BARGAN, Vasily Aleksandrovich (ul. Yartsevskyaya, 5-3Moscow, 1, 12135, RU)
| CLAIMS: 1. A flat heater comprising a container disposed in a body and made from flexible gas-water-permeable material with exothermic composition in a solid state, initiated by liquid reagent, characterized in that the body is made of two equal sheets from gas-water-proof and heat- conducting material, which are hermetically connected to each other about a closed circuit thus forming a closed cavity with two opposite heat- conducting walls for at least one container with exothermic composition in a solid state, the closed circuit includes two opposite spout parts coupled with each other by their upper ends by means of a plug section, and two opposite side parts, bottom ends of which are coupled with each other by a bottom part, a bottom end of each spout part is coupled with the upper end of its corresponding side part by means of corresponding shoulder part, the body sheets are made in the shape providing the formation of protruding heat-dissipated sections of the sheets, which are disposed exteriorly and between each shoulder part of the closed circuit and adjacent spout part. |
FIELD OF THE INVENTION
The present invention relates to food industry, specifically to the devices for heating a food product prior its use by heat, released in exothermic chemical reaction between reagents in solid and liquid states.
BACKGROUND OF THE INVENTION
A flat heater with reagents in liquid and solid states is known from the Pat. US 5035230, publish. 30.07.1991. Said heater comprises a flexible container, which is made from thermally conductive material and is divided into the zones, namely, a fuel zone and an oxidizer zone, which are filled by fuel and oxidizing reagent, respectively. Said zones are separated by a seal. By manually destructing this seal the exothermic oxidation reaction is initiated between reagents in liquid and solid states.
The main disadvantage of the above described flat heater with two opposite contact surfaces is that it is inconvenient both in use and in transportation and storage. In reality, having a zone filled with liquid reagent results in the increase of its overall weight characteristics, and necessity to use (even for heating the objects of small area) several successively broken seals (separators) in the form of threadlike overwinds with untied knot, leads not only to complication of a flat heater construction, but also to increase in time spent by user on actuation of the flat heater. Moreover, the existence in the flat heater of a zone filled with liquid reagent and manually destructing separators, which are characterized by low reliability, leads to necessity for special precautionary measures in the course of transportation and storage of the flat heater. It is known a flat heater taken as a prototype and including a container (packaging means), which is placed in a body, with two opposite walls (a bottom portion and a top portion) made from flexible porous (gas- water-permeable) material, and which are edge-connected to each other, forming a cavity where there is a reagent in solid state sintered in the form of a plate. Herewith, said body is constructed in the form of a tray and provided with a nozzle for reagent feeding to its cavity in liquid state - water (Pat. US 5355869, publish. 18.10.1994).
The advantage of a prototype over the above described flat heater is the absence of a cavity , filled with reagent in liquid state, and breakable locks. Therefore, there is no more necessity for special precautionary measures in the course of transportation and in storage of a flat heater, taken as a prototype, and also the process of actuation of said flat heater is simplified.
However a prototype has the following disadvantages:
- Low efficiency of heat utilization, generated as a result of exothermic chemical reaction, whereas, firstly, thermal contact with a flat heater (taken as a prototype) can be realized only from its one side, and secondly, due to the implementation of the flat heater's body in the form of tray, a considerable part of water vapor, producing as a result of exothermic chemical reaction execution, dispels to surrounding space, in other words, does not participate in the process of heating a food product;
- Uncomfortable in use due to direct contact of a heated food product with the products of exothermic reaction.
DISCLOSURE OF INVENTION
The present invention is focused on solving a technical problem of increasing the efficiency of utilization of heat released as a result of exothermic chemical reaction, together with simultaneous increasing of usability of a flat heater and reduction in consumption of its body materials. However, achievable technical result consists, on the one hand, in twofold increase (having the same size of a container with exothermic composition in solid state like the prototype) of heat-release surface area due to double- sided construction of the heater (with two opposite heat-conducting walls of the heater's body), and also in an essential decrease in water vapor loss to surrounding space, which (water vapor) is generated as a result of exothermic chemical reaction, and, on the other hand, in elimination of a contact between an object being heated and the products of exothermic chemical reaction. Additional achievable technical result consists in reduction of the requirements to mechanical strength characteristics of the flat heater's body due to water vapor pressure maximum value decrease in the body's cavity in the course of exothermic chemical reaction.
The defined problem is solved by means of a flat heater comprising a container disposed in a body and made from flexible gas-water- permeable material, the container being filled with exothermic composition in a solid state, initiated by liquid reagent, the body is made of two equal sheets from gas-water-proof and heat-conducting material, which are hermetically connected to each other about a closed circuit thus forming a closed cavity with two opposite heat-conducting walls, for at least one container with exothermic composition in a solid state. In this case the closed circuit includes two opposite spout parts coupled with each other by their upper ends by means of a plug section, and two opposite side parts, the bottom ends of which are coupled with each other by a bottom part, a bottom end of each spout part is coupled with the upper end of its corresponding side part by means of corresponding shoulder part. Herewith the body sheets are made in the shape providing the formation of protruding heat-dissipated sections of the sheets, which are disposed exteriorly and between each shoulder part of the closed circuit and adjacent spout part.
The advantage of proposed flat heater over the prototype is that fulfillment of its body from two equal sheets from gas-water-proof and heat-conducting material, which are hermetically connected to each other about a closed circuit thus forming a closed cavity with two opposite heat- conducting walls for at least one container with exothermic composition in a solid state. Such fulfillment provides the increase in efficiency of heat utilization, which is generated as a result of exothermic chemical reaction due to twofold increase in heat-release surface area of the flat heater (as in contrast to prototype, the proposed flat heater is double-sided), and also due to essential decrease in water vapor loss to surrounding space, which (water vapor) is generated as a result of exothermic chemical reaction. Therewith, increase in usability of the flat heater is provided due to exclusion of a contact between an object being heated and the products of exothermic chemical reaction.
Furthermore, the features, which relate to fulfillment of body sheets in the form providing formation of protruding heat-dissipating sections of the sheets, which are disposed exteriorly and between each shoulder part of the closed circuit and the spout part adjacent to it, provide, due to heat removal, intensification of water vapor condensation process, generated (water vapor) in a body cavity of the flat heater in the course of exothermic chemical reaction, and consequently, decrease in maximum achievable water vapor pressure in the body's cavity in the process of exothermic chemical reaction. The consequences of the above-stated is reduction of the requirements to mechanical strength characteristics of the flat heater's body, and, hence, decrease in the body materials consumption, and hence, cost of the flat heater.
The foregoing description illustrates the preferred embodiment of the invention which is not limited to this particular configuration.
BRIEF DESCRIPTION OF DRAWINGS
Fig. 1 illustrates a flat heater, its front view, partial section;
Fig. 2 is a partial cross section of a flat heater;
Fig. 3 and Fig. 4 is the embodiment of a flat heater of the other form;
Fig. 5 illustrates a container with four compartments;
Fig. 6 illustrates a flat heater with broke away plug part of a closed circuit of thermoj unction;
Fig. 7 schematically illustrates the application of flat heaters for heating several packages with food products.
DETAILED DESCRIPTION OF THE INVENTION A flat heater (Fig. 1 and Fig. 2) contains a body, in a closed cavity 1 of which there is, at least, one container 2 with exothermic composition 3 in solid state, which is initiated by liquid reagent. Container 2 is made from gas-water-permeable material, whereas, in preferred embodiment of the invention each wall of the container 2 is double-layered: external layer is gas-water-permeable fiberglass and inner layer is flexible porous nonwoven material, for example, polypropylene. Fulfillment of the walls of the container 2 from above mentioned materials, on one hand, provides safety of the container's 2 content in the course of transportation of the flat heater because cell size in nonwoven material is much smaller than minimum cell size of exothermic composition 3 in solid state, and heat stability, corresponding to heat stability of fiberglass, and on the other hand, provides a possibility of connecting the walls of the container 2 together and layers in each wall together by means of common thermojunction.
A body of the flat heater is made of two equal sheets 4 and 5 from gas- water-proof and heat-conducting material: aluminum foil, saturated fiberglass, etc. Sheets 4 and 5 are hermetically connected to each other about a closed circuit (by thermojunction 6, for example) thus forming, a closed cavity 1 with two opposite heat-conducting walls for at least one container with exothermic composition in solid state (preferably on the basis of calcium oxide). Sheets 4 and 5 may be hermetically connected together about a closed circuit not only by thermojunction 6 but also by means of glue, soldering or welding.
The closed circuit (of the thermojunction 6 in Fig. 1, Fig. 3, Fig. 4) contains opposite first 7 and second part 7' spout parts, which are coupled with each other by their upper ends by means of a plug part 8, which is broken away or destroyed by a user before liquid reagent feeding into the body of the flat heater; first 9 and second 9' side part, disposed also opposite to each other and coupled with each other by the bottom ends by means of a bottom part 10. The bottom end of first spout part 7 is coupled with the upper end of its corresponding first side part 9 by means of first shoulder part 11, and the bottom end of second spout part 7' is coupled with the upper end of its corresponding second side part 9' by means of second shoulder part 11'. Necessary to note that the borders of coupled together parts 7, 8, 7', 11', 9', 10, 9 and 11 are indicated on figures by dashed lines 12. In preferred embodiment of the invention the sheets 4 and 5 have rectangular shape, a closed circuit of thermojunction 6 has symmetric shape toward axis 13, and parts 8, 9, 9' and 10 are placed on the periphery of sheets 4 and 5 (Fig. 1). However, the sheets 4 and 5 may have another shape (for example, shape of pentagon - Fig. 3, or trapeziform - Fig. 4), but surely forming protruding heat-dissipated sections 14 and 14' of, accordingly, sheets 4 and 5, which are disposed exteriorly and between each shoulder part 11 and 11' and adjacent spout part 7 and 7' of the closed circuit correspondingly.
Shouldered sections 11 and 11' of the closed circuit have, preferably straight (Fig. 1 and Fig. 4) or arcuated shape (Fig. 3) with protruding bulge. The latter embodiment is preferable because length increase of the shoulder parts 11 and 1 1 ' leads to increase in heat flow that passes through these parts.
Spout parts 7 and 7', preferably, are placed relative to each other at an acute angle, which point is downly directed. It provides convenience of liquid reagent feeding into a body cavity.
For increasing the usability the flat heater may be provided with elements denoting the recommended place of cutting off or the place of break away of the upper part of each sheet 4 and 5 with located there spout part 8 of thermoj unction 6, for example, in the shape of cutouts 15 (Fig.l) or with the cutting or break line applied on the external surface, at least, of one of the sheets 4 or 5 (not shown on Figures). Additionally, there may be a strip 16 with reduced mechanical strength on the sheets 4 and 5 (Fig. 4).
The container 2 may be carried out with a cavity divided at least into two sections (for example, by means of thermoj unctions 17 formation, Fig. 5), whereas exothermic composition in solid state is divided between said sections in proportion to their volumes. The better keeping of a flat heater shape in the course of transportation and in storage is the consequence of the above stated.
A formed opening is specified by position 18 in Fig.6; flat heaters are specified by position 19, the packages with food products are specified by position 20 and the heat- insulating body is specified by position 21 are shown in Fig.7.
The flat heater is manufactured in the following manner. Equal sheets 4 and 5 from gas-water-proof and heat-conducting material (aluminum foil, lamister, etc.) are put one upon the other providing the alignment of their corresponding edges. Sheets 4 and 5 are hermetically connected to each other about an opened circuit including parts 9, 11, 7 , 8, 7 ' , 11 ' and 9'. Then, a container 2 with exothermic composition 3 in solid state initiated by liquid reagent (water) is put into a cavity between the sheets 4 and 5 through the hole between the bottom ends of side sections 9 and 9'. Preferably as exothermic composition 3 in solid state it is used uniform mix of calcium oxide and anhydrous silicagel with the content of anhydrous silicagel in amounts of 1 part in 3,0-6,0 weight parts of calcium oxide, and this mix provides the duration of heat generation of 8-10 minutes. Afterwards a cavity between the sheets 4 and 5 is vacuumized with the formation of a bottom part 10 of the closed circuit and, consequently, the closed cavity 1.
The flat heater is used in the following manner. For starting operation of the flat heater (in other words, for initiating the exothermic chemical reaction between located in the container 2 exothermic composition 3 in solid state and liquid reagent) previously it is necessary to form an opening for feeding a liquid reagent into a body cavity of the flat heater. In the preferred embodiment of the invention the opening 18 is formed as a result of the removal (by means of breaking away or cutting off) of an upper part of the sheets 4 and 5 with placed there plug part 8 of the closed circuit of the thermoj unction 6 (Fig. 6) in compliance with the elements applied on the body of the flat heater denoting the recommended place of cutting off or breaking away (cutouts 15, for example).
The initiation of exothermic chemical reaction between exothermic composition 3 in solid state (preferably of uniform mix of calcium oxide and anhydrous silicagel) and liquid reagent is realized by filling of experimentally determined volume of liquid reagent (water) into the body cavity of the flat heater through the formed opening 18 (Fig. 6). For this operation for example, a measuring tank (as described in a prototype) can be used. After filling of the corresponding amount of liquid reagent the formed opening 18 is closed by pressing the parts near the opening 18 of the sheets 4 and 5 to each other followed by accompanied one-side bend of these parts on 180 angle degree.
Afterwards the flat heater is used for heating up one or two packaged food products. The main advantage of the proposed flat heater is that it may be used for simultaneous heating of several packages 20 with food product, namely, by means of disposing of vertically positioned identical flat heaters 19, and also the vertically positioned identical packages 20 with food product (Fig. 7) closed by each other in interleaved order in a general body 21.
The flat heater functions in the following manner. Liquid reagent (water), is filled through the opening 18 into the cavity of the flat heater's body, first passing through cells in walls' layers of the container 2, enters into its cavity, filled with exothermic composition 3 (uniform mix of calcium oxide and anhydrous silicagel). Upon contact between calcium oxide with water exothermic reaction takes place. Heat generated under exothermic chemical reaction between calcium oxide and water is transferred, first through the walls of a container 2, and then through sheets 4 and 5, to the objects being heated from two opposite sides. Exothermic chemical reaction between calcium oxide and water is accompanied by water vapor formation, and this leads to pressure increase in a cavity of the flat heater's body.
However, the existence of protruding heat-dissipated sections 14 and 14' (accordingly, of sheets 4 and 5) in proposed flat heater, leads to increase in heat-removing from body walls sections, adjacent to the shoulder parts 11 and 11' of a thermoj unction 6. Consequently, in body's cavity areas of the flat heater, adjacent to these parts, the intensity of water vapor condensation process increases, and this leads to decrease of maximum value of water vapor pressure in body cavity of the flat heater, which is achieved in the process of exothermic chemical reaction . The consequence of the above stated is reduction of the requirements to mechanical strength of the flat heater's body, namely, to thickness of the sheets 4 and 5. This conclusion follows from results, obtained under testing of the flat heaters, made with heat-dissipated sections 14 and 14' and without them. In all tests the sheets 4 and 5 were made from lamister film of 0,07mm thickness. Also in all tests there were used: exothermic composition 3 in the form of uniform mix of 50g of calcium oxide and 1Og of anhydrous silicagel of "MCKM" grade, and liquid reagent - water, in the amount of 50ml. 80 flat heaters were prepared, which are shown in Fig. 1; 100 flat heaters of analogues construction but without heat-dissipated sections 14 and 14' (in other words with parts 7, 7', 11 and 11' of thermoj unction 6, placed on edges of the sheets 4 and 5); and 50 flat heaters shown in Fig. 3. As a result of the tests there was a destruction of the body: in four flat heaters of 80; in 39 flat heaters of 100 and in one of 50, correspondingly.
Therefore the features, which relate to existence of heat-dissipated sections in the flat heater, are essential in terms of the materials consumption decrease, and hence, cost of a flat heater.
INDUSTRIAL APPLICABILITY
Industrial applicability of the proposed invention is supported by the possibility of its realization using popular materials and technological processes, extensively used in the food industry.