A pharmaceutical intermediate low-temperature freeze-drying apparatus and a control method thereof

Abstract

The application discloses a kind of pharmaceutical intermediates low-temperature freeze-drying equipment and control method thereof, it is related to pharmaceutical intermediates raw material refrigeration equipment field.In the application: freeze-drying equipment is built-in multi-layer shelf plate and forms placement cavity, each layer placement cavity is equipped with air inlet, back gas nozzle, pressure sensing module and temperature sensing module, cold box with cold flow core is inserted in placement cavity, and cold flow core is provided with airflow channel and airflow gap.The application determines the empty or non-empty state of work station by pressure sensing module, closes corresponding air valve and stops temperature sensing module when empty, adjusts air valve opening degree according to the weight proportion of raw material when non-empty, and combines temperature sensing module to monitor and control cooling cycle in real time.The application realizes accurate cold air circulation and partition storage, solves the problem of uneven temperature of traditional equipment, material taking influences storage environment and energy waste, guarantees the storage quality of pharmaceutical intermediates, and considers the freezing-drying effect and energy-saving demand.

Description

Technical Field

[0001] This invention relates to the field of pharmaceutical intermediate raw material refrigeration equipment, and more particularly to a low-temperature freeze-drying equipment for pharmaceutical intermediates and its control method. Background Technology

[0002] Low-temperature freeze-drying of pharmaceutical intermediates is a crucial step in ensuring their chemical stability, activity, and subsequent processing performance, placing stringent requirements on the temperature uniformity, airtightness, and energy consumption control of the storage environment. However, existing low-temperature freeze-drying equipment faces numerous technical bottlenecks in practical applications, severely impacting the storage quality and production efficiency of pharmaceutical intermediates.

[0003] In terms of temperature control, traditional equipment often adopts an integrated cooling air supply mode, lacking precise matching design between the air inlet and outlet channels. This results in uneven airflow distribution within the chamber, leading to significant differences in localized heating or cooling of the drug intermediates. Furthermore, the cooling components are mostly made of ordinary metals, resulting in low heat transfer efficiency. Additionally, the unreasonable airflow channel structure makes it difficult for the cooling air to fully contact the raw materials for heat exchange. This can lead to incomplete drying or over-freezing in certain areas, directly affecting the purity of the drug intermediates and their subsequent reactivity.

[0004] In the material handling process, existing equipment mostly adopts an open or semi-open chamber design, lacking an independent partitioned storage structure. When it is necessary to remove a portion of the drug intermediate, the entire chamber or a large area of ​​the storage area needs to be opened, allowing ambient air to rush in. This causes rapid temperature fluctuations within the chamber, leaving the remaining drug intermediate in an unstable temperature environment for an extended period. This makes it prone to moisture absorption and deterioration, severely affecting its shelf life and performance, especially for heat-sensitive and easily oxidized drug intermediates.

[0005] In terms of energy consumption control, traditional equipment lacks load sensing and dynamic adjustment mechanisms, maintaining a constant cooling supply intensity regardless of whether the storage chamber is loaded with materials or the weight of the materials. The phenomenon of continuous cooling at idle workstations and a mismatch between the cooling capacity and actual demand at loaded workstations is common. This not only causes a large amount of energy waste, but may also lead to excessive load on the equipment's refrigeration system due to over-cooling, shortening the equipment's service life and increasing production and operating costs.

[0006] The aforementioned technical problems have collectively constrained the development of low-temperature freeze-drying technology for pharmaceutical intermediates. How to effectively overcome these technical pain points and complete the low-temperature freeze-drying and preservation of pharmaceutical intermediates efficiently, accurately, and energy-savingly has become a challenge. Summary of the Invention

[0007] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0008] This invention provides a low-temperature freeze-drying device for pharmaceutical intermediates. The freeze-drying device has multiple layers of shelves inside. Placement cavities are provided between adjacent shelves and between the top shelf and the top plate of the freeze-drying device. The back plate of each placement cavity is equipped with multiple air inlets. Each air inlet is independently equipped with an air return valve directly above it. Each air inlet is independently equipped with an air inlet valve, and each air return valve is independently equipped with an air return valve.

[0009] Each layer of the placement chamber independently holds multiple freezing boxes. Each freezing box also includes a cold flow core inserted into its inner cavity from the side end of the freezing box. The cold flow core includes a thin plate part and airflow ends located at the upper and lower ends of the thin plate part. The airflow ends are provided with an airflow channel with an open side. The thin plate part is provided with an airflow gap connecting the upper and lower airflow channels. The lower airflow channel is aligned with the air inlet, and the upper airflow channel is aligned with the air return nozzle.

[0010] Multiple pressure sensing modules are embedded in the bottom wall of the placement chamber for detecting the status of the freezer box, and multiple temperature sensing modules are installed on the top wall of the placement chamber. A sliding cover is installed on the top of the freezer box, with a vertically penetrating side notch and a detection port. Each side notch is independently equipped with a temperature sensing module. The freeze-drying equipment is also equipped with a cold air supply mechanism connected to the air inlet via a cold air pipeline and a return air mechanism connected to the return air inlet via a return air pipeline.

[0011] As a preferred embodiment of the freeze-drying equipment of the present invention: multiple bottom grooves are formed on the top side of each rack, and pressure sensing modules are embedded in the bottom grooves. Multiple top grooves are formed on the bottom surface of the non-bottom racks and the top plate of the freeze-drying equipment, and temperature sensing modules are disposed in the top grooves.

[0012] As a preferred technical solution of the freeze-drying equipment of the present invention: a slot for cooperating with the cold flow core is opened on one side end plate of the freezing box, and an end notch that aligns with the edge notch is opened on the top of the side end plate.

[0013] As a preferred technical solution of the freeze-drying equipment of the present invention: the cold flow core is made of copper alloy material, and the sidewall of the airflow gap of the cold flow core is coated with graphene coating.

[0014] As a preferred technical solution of the freeze-drying equipment of the present invention: a trapezoidal open structure is provided on one side of the airflow gap of the cold flow core, and a sealing strip is inserted into the trapezoidal open structure. The sealing strip includes a rectangular part inserted into the airflow gap and a trapezoidal part that cooperates with the trapezoidal open structure.

[0015] As a preferred technical solution of the freeze-drying equipment of the present invention: the top of the freezing box is provided with a material guide opening for installing the sliding cover, and a heat-insulating sealing strip is provided at the material guide opening position to press against the sliding cover.

[0016] As a preferred technical solution of the freeze-drying equipment of the present invention: an air inlet pipe is fixedly installed on the back plate of each placement chamber, the air inlet pipe is connected to the cold air pipeline, and the air inlet valve of the air inlet nozzle is connected to the air inlet pipe. An air collecting pipe is fixedly installed on the back plate of each placement chamber, the air collecting pipe is connected to the return air pipeline, and the return air valve of the return air nozzle is connected to the air collecting pipe.

[0017] This invention provides a control method for a low-temperature freeze-drying equipment for pharmaceutical intermediates, comprising the following:

[0018] Step 1: Material loading and sealing: Open the sliding cover of the freezer box, evenly inject the drug intermediate into the inner cavity, avoiding spillage into the sealed area, and close the sliding cover to ensure a tight fit with the heat insulation sealing strip.

[0019] Step 2, Precise Placement of Freezing Box: Insert the frozen box containing the materials into the idle position of the placement cavity, aligning the notch on the sliding cover with the installation position of the temperature sensing module.

[0020] Step 3: No-load status determination: The pressure sensing module detects the pressure signal of the freezer box and compares it with the preset no-load threshold to distinguish between no-load and non-no-load workstations.

[0021] Step 4: Idle workstation control: After determining that the workstation is idle, close the corresponding air intake valve and air return valve, and stop the temperature sensing module of that workstation from working.

[0022] Step 5: Non-no-load weight conversion: Under non-no-load conditions, the actual weight of the raw materials is calculated using pressure parameters and transmitted to the control system.

[0023] Step 6: Adjusting the opening degree of the air valve: Adjust the opening degree of the corresponding air intake valve and air return valve linearly according to the ratio of the actual weight to the full load weight.

[0024] Step 7: Real-time temperature monitoring: The temperature sensing module detects the temperature inside the freezer compartment through the detection port and feeds it back to the control system in real time.

[0025] Step 8: Cooling Circulation Control: When the temperature is higher than the preset threshold, the cooling supply mechanism is activated to form a cooling circulation. When the temperature reaches the target, the air valve and cooling mechanism are closed.

[0026] Step 9: Reset the status after material removal: After the freezing box is removed, the pressure sensor module re-detects the station status and executes subsequent control according to the no-load or non-no-load logic.

[0027] Compared with existing technologies, the beneficial effects of this invention are:

[0028] The device of this invention constructs a precise cold air circulation path by setting corresponding air inlets and outlets and controlling them with independent valves, in conjunction with the airflow channels of the copper alloy cold flow core inside the freezing box and the airflow gaps of the graphene coating. The cold air and the drug intermediates exchange heat fully, solving the problem of uneven heating in traditional equipment. At the same time, the multi-layer placement chambers combined with independent freezing boxes achieve partitioned storage. When materials are retrieved, only a single freezing box is affected, avoiding the impact of material retrieval on raw materials in areas that have not been retrieved in traditional equipment, and ensuring the stability of the overall storage environment.

[0029] In this invention, the pressure sensing module detects the load status of the freezer box. When it is unloaded, the corresponding air valve is closed and the temperature sensing module stops working to avoid ineffective cooling and energy waste. When it is not unloaded, the air valve opening is linearly adjusted according to the ratio of the actual weight of the raw material to the full load weight, so that the supply of cold air is precisely matched with the demand of raw materials, taking into account both the freeze-drying effect and energy saving requirements. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the freeze-drying equipment in this invention.

[0031] Figure 2 for Figure 1 A magnified structural diagram of part A in the middle.

[0032] Figure 3 This is a schematic diagram of the overall structure of the freezing box in this invention.

[0033] Figure 4 This is a schematic diagram of the internal structure of the freezer box in this invention.

[0034] Figure 5 This is a structural diagram showing the disassembly of the main components of the freezer box in this invention.

[0035] Figure 6 for Figure 5 A magnified structural diagram of section B in the middle.

[0036] Figure 7 for Figure 5 A magnified structural diagram of part C in the middle.

[0037] Figure 8 This is a schematic diagram of the cooling and cold air recirculation piping system in this invention.

[0038] Wherein: 1-Freeze-drying equipment; 2-Shelf; 3-Placement cavity; 4-Freezing box; 401-Inner cavity; 402-Cold flow core; 4021-Thin plate section; 4022-Airflow end; 4023-Airflow gap; 4024-Airflow channel; 4025-Graphene coating; 4026-Trapezoidal open structure; 403-Sliding cover; 4031-Side notch; 4032-Detection port; 404-Slot; 405- End notch, 406-material guide opening, 407-sealing strip, 4071-rectangular section, 4072-trapezoidal section; 5-bottom groove; 6-top groove; 7-pressure sensing module; 8-temperature sensing module; 9-air inlet; 10-air return nozzle; 11-cold air supply mechanism; 12-cold air pipeline; 13-air inlet pipe; 14-air inlet valve; 15-air collection pipe; 16-air return valve; 17-air return pipeline; 18-air return mechanism. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] Example 1: The present invention designs a low-temperature freeze-drying device for pharmaceutical intermediates. The freeze-drying device 1 has multiple layers of shelves 2 inside. Placement cavities 3 are formed between adjacent shelves 2 and between the top shelf 2 and the top plate of the freeze-drying device 1. Each layer of placement cavity 3 is used to insert multiple independent freezing boxes 4 (the shell of the freezing box 4 can be made of non-metallic material to reduce heat conduction), so as to realize the partitioned storage and drying of pharmaceutical intermediates.

[0041] Referring to Figures 1 and 8, an air inlet pipe 13 is fixedly installed on the back plate of each placement chamber 3. The air inlet pipe 13 is connected to the cold air pipeline 12, which is connected to the cold air supply mechanism 11. Multiple air inlets 9 are connected to the air inlet pipe 13, and each air inlet 9 is independently equipped with an air inlet valve 14 to achieve independent control of a single air inlet channel. An air collecting pipe 15 is fixedly installed on the back plate of each placement chamber 3. The air collecting pipe 15 is connected to the return air pipeline 17, which is connected to the return air mechanism 18. Multiple return air nozzles 10 are connected to the air collecting pipe 15, and each return air nozzle 10 is independently equipped with a return air valve 16. Each return air nozzle 10 is positioned directly above an air inlet 9, forming corresponding vertical air circulation channels.

[0042] Referring to Figures 3, 4, 5, and 6, the freezer box 4 has an inner cavity 401 and a material guide opening 406 at the top. The material guide opening 406 is used to install the sliding cover 403. A heat-insulating sealing strip is provided at the material guide opening 406, which presses against the sliding cover 403 to achieve a seal, preventing cold air leakage and interference from external temperature. A slot 404 is provided on one side end plate of the freezer box 4 for inserting the cold flow core 402. An end notch 405 is provided at the top of this side end plate, which aligns and fits with the edge notch 4031 of the sliding cover 403.

[0043] As shown in Figures 3, 4, and 6, the sliding cover 403 is provided with a vertically penetrating edge notch 4031 and a detection port 4032. The edge notch 4031 is used to adapt to the installation and embedding of the temperature sensing module 8, and the detection port 4032 provides a channel for temperature detection.

[0044] As shown in Figures 2, 4, 5, and 7, the cooling core 402 is made of copper alloy and includes a thin plate portion 4021 and airflow end portions 4022 located at the upper and lower ends of the thin plate portion 4021. The airflow end portion 4022 has an airflow channel 4024 with one open side. The lower airflow channel 4024 is aligned with the air inlet 9, and the upper airflow channel 4024 is aligned with the air return nozzle 10. The thin plate portion 4021 has an airflow gap 4023 connecting the upper and lower airflow channels 4024. The sidewall of the airflow gap 4023 is coated with a graphene coating 4025 to improve thermal conductivity. A trapezoidal open structure 4026 is provided on one side of the airflow gap 4023. A sealing strip 407 is inserted into the trapezoidal open structure 4026. The sealing strip 407 includes a rectangular portion 4071 inserted into the airflow gap 4023 and a trapezoidal portion 4072 that mates with the trapezoidal open structure 4026. In order to reduce the difficulty of manufacturing process, the airflow gap 4023 adopts an open structure on one side during manufacturing. When used in the future, it is used in conjunction with the sealing strip 407 to ensure that the airflow will not flow out directly from the opening on the outside of the airflow gap 4023.

[0045] Combination Figure 1 , Figure 2 Multiple pressure sensing modules 7 are embedded in the bottom wall of the placement cavity 3. Multiple bottom grooves 5 are formed on the top side of each shelf 2, with the pressure sensing modules 7 embedded in the grooves 5 to sense and detect the placement status of the freezing box 4 and the weight of the internal materials. Multiple temperature sensing modules 8 are configured on the top wall of the placement cavity 3. Multiple top grooves 6 are formed on the bottom surface of the non-bottom shelf 2 and the top plate of the freeze-drying equipment 1, with the temperature sensing modules 8 positioned in the top grooves 6.

[0046] Referring to Figures 3, 4, and 6, a temperature sensing module 8 is also independently configured at each edge notch 4031 position. The temperature sensing module 8 protrudes downward and can be fully embedded into the edge notch 4031 and aligned with the detection port 4032 during installation, so as to achieve accurate detection of the temperature of the inner cavity 401 of the freezer box 4 and avoid external temperature interference.

[0047] Example 2: This invention designs a control method for a low-temperature freeze-drying equipment for pharmaceutical intermediates, the specific steps of which are as follows:

[0048] (a) Material loading

[0049] Open the sliding cover 403 on the top of the freezing box 4, and evenly inject the drug intermediate raw material to be freeze-dried into the inner cavity 401 of the freezing box 4. During the injection process, avoid spilling the raw material into the sealed area at the edge of the freezing box 4.

[0050] After injection, close the sliding cover 403 to ensure that the sliding cover 403 and the heat insulation sealing strip at the feed opening 406 are in tight contact to achieve a seal.

[0051] (ii) Positioning of freezer boxes

[0052] Insert the frozen box 4 loaded with the drug intermediate into the unused position of the placement cavity 3 in sequence. When inserting, make sure that the notch 4031 of the sliding cover 403 on the top of the frozen box 4 is aligned with the installation position of the temperature sensing module 8 on the top wall of the placement cavity 3, so that the temperature sensing module 8 can be fully embedded in the notch 4031 and aligned with the detection port 4032.

[0053] (III) No-load detection and condition determination

[0054] After the freezer box 4 is placed in position, the pressure sensing module 7 on the bottom wall of the placement cavity 3 detects the pressure signal of the freezer box 4 in real time and transmits the pressure parameters to the equipment control system. The control system compares the real-time pressure parameters with the preset no-load pressure threshold to determine the status of the freezer box 4.

[0055] If the pressure parameter is less than or equal to the preset no-load pressure threshold, the freezer box 4 (station) is determined to be in a no-load state.

[0056] If the pressure parameter is greater than the preset no-load pressure threshold, the freezer box 4 is determined to be in a non-no-load state.

[0057] (iv) Idle state processing logic

[0058] If the freezer box 4 (station) is determined to be in an unloaded state, the control system issues a command: the temperature sensing module 8 at the corresponding position stops working, and the air inlet valve 14 and air return valve 16 corresponding to the freezer box 4 (station) remain closed to avoid waste of cold air and ineffective operation of the equipment.

[0059] (v) Airflow regulation in non-idle conditions

[0060] If the freezer box 4 is determined to be in a non-empty state, the pressure sensing module 7 further calculates the actual weight of the drug raw materials inside the freezer box 4 using pressure parameters and transmits the weight data to the control system. The control system linearly adjusts the opening ratio of the corresponding air inlet valve 14 and air return valve 16 according to the ratio of the actual weight to the preset full load weight: the closer the actual weight of the drug raw materials is to the preset full load weight, the greater the opening degree of the air inlet valve 14 and air return valve 16, and the higher the cold air flow. The smaller the actual weight of the drug raw materials, the smaller the opening degree of the air inlet valve 14 and air return valve 16, and the lower the cold air flow, ensuring a precise match between the cold air supply and the raw material demand.

[0061] (vi) Temperature monitoring and cooling control

[0062] The temperature sensing module 8 detects the temperature of the inner cavity 401 of the freezing box 4 in real time through the detection port 4032 of the sliding cover 403, and feeds the temperature data back to the control system in real time; the control system compares the real-time temperature with the preset freeze-drying temperature threshold and executes the following control logic.

[0063] (1) When the real-time temperature is higher than the preset threshold: the cold air supply mechanism 11 is activated. The cold air enters the lower airflow channel 4024 of the cold flow core 402 through the cold air pipeline 12, the air inlet pipe 13, and the air inlet nozzle 9. Then, it exchanges heat with the drug intermediate through the airflow gap 4023 of the thin plate part 4021. The exchanged gas enters the return gas mechanism 18 from the upper airflow channel 4024 through the return gas nozzle 10, the gas collection pipe 15, and the return gas pipeline 17 to realize the cold air circulation.

[0064] (2) The real-time temperature is the same as the preset threshold: close the intake valve 14 and the return valve 16, and control the cold air supply mechanism 11 to stop supplying cold air.

[0065] (3) If the real-time temperature is higher than the preset threshold: the air inlet valve 14 and the air return valve 16 are restored to their opening ratio before closing, and the cold air supply mechanism 11 supplies cold air again to ensure that the temperature of the inner cavity 401 of the freezer box 4 is always stable within the preset freeze-drying range.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A low-temperature freeze-drying apparatus for pharmaceutical intermediates, wherein the freeze-drying apparatus (1) has multiple layers of shelves (2) inside, and placement cavities (3) are provided between adjacent shelves (2) and between the top shelf (2) and the top plate of the freeze-drying apparatus (1), characterized in that: Each layer of the placement cavity (3) has multiple air inlets (9) on its back plate. Each air inlet (9) has an independent air return nozzle (10) directly above it. Each air inlet (9) has an independent air inlet valve (14) and each air return nozzle (10) has an independent air return valve (16). Each layer of placement cavity (3) independently holds multiple freezing boxes (4). The freezing box (4) also includes a cold flow core (402) inserted into its inner cavity (401) from the side end of the freezing box (4). The cold flow core (402) includes a thin plate part (4021) and airflow end parts (4022) located at the upper and lower sides of the thin plate part (4021). The airflow end parts (4022) are provided with an airflow channel (4024) with one side open. The thin plate part (4021) is provided with an airflow gap (4023) connecting the upper and lower airflow channels (4024). The lower airflow channel (4024) is aligned with the air inlet (9), and the upper airflow channel (4024) is aligned with the air return nozzle (10). The bottom wall of the placement cavity (3) is embedded with multiple pressure sensing modules (7) for sensing and detecting the state of the freezing box (4). The top wall of the placement cavity (3) is equipped with multiple temperature sensing modules (8). The top of the freezing box (4) is equipped with a sliding cover (403). The sliding cover (403) is provided with a vertical through edge notch (4031) and a detection port (4032). Each edge notch (4031) is independently equipped with a temperature sensing module (8). The freezer box (4) has a slot (404) on one side end plate that matches the cold flow core (402), and an end notch (405) on the top of the side end plate that matches the edge notch (4031). The freeze-drying equipment (1) is also equipped with a cold air supply mechanism (11) connected to the air inlet (9) via a cold air pipeline (12) and a return air mechanism (18) connected to the return air inlet (10) via a return air pipeline (17).

2. The low-temperature freeze-drying equipment for pharmaceutical intermediates according to claim 1, characterized in that: Multiple bottom grooves (5) are opened on the top side of each shelf (2), and the pressure sensing module (7) is embedded in the bottom groove (5); Multiple top grooves (6) are provided on the bottom surface of the non-bottom shelf (2) and the top plate of the freeze-drying equipment (1), and the temperature sensing module (8) is located at the top groove (6).

3. The low-temperature freeze-drying equipment for pharmaceutical intermediates according to claim 1, characterized in that: The cold flow core (402) is made of copper alloy, and the sidewall of the airflow gap (4023) of the cold flow core (402) is coated with a graphene coating (4025).

4. The low-temperature freeze-drying equipment for pharmaceutical intermediates according to claim 1, characterized in that: A trapezoidal opening structure (4026) is provided on one side of the airflow gap (4023) of the cold flow core (402). A sealing strip (407) is inserted into the trapezoidal opening structure (4026). The sealing strip (407) includes a rectangular part (4071) inserted into the airflow gap (4023) and a trapezoidal part (4072) that cooperates with the trapezoidal opening structure (4026).

5. The low-temperature freeze-drying equipment for pharmaceutical intermediates according to claim 1, characterized in that: The top of the freezer box (4) is provided with a material guide opening (406) for installing the sliding cover (403), and a heat-insulating sealing strip is provided at the position of the material guide opening (406) to press against the sliding cover (403).

6. The low-temperature freeze-drying equipment for pharmaceutical intermediates according to claim 1, characterized in that: An air inlet pipe (13) is fixedly installed on the back plate of each placement cavity (3). The air inlet pipe (13) is connected to the cold air pipeline (12). The air inlet valve (14) of the air inlet nozzle (9) is connected to the air inlet pipe (13). A gas collection pipe (15) is fixedly installed on the back plate of each placement cavity (3). The gas collection pipe (15) is connected to the return gas pipeline (17). The return gas valve (16) of the return gas nozzle (10) is connected to the gas collection pipe (15).

7. A control method for a low-temperature freeze-drying apparatus for pharmaceutical intermediates, characterized in that, A low-temperature freeze-drying apparatus for a pharmaceutical intermediate according to any one of claims 1 to 6, comprising the following: Step 1, Material Loading and Sealing: Open the sliding cover (403) of the freezing box (4), and evenly inject the drug intermediate into the inner cavity (401) to avoid spilling into the sealed area. Close the sliding cover (403) to ensure that it fits tightly with the heat insulation sealing strip. Step 2, Precise placement of the freezing box: Insert the freezing box (4) containing the material into the idle position of the placement cavity (3), so that the notch (4031) on the side of the sliding cover (403) is aligned with the installation position of the temperature sensing module (8); Step 3, Determining the No-load Status: The pressure sensing module (7) detects the pressure signal of the freezing box (4), compares it with the preset no-load threshold, and distinguishes between no-load and non-no-load workstations; Step 4, Idle workstation control: After determining that the workstation is idle, close the corresponding air intake valve (14) and air return valve (16) and stop the temperature sensing module (8) of the workstation from working; Step 5: Non-no-load weight conversion: Under non-no-load conditions, the actual weight of the raw materials is calculated using pressure parameters and transmitted to the control system. Step 6, Adjusting the opening degree of the air valve: Adjust the opening degree of the corresponding air inlet valve (14) and air return valve (16) linearly according to the ratio of the actual weight to the full load weight; Step 7, Real-time temperature monitoring: The temperature sensing module (8) detects the temperature of the inner cavity (401) of the freezer box (4) through the detection port (4032) and feeds it back to the control system in real time; Step 8, Cooling Circulation Control: When the temperature is higher than the preset threshold, the cooling supply mechanism (11) is activated to form a cooling circulation. When the temperature reaches the target, the air valve and the cooling mechanism are closed. Step 9: Reset the status after material removal: After the freezing box (4) is removed, the pressure sensing module (7) re-detects the status of the workstation and executes subsequent control according to the no-load or non-no-load logic.

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