to 8, characterized in that said rollers are arranged essentially transversely in the direction of scrolling of the article or articles (1a) on the sole (2).

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