JPS6132950B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for subjecting food to heat treatment, such as defrosting or cooling/freezing, using a fluid, particularly a liquid, which causes heat exchange in the food.

The invention also relates to a device for carrying out this method.

One form of heat treatment that is often performed on an industrial scale is the thawing of deep frozen foods. Various methods are used for this purpose, including, among others, the use of stationary or circulating hot air, circulating cold or hot water, and treatments by dielectric heating.

However, the commonly used methods have obvious disadvantages, for example, air treatment causes drying of the surface layer of the food product, while direct treatment methods using water lead to leaching and undesired decomposition or dissolution of the food product.

A similar problem arises in the opposite case, ie when lowering the temperature of the food product and especially when the temperature is reduced to a temperature range where the food product has not yet transitioned from a plastic state to a solidification state. Thus, for example, current air treatment methods using cold air result in drying, whereas liquid treatment methods result in leaching or decomposition or dissolution of at least part of the food product or its external parts.

It is an object of the present invention to provide a method and an apparatus for implementing this method, which retains the undeniable advantages from the point of view of heat transfer associated with the use of a fluid as a heat treatment agent, while at the same time eliminating the disadvantages necessarily associated therewith. Our goal is to provide the following.

The method of the present invention involves placing the food product on a conveyor belt-like support with high thermal conductivity;
moving a fluid-tight and flexible coating layer with said support as a continuous web; covering the food product on the support with the continuous web coating layer so that no fluid comes into contact with the food product; A fluid at a temperature is allowed to flow to the underside of the support and at the same time to flow under pressure to the top of the coating layer of the continuous web, so that the fluid supplies heat to the food product or removes heat from the food product, so that heat is transferred to the food product and heat is removed from the food product. to replace; pressing the coating layer onto the upper side of the coating layer of the continuous web;
moving the web closely to the free surface of the food product and adjacent to a support portion to maximize the area over which heat exchange with the fluid occurs; removing the continuous web from the food product on the support; It is characterized by: winding a continuous web on a roller.

The apparatus for carrying out this method comprises a conveyor belt made of a highly thermally conductive material to which a fluid is applied from below as well as from above, and a thin, fluid-tight and flexible covering layer, the covering layer being said to be It is characterized in that the food product can be placed on the conveyor belt and can move parallel thereto and has a width greater than the width of the food product placed on the conveyor belt.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments and the accompanying drawings.

An endless conveyor belt 1 made of stainless steel or an equivalent material is connected to a chamber 4 shown by thin lines in the figure.
It runs on end rollers 2 placed at each end of the. The chamber is closed but has an opening 3 at each end. The forward run of the belt 1 carrying the food product X, such as meat, passes through the chamber 4, while the return run preferably passes outside the chamber as shown. In the chamber 4 above and below the belt 1 a number of outlet nozzles for regulated fluids are arranged. Connected to the supply conduit 6 for fluid from a heat exchanger 7 or similar device. In the heat exchanger the fluid is provided with the intended temperature. A discharge or return conduit 8 connects to the sloping bottom of the chamber 4 through which water exiting into the chamber is returned to the heat exchanger 7.

According to the invention, a covering layer 9 made of a thin, waterproof and flexible material is placed on the conveyor belt 1. In the embodiment of FIG. 1, the covering layer 9 consists of a film strip 9' which is unwound from a roller 10 and runs parallel to the conveyor belt 1.
1. This film strip may be of a disposable or reusable type.

In the embodiment shown in FIG.
It forms an endless band 9' passing over 2.

As can be seen in FIG. 3, the coating layer 9 in the preferred embodiment is wider than the conveyor belt 1 so that the coating layer sags at the edge of the conveyor belt.
In order to prevent parts of the food such as brine, meat juice or similar substances from escaping over the edge of the belt, said belt has a raised edge, preferably in the form of a vulcanized rubber or bead. 13.

As the fluid is supplied under pressure from the nozzle 5 above the belt, the covering layer 9 is forced against the upper side and edge surface of the food product X, thus providing a large contact surface with the fluid and good heat transfer. Using the device of the invention, the food product X is completely covered by a coating layer that closely follows the contour of the food product under the influence of the fluid. Due to the small thickness of the material of the covering layer, the transfer of heat from the fluid to the food product and vice versa is hardly inhibited. Because large quantities of fluid can be supplied, deep-frozen foods, for example, can be thawed in a considerably shorter time than with previously known methods, without the risk of leaching or melting phenomena occurring.

Since the substances coming from the food are retained on the belt and do not mix with the fluid, this fluid can be circulated and therefore used repeatedly. Fluid consumption, which has a significant cost impact, can be kept at an acceptable level through reuse.

Although the illustrated device is primarily intended for thawing deep-frozen products, it is clear that it can be used for cooling and/or freezing food products as well.

The fluid used for deicing is generally hot water. Cold water or water mixed with an agent to lower the freezing point can also be used for cooling. Liquefied gas is commonly used for deep freezing, but cold air or gas can also be used for this purpose.

The present invention is not limited to the above embodiments, but
Of course, various design changes are possible within the scope of the present invention.

[Brief explanation of the drawing]

1 is a schematic side elevational view of one embodiment of the apparatus of the invention, FIG. 2 is a schematic side elevational view of another embodiment, and FIG. 3 is a plane A--A of FIGS. 1 and 2. It is a schematic enlarged sectional view taken above. 1...Endless conveyor belt, 2...End roller, 4...
Chamber, 5... Nozzle, 6... Supply conduit, 7... Heat exchanger, 9... Covering layer, 9'... Film strip, 10,
11...roller, 12...end roller, 13...raised edge.

Claims (1)

[Scope of Claims] 1. A food product is placed on a conveyor belt-like support having high thermal conductivity; a thin, fluid-tight and flexible product having a width greater than the width of the food product resting on said support. moving the blessed layer together with the support as a continuous web; covering the food on the support with a coating layer of the continuous web so that the fluid does not touch the food; and moving the fluid at a temperature different from that of the food. The liquid flows to the underside of the support, and at the same time flows under pressure to the top of the coating layer of the continuous web, so that the fluid exchanges heat with the food by supplying or removing heat from the food. no pressure flow onto the top of the coating layer of the continuous web to force said coating layer and move said web into close contact with the free surface of said food product and adjacent to the support portion to exchange heat with the fluid. 1. A method for heat treating exposed, unwrapped food products, comprising: maximizing the area over which food deterioration occurs; removing the continuous web from the food product on the support; and winding the continuous web on rollers. 2. A conveyor belt made of a material with high thermal conductivity that can be flowed with fluid from above and below, and a thin, fluid-tight and flexible covering layer, the covering layer being able to cover the food and placing it on the conveyor belt. 1. An apparatus for heat-treating foods, characterized in that the apparatus is capable of moving parallel to the conveyor belt and has a width greater than the width of the foods placed on the conveyor belt. 3. characterized in that the conveyor belt has a raised edge in the form of a bead or the like, the width of the covering layer is greater than the width of the conveyor belt, and the edge portion of the covering layer hangs down at the edge of the conveyor belt. An apparatus according to claim 2. 4. Device according to claim 2, characterized in that the covering layer placed on the conveyor belt consists of an endless film strip, which strip can move together with the conveyor belt. 5. A movable cover layer placed on the conveyor belt consists of a strip of film, said strip being movable together with the conveyor belt and unwound from a supply reel placed at one end of the conveyor belt and at the opposite end of the conveyor belt. 3. Device according to claim 2, characterized in that it is adapted to be wound up. 6. A conveyor belt made of a material with high thermal conductivity while flowing fluid from above and below, and a thin, fluid-tight and flexible covering layer, the covering layer being able to cover food and placing it on the conveyor belt. , and a portion of the conveyor belt capable of moving parallel to said conveyor belt and having a width greater than the width of the food product placed on the conveyor belt and supporting the food product to be heat-treated and the coating layer passes through the chamber; The chamber has an upwardly directed fluid nozzle located below the conveyor belt and a generally downwardly directed nozzle located above the conveyor belt and an overlying coating layer for allowing fluid to exit from above. and wherein the chamber is provided with a device for collecting and returning spent fluid.