Freeze-drying device and freeze-drying method

Abstract

The present invention discloses a freeze-drying device and a freeze-drying method. Compared with the stainless steel shallow bottom tray used in the traditional freeze-drying device, which can only perform sublimation drying in one direction, the special deep bottom tray used in the present invention can simultaneously perform sublimation drying in six directions: front, back, left, right, top, and bottom, which greatly shortens the freeze-drying time and increases the amount of sample freeze-dried each time. At the same time, compared with the traditional freeze-drying device that uses a hollow sandwich structure for cooling and heating, the present invention places a special deep bottom screen tray on a parallel bracket and uses a refrigeration compressor to provide refrigeration liquid for the cold air circulation fan, which can not only save a large number of stainless steel plate layers with complex structures; but also uses a circulating air mode in the freeze-drying field instead of traditional plate layer cooling and heating, which is more convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of freeze drying devices, and more particularly to a novel and efficient freeze drying device. Background Art

[0002] Freeze-drying utilizes the principle of ice crystal sublimation. Under a high vacuum, the water in frozen food materials sublimates directly from the solid ice into vapor, without melting the ice. Generally, during vacuum drying, the water in the material is converted from liquid to vapor, drying the food. Therefore, freeze-drying is also known as freeze sublimation. Freeze-drying technology offers advantages such as maintaining the original chemical composition and physical properties (such as porous structure and colloidal properties) of the dried material, while consuming less heat than other drying methods. However, compared to other drying methods, freeze-drying is more expensive, making it less widely adopted.

[0003] The freeze-drying devices sold on the market generally use food-grade stainless steel shallow-bottom trays (4 to 5 cm), which take a long time to freeze-dry. For frozen liquid, it usually takes 2-3 days of freeze-drying time. Moreover, in order to shorten the freeze-drying time as much as possible, the frozen material must be processed "very thin" in traditional freeze-drying devices. This means that in traditional freeze-drying devices, sublimation drying is carried out simultaneously by using multiple layers of shallow-bottom trays. Therefore, each freeze-drying process requires a large number of stainless steel shallow-bottom trays and a complex stainless steel plate layer underneath to be densely arranged, which undoubtedly causes waste of consumables.

[0004] Due to the limitation that traditional freeze-drying equipment can only sublimate and dry one surface (upper surface) of the frozen material, the direction of large-scale freeze-drying production to date is still to increase the area of ​​the sublimation surface (upper surface) of the frozen material as much as possible. This means that the freeze-drying equipment needs to have a larger floor space and a higher equipment height. Therefore, larger freeze-drying equipment has become the current direction and model for large-scale production of freeze-drying equipment.

[0005] This is obviously unreasonable. We need to develop more sophisticated and cheaper freeze-drying equipment based on scientific principles to achieve large-scale production of freeze-drying. Summary of the Invention

[0006] One of the purposes of the present invention is to provide a freeze-drying tray.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A freeze drying tray, comprising a front plate (47), a rear plate (35), a left plate (36), a right plate (42), a lower plate (48), a front air-permeable screen (43), a rear air-permeable screen (41), a left air-permeable screen (40), a right air-permeable screen (44), a lower air-permeable screen (46), a stainless steel frame (38), a bottom support rod (45) and a waterproof sealing strip (49); the front air-permeable screen (43), the rear air-permeable screen (41), the left air-permeable screen (40), the right air-permeable screen (44), the lower air-permeable screen (46), a stainless steel frame (38), a bottom support rod (45) and a waterproof sealing strip (49); The net (40), the right air permeable screen (44) and the lower air permeable screen (46) are embedded in the stainless steel frame (38) to form a box shape with an open top; the front layer (47), the rear layer (35), the left layer (36), the right layer (42) and the lower layer (48) are respectively inserted into the slot (39) of the stainless steel frame (38) and the outer side of the screen; each gap is sealed with a waterproof sealing strip (49); the bottom of the lower air permeable screen (46) is provided with a bottom support rod (45),

[0009] Furthermore, the bottom support rods (45) are multiple and arranged in a mesh shape.

[0010] Furthermore, the tray has a depth ranging from 20 to 50 centimeters.

[0011] Furthermore, the mesh size of the front air-permeable screen (43), the rear air-permeable screen (41), the left air-permeable screen (40), the right air-permeable screen (44), and the lower air-permeable screen (46) ranges from 80 to 800 meshes.

[0012] Another object of the present invention is to provide a freeze-drying device comprising the aforementioned freeze-drying tray.

[0013] Furthermore, the freeze drying device includes a freeze drying box (19), wherein the freeze drying box (19) is provided with a freeze drying chamber, and the freeze drying chamber is divided into two parts, the left half being a drying chamber, and the right half being a condensing chamber; parallel brackets (15) are provided at intervals above and below the drying chamber for placing the freeze drying tray;

[0014] A cold trap coil (20) and a condensation chamber temperature monitoring probe (25) are provided in the condensation chamber;

[0015] The freeze drying box (19) is provided with a cold air circulation fan (10) on the top and a refrigeration compressor (16) on the bottom. The outlet of the refrigeration compressor (16) is connected to the cold air circulation fan (10) via a condensate input line (9), and then flows back to the refrigeration compressor (16) via a condensate circulation line (50). In other words, the refrigeration compressor (16) provides refrigeration liquid for the cold air circulation fan (10).

[0016] A circulating fan pipe (11) is also provided on the top of the freeze drying box (19). The circulating fan pipe (11) has a drying chamber air inlet (13) and a drying chamber air outlet (14). The cold air blown out by the cold air circulating fan (10) enters the drying chamber through the drying chamber air inlet (13) at the top and is then discharged from the drying chamber air outlet (14). The circulating fan pipe (11) enters the condensing chamber through the condensing chamber air inlet (18). The air in the condensing chamber enters the vacuum pump.

[0017] Furthermore, a circulating fan pipeline valve (12) is provided on the pipeline between the drying chamber air outlet (14) and the condensing chamber air inlet (18); and a vacuum pump valve (21) is provided on the pipeline between the condensing chamber and the vacuum pump.

[0018] Another object of the present invention is to provide a freeze-drying method comprising the following steps:

[0019] Step 1, assembling the freeze drying tray, the freeze drying tray comprising a front plate (47), a rear plate (35), a left plate (36), a right plate (42), a lower plate (48), a front air permeable screen (43), a rear air permeable screen (41), a left air permeable screen (40), a right air permeable screen (44), a lower air permeable screen (46), a stainless steel frame (38), a bottom support rod (45) and a waterproof sealing strip (49); the front air permeable screen (43), the rear air permeable screen (41) ), the left breathable screen (40), the right breathable screen (44) and the lower breathable screen (46) are embedded in the stainless steel frame (38) to form a box shape with an open top; the front layer (47), the rear layer (35), the left layer (36), the right layer (42) and the lower layer (48) are respectively inserted into the slot (39) of the stainless steel frame (38) and the outer side of the screen; each gap is sealed with a waterproof sealing strip (49); a bottom support rod (45) is provided at the bottom of the lower breathable screen (46);

[0020] Step 2: Load the material to be dried into the assembled freeze drying tray;

[0021] Step 3: Place the freeze drying tray filled with materials into the freeze drying device and start freezing; observe the material through the observation window until the material is frozen into a solid state;

[0022] Step 4: Open the door, take out the freeze drying tray, remove the sealing strip, the front plate (47), the rear plate (35), the left plate (36), the right plate (42) and the lower plate (48), and then reinstall the freeze drying tray into the freeze drying chamber to continue freeze drying;

[0023] Step 5: After freeze drying is completed, take out the freeze drying tray and gently tap the screen to separate the material from the screen.

[0024] Furthermore, in step 2, the material is liquid.

[0025] Furthermore, when the vacuum freeze drying is continued in step 4, the refrigeration compressor provides refrigeration liquid to the cold air circulation fan.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The freeze-drying tray provided by the present invention differs from the shallow, food-grade stainless steel trays commonly used in previous patents and commercially available freeze-drying devices. The present invention utilizes a custom deep-bottomed mesh tray, supported by a stainless steel frame on all four sides. Air-permeable mesh surfaces are located in the front, back, left, right, and bottom directions, ensuring that frozen samples can be sublimated and dried simultaneously in all six directions. Therefore, compared to the shallow stainless steel trays (4-5 cm) used in conventional freeze-drying devices, which only allow sublimation drying in the top direction, the custom deep-bottomed tray used in the present invention significantly shortens the freeze-drying time with sublimation drying in all six directions, making it ideal for large-scale production.

[0028] 2. Limited by the fact that conventional freeze-drying apparatuses can only sublimate and dry a single surface (the upper surface) of the frozen material, the current trend in large-scale freeze-drying production has been to maximize the area of ​​the sublimation surface (the upper surface) of the frozen material, requiring a larger freeze-drying apparatus. Furthermore, to minimize freeze-drying time, conventional freeze-drying apparatuses must process the frozen material very thinly. This means that conventional freeze-drying apparatuses employ multiple layers of shallow trays for simultaneous sublimation drying. Consequently, each freeze-drying operation requires densely stacking a large number of stainless steel shallow trays, which undoubtedly wastes consumables. The specially designed deep trays employed in the present invention, however, allow for simultaneous sublimation drying in multiple directions (front, back, left, right, up, and down). These specially designed mesh trays can be constructed with depths exceeding those previously employed in freeze-drying apparatuses (20 to 50 cm), significantly increasing the amount of sample freeze-dried per operation. Therefore, the present invention can meet the technical requirements of large-scale freeze-drying and even change the current direction and model for scaled-up freeze-drying production, demonstrating significant innovation.

[0029] 3. The present invention provides a novel and highly efficient freeze-drying device. Unlike commercially available freeze-drying devices, which typically place stainless steel trays on a single stainless steel sheet, the stainless steel sheet typically has a hollow sandwich structure. Both cooling and heating of the sheet are achieved by circulating an intermediate fluid through fluid channels within the sheet. Therefore, the temperature uniformity and flatness of the sheet significantly impact the quality uniformity of the freeze-dried product. The present invention, on the other hand, places a specially designed deep-bottomed mesh tray on parallel supports and uses a refrigeration compressor to supply refrigeration liquid to a cold air circulation fan. This not only saves a large amount of complex stainless steel sheet structure, but also utilizes a circulating air mode in the freeze-drying field, replacing the traditional cooling and heating between stainless steel sheets, providing greater convenience.

[0030] 4. The current direction and model for large-scale production of freeze-drying equipment is to manufacture larger and taller freeze-drying equipment, adding more stainless steel shallow-bottom trays and the hollow sandwich panels underneath. This means more expensive equipment and more complex mechanical structures. Ultimately, no matter how the freeze-drying equipment is developed and updated, the cost of freeze-drying remains high. Therefore, this previous direction and model of extensive scale-up production is obviously not desirable. The present invention, based on the scientific principles of freeze-drying, has developed a more sophisticated and inexpensive freeze-drying equipment, which is highly innovative.

[0031] 5. This invention provides a novel and highly efficient freeze-drying tray. The tray's bottom and sides are made of low-temperature-resistant polytetrafluoroethylene mesh. The breathable mesh on the bottom has a lower load-bearing capacity than that of a conventional shallow stainless steel tray. To this end, the tray is equipped with several crisscrossing support rods (made of food-grade stainless steel) at its base to enhance its load-bearing capacity. This makes the tray practical, reliable, and highly practical.

[0032] 6. The present invention provides a novel and highly efficient freeze-drying tray. The bottom and sides of the specially designed deep-bottomed mesh tray are made of low-temperature-resistant polytetrafluoroethylene mesh. This material's elasticity and non-stick properties far surpass those of common shallow stainless steel trays on the market, effectively preventing the bottom of the material from sticking to the stainless steel tray during the freeze-drying process. This means that simply tapping the bottom and sides of the specially designed deep-bottomed mesh tray, without the need for auxiliary tools (such as a shovel or hammer), perfectly separates the tray from the freeze-dried material. Consequently, the present invention effectively ensures the integrity of the freeze-dried material. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below with reference to the accompanying drawings and examples.

[0034] Figure 1It is a schematic diagram of the front structure of the freeze-drying device of the present invention.

[0035] Figure 2 It is a schematic diagram of the back structure of the freeze-drying device of the present invention.

[0036] Figure 3 Schematic diagram of the structure of a special deep bottom screen tray.

[0037] Figure 4 Schematic diagram of the control panel of a new and efficient freeze-drying device.

[0038] In the figure, 1. Circulation fan cover; 2. Exhaust valve; 3. Exhaust port; 4. Device door; 5. Door buckle; 6. Observation port; 7. Drying chamber temperature monitoring probe; 8. Device switch; 9. Condensate input pipeline; 10. Cold air circulation fan; 11. Circulation fan pipeline; 12. Circulation fan pipeline valve; 13. Drying chamber air inlet; 14. Drying chamber air outlet; 15. Parallel bracket; 16. Refrigeration compressor; 17. Device column foot; 18. Condensation chamber air inlet; 19. Freeze drying box; 20. Cold trap coil; 21. Vacuum pump valve; 22. Vacuum pump pipeline; 23. Vacuum control signal transmission line; 24. Vacuum pump; 25. Device condensation chamber temperature monitoring Probe; 26. Drain switch; 27. Vacuum pump switch; 28. Device controller; 29. ​​Drain; 30. Device control electrical signal transmission line; 31. Device controller switch; 32. Device controller panel; 33. Device controller keyboard; 34. Device controller brake pulley; 35. Rear panel; 36. Left panel; 37. Deep bottom screen tray; 38. Stainless steel frame; 39. Card slot; 40. Left breathable screen; 41. Rear breathable screen; 42. Right panel; 43. Front breathable screen; 44. Right breathable screen; 45. Bottom support rod; 46. Lower breathable screen; 47. Front panel; 48. Lower panel; 49. Waterproof sealing strip; 50. Condensate circulation pipeline. DETAILED DESCRIPTION

[0039] The following embodiments will be described in detail with reference to the accompanying drawings. In actual applications, the shape, thickness, or height of each component may be enlarged or reduced. The embodiments listed in the present invention are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Any obvious modifications or changes made to the present invention do not depart from the spirit and scope of the present invention. Example

[0040] See also Figures 1 to 3 A freeze drying device includes a freeze drying box 19, a vacuum pump 24, a device controller 28 and a special deep bottom screen tray 37.

[0041] The special deep bottom screen tray 37 includes a front plate 47, a rear plate 35, a left plate 36, a right plate 42, a lower plate 48, a front air-permeable screen 43, a rear air-permeable screen 41, a left air-permeable screen 40, a right air-permeable screen 44, a lower air-permeable screen 46, a stainless steel frame 38, a bottom support rod 45, and a waterproof sealing strip 49. Each screen is made of polytetrafluoroethylene.

[0042] The stainless steel frame 38 is a cube-shaped frame, each of which is provided with slots 39. The front, rear, left, right, and lower air screens 43, 41, 40, 44, and 46 are integrally embedded in the stainless steel frame, forming a cube-shaped screen structure with an open top. The slots 39 are distributed throughout the stainless steel frame to facilitate insertion of the front, rear, left, right, and lower panels 47, 35, 36, 42, and 48 into the four sides and bottom of the cube-shaped screen structure. The gaps between the front, rear, left, right, and lower panels 48 and the stainless steel frame 38 are sealed with waterproof sealing strips 49.

[0043] The lower air-permeable screen 46 is further provided with a plurality of bottom support rods 45. In this embodiment, these bottom support rods 45 are arranged in a mesh shape at intervals in the front-to-back direction and the left-to-right direction to play a load-bearing role.

[0044] The depth of the deep bottom screen tray 37 is in the range of 20 to 50 centimeters, while the depth of an ordinary tray is generally 4 to 5 centimeters.

[0045] The mesh size of the front air-permeable screen 43, the rear air-permeable screen 41, the left air-permeable screen 40, the right air-permeable screen 44 and the lower air-permeable screen 46 ranges from 80 to 800 meshes.

[0046] The freeze-drying chamber 19 is housed in a freeze-drying chamber, which is divided into two sections: the left half is the drying chamber, and the right half is the condensing chamber. Parallel brackets 15 are spaced above and below the drying chamber to accommodate multiple, custom-made, deep-bottomed mesh trays 37. A drying chamber temperature monitoring probe 7 is located at the bottom of the drying chamber, while a cold trap coil 20 and a condensing chamber temperature monitoring probe 25 are located within the condensing chamber.

[0047] The freeze-drying chamber 19 is equipped with a cold air circulation fan 10 at the top and a refrigeration compressor 16 at the bottom. The cold air circulation fan 10 is protected by a circulating fan cover 1. The outlet of the refrigeration compressor 16 is connected to the cold air circulation fan 10 via a condensate inlet line 9. The condensate then flows back to the refrigeration compressor 16 via a condensate circulation line 50. In other words, the refrigeration compressor 16 provides refrigerant liquid for the cold air circulation fan 10.

[0048] A circulating fan pipe 11 is also provided on the top of the freeze drying box 19, and the circulating fan pipe 11 has a drying chamber air inlet 13 and a drying chamber air outlet 14; the cold air blown out by the cold air circulating fan 10 enters the drying chamber through the drying chamber air inlet 13 on the top (a partition is provided on the circulating fan main pipe between the drying chamber air inlet 13 and the drying chamber air outlet 14, so that the cold air will not directly bypass the drying chamber. Figure 1 The air then exits the drying chamber through the drying chamber outlet 14. The circulating fan line 11 enters the condensing chamber through the condensing chamber air inlet 18. The air from the condensing chamber enters the vacuum pump. Once the temperature inside the freeze-drying unit reaches the desired level, the circulating fan stops and the internal air inlet closes to maintain the freeze-drying unit's vacuum level.

[0049] A circulating fan pipeline valve 12 is provided on the pipeline between the drying chamber air outlet 14 and the condensing chamber air inlet 18; a vacuum pump valve 21 is provided on the pipeline between the condensing chamber and the vacuum pump.

[0050] The front of the freeze drying box body 19 is provided with a device box door 4. The device box door 4 includes an observation port 6 and a box door buckle 5. The observation port 6 is located at the center of the device box door 4 to facilitate observation of the freeze drying of the material.

[0051] See also Figure 1 The vacuum pump 24 , the vacuum pump valve 21 , the vacuum pump pipeline 22 and the vacuum pump switch 27 constitute a vacuum unit, which can provide a vacuum degree for the freeze drying box 19 .

[0052] See also Figure 1 The device controller 28, the vacuum degree control electric signal transmission line 23, the device control electric signal transmission line 30, the device controller switch 31, the device controller panel 32, the device controller keyboard 33 and the device controller brake pulley 34 constitute a control unit; the device controller 28 controls the operation of the vacuum pump 24 and the freeze-drying device 19 respectively through the vacuum degree control electric signal transmission line 23 and the device control electric signal transmission line 30.

[0053] See also Figure 3 The device controller panel 32 is a touch screen, including a "temperature" column, a "time" column, a "stage" column, a "vacuum degree" column, a "run" menu, a "stop" menu, a "set program" menu, a "observe program" menu, a "start vacuum pump" menu, a "stop vacuum pump" menu, a "confirm" menu, and a "modify" menu. The specific values ​​of the "temperature" column, the "time" column, the "stage" column, and the "vacuum degree" column are input through the device controller keyboard (33). During the freeze-drying process, clicking the "observe program" menu can view the program operation status of the freeze-drying operation.

[0054] The use of the present invention is as follows:

[0055] Before freeze-drying, the custom deep-bottomed mesh tray 37 is assembled: the front panel 47, rear panel 35, left panel 36, right panel 42, and lower panel 48 are sequentially inserted into the slots 39 on the stainless steel frame 38. All gaps are sealed with waterproof sealing tape 49 to prevent leakage. The liquid is then poured into the assembled custom deep-bottomed mesh tray 37 and placed in a freezer for freezing. Once the liquid in the custom deep-bottomed mesh tray 37 has solidified, it is removed from the freezer. The waterproof sealing tape 49 is removed, and the front panel 47, rear panel 35, left panel 36, right panel 42, and lower panel 48 are sequentially removed from the slots. The device door 4 is then opened, and the entire custom deep-bottomed mesh tray 37 is placed on the parallel brackets 15 in the drying chamber of the device. The device door 4 is closed and the door latch 5 is fastened, preparing to begin freeze-drying.

[0056] When freeze drying starts, first start the device switch 8, vacuum pump switch 27 and device controller switch 31 in sequence, then close the exhaust valve 2 and drain outlet switch 26 in sequence, and open the circulation fan pipeline valve 12 and vacuum pump valve 21 in sequence; click the "Set Program" menu on the device controller panel 32, enter the specific values ​​of the "Temperature" column, "Time" column, "Stage" column and "Vacuum Degree" column through the device controller keyboard 33, click the "OK" menu on the device controller panel 32, and the device controller 28 can save the set freeze drying program; finally, click the "Start Vacuum Pump" and "Run" menus on the device controller panel 32, the vacuum pump 24 and the circulation fan 10 of the freeze drying device 19 start working, and the program for freeze drying the sample is run.

[0057] When freeze drying is completed, the vacuum pump 24 and the freeze drying device 19 have completed the set program saved by the device controller 28, and the circulation fan 10 in the freeze drying device 19 is automatically shut down. First, close the circulation fan pipeline valve 12 and the vacuum pump valve 21 in sequence, click the "Turn off vacuum pump" and "Stop" menus, and then open the exhaust valve 2 and the drain outlet switch 26 in sequence. When the vacuum degree in the freeze drying device 19 reaches one atmosphere and the atmospheric pressure inside and outside the freeze drying device 19 is balanced, open the door buckle 5 and open the device door 4, remove the special deep bottom screen tray 37 from the parallel bracket 15, turn the special deep bottom screen tray 37 upside down in a dry environment, and tap the front air permeable screen 43, the rear air permeable screen 41, the left air permeable screen 40, the right air permeable screen 44 and the lower air permeable screen 46 embedded in the stainless steel frame 38 to easily collect the freeze-dried sample. Finally, turn off the vacuum pump switch 27, the device controller switch 31 and the device switch 8 in sequence, close the device box door 4, fasten the box door buckle 5, and end the freeze drying. Example

[0058] The difference between Example 2 and Example 1 is that:

[0059] Before freeze-drying, assemble the special deep-bottom mesh tray 37 first: insert the front plate 47, rear plate 35, left plate 36, right plate 42, and lower plate 48 into the slots 39 distributed on the stainless steel frame 38 in sequence, and fill and seal all gaps with waterproof sealing strips 49 to prevent leakage; then pour the slurry into the assembled special deep-bottom mesh tray 37. Open the device door 4, place the special deep-bottom screen tray 37 filled with liquid on the parallel bracket 15, close the device door 4 and fasten the door buckle 5; then start the device switch 8 and the device controller switch 31 in sequence, then close the exhaust valve 2 and the drain outlet switch 26 in sequence, and then open the circulation fan pipeline valve 12; click the "Set Program" menu on the device controller panel 32, and enter the specific values ​​of the "Temperature" column, "Time" column and "Stage" column through the device controller keyboard 33, click the "OK" menu on the device controller panel 32, and the device controller 28 can save the set freezing program; finally, click the "Run" menu on the device controller panel 32, and the cold air circulation fan 10 of the freeze-drying device 19 starts working, running the program for freezing samples.

[0060] When it is observed through the observation port 6 of the device box door 4 that the liquid in the special deep-bottom screen tray 37 has been frozen into a solid, click the "Stop" menu on the device controller panel 32, open the device box door 4 and remove the special deep-bottom screen tray 37 with the liquid frozen into a solid from the parallel bracket 15; first tear off the waterproof sealing strip 49, then take out the front layer 47, the rear layer 35, the left layer 36, the right layer 42, and the lower layer 48 from the card slot in turn, and then open the device box door 4, and place the entire special deep-bottom screen tray 37 on the parallel bracket 15 in the device drying chamber; close the device box door 4 and buckle the door buckle 5 to prepare to start freeze drying.

[0061] When freeze drying starts, first start the vacuum pump switch 27, then open the vacuum pump valve 21; click the "Set Program" menu on the device controller panel 32, enter the specific values ​​of the "Temperature" column, "Time" column, "Stage" column and "Vacuum Degree" column through the device controller keyboard 33, click the "OK" menu on the device controller panel 32, and the device controller 28 can save the set freeze drying program; finally, click the "Start Vacuum Pump" and "Run" menus on the device controller panel 32, the vacuum pump 24 and the circulation fan 10 of the freeze drying device 19 start working, and the program for freeze drying the sample runs.

[0062] When it is observed through the observation port 6 of the device box door 4 that the material liquid in the special deep-bottom screen tray 37 has been basically freeze-dried and formed, first close the circulating fan pipeline valve 12 and the vacuum pump valve 21 in sequence, click the "Turn off vacuum pump" and "Stop" menus, and then open the exhaust valve 2 and the drain outlet switch 26 in sequence. When the vacuum degree in the freeze-drying device 19 reaches one atmosphere and the atmospheric pressure inside and outside the freeze-drying device 19 is balanced, open the box door buckle 5 and open the device box door 4, remove the special deep-bottom screen tray 37 from the parallel bracket 15, turn the special deep-bottom screen tray 37 upside down in a dry environment, and tap the front air-permeable screen 43, the rear air-permeable screen 41, the left air-permeable screen 40, the right air-permeable screen 44 and the lower air-permeable screen 46 embedded in the stainless steel frame 38 to easily collect the freeze-dried sample. Finally, turn off the vacuum pump switch 27, the device controller switch 31 and the device switch 8 in sequence, close the device box door 4, fasten the box door buckle 5, and end the freeze drying.

[0063] Table 1 below is a comparison of freeze drying performance of the present invention and a conventional freeze drying apparatus:

[0064] Indicators required for freeze-drying 10 kg of frozen material The present invention Traditional freeze drying equipment Pallet (quantity) 55cm (length) × 25cm (width) × 50cm (height) freeze-drying tray (1 piece) 55cm (length) × 25cm (width) × 5cm (height) stainless steel shallow bottom trays (10), arranged in pairs Do you need stainless steel plate layer (quantity) Not required (0 yuan) Required (5 pieces) Freeze-drying time (using the method of pre-freezing in a freezer according to Example 1) 7 hours 48 hours Freeze-drying time (using the method of freezing and then freeze-drying in a freeze-drying apparatus as in Example 2) 12 hours 72 hours

[0065] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A freeze drying device, characterized in that: The freeze drying device comprises a freeze drying box (19), wherein a freeze drying chamber is provided in the freeze drying box (19), and the freeze drying chamber is divided into two parts, the left half being a drying chamber and the right half being a condensing chamber; parallel brackets (15) are provided at upper and lower intervals of the drying chamber for placing freeze drying trays; a cold trap coil (20) is provided in the condensing chamber; The freeze drying box (19) is provided with a cold air circulation fan (10) on the top and a refrigeration compressor (16) on the bottom; the outlet of the refrigeration compressor (16) is connected to the cold air circulation fan (10) via a condensate input pipeline (9), and then flows back to the refrigeration compressor (16) via a condensate circulation pipeline (50); A circulating fan pipeline (11) is also provided on the top of the freeze drying box (19), and the circulating fan pipeline (11) has a drying chamber air inlet (13) and a drying chamber air outlet (14); the cold air blown out by the cold air circulating fan (10) enters the drying chamber through the drying chamber air inlet (13) at the top, and is then discharged from the drying chamber air outlet (14); the circulating fan pipeline (11) enters the condensing chamber through the condensing chamber air inlet (18); the air in the condensing chamber enters the vacuum pump; The freeze drying tray comprises a front plate (47), a rear plate (35), a left plate (36), a right plate (42), a lower plate (48), a front air-permeable screen (43), a rear air-permeable screen (41), a left air-permeable screen (40), a right air-permeable screen (44), a lower air-permeable screen (46), a stainless steel frame (38), a bottom support rod (45) and a waterproof sealing strip (49); the front air-permeable screen (43), the rear air-permeable screen (41), the left air-permeable screen (40), the right air-permeable screen (44), the lower air-permeable screen (46), a stainless steel frame (38), a bottom support rod (45) and a waterproof sealing strip (49); (40), the right breathable screen (44) and the lower breathable screen (46) are respectively embedded in the stainless steel frame (38) to form a box shape with an open top; the front layer (47), the rear layer (35), the left layer (36), the right layer (42) and the lower layer (48) are respectively inserted into the slot (39) of the stainless steel frame (38) and the outer side of the screen; each gap is sealed with a waterproof sealing strip (49); a bottom support rod (45) is provided at the bottom of the lower breathable screen (46).

2. A freeze-drying device according to claim 1, characterized in that: The bottom support rods (45) are multiple and arranged in a mesh shape.

3. A freeze-drying device according to claim 1, characterized in that: The depth of the tray ranges from 20 to 50 centimeters.

4. A freeze-drying device according to claim 1, characterized in that: The mesh sizes of the front air-permeable screen (43), the rear air-permeable screen (41), the left air-permeable screen (40), the right air-permeable screen (44) and the lower air-permeable screen (46) are 80 to 800 meshes.

5. A freeze-drying device according to claim 1, characterized in that: A circulating fan pipeline valve (12) is provided on the pipeline between the drying chamber air outlet (14) and the condensing chamber air inlet (18); and a vacuum pump valve (21) is provided on the pipeline between the condensing chamber and the vacuum pump.

6. A freeze-drying method, applied to the freeze-drying apparatus according to claim 1, comprising the following steps: Step 1, assembling a freeze drying tray, the freeze drying tray comprising a front plate (47), a rear plate (35), a left plate (36), a right plate (42), a lower plate (48), a front air permeable screen (43), a rear air permeable screen (41), a left air permeable screen (40), a right air permeable screen (44), a lower air permeable screen (46), a stainless steel frame (38), a bottom support rod (45) and a waterproof sealing strip (49); the front air permeable screen (43), the rear air permeable screen (41) , the left breathable screen (40), the right breathable screen (44) and the lower breathable screen (46) are respectively embedded in the stainless steel frame (38) to form a box shape with an open top; the front layer (47), the rear layer (35), the left layer (36), the right layer (42) and the lower layer (48) are respectively inserted into the slot (39) of the stainless steel frame (38) and the outer side of the screen; each gap is sealed with a waterproof sealing strip (49); a bottom support rod (45) is provided at the bottom of the lower breathable screen (46); Step 2: Load the material to be dried into the assembled freeze drying tray; Step 3: Place the freeze drying tray filled with materials into the freeze drying device and start freezing; observe the material through the observation window until the material is frozen into a solid state; Step 4: Open the door, take out the freeze-drying tray, remove the sealing strip, the front plate (47), the rear plate (35), the left plate (36), the right plate (42) and the lower plate (48), and then reinstall the freeze-drying tray into the freeze-drying manufacturing box to continue vacuum freeze drying; Step 5: After freeze drying is completed, take out the freeze drying tray and tap the sieve to separate the material from the sieve.

7. A freeze-drying method according to claim 6, characterized in that: In step 2, the material is liquid.

8. A freeze-drying method according to claim 6, characterized in that: When the vacuum freeze drying is continued in step 4, the refrigeration compressor provides refrigeration liquid to the cold air circulation fan.

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