Experimental type freeze dryer steam defrosting device

Abstract

The utility model provides a steam defrosting device of an experimental freeze dryer. The steam defrosting device comprises a cold trap, a steam generating device and a water circulation system, the cold trap comprises a cold trap box body, a front box interface, a water catcher and an evacuation pipe; a steam opening is formed in the bottom of the cold trap; a steam generating device is mounted at the lower part of the steam opening; a water outlet is formed in the bottom of the cold trap; a water circulation system is arranged between the water outlet and the steam generation device; the steam generating device is arranged on the lower portion of the cold trap, steam is sprayed into the box body of the cold trap, steam is fully diffused and distributed through the structure, beneficial to natural convection circulation of the steam, of the cold trap, the steam is captured and condensed when encountering a frost layer on the surface of the water catcher, sensible heat and latent heat are released at the same time, and the frost layer is rapidly melted; the melted frost layer can flow into the water circulation system, and melted water is used for supplementing water to the steam generation device.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of freeze dryer, especially to an experimental freeze dryer steam defrosting device. BACKGROUND

[0002] The experimental vacuum freeze dryer is mainly applied to the field of research and development and process development, and the drying bin shelf area is generally controlled within 0.5 square meters. However, after completing a working cycle, in order to ensure that the equipment can smoothly enter the next working cycle, defrosting operation must be performed on the cold trap.

[0003] At present, the defrosting methods of the experimental freeze dryer mainly include natural melting, manual breaking, water injection defrosting and hot fluorine defrosting. However, these methods all have their own limitations. The natural melting method is simple but has extremely low efficiency, which seriously affects the utilization rate of the equipment. The manual breaking method requires an additional cold trap operation door and limits the structure of the water catcher, resulting in increased cost, decreased water catching efficiency and inconvenient operation. The water injection defrosting method requires laying a special water supply pipeline, which is not only complicated to operate but also consumes a large amount of water resources. The hot fluorine defrosting method makes the refrigeration system more complex, has high cost, increases the loss of the compressor, reduces efficiency, and is prone to ice accumulation and other problems. SUMMARY

[0004] To solve the problems of low defrosting efficiency and complex steps of the natural melting, manual breaking, water injection defrosting and hot fluorine defrosting methods in the prior art, the utility model provides an experimental freeze dryer steam defrosting device.

[0005] The experimental freeze dryer steam defrosting device provided by the utility model adopts the following technical solution:

[0006] An experimental freeze dryer steam defrosting device, comprising a cold trap, a steam generating device and a water circulation system. The bottom of the cold trap is provided with a steam port, and the lower part of the steam port is installed with a steam generating device. The bottom of the cold trap is provided with a drain port, and a water circulation system is arranged between the drain port and the steam generating device.

[0007] Further, the cold trap comprises a cold trap box, a water catcher, an evacuation pipe and a front box interface; the cold trap box is a flat cuboid structure; the front box interface is arranged on the narrow vertical surface adjacent to the freeze dryer of the cold trap box; the evacuation pipe is arranged through the top surface of the cold trap box; the water catcher is arranged inside the cold trap box and keeps a certain distance from the two side surfaces; the water catcher can be one of S-shaped serpentine pipe type and heat exchange plate type.

[0008] Further, the steam port is arranged at the bottom of the cold trap and close to one side of the front box interface.

[0009] Further, the bottom surface of the cold trap box is a conical slope structure, and the lowest part of the slope is located at the drainage port.

[0010] Further, the steam generating device comprises a steam generator; one end of a steam valve is arranged at the top steam outlet of the steam generator; the other end of the steam valve is connected with the steam port through a steam quick connector; a water supply port is arranged at the top of the steam generator; an electric heater is arranged at the bottom of the steam generator; and the electric heater is connected with an external power supply.

[0011] Further, the water circulation system comprises a water collecting tank; one end of a drainage valve is connected with the water inlet of the water collecting tank; the other end of the drainage valve is connected with the drainage port through a drainage quick connector; a water pump for pumping water from the water collecting tank to the steam generator is connected between the outer wall of the water collecting tank and the outer wall of the steam generator through a water pipe; and a water supply valve is arranged at the water pipe between the water pump and the steam generator.

[0012] Further, the water supply valve can be one of an electric valve and a one-way valve.

[0013] Further, a water level sensor is arranged inside the steam generator; and the water level sensor can control the on-off of the motor current of the water pump.

[0014] Further, a drainage pipe is arranged through the bottom of the water collecting tank; one end of the drainage pipe arranged inside the water collecting tank extends to the top of the water collecting tank; and the highest point of the drainage pipe is always higher than the position height of the water pumping end of the water pump arranged in the water collecting tank.

[0015] In summary, the utility model has the advantages that:

[0016] The utility model achieves the purpose of using steam to defrost the interior of the cold trap box by adding a steam generating device and a water circulation system, and uses the defrosted water to participate in the circulation of water vapor, thereby achieving the purpose of saving water. The utility model adds a steam generating device at the bottom of the cold trap box, uses steam to spray into the cold trap box, and then combines the optimized design of the cold trap shape, the water trap arrangement, the steam port and the drain port position setting, thereby facilitating the formation of a natural convection circulation of steam inside the cold trap, so that the water vapor is fully diffused and evenly distributed, and the water vapor is captured and condensed when encountering the frost layer on the surface of the water trap, while releasing sensible heat and a large amount of latent heat, quickly melting the frost layer, and the melted frost layer can flow into the water circulation system, and the melted water is used to replenish water in the steam generating device. Through such a design, the cold trap of the experimental freeze dryer can be better defrosted, meeting the comprehensive requirements of good effect, high efficiency, compactness, convenience, low cost and water saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0018] Figure 2 This is a schematic diagram of the internal structure of the cold trap of the utility model;

[0019] Figure 3 This is a structural diagram of a second embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the steam flow during the defrosting process of the present invention.

[0021] As shown in the figure: 1-cold trap box, 2-water trap, 3-evacuation pipe, 4-drain port, 5-steam port, 6-front box interface, 7-drain valve, 8-water collecting tank, 9-drain pipe, 10-water pump, 11-water supply valve, 12-water level sensor, 13-electric heater, 14-steam generator, 15-water supply port, 16-steam valve, 17-drain quick connector, 18-steam quick connector. DETAILED DESCRIPTION

[0022] The following is combined with Figures 1-4 The utility model is further described in detail:

[0023] The present invention discloses an experimental freeze dryer steam defrosting device and method. Figure 1As shown, an experimental freeze dryer steam defrosting device includes a cold trap, a steam generating device, and a water circulation system. The cold trap includes a cold trap box 1, a water trap 2, an evacuation pipe 3, a drain 4, a steam port 5, and a front box interface 6. The bottom of the cold trap is provided with the steam port 5. The lower part of the steam port 5 is provided with the steam generating device. The bottom of the cold trap is provided with the drain 4. The water circulation system is arranged between the drain 4 and the steam generating device. In this embodiment, the freeze dryer cold trap is the core component during the freeze drying process. Its main function is to collect and condense the water vapor evaporated from the material, effectively preventing water vapor from polluting and damaging the vacuum system. The inside includes the water trap 2, and the performance of the water trap 2 directly affects the drying efficiency of the freeze dryer and the drying quality of the product. An efficient water trap 2 can quickly capture and condense a large amount of water vapor, thereby accelerating the freeze drying speed and reducing the residual moisture content of the product. On the contrary, if the performance of the water trap 2 is poor, it may cause problems such as prolonged freeze drying time, uneven product drying, or excessive residual moisture. The evacuation pipe 3 is used for freeze dryer vacuum pumping and removal of non-condensable gases to maintain a vacuum environment. The steam generating device is arranged on the bottom surface of the cold trap box 1. Steam is sprayed into the cold trap box 1. The water vapor meets the frost layer on the surface of the water trap 2 and is captured and condensed, releasing sensible heat and a large amount of latent heat, quickly melting the frost layer. The melted frost layer can flow into the water circulation system, and the melted water is used to supplement the water in the steam generating device, achieving the purpose of water saving. The front box interface 6 is a steam passage connecting the cold trap and the drying chamber. During freeze drying, the water vapor sublimated by the dried material in the drying chamber enters the cold trap and is captured by the water trap 2. The remaining small amount of non-condensable gas is removed by the evacuation pipe 3.

[0024] As Figure 2The cold trap internal structure is shown, the cold trap includes a cold trap box 1, a water catcher 2, an evacuation pipe 3, and a front box interface 6; the cold trap box 1 is a flat cuboid structure; the front box interface 6 is arranged on the narrow vertical surface adjacent to the freeze dryer of the cold trap box 1; the top surface of the cold trap box 1 is provided with the evacuation pipe; the water catcher 2 is arranged inside the cold trap box 1 and keeps a certain distance from the two side surfaces; the water catcher 2 can be one of an S-shaped serpentine pipe type and a heat exchange plate type; in this embodiment, the evacuation pipe 3 is located at the rear part of the cold trap box 1 opposite to the front of the cold trap box 1 and penetrates the top surface of the cold trap box 1; in this embodiment, the relative positions of the front box interface 6, the water catcher 2, and the evacuation pipe 3 and the shape of the cold trap box form a relatively narrow and smooth channel from the front box interface 6 to the evacuation pipe 3, so that the water vapor entering the cold trap from the front box interface 6 can pass through the narrow channel and be fully captured and frozen by the water catchers 2 on the two sides, and finally the remaining small amount of non-condensable gas is removed by the evacuation pipe 3; the bottom surface of the cold trap box 1 is provided with a steam port 5 near the side of the front box interface 6; in this embodiment, the arrangement position of the steam port 5 enables the defrosting steam entering therefrom to first dissolve the frost layer near the front box interface 6 where the frost is thickest, and at the same time, the steam can fully and naturally circulate in the cold trap under the interaction of thermal power and gravity, so that the steam can be fully and uniformly distributed everywhere in the water catchers;

[0025] As shown in Figure 2 , the bottom of the cold trap box 1 is a conical slope structure, and the lowest part of the slope is located at the drain port 4; the drain port 4 is arranged in the middle of the bottom surface of the cold trap box 1; in this embodiment, through the design of the conical slope structure of the bottom of the cold trap box 1, the melted water is promoted to converge at the drain port 4, the drainage is accelerated, and at the same time, the residual melted water is avoided to cause the breeding of bacteria;

[0026] As shown in Figure 1 , the steam generating device includes a steam generator; one end of a steam valve 16 is installed at the top steam outlet of the steam generator 14; the other end of the steam valve 16 is connected with the steam port 5 through a steam quick connector 18; a water supply port 15 is opened at the top of the steam generator 14; an electric heater 13 is arranged at the bottom inside the steam generator 14; the electric heater 13 is connected with an external power supply; in this embodiment, the steam generator 14 heats the distilled water by the heating mode of the electric heater 13 at the bottom to make the water boil, and the water vapor is discharged to the inside of the cold trap box 1 by opening the steam valve 16 at the same time to heat and melt the frost on the surface of the cold trap box 1 and the water catcher 2;

[0027] As shown in Figure 1As shown, the water circulation system comprises a water collecting tank 8; one end of a drain valve 7 is connected to the top water inlet of the water collecting tank 8; the other end of the drain valve 7 is connected to the drain port 4 through a drain quick connector 17; a water supply pump 10 for pumping water from the water collecting tank 8 into the steam generator 14 is connected between the outer sidewall of the water collecting tank 8 and the outer sidewall of the steam generator 14 through a water pipe; a water supply valve 11 is arranged at the water pipe between the water supply pump 10 and the steam generator 14; in this embodiment, when the drain valve 7 is opened, the water vapor in the cold trap box 1 will flow to the drain port 4 and enter the water circulation system after being melted; when the water level in the steam generation device is lower than the set value, the water supply valve 11 is opened to supply water to the steam generator 14 through the water supply pump 10;

[0028] As shown in Figure 1 , 3 , the water supply valve 11 can be one of an electric valve and a one-way valve; in this embodiment, the water supply valve 11 can be an electric valve and a one-way valve, which are two embodiments of the present application; when the electric valve is used, the electric valve can be an electromagnetic valve and an electric ball valve or an electric gate valve, which needs to be opened in advance before the water supply pump 10 can pump water; when the steam defrosting of the steam generation device starts, the water supply valve 11 needs to be closed to prevent the water vapor from flowing back to the water collecting tank 8;

[0029] In the second embodiment, the water supply valve 11 adopts a one-way valve, which can effectively open when the water supply pump 10 pumps water and can effectively prevent the steam from flowing back into the water collecting tank 8 when the pump stops;

[0030] As shown in Figure 1 , the steam generator 14 is provided with a water level sensor 12; the water level sensor 12 provides a signal to the control system to control the on-off of the current of the motor of the water supply pump 10; in this embodiment, the water level sensor 12 needs to be arranged at a suitable position on the inner wall of the steam generator 14; when the water level in the steam generator is lower than the set value, the water level sensor 12 sends a signal to the control system to open the water supply valve 11 and the water supply pump 10; the water supply pump 10 pumps the water in the water collecting tank 8 to the steam generator, thereby completing the self-circulation of the defrosting water

[0031] As shown in Figure 1As shown, the bottom of the water collecting tank 8 is provided with a drain pipe 9; one end of the drain pipe 9 inside the water collecting tank 8 extends to the top of the water collecting tank 8; the highest point of the drain pipe 9 is always higher than the position height of the water pump 10 at the water pumping end arranged in the water collecting tank 8; in the embodiment, when the steam condensate and frost layer melt water drop to the bottom of the cold trap box 1 through the drain port 4 and gather in the water collecting tank 8, the water is discharged from the top of the drain pipe 9 when the water level exceeds the height limited by the drain pipe 9, so that it is ensured that the water collecting tank 8 can store enough water, and the water overflow into the cold trap box 1 caused by excessive water collecting is avoided;

[0032] The implementation principle of the embodiment of the present application is:

[0033] As shown in Figure 1 , 4 , when used for the first time, a specified amount of distilled water needs to be added from the water supplement port 15; when the defrosting starts, the control system starts the electric heater 13 to heat the water in the steam generator 14, and simultaneously controls the steam valve 16 and the drain valve 7 to be opened; after being heated to the boiling state, the water vapor enters the cold trap box 1 through the steam port 5, and the water vapor is captured and condensed when meeting the frost layer on the surface of the water trap 2, and at the same time, the sensible heat and a large amount of latent heat are released, so that the frost layer is quickly melted. The steam first heats the area with the largest frost layer near the front box interface 6, and then is transported to the far end of the cold trap box 1 in a natural convection manner under the driving of thermal power through the gas flow channel. The steam condensate and the frost layer melt water drop to the bottom of the cold trap box 1 through the drain port 4 and gather in the water collecting tank 8, and the water is discharged from the top of the drain pipe 9 when the water level exceeds the height limited by the drain pipe 9. When the water level in the steam generator 14 is lower than the set value, the water level sensor 12 sends a signal, and the control system opens the water supply valve 11 and the water pump 10, and the water pump 10 pumps the water in the water collecting tank 8 to the steam generator 14, so that the self-circulation utilization of the defrosting water is completed. The working time length of the water pump 10 can be set by time or controlled by adding a corresponding sensor to avoid long-time idling, and the water supply valve 11 is closed at the same time after the pump stops; since the defrosting process is from the surface layer to the inside, and the steam pressure is low and the heat exchange intensity is controllable, the frost layer will gradually melt, so that the phenomenon of large ice shell falling off and causing the drain port 4 to be blocked and aggregated and the defrosting being incomplete is avoided. At the same time, the steam also has a good heating effect on the area near the drain port 4 under the transportation action of natural convection, and the aggregation and blockage of a small amount of ice particles are also avoided. After the set defrosting time is reached, the defrosting stops, the steam valve 16 is closed after a delay, and the remaining water in the steam generator 14 can be used for the next defrosting;

[0034] In summary, a steam defrosting method of an experimental freeze dryer can be completed through the following steps:

[0035] SP1. Initial preparation and water addition: when used for the first time, a specified amount of distilled water is added from the water supplement port 15.

[0036] SP2. Defrosting start and heating: the control system opens the electric heater 13 to heat the water in the steam generator; at the same time, the steam valve and the drain valve 7 are opened.

[0037] SP3. Water vapor generation and delivery: after being heated to the boiling state, the water vapor enters the cold trap box 1 from the steam port 5; the water vapor is captured and condensed by the frost layer on the surface of the water trap 2, while releasing sensible heat and latent heat, quickly melting the frost layer.

[0038] SP4. Steam distribution and frost melting: the steam first heats the area with the most frost near the front box interface 6; then it is transported to the far end of the cold trap box 1 through the gas flow channel in a natural convection manner driven by thermal power.

[0039] SP5. Condensed water and melted water droplet discharge: the condensed steam and the melted frost water droplets fall to the bottom of the cold trap box 1 and flow out through the drain port 4 and are collected in the water collection tank 8; when the water level exceeds the height limited by the drain pipe 9, it is discharged from the top of the drain pipe 9.

[0040] SP6. Water level monitoring and water replenishment cycle: when the water level in the steam generator is below the set value, the water level sensor 12 sends a signal; the control system opens the water supply valve 11 and the water supply pump 10, and the water supply pump 10 pumps the water in the water collection tank 8 to the steam generator, thereby completing the self-circulation of the defrosting water.

[0041] SP7. Water supply pump 10 operation and stop: the working time of the water supply pump 10 can be set by time or controlled by a sensor to avoid long-term idling; the water supply valve 11 is closed at the same time when the pump stops.

[0042] SP8. Defrosting end and subsequent processing: after reaching the set defrosting time, defrosting stops; the steam valve 16 is closed after a certain delay, and the remaining water in the steam generator 14 can be used for the next defrosting.

[0043] The above shows and describes the basic principles and main features of the present application and the advantages of the present application. The various components mentioned in the present application are common techniques in the existing field, which should be understood by those skilled in the art. The present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. An experimental freeze dryer steam defrosting device, characterized in that: The invention comprises a cold trap, a steam generating device and a water circulation system; a steam port (5) is provided at the bottom of the cold trap, and a steam generating device is installed below the steam port (5); a drain port (4) is provided at the bottom of the cold trap; a water circulation system is provided between the drain port (4) and the steam generating device; the steam generating device comprises a steam generator (14); one end of a steam valve (16) is installed at the steam outlet on the top of the steam generator (14); the other end of the steam valve (16) is connected to the steam port (5) through a steam quick connector (18); a water supply port (15) is provided at the top of the steam generator (14); an electric heater (13) is provided at the bottom inside the steam generator (14); and the electric heater (13) is connected to an external power supply.

2. The experimental freeze dryer steam defrosting device according to claim 1, characterized in that The cold trap comprises a cold trap box (1), a water trap (2), an evacuation pipe (3), and a front box interface (6); the cold trap box (1) is a flat rectangular parallelepiped structure; the front box interface (6) is arranged on a narrow vertical surface of the cold trap box (1) adjacent to the freeze dryer; an evacuation pipe is provided through the top surface of the cold trap box (1); the water trap (2) is arranged inside the cold trap box (1) and maintains a certain distance from the two side surfaces; the water trap (2) can be of an S-shaped serpentine tube type or a heat exchange plate type.

3. The experimental freeze dryer steam defrosting device according to claim 2, characterized in that The steam port (5) is arranged on one side of the bottom of the cold trap close to the front box interface (6).

4. The experimental freeze dryer steam defrosting device according to claim 2, characterized in that The bottom surface of the cold trap box (1) is a conical slope structure, the lowest point of the slope is located at the drain outlet (4), and the drain outlet (4) is located in the middle of the bottom surface of the cold trap box (1).

5. The experimental freeze dryer steam defrosting device according to claim 1, characterized in that The water circulation system comprises a water collecting tank (8); one end of a drain valve (7) is connected to the water inlet at the top of the water collecting tank (8); the other end of the drain valve (7) is connected to the drain outlet (4) via a drain quick connector (17); a water supply pump (10) is connected between the outer wall of the water collecting tank (8) and the outer wall of the steam generator (14) via a water pipe, and the water supply pump (10) can pump water inside the water collecting tank (8) into the steam generator (14); a water supply valve (11) is provided on the water pipe between the water supply pump (10) and the steam generator (14).

6. The experimental freeze dryer steam defrosting device according to claim 5, characterized in that The water supply valve (11) may be one of an electric valve and a one-way valve.

7. The experimental freeze dryer steam defrosting device according to claim 5, characterized in that A water level sensor (12) is provided inside the steam generator (14); the water level sensor (12) is used to control the current on and off of the motor in the water feed pump (10).

8. The experimental freeze dryer steam defrosting device according to claim 5, characterized in that A drainage pipe (9) is provided through the bottom of the water collecting tank (8); one end of the drainage pipe (9) is provided inside the water collecting tank (8) and extends toward the top of the water collecting tank (8), and the highest point of the drainage pipe (9) is always higher than the height of the position where the water pump (10) pumping end is provided in the water collecting tank (8).

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