RU218125U1 - FREEZE DRYING DEVICE - Google Patents

Abstract

The claimed technical solution relates to devices used in public catering establishments for drying products (for example, vegetables, meat, fish, fruits, coffee, etc.) in a freezer in a vacuum environment without loss of useful properties, the reduction of which during sublimation is not more than 3%. The freeze drying device contains a hermetically sealed heat-insulated drying chamber connected to an evaporator made in the form of a shell with a jacket, a condenser, inside a heat-insulated drying chamber made with a transparent door, there is a retractable cassette equipped with fixed shelves, heating elements and a fan, a shell and a jacket , connected to each other along the contour to form an internal closed volume, are additionally connected to each other at points located evenly over the entire cylindrical surface of the evaporator, three tubes emanating from the capillary tube for supplying refrigerant from the compressor to the evaporator are made parallel, three tubes brought together into one the refrigerant outlet pipe from the evaporator to the compressor is made parallel, and the capillary tube is made in the form of a coil wrapped around the refrigerant outlet pipe, an additional condenser is made on the rear wall of the device. The technical result of the claimed utility model is the creation of a device with increased efficiency of freeze-drying products. 6 w.p. f-ly, 4 ill.

Description

The claimed technical solution relates to devices used in public catering establishments for drying products (for example, vegetables, meat, fish, fruits, coffee, etc.) in a freezer in a vacuum environment without loss of useful properties, the reduction of which during sublimation is not more than 3%.

The closest technical solution (prototype) is a freeze-drying device according to RF patent No. 210990, F26B 9/06, publ. 05/16/2022 Bull. No. 14, containing a hermetically sealed heat-insulated drying chamber connected to an evaporator made in the form of a shell with a jacket, a condenser.

Prototype Disadvantages:

1) the presence of an opaque hatch that hermetically closes the heat-insulated drying chamber does not allow the user to quickly (visually) control the process of product preparation, which reduces the quality of product preparation and the efficiency of the device as a whole;

2) the use of sliding shelves in a heat-insulated drying chamber increases the time for loading / unloading the product into / out of the drying chamber, complicates and also prolongs the process of cleaning the device after completion of work;

3) the presence between the shell and the jacket of several slotted channels with spiral or zigzag refrigerant passages reduces the volume of the evaporator, respectively, the performance of the device decreases due to an increase in the sublimation time of the product;

4) the refrigerant is supplied to the evaporator through a single tube coming from the capillary tube, which does not allow uniform filling of slotted channels with refrigerant, and this reduces the performance of the evaporator and the entire device as a whole;

5) the removal of the refrigerant from the evaporator is carried out by means of a single tube, which does not allow uniform removal of the refrigerant from the evaporator, underestimating the performance of its operation and the entire device as a whole;

6) a capillary tube that directly supplies the refrigerant to the evaporator does not allow additional cooling of the refrigerant before it is supplied to the evaporator, which reduces the efficiency of the device;

7) the presence of a single condenser does not allow the use of a large amount of refrigerant, which reduces the performance of the device.

The technical problem solved by the creation of the claimed utility model is that a modern consumer needs environmentally friendly and tasty food products dried in the most modern way in a freeze-drying device, while not changing their appearance, retaining useful properties and structure for a long shelf life without refrigerator, as well as having a low weight and not subject to contamination by bacteria. The need for such food for a modern person, including for long-term expeditions of space stations, long-distance hiking trips, athletes, etc., is growing from year to year. It is known that a freeze-dried product has a greater nutritional value (up to 98% of nutritional properties) than a product preserved in another way, for example, by thermal or microwave drying.

The technical result of the claimed utility model is the creation of a device with increased efficiency of freeze-drying of products (including increased productivity of the product sublimation process, as well as increased efficiency of the device).

The technical result is achieved by the fact that a freeze-drying device containing a hermetically sealed heat-insulated drying chamber connected to an evaporator made in the form of a shell with a jacket, a condenser, and inside the heat-insulated drying chamber made with a transparent door, there is a retractable cassette equipped with fixed shelves, heating elements and a fan, the shell and the jacket, interconnected along the contour to form an internal closed volume, are additionally interconnected at points located evenly over the entire cylindrical surface of the evaporator, three tubes coming from the capillary tube for supplying refrigerant from the compressor to the evaporator are made parallel, three tubes brought together into one refrigerant outlet pipe from the evaporator to the compressor are made in parallel, and the capillary tube is made in the form of a coil wrapped around the refrigerant outlet pipe, an additional condenser is made on the rear wall of the device. At the same time, the transparent door has a flat shape. At the same time, the heating elements of the retractable cassette are made under the fixed shelves. At the same time, the upper shelf of the retractable cassette is made with an additional heating element located above it. In this case, the fixed shelves of the cassette are equipped with drawers. The fan is located at the rear of the cassette. At the same time, the connection points of the shell and the jacket are made by welding.

New essential distinguishing features of the proposed technical solution are the following features:

the heat-insulated drying chamber is made with a transparent door,

inside the heat-insulated drying chamber there is a retractable cassette equipped with fixed shelves, heating elements and a fan;

the shell and the shirt, connected to each other along the contour with the formation of an internal closed volume, are additionally connected to each other at points spaced evenly over the entire cylindrical surface of the evaporator;

three tubes coming from the capillary tube for supplying refrigerant from the compressor to the evaporator are made in parallel;

three tubes brought together into one refrigerant outlet tube from the evaporator to the compressor are made in parallel;

the capillary tube is made in the form of a coil wrapped around the refrigerant outlet tube;

an additional capacitor is made on the rear wall of the device.

The totality of new essential distinguishing features, along with the features known from the prior art, is sufficient to solve the specified technical problem and obtain the technical result provided by the utility model - the creation of a device with increased work efficiency (including increased productivity of the product sublimation process, as well as increased efficiency of the device ).

The essence of the proposed utility model, its feasibility and the possibility of industrial application is illustrated by drawings (Fig. 1, 2, 3, 4), where:

in fig. 1 - device in axonometric projection;

in fig. 2 - longitudinal section of a heat-insulated drying chamber;

in fig. 3 - cross section of the evaporator of the heat-insulated drying chamber;

in fig. 4 - development of the evaporator of the heat-insulated drying chamber.

On the presented drawings there are the following symbols:

1 - heat-insulated drying chamber;

2 - cassette;

3 - shelves;

4 - door;

5 - evaporator;

6 - bottom;

7 - trays;

8 - fan;

9 - shell;

10 - metal shirt;

11, 11a - welds;

12 - welding points;

13, 14, 15 - refrigerant inlet pipes;

16 - the upper zone of the evaporator;

17, 18, 19 - refrigerant outlet pipes;

20 - heat-insulating layer;

21 - heating elements;

22 - compressor;

23 - capacitor;

24 - fan;

25 - tube;

26 - capacitor;

27 - tube;

28 - filter-drier;

29 - capillary tube;

30 - outlet tube;

31 - vacuum pump;

32 - heat-insulating layers;

33, 34 - upper and lower heating elements.

The freeze-drying device (Fig. 1, 2, 3, 4) contains a heat-insulated drying chamber 1 (Fig. 2, 3), made for example, of a cylindrical shape, inside of which there is a cassette 2 (Fig. 1) with shelves 3 fixed in it (Fig. 2).

Thermally insulated drying chamber 1 (Fig. 2, 3) is hermetically sealed with a flat-shaped door 4 (Fig. 1, 2) made of Plexiglas (transparent door). The tightness of the door 4 is ensured by the presence of a seal (not shown in the figure) attached to the front surface (not shown in the figure) of the device.

The inner surface of the heat-insulated drying chamber 1 (Fig. 2, 3) forms the evaporator 5, surrounding (covering) the cassette 2 (Fig. 1).

The bottom 6 (Fig. 2) is located on the end surface (not shown in Fig.) of the heat-insulated drying chamber 1 (Fig. 2, 3) (hereinafter referred to as the drying chamber), opposite the front surface (not shown in Fig.) of the device, on which the door 4 is made (Fig. 1, 2).

For loading and unloading products, the cassette 2 (Fig. 1) is made retractable from the volume of the drying chamber 1 (Fig. 2, 3). On the fixed shelves 3 (Fig. 2) of the cassette 2 (Fig. 1) there are trays 7 (Fig. 2, 3), which can be pulled out or pushed inside the cassette 2 (Fig. 1) along the corresponding flanges operating (in Fig. 1). not shown), as guides that prevent the trays 7 (Fig. 2, 3) from falling out of the cassette 2 (Fig. 1).

The composition of the cassette 2 includes a fan 8 (Fig. 2, 3), located in its rear part. The fan 8 is designed to increase the efficiency of moisture transfer, which is carried out by additional circulation of the steam-air medium inside the drying chamber 1.

The cylindrical evaporator 5 is made consisting of an inner metal layer - a shell 9 and an outer metal layer - a shirt 10. The shell 9 and the shirt 10 are welded to each other along the generatrix of the cylindrical surface of the evaporator 5, where the weld 11 (Fig. 1, 3, 4) made in the upper part of the evaporator 5 (Fig. 2, 3). The ends of the shirt 10 are made welded to the shell 9 (in front and behind the chamber 1) by means of a weld 11a (Fig. 1). As a result of this, a closed volume of the evaporator 5 is formed (Fig. 2, 3).

The metal jacket 10 is additionally welded to the shell 9 with evenly spaced weld spots 12 (Fig. 1, 4) over the entire cylindrical surface of the evaporator 5 (Fig. 2, 3).

The formation of the internal volume of the evaporator 5 is achieved due to the tensile deformation of the surface of the metal sheet of the jacket 10 to the outside when high-pressure air is supplied to the space between the shell 9 and the jacket 10. The indicated tensile deformation is achieved due to the fact that the thickness of the sheet of the jacket blank 10 is less than the thickness of the blank sheet shells 9.

The movement of the refrigerant in the device is carried out through a closed system of interconnected structural elements: compressor 22, condenser 23, fan 24, tube 25, condenser 26, tube 27, filter-drier 28, capillary tube 29 with three parallel tubes 13, 14 emanating from it , 15, evaporator 5, three parallel tubes 17, 18, 19, combined into a single tube 30 for refrigerant removal from the evaporator to compressor 22.

To achieve the effect of cooling the product, the refrigerant in the form of a low-pressure liquid is supplied from the compressor 22 (Fig. 1) to the evaporator 5 (Fig. 2, 3) through three parallel tubes (channels) 13, 14, 15 (Fig. 1, 3, 4 ) located in the upper zone 16 (Fig. 2, 3) of the cylindrical evaporator 5, on one side of the weld 11 (Fig. 1, 3, 4).

Removal of the refrigerant in the form of low pressure gas from the cylindrical evaporator 5 (Fig. 2, 3) to the compressor 22 (Fig. 1) is carried out through three parallel tubes (channels) 17, 18, 19 (Fig. 1, 3, 4), located on the other side of the weld 11, i. e. from the side opposite to the location of the tubes (channels) 13, 14, 15.

On the outer surface of the evaporator 5 (Fig. 2, 3) behind the jacket 10, a heat-insulating layer 20 is made, which is also applied to the outer surface of the bottom 6 (Fig. 2).

The claimed device is equipped with heating elements 21, 33, 34 (Fig. 2, 3). The heating elements 21, 34 are attached from below to the shelves 3 (Fig. 2) of the cassette 2 (Fig. 1). The heating element 33 (Fig. 2, 3) is located above the upper shelf 3 (Fig. 2). Thus, each shelf 3 is subjected to heating acting on it simultaneously from above and below from two heating elements 21, 33, 34 (Fig. 2, 3), which increases the rate of heat exchange of the heating parts of the device with the product located on the trays 7 of the shelves 3 (Fig. 2) cassettes 2 (Fig. 1).

Each heating element 21, 33, 34 (Fig. 2, 3) can be made in the form of an electric heating mat, consisting of a thin heating section, fixed on the basis of a reinforcing mesh to reduce elasticity and protect the silicone shells covering both sides, sheets. Each heating section consists of a heating cable, a power wire and a connector (not shown in the figure), which provides a tight connection between the cable and the power wire.

The device works as follows. Sublimation drying of the product occurs in several stages: "Preparation"; "Freeze"; "Vacuumization"; "Drying"; "Final Drying"

At the "Preparation" stage, chamber 1 is pre-cooled (Fig. 2, 3), the temperature of the tray should be below 10°C, which is carried out within 15 minutes. To do this, the compressor 22 (Fig. 1) is turned on, which builds up pressure, causing forced circulation of the refrigerant. The refrigerant in the state of high pressure gas is supplied to the condenser 23, located under the drying chamber 1 (Fig. 2, 3), in the front.

To reduce the initial temperature of the refrigerant and transfer it to a high-pressure liquid, the fan 24 (Fig. 1) mounted on the condenser 23 is turned on.

Further, the refrigerant is fed through the tube 25 to the condenser 26, where the refrigerant, getting into a relatively large volume of the condenser 26, passes into the state of a low-pressure liquid, giving off heat through the outer surface of the condenser 26 to the environment. Capacitor 26 is located on the rear wall-surface (not shown in Fig.) of the device.

Further, the refrigerant is fed through the tube 27 to the filter-drier 28, which is necessary to maintain a low level of refrigerant humidity. The refrigerant is then fed into the capillary tube 29, which serves to control the refrigerant flow.

The refrigerant from the capillary tube 29 enters the evaporator 5 (Fig. 2, 3) through three parallel tubes 13, 14, 15 (Fig. 1, 3, 4) connected to the capillary tube 29 (Fig. 1), which allows uniform filling the volume of the evaporator 5 (Fig. 2, 3).

Getting into a large volume of the evaporator 5, the refrigerant, expanding, boils and passes from a liquid state to a gaseous state, while it cools and intensively absorbs heat from the interior of the drying chamber 1 through the shell 9. The selection of cold into the jacket 10 does not occur due to the presence of a heat-insulating layer 20 .

Further, the refrigerant in the form of a low-pressure gas, having passed through the volume of the evaporator 5, is discharged through three parallel tubes 17, 18, 19 (Fig. 1, 3, 4), connected to the refrigerant outlet tube 30 (Fig. 1), and is sent to the compressor 22.

The movement of the refrigerant in the evaporator 5 (Figs. 2, 3) is indicated by white arrows in Figs. 1.

The capillary tube 29 (Fig. 1) is made in the form of a coil wrapped around the refrigerant outlet tube 30, which is intended for more intensive cooling of the supplied refrigerant before being fed into the evaporator 9 (Fig. 2, 3), and this increases the efficiency of the claimed device.

After the trays 7 have cooled down to a temperature below 10°C, the device automatically proceeds to the next stage - "Freezing".

At the "Freeze" stage, the original products placed on trays 7 of shelves 3 (Fig. 2) of the cassette 2 (Fig. 1) are cooled from the initial temperature (for example, + 20 ° C) to a temperature of (-35 ..-50) ° WITH. To speed up the process of cooling the initial product with high humidity, located on the trays 7 (Fig. 2, 3) shelves 3 (Fig. 2) of the cassette 2 (Fig. 1), the fan 8 is turned on (Fig. 2, 3).

Upon reaching the required temperature of the product located on the trays 7 of the shelves 3 (Fig. 2) of the cassette 2 (Fig. 1) below, for example, -40°C, the freeze-drying process automatically proceeds to the next stage "Vacuumization".

At the "Evacuum" stage, it is necessary to maintain the achieved temperature of the product and create a vacuum inside the drying chamber 1 (Fig. 2, 3) to a value of 10 mbar with a vacuum pump 31.

When the modes are reached, the water from the state of "ice" inside the product passes into the state of "steam". This vapor condenses on the cold inner surface of the evaporator 5 (on the inner surface of the shell 9) in the form of ice. Until the pressure inside the chamber 1 falls below a certain threshold value, the fan 8 continues to operate, intensifying the process of transferring the steam released from the product to the inner surface of the evaporator 5 (shell 9). Next, the fan 8 is turned off.

When the required vacuum level is reached, the device automatically switches to the next stage “Drying”, where:

a) the operation of the refrigeration unit continues as part of the compressor 22 (Fig. 1), condenser 23, fan 24, condenser 26, filter-drier 28, capillary tube 29 and evaporator 5 (Fig. 2, 3), maintaining a low temperature on the inner surface evaporator 5 (shells 9);

b) the operation of the vacuum pump 31 (Fig. 1) continues, maintaining the required level of vacuum (vacuum) inside the drying chamber 1 (Fig. 2, 3);

c) to increase the speed of freeze drying, heating elements 21, 33, 34 are turned on (Fig. 2, 3). Heating of the products located on the trays 7 of the shelves 3 (Fig. 2) of the cassette 2 (Fig. 1) between the heating elements 21, 33, 34 (Fig. 2, 3) occurs due to the physical contact of the product through the shelves 3 (Fig. 2) with heating elements 21, 33, 34 (Fig. 2, 3). But the main way of heating the product is thermal radiation transmitted from the heating elements 21, 33, 34 to the product on the trays 7 of the shelves 3 (Fig. 2) of the cassette 2 (Fig. 1) under conditions of strong vacuum (vacuum). Convective heat exchange between the product and the heating elements 21, 33, 34 (Fig. 2, 3) is practically absent under these conditions; the product is heated to a temperature of approximately 20°C, which leads to a more intense phase transition of moisture in the form of ice from the product to steam. The released steam condenses on the cold inner surface of the evaporator 5 (shell 9) in the form of ice. Freeze-drying of the product takes place.

In the cassette 2 (Fig. 1) additional heat-insulating layers 32 (Fig. 2, 3) are installed, located above the upper and lower heaters 33, 34, which is necessary to prevent unnecessary transition to steam of already formed ice on the upper and lower inner surfaces of the evaporator 5 (shells 9), which is possible in the implementation of thermal radiation of these heaters.

Upon completion of freeze drying, the product on the trays 7 remains dry, and all the moisture from it is condensed in the form of ice on the inner surface of the evaporator 5 (shells 9).

The "Final Drying" stage is used to continue the operation of the device in case the user is busy or it is inconvenient for him to take out the products at night. At this stage, the user can at any time remove the products from the trays 7 of the cassette 2 (FIG. 1) of the drying chamber.

After the drying process is completed, the drain valve is opened (not shown in Fig.) to equalize the pressure in the drying chamber 1 (Fig. 2, 3) with the environment and open the door 4 (Fig. 1, 2). The pressure inside the drying chamber 1 (Fig. 2, 3) rises to atmospheric pressure. The door 4 (Fig. 1, 2) of the drying chamber 1 (Fig. 2, 3) is opened and the cassette 2 (Fig. 1) with trays 7 (Fig. 2, 3) with the dried product is pulled out of the drying chamber 1, and the resulting product transferred to an outer container. The resulting ice is removed from the drying chamber 1. After thawing and cleaning, the device is ready for the next cycle of operation.

The operation is controlled automatically by a software and hardware complex, the basis of which is a programmable logic controller (not shown in Fig.) to control the functions of the device. The device is equipped with a control panel (not shown in Fig.).

Unlike the prototype, where the thermally insulated drying chamber is made with an opaque door hatch, in the proposed technical solution, the thermally insulated drying chamber is closed with a transparent flat Plexiglas door, which allows the user to effectively control the product sublimation process, provides convenience and increases the efficiency of the device.

Unlike the prototype, where retractable shelves are made inside the heat-insulated drying chamber, on the side of which the fan is located, in the proposed technical solution inside the heat-insulated drying chamber there is a retractable cassette with fixed shelves, heating elements and trays, and the retractable cassette includes a fan installed in its rear part, which allows more efficient removal of moisture from each tray due to the longitudinal movement of air along the trays, and this increases the productivity of the device by reducing the sublimation time of the product. The presence of a retractable cassette with fixed shelves on which trays are installed increases the productivity of the device by reducing the time of loading / unloading the product and facilitating (accelerating) the process of cleaning the device after work is completed. All of the above increases the efficiency of the device.

Unlike the prototype, where slotted channels with spiral or zigzag passages are used in the evaporator, in the proposed technical solution, the internal volume of the evaporator does not have slotted channels, but is made in the form of a single space interrupted by individual welded points, which allows increasing the volume of the evaporator, contributing to increased productivity devices by reducing the time spent on sublimation of the product, increasing the efficiency of the sublimation process.

Unlike the prototype, where the refrigerant is supplied to the evaporator through a single tube coming from the capillary tube, the proposed technical solution for supplying the refrigerant directly to the evaporator uses three parallel tubes coming from the capillary tube, which makes it possible to evenly fill a larger volume of the evaporator, providing an increase the performance of the evaporator and the entire device as a whole.

Unlike the prototype, where the refrigerant is removed from the evaporator to the compressor through a single tube, in the proposed technical solution, the refrigerant is removed from the evaporator to the compressor using three parallel tubes brought together into one tube, which makes it possible to evenly remove the refrigerant from the evaporator, increasing work productivity evaporator and the whole device.

Unlike the prototype, where the capillary tube directly supplies the refrigerant from the compressor to the evaporator, in the proposed technical solution, the capillary tube is made in the form of a coil wrapped around the cooled refrigerant outlet pipe from the evaporator to the compressor, which allows additional cooling of the refrigerant before supplying it to the evaporator, increasing the efficiency of the device, respectively - to increase the efficiency of the device.

Unlike the prototype, which uses one single condenser located under the drying chamber in its front part, in the proposed technical solution, along with the condenser located under the drying chamber in its front part, there is an additional condenser located on the rear wall of the device, which allows to increase productivity. operation of the device by reducing the time for the implementation of sublimation of the product (due to the use of an additional condenser), the possibility of using a compressor of greater productivity and using more refrigerant.

In accordance with these design improvements, the efficiency of freeze-drying of the created device is increased.

All components of the claimed technical solution are interconnected by assembly operations, i.e. are in functional and constructive unity.

Implementation of the proposed utility model allows solving the claimed technical problem and ensuring the achievement of the claimed technical result.

The proposed technical solution, having a constructive unity, implements a common functional purpose (functional unity).

In the prior art, no analogue has been found, characterized by features identical to all essential features of the claimed utility model.

The applicant tested (tested) the proposed device in the process of cooking food in it, which confirmed the purpose, feasibility and performance, and therefore the claimed utility model meets the condition of patentability "industrial applicability".

Claims (7)

1. A freeze-drying device containing a hermetically sealed heat-insulated drying chamber connected to an evaporator made in the form of a shell with a jacket, a condenser, characterized in that inside the heat-insulated drying chamber made with a transparent door, there is a retractable cassette equipped with fixed shelves, heating elements and a fan, the shell and the jacket, connected to each other along the contour to form an internal closed volume, are additionally connected to each other at points located evenly over the entire cylindrical surface of the evaporator, three tubes emanating from the capillary tube for supplying refrigerant from the compressor to the evaporator are made parallel , three pipes brought together into one refrigerant outlet pipe from the evaporator to the compressor are made parallel, and the capillary tube is made in the form of a coil wrapped around the refrigerant outlet pipe, an additional condenser is made on the rear wall of the device. 2. The device according to claim 1, characterized in that the transparent door has a flat shape. 3. The device according to claim. 1, characterized in that the heating elements of the retractable cassette are made under the fixed shelves. 4. The device according to claim 1, characterized in that the upper fixed shelf of the retractable cassette is made with an additional heating element located above it. 5. The device according to claim 1 or 3, characterized in that the fixed shelves of the cassette are equipped with drawers. 6. The device according to claim 1, characterized in that the fan is located at the rear of the cassette. 7. The device according to claim 1, characterized in that the connection points of the shell and jacket are made by welding.

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