Vacuum freeze drying system

Abstract

The utility model provides a vacuum freeze drying system which comprises a vacuum stock bin, an inner heat exchange pipeline, a refrigeration pipeline and a heating pipeline, the vacuum stock bin is used for containing materials so as to conduct vacuum freezing and drying on the materials, and a cold trap is arranged in the vacuum stock bin; the inner heat exchange pipeline comprises a connector pipeline installed in the vacuum stock bin and a heat exchange plate which is arranged on the skip car and can be connected into the connector pipeline. The refrigeration pipeline can selectively communicate with the inner heat exchange pipeline and / or the cold trap and is used for freezing materials on the heat exchange plate or capturing steam in the vacuum stock bin; the heating pipeline can communicate with the inner heat exchange pipeline and heat the inner heat exchange pipeline so that ice on the materials can be sublimated and dehydrated. The vacuum freeze drying system is compact in structure, small in occupied space, high in working efficiency and good in effect.

Description

Technical Field

[0001] The utility model relates to a drying system, in particular to a vacuum freeze drying system. Background Art

[0002] Vacuum freeze drying technology is one of the most advanced food processing technologies. The existing vacuum freeze drying technology mainly freezes the material in the cold storage to the eutectic point, about -40℃, and then manually pushes the frozen material into the drying chamber for drying. There are two main types of common freeze drying equipment on the market, namely intermittent freeze drying equipment and contact freeze drying equipment. However, both types of freeze drying equipment must go through the freezing and drying process, and their operation process is complicated and the plant occupies a large area. Utility Model Content

[0003] [1] Technical issues to be solved

[0004] The technical problem to be solved by the utility model is to provide a vacuum freeze drying system which integrates freezing and drying, occupies a small area, has a simple process and is flexible in feeding and discharging materials.

[0005] 【2】Technical solutions to solve the problem

[0006] The utility model provides a vacuum freeze drying system, which comprises:

[0007] A vacuum silo 3 is used to place materials so as to vacuum freeze and dry the materials. A cold trap is provided in the vacuum silo 3;

[0008] The internal heat exchange pipeline 4 includes an interface pipeline installed in the vacuum silo 3 and a heat exchange plate 43 arranged on the material vehicle and connected to the interface pipeline;

[0009] A refrigeration pipeline 1, which can selectively connect to the internal heat exchange pipeline 4 and / or the cold trap, and is used to freeze the material on the heat exchange plate 43 or to capture water from the vacuum silo;

[0010] The heating pipeline 2 can be connected to the internal heat exchange pipeline 4 and heat it to achieve sublimation and dehydration of ice on the material.

[0011] Furthermore, the interface pipeline includes a plurality of parallel interface branches 421 , and the heat exchange plates 43 are multiple and can be connected to the interface branches 421 respectively.

[0012] Furthermore, the heat exchange plate 43 includes one or more material placement plates for placing materials, and a medium pipe that can be connected to the interface pipeline and perform heat exchange is provided in the material placement plate, and switch valves are provided at both ends of the medium pipe and on the interface pipeline.

[0013] Furthermore, the heating pipeline 2 is provided with a heating pipeline 6 for heating the medium inside thereof and a cooling pipeline 7 for cooling.

[0014] Furthermore, it also includes a liquid return pipeline connected to the internal heat exchange pipeline 4 and used for recovering the medium in the internal heat exchange pipeline 4, and a flow meter is provided on the liquid return pipeline.

[0015] Furthermore, the medium in the refrigeration pipeline 1 and the heating pipeline 2 is the same and both are glacial refrigerant.

[0016] Furthermore, there are at least two cold traps which are arranged in parallel.

[0017] Furthermore, the refrigeration pipeline 1 includes a cold tank 11, a first pipeline 12 is provided at the output end of the cold tank 11, a first circulating pump is provided on the first pipeline 12, and the end of the first pipeline 12 is branched into a first branch 13 connected to the input end of the cold trap, and a second branch 42 connected to the first end of the internal heat exchange pipeline 4; a second pipeline 16 is provided at the input end of the cold tank 11, an external refrigeration pipeline 5 for cooling the internal medium is provided on the second pipeline 16, and the end of the second pipeline 16 is branched into a third branch 17 connected to the output end of the cold trap, and a fourth branch 41 connected to the second end of the internal heat exchange pipeline.

[0018] Furthermore, the heating pipeline 2 includes a hot tank 21, which is provided with a heating pipeline 6 for heating the internal medium, a third pipeline 26 is provided at the output end of the hot tank 21, and a second circulation pump is provided on the third pipeline 26. The end of the third pipeline 26 branches into a fifth branch 28 and a sixth branch 24, and the fifth branch 28 is connected to the first end of the internal heat exchange pipeline 4; the end of the sixth branch 24 branches into a seventh branch 23 connected to the second end of the internal heat exchange pipeline 4, and an eighth branch 22 connected to the input end of the hot tank, and a fourth pipeline 25 is provided between the second end of the internal heat exchange pipeline and the hot tank 24, and the fourth pipeline 25 is provided with a gas source for forming internal pressure in the pipe and realizing liquid return.

[0019] Furthermore, the air source is an air pump or a high-pressure blower.

[0020] Furthermore, the output end of the hot tank is connected to the third pipeline 26 via a sixth pipeline 29 , and a cooling pipeline is connected in parallel to the sixth pipeline 29 .

[0021] Furthermore, the medium in the heating pipeline is steam.

[0022] 【3】Beneficial effects

[0023] The utility model vacuum freeze drying system places freezing and drying in the same bin, which greatly reduces the space occupied by the system, reduces the use area of ​​the plant, and thus reduces the use cost; at the same time, it eliminates the steps of switching between the traditional freezing and drying zones, simplifies the freeze drying process, improves production efficiency, and has high production benefits; the heat exchange plate is arranged on the material vehicle, which can be quickly connected to the heat exchange pipeline, is flexible to use, and is convenient and labor-saving to load and unload materials, which greatly reduces the labor intensity and improves production efficiency; a double cold trap structure is arranged, which can realize alternating work, ensure the vacuum degree in the bin, and has good drying effect and high efficiency; the low freezing point and high boiling point are used A new medium with dual characteristics replaces the hot water in the hot water system and the Freon in the cold trap system, so that the freezing and drying processes of the material can be realized in one drying bin, with good freezing and heating effects, greatly reducing the freeze-drying time and high production efficiency; a cooling pipeline is provided to cool the medium in the heating pipeline to prepare for the next bin production and improve the drying quality of the material; a liquid return pipeline is provided to quickly recover the medium in the material truck, reducing the medium dosage, with low cost and good use effect; the vacuum freeze-drying system of the utility model has a compact structure, small footprint, high working efficiency and good effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a system block diagram of the vacuum freeze-drying system of the utility model;

[0025] Figure 2 It is a schematic diagram of the connection of the internal heat exchange pipeline of the vacuum freeze-drying system of the utility model;

[0026] Figure 3 It is a schematic diagram of the connection of the refrigeration pipeline of the vacuum freeze-drying system of the utility model;

[0027] Figure 4 It is a schematic diagram of the connection of the heating pipeline of the vacuum freeze-drying system of the utility model;

[0028] Figure 5 This is a schematic diagram of the pipeline connection when the cold medium enters the vacuum freeze-drying system of the utility model;

[0029] Figure 6 This is a schematic diagram of the pipeline connection of the vacuum freeze-drying system of the utility model during cold freezing;

[0030] Figure 7 This is a schematic diagram of the pipeline connection when the heat medium enters the vacuum freeze-drying system of the utility model;

[0031] Figure 8 It is a schematic diagram of the pipeline connection of the left cold trap to capture water during drying of the vacuum freeze-drying system of the utility model;

[0032] Fig. 9It is a schematic diagram of the pipeline connection of the right cold trap to capture water during drying in the vacuum freeze-drying system of the utility model;

[0033] Fig.10 It is a schematic diagram of the pipe connection when the heat exchange pipe in the vacuum freeze drying system of the utility model is cooled;

[0034] Fig.11 It is a schematic diagram of the pipeline connection for shutting down and cooling the vacuum freeze-drying system of the utility model;

[0035] Fig.12 The utility model is a schematic diagram of the pipeline connection when the cold medium is recovered in the vacuum freeze drying system. DETAILED DESCRIPTION

[0036] The following is a detailed description of the embodiments of the present utility model in conjunction with the accompanying drawings.

[0037] See also Figure 1-Figure 4 The utility model provides a vacuum freeze-drying system, which includes a vacuum silo 3, an internal heat exchange pipeline 4, a refrigeration pipeline 1 and a heating pipeline 2.

[0038] The vacuum silo 3 includes a cabin body, and a sealed chamber is formed in the cabin body for placing the material to be dried. The inner wall of the vacuum silo 3 is provided with an insulation layer to avoid heat transfer between the inside and the outside, thereby achieving insulation. At the same time, the vacuum silo is equipped with a vacuum pump, which includes a vacuum pump. The vacuum pump is used to evacuate the air in the vacuum silo and form a vacuum environment inside it. Since water has three phases: solid, liquid and gas, according to the phase equilibrium theory in thermodynamics, as the pressure decreases, the freezing point of water does not change much, while the boiling point becomes lower and lower, approaching the freezing point. When the pressure drops to a certain vacuum degree, the boiling point and freezing point of water coincide, and ice can be directly vaporized into gas without passing through the liquid state. This process is called sublimation. The above-mentioned vacuum pump can evacuate the chamber and provide a vacuum environment for drying.

[0039] A cold trap is provided in the vacuum silo 3, and the cold trap is used to absorb the steam in the vacuum chamber and maintain the vacuum degree in the chamber. In this embodiment, there are multiple cold traps, which are arranged in parallel. Preferably, there are two cold traps, namely a left cold trap 31 and a right cold trap 32.

[0040] In this application, the internal heat exchange pipeline 4 includes an interface pipeline and a heat exchange plate 43, see Figure 2, wherein the interface pipeline is installed on the vacuum silo 3, and its main function is to connect. The heat exchange plate 43 is arranged on the material cart and can be connected to the interface pipeline to form a complete heat exchange pipeline; in this embodiment, the interface pipeline includes a plurality of parallel interface branches 421, each of which has a first access end and a second access end, and the first access end and the second access end form an access area for accessing the heat exchange plate 43; the heat exchange plate 43 includes one or more material placement plates, which are used to place materials. A medium pipe is arranged in the material placement plate, and the medium pipe is in full contact with the material placement plate and can realize heat transfer (heat conduction), thereby realizing heating or cooling; the two ends of the medium pipe can be connected to the first access end and the second access end of the interface branch pipe respectively, thereby realizing the connection and communication of the entire pipeline; at the same time, a switch valve is arranged at the first access end and the second access end of each interface branch pipe, and a switch valve is also arranged at both ends of the medium pipe. In this embodiment, the above-mentioned switch valves are all pneumatic cut-off valves.

[0041] In the present application, there are multiple interface branches 421, and the access area of ​​one interface branch corresponds to one material cart (heat exchange plate). Each material cart is treated as an independent individual. When the access quantity of the material cart is at least one, the connection of the overall pipeline can be realized, and freeze-drying operations can be carried out at this time. In this embodiment, there are 8 interface branches, so when the access quantity of the material cart is 1-8, freeze-drying operations can be carried out; in order to improve the docking efficiency, the interface branch and the medium pipe are connected by a quick connector, which can realize quick connection and disassembly, can reduce the labor intensity of workers, make the operation more convenient and labor-saving, and thus improve the overall work efficiency.

[0042] The refrigeration pipeline 1 is used to refrigerate the system. It can selectively connect to the internal heat exchange pipeline 4 or the cold trap, or connect to the internal heat exchange pipeline 4 and the cold trap (for cold medium inlet) at the same time. It is used to freeze the material on the heat exchange plate 43 or to capture water in the vacuum silo. For details, refer to Figure 3The refrigeration pipeline 1 includes a cold tank 11, which is filled with a cold medium. A first pipeline 12 is provided at the output end of the cold tank 11. A first circulation pump, a stop valve and a filter are provided on the first pipeline 12, wherein the stop valve and the filter are arranged at the front end (input end) of the first circulation pump. The end of the first pipeline 12 branches into a first branch 13 and a second branch 42, wherein the first branch 13 is connected to the input end of the cold trap. In this embodiment, a left cold trap 31 and a right cold trap 32 are included. Therefore, the end of the first branch 13 branches into first branch 131 connected to the left cold trap 31 and the right cold trap 32 respectively, and a switch valve is provided on each first branch 131; the second branch 42 is connected to the first end of the internal heat exchange pipeline 4, and a switch valve is provided on the second branch 42; the input end of the cold tank 11 is provided with a second Pipeline 16, an external refrigeration pipeline 5 is provided on the second pipeline 16, and the external refrigeration pipeline 5 is one or more, which can refrigerate the medium in the refrigeration pipeline by heat exchange. In this embodiment, the external refrigeration pipeline is an R22 refrigeration system, and a stop valve and a switch valve are provided on the second pipeline 16, wherein there are two stop valves, which are respectively arranged at both ends of the external refrigeration pipeline, and the end of the second pipeline 16 is branched into a third branch 17 and a fourth branch 41, wherein the third branch 17 is connected to the output end of the cold trap, and the fourth branch 41 is connected to the second end of the internal heat exchange pipeline, specifically, connected to the second end of the interface pipeline of each internal heat exchange pipeline, and a switch valve is provided on the fourth pipeline; by controlling the switch valves on each pipeline, the cold medium can enter the cold trap or the internal heat exchange pipeline to respectively realize water capture and material freezing.

[0043] The heating pipeline 2 can be connected to the internal heat exchange pipeline 4, which is used to heat the internal heat exchange pipeline, thereby sublimating the ice on the material on the heat exchange plate (material car), and then realizing dehydration and drying; in the present application, a heating pipeline 6 and a cooling pipeline 7 are provided on the heating pipeline 2, wherein the heating pipeline 6 is used to heat the medium inside it, and then heat the internal heat exchange pipeline (heat exchange plate) through the heat medium to realize biochemical drying, and the cooling pipeline 7 is used to cool the heat medium after the drying operation is completed, so as to avoid the next round of high-temperature heat medium directly entering the internal heat exchange pipeline and affecting the drying quality of the material; at the same time, a return liquid pipeline is also provided on the heating pipeline, which is connected to the internal heat exchange pipeline 4 and is used to recover the medium in the internal heat exchange pipeline 4, and a flow meter is provided on the return liquid pipeline for performing flow statistics on the recovered medium to determine whether the recovery is completed.

[0044] For details, see Figure 4The heating pipeline 2 includes a hot tank 21, on which a heating pipeline 6 is provided, and the heating pipeline 6 is used to heat the medium in the hot tank 21. In this embodiment, the medium in the heating pipeline is steam. A stop valve and a switch valve are provided on the heating pipeline, which are connected to the heating coil or heat exchanger in the hot tank to achieve heating; a sixth pipeline 29 is provided at the output end of the hot tank 21, and a cooling heat exchange pipeline 27 is connected in parallel to the sixth pipeline 29, which can achieve cooling through the cooling pipeline 7, and the sixth pipeline 29 and the end of the cooling heat exchange pipeline are connected to the third pipeline 26, and a second circulating pump is provided on the third pipeline. The end of the third pipeline 26 branches into a fifth branch 28 and a sixth branch 24, and the fifth branch 28 is connected to the first end of the internal heat exchange pipeline 4; the end of the sixth branch 24 branches into a seventh branch 23 and an eighth branch 22, wherein the seventh branch 23 is connected to the second end of the internal heat exchange pipeline 4, and the eighth branch 22 is connected to the eighth branch 22. The eighth branch 22 is connected to the input end (liquid return end) of the hot tank. At the same time, a fourth pipeline 25 is provided between the second end of the internal heat exchange pipeline and the hot tank 21. An air source is provided on the fourth pipeline 25, which is used to form an internal pressure (air pressure) in the pipe and push the internal medium back to the hot tank to achieve liquid return. The above-mentioned air source is an air pump or a high-pressure fan; the above-mentioned fourth pipeline 25 and the sixth branch 24 can realize the connection between the internal heat exchange pipeline and the hot tank (input end) to achieve rapid liquid return; a switch valve is provided in each pipeline section of the heating pipeline. Specifically, a switch valve is provided on the sixth pipeline 29, the cooling heat exchange pipeline 27, the third pipeline 26, the fifth branch 28, the sixth branch 24, the seventh branch 23, the eighth branch 22 and the fourth pipeline 25, which are used to control the connection or blocking of each pipeline, thereby realizing different medium flow directions and different functions. At the same time, a stop valve is provided at the input and output ends of the hot tank.

[0045] In the present application, the switch valves on the refrigeration pipeline and the heating pipeline are both pneumatic shut-off valves, which have the function of rapid shut-off, simple structure, sensitive response, reliable operation and the like.

[0046] In this embodiment, the medium in the refrigeration pipeline 1 and the heating pipeline 2 is the same, which is glacial refrigerant. As a new heat transfer medium, glacial refrigerant has the excellent characteristics of not solidifying at -40°C and not boiling at 100°C, and is stable and reliable to use.

[0047] The working principle of the vacuum freeze-drying system of the present application is described below, which includes the following steps:

[0048] S1. Place the material to be dried on a material cart, push the material cart into the vacuum silo 3, connect the medium pipe on the heat exchange plate on the material cart with the interface pipe in the vacuum silo 3, and form a complete pipeline;

[0049] S2, start the vacuum pump and evacuate the vacuum silo 3 to form a vacuum environment in the silo;

[0050] S3, cold medium inlet, see Figure 5 , so that the refrigeration pipeline is connected to the internal heat exchange pipeline 4 and the cold trap at the same time, that is, the valves on the first pipeline 12, the first branch 13 (including two first branch branches 131), the second branch 42, the fourth branch 41 and the second pipeline 16 are opened at the same time, and the first circulation pump is started at the same time, which can fill the internal medium into the cold trap and the internal heat exchange pipeline 4, and return to the cold tank to form a circulation pipeline; in order to ensure sufficient entry of the medium, in this embodiment, the liquid entry time of the cold medium is 3min-10min, preferably 5min;

[0051] S4, material freezing, see Figure 6 , cut off the connection between the cold trap and the refrigeration pipeline, that is, close the switch valve on the first branch 13 (including the two first branch branches 131), so that the refrigeration pipeline is only connected to the internal heat exchange pipeline to form a material freezing pipeline; at the same time, start the external refrigeration pipeline 5, the external refrigeration pipeline 5 cools the medium in the refrigeration pipeline to form a functionally complete refrigeration pipeline, the medium in the refrigeration pipeline absorbs the heat of the material on the internal heat exchange pipeline, specifically, absorbs the heat of the material on the heat exchange plate, and freezes the material. In this embodiment, the freezing time is 3h-5h, and the cooling temperature is -45℃~-10℃, and the freezing time and cooling temperature can be adjusted according to different materials;

[0052] S5, heat medium inlet, see Figure 7 , cut off the connection between the refrigeration pipeline and the internal heat exchange pipeline 4, that is, close the switch valves on the second branch 42 and the fourth branch 41, so that the internal heat exchange pipeline is not connected to the refrigeration pipeline, and at the same time, connect the heating pipeline to the internal heat exchange pipeline 4, that is, open the switch valves on the seventh branch 23 and the fifth branch 28, and at the same time, open all the switch valves on the heating pipeline except the fourth pipeline 25, that is, open all the switch valves on the sixth pipeline 29, the cooling heat exchange pipeline 27, the third pipeline 26, the fifth branch 28, the sixth branch 24, the seventh branch 23 and the eighth branch 22, so that the medium can fully enter the above pipelines and prepare for heating; start the second circulation pump to fill the internal medium into the internal heat exchange pipeline and the entire heating pipeline to form a circulating heating pipeline;

[0053] S6. Drying:

[0054] Start the heating pipeline 6, that is, open the switch valve on the heating pipeline, and allow the steam in the heating pipeline 6 to enter the coil in the hot tank, thereby heating the internal medium. The internal medium flows to the internal heat exchange pipeline through the pipeline and exchanges heat with the material on the heat exchange plate, that is, heats the material plate to sublime the ice on the material to form steam. In this process, the switch valves on the sixth pipeline 29, the third pipeline 26, the fifth branch 28, the seventh branch 23 and the eighth branch 22 are opened and in an open state, and the medium in the pipeline can enter the internal heat exchange pipeline and realize cyclic heating, while the sixth branch 24, the cooling heat exchange pipeline 27 and the switch valve on the sixth branch 24 are in a closed state;

[0055] At the same time, the refrigeration pipeline is connected to the cold trap, which cools down and captures the water vapor in the vacuum silo 3 and maintains the internal vacuum degree;

[0056] In this embodiment, the refrigeration pipeline is alternately connected to the two cold traps, so that the two cold traps capture water and melt ice alternately;

[0057] For details, see Figure 8 , the refrigeration pipeline is connected to the left cold trap 31, that is, the first pipeline 12, the first branch 131 of the left cold trap, the third branch 17, and the second pipeline 16 are in a connected state. At the same time, the external refrigeration pipeline 5 is also in a working state. At this time, the left cold trap is in a water capturing state, and the right cold trap is in an ice melting state. Specifically, a negative pressure steam generator (also called an ice melting tank) is connected to the bottom of the cold trap. When the left cold trap is in a water capturing state, the cover above it opens automatically. At this time, the left cold trap is connected to the cabin body, which can capture the steam in the cabin and is in a water capturing state; at the same time, the valve between the right cold trap and the ice melting tank is opened, and the pressure in the ice melting tank is about 2500pa. Under the low-pressure environment of the water in the ice melting tank, it is heated by steam to generate low-temperature and low-pressure water vapor. The water vapor enters the right cold trap from the ice melting tank, and the ice in the right cold trap absorbs heat and melts into liquid water, which flows into the ice melting tank and is discharged through the ice melting tank, thereby achieving the effect of ice melting.

[0058] After the left cold trap captures water and the right cold trap melts ice for a period of time, the refrigeration pipeline is disconnected from the left cold trap 31 and connected to the right cold trap. Fig. 9That is, the first pipeline 12, the first branch 131 of the right cold trap, the third branch 17, and the second pipeline 16 are in a connected state. At the same time, the external refrigeration pipeline 5 is also in a working state. At this time, the left cold trap is in an ice-melting state, and the right cold trap is in a water-catching state. Specifically, a negative pressure steam generator (also called an ice-melting tank) is connected to the bottom of the cold trap. When the right cold trap is in a water-catching state, the cover above it automatically opens. At this time, the right cold trap is connected to the cabin body, can capture the steam in the cabin, and is in a water-catching state; at the same time, the valve between the left cold trap and the ice-melting tank is opened, and the pressure in the ice-melting tank is about 2500pa. Under the low-pressure environment of the water in the ice-melting tank, it is heated by steam to generate low-temperature and low-pressure water vapor. The water vapor enters the left cold trap from the ice-melting tank, and the ice in the left cold trap absorbs heat and melts into liquid water, which flows into the ice-melting tank and is discharged through the ice-melting tank, thereby achieving the effect of melting ice.

[0059] During the drying stage, the left cold trap and the right cold trap are alternately connected to the refrigeration pipeline, that is, the left cold trap and the right cold trap capture water and melt ice alternately, which has good water capture and ice melting effects and high efficiency, and a good drying effect.

[0060] The above drying time is 18h-30h, and the heating temperature is 80℃-100℃, which can completely discharge the ice (water) in the material.

[0061] S7, cooling the internal heat exchange pipeline. After drying is completed, the heating pipeline 6 is closed and the cooling pipeline 7 is opened to cool the medium in the heating pipeline and the internal heat exchange pipeline; see Fig.10 In this stage, the left cold trap and the right cold trap are still in the alternating working state. At the same time, the cooling heat exchange pipeline 27, the third pipeline 26, the fifth branch 28, the internal heat exchange pipeline, the seventh branch 23 and the eighth branch 22 are in the connected state. At the same time, the cooling pipeline 7 is started, and it exchanges heat with the cooling heat exchange pipeline and cools the medium in the pipeline. In this stage, the internal heat exchange pipeline and the hot tank body are connected and circulated, that is, the medium in the internal heat exchange pipeline and the hot tank is cooled down at the same time;

[0062] S8, shut down and cool down, close the refrigeration pipeline, and cut off the connection between the heating pipeline and the internal heat exchange pipeline. The cooling pipeline 7 continues to cool part of the heating pipeline and the medium in the hot tank. Fig.11 In this stage, the left cold trap and the right cold trap stop working. At the same time, the cooling heat exchange pipeline 27, the third pipeline 26, the sixth branch 24, and the eighth branch 22 are in a connected state, while the cooling pipeline 7 is still in a working state. It exchanges heat with the cooling heat exchange pipeline and cools the medium in the pipeline. In this stage, a self-circulation is formed between the input and output ends of the hot tank, that is, the medium in the hot tank continues to be cooled.

[0063] The above cooling time, including the cooling of the internal heat exchange pipeline and the cooling of shutdown, is 5min-20min. After cooling, the medium temperature is less than or equal to 50°C. It is mainly used to prepare for the next warehouse production. When the material is just put into the warehouse for production, the temperature continues to rise. The sudden high temperature affects the quality of the material. Therefore, it is necessary to cool the medium after the end.

[0064] S9, medium recovery, close the cooling pipeline and open the liquid return pipeline, and recover the medium in the internal heat exchange pipeline to the hot tank through the gas source; refer to Fig.12 , the fourth pipeline 25 is connected to the internal heat exchange pipeline. At this time, the fourth pipeline 25, the internal heat exchange pipeline, the fifth branch 28, the sixth branch 24 and the eighth branch 22 are in a connected state. At the same time, the gas source on the fourth pipeline 25 generates internal pressure. The gas source is an air pump or a high-pressure fan, and its pressure end is toward the internal heat exchange pipeline, thereby pushing the medium in the pipe through the internal heat exchange pipeline, the fifth branch 28, the sixth branch 24 and the eighth branch 22 in sequence and then back into the hot tank 21 to complete the medium recovery. The working time of this stage is 10min-20min, ensuring that the medium in the pipe is fully discharged, especially the medium in the internal heat exchange pipeline is fully discharged. A flow meter is set on the above pipeline to monitor the flow of the medium during recovery to determine whether the recovery is completed.

[0065] S10, turn off the gas source, complete the vacuum pressure relief (let air in), release the connection between the interface pipeline and the heat exchange plate, that is, the material cart is separated from the interface pipeline, the material cart is removed, and the freeze drying is completed.

[0066] The above steps S1-S10 are a vacuum freeze-drying process, and there may be one or more material trucks connected.

[0067] Above Figure 5-Figure 12 In the figure, the dotted line pipeline represents the pipeline in the disconnected state, and the solid line pipeline represents the pipeline in the connected state.

[0068] The utility model vacuum freeze drying system places freezing and drying in the same bin, which greatly reduces the space occupied by the system, reduces the use area of ​​the plant, and thus reduces the use cost; at the same time, it eliminates the steps of switching between the traditional freezing and drying zones, simplifies the freeze drying process, improves production efficiency, and has high production benefits; the heat exchange plate is arranged on the material vehicle, which can be quickly connected to the heat exchange pipeline, is flexible to use, and is convenient and labor-saving to load and unload materials, which greatly reduces the labor intensity and improves production efficiency; a double cold trap structure is arranged, which can realize alternating work, ensure the vacuum degree in the bin, and has good drying effect and high efficiency; the low freezing point and high boiling point are used A new medium with dual characteristics replaces the hot water in the hot water system and the Freon in the cold trap system, so that the freezing and drying processes of the material can be realized in one drying bin, with good freezing and heating effects, greatly reducing the freeze-drying time and high production efficiency; a cooling pipeline is provided to cool the medium in the heating pipeline to prepare for the next bin production and improve the drying quality of the material; a liquid return pipeline is provided to quickly recover the medium in the material truck, reducing the medium dosage, with low cost and good use effect; the vacuum freeze-drying system of the utility model has a compact structure, small footprint, high working efficiency and good effect.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A vacuum freeze drying system, characterized in that: include: A vacuum silo is used to place materials so as to vacuum freeze and dry the materials, and a cold trap is provided in the vacuum silo; The internal heat exchange pipeline includes an interface pipeline installed in the vacuum silo and a heat exchange plate arranged on the material vehicle and connected to the interface pipeline; A refrigeration pipeline, which can selectively connect to the internal heat exchange pipeline and / or the cold trap, and is used to freeze the material on the heat exchange plate or capture the steam in the vacuum silo; The heating pipeline can be connected to the internal heat exchange pipeline and heat it to achieve sublimation and dehydration of ice on the material.

2. The vacuum freeze-drying system according to claim 1, characterized in that: The interface pipeline includes a plurality of parallel interface branches, and the heat exchange plate is one or more and can be connected to the interface branches.

3. The vacuum freeze-drying system according to claim 1, characterized in that: The heat exchange plate includes one or more material placement plates for placing materials, and a medium pipe that can be connected to the interface pipeline for heat exchange is arranged in the material placement plate, and switch valves are arranged on both ends of the medium pipe and the interface pipeline.

4. The vacuum freeze-drying system according to claim 1, characterized in that: The heating pipeline is provided with a heating pipeline for heating the medium inside the heating pipeline and a cooling pipeline for cooling.

5. The vacuum freeze-drying system according to claim 1, characterized in that: It also includes a liquid return pipeline connected to the internal heat exchange pipeline and used for recovering the medium in the internal heat exchange pipeline, and a flow meter is arranged on the liquid return pipeline.

6. The vacuum freeze-drying system according to claim 1, characterized in that: The medium in the refrigeration pipeline and the heating pipeline is the same and is glacial refrigerant.

7. The vacuum freeze-drying system according to claim 1, characterized in that: There are at least two cold traps which are arranged in parallel.

8. The vacuum freeze-drying system according to claim 1, characterized in that: The refrigeration pipeline includes a cold tank, a first pipeline is provided at the output end of the cold tank, a first circulating pump is provided on the first pipeline, an end of the first pipeline is branched into a first branch connected to the input end of the cold trap, and a second branch connected to the first end of the internal heat exchange pipeline; a second pipeline is provided at the input end of the cold tank, an external refrigeration pipeline for cooling the internal medium is provided on the second pipeline, and an end of the second pipeline is branched into a third branch connected to the output end of the cold trap, and a fourth branch connected to the second end of the internal heat exchange pipeline.

9. The vacuum freeze-drying system according to claim 1, characterized in that: The heating pipeline includes a hot tank, which is provided with a heating pipeline for heating the internal medium. A third pipeline is provided at the output end of the hot tank, and a second circulation pump is provided on the third pipeline. The end of the third pipeline is branched into a fifth branch and a sixth branch, and the fifth branch is connected to the first end of the internal heat exchange pipeline; the end of the sixth branch is branched into a seventh branch connected to the second end of the internal heat exchange pipeline, and an eighth branch connected to the input end of the hot tank. A fourth pipeline is provided between the second end of the internal heat exchange pipeline and the hot tank, and a gas source is provided on the fourth pipeline for forming internal pressure in the pipe and realizing liquid return.

10. The vacuum freeze-drying system according to claim 9, characterized in that: The output end of the hot tank is connected to the third pipeline through a sixth pipeline, and a cooling pipeline is connected in parallel to the sixth pipeline.

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