Novel freeze dryer utilizing waste heat recovery rotary wheel for dehumidification and operation method of novel freeze dryer

Abstract

The invention discloses a novel freeze dryer for dehumidification through a waste heat recovery rotating wheel and an operation method of the novel freeze dryer. A refrigerating system of the novel freeze dryer comprises a low-pressure-stage compressor, a high-pressure-stage compressor, a condenser, an intercooler, a throttling valve, an electromagnetic valve, an auxiliary evaporator and a main evaporator. The waste heat collecting system comprises a main evaporator, a cold oil pump, a condenser, a hot oil pump, a regulating valve, an oil tank and a heat exchanger. The vacuumizing system comprises an oil pump, a drying box, a rotating wheel dehumidification box, a valve and a vacuum pump; the rotating wheel dehumidification system comprises a rotating wheel dehumidification box, a dehumidification rotating wheel, a vacuum pump, a fan and a regeneration heater; the drying efficiency is improved, the energy utilization rate of the system is remarkably improved, energy waste is reduced, the operation cost is reduced, it is ensured that the humidity environment in the freeze-drying process is more uniform and controllable, and the frosting phenomenon caused by low temperature in the dehumidification process is avoided.

Description

Technical Field

[0001] The invention relates to a novel freeze dryer utilizing residual heat recovery rotary wheel for dehumidification and an operation method thereof, belonging to the technical field of refrigeration. Background Art

[0002] With the widespread application of freeze-drying technology in the fields of biological products, pharmaceutical products and high-end foods, higher requirements are placed on the performance of freeze-drying equipment. These materials usually have strict requirements for low-temperature environment and humidity control, while traditional freeze-drying equipment has significant deficiencies in deep freezing capacity, energy utilization efficiency and temperature and humidity control. Single-stage refrigeration systems are difficult to provide sufficient deep freezing capacity, resulting in low material freezing efficiency; the waste heat of the condenser is usually not effectively recycled and utilized, relying on traditional heating methods, which not only causes energy waste, but also significantly increases operating costs. In addition, the traditional temperature regulation method is achieved by switching between cooling and heating, with slow response speed and large temperature fluctuations, affecting the stability of the drying process. At the same time, traditional cold traps or water replenishers use evaporators or refrigerants to capture the removed moisture, and the required temperature is relatively low, and the corresponding evaporation temperature will be relatively low, reducing the efficiency of the entire refrigeration. At the same time, the moisture captured by the cold trap or water replenisher adheres to its surface. After the drying is completed, it is necessary to wait for the moisture to melt or heat to melt. After the defrosting process is completed, the next batch of drying can be carried out, and the drying cycle is long. Therefore, the industry urgently needs an innovative freeze-drying equipment that can break through the bottleneck of traditional technology to meet the stringent requirements for freeze-drying of high-end materials. Summary of the invention

[0003] The object of the present invention is to overcome the above-mentioned deficiencies of the prior art and to provide a novel freeze dryer utilizing residual heat recovery rotary dehumidification and an operating method thereof.

[0004] The technical solution provided by the present invention is as follows: a novel freeze dryer utilizing residual heat recovery and rotary dehumidification, characterized in that it comprises a refrigeration system, a residual heat collection system, a vacuum system, and a rotary dehumidification system; The refrigeration system includes a low-pressure compressor, a high-pressure compressor, a condenser, an intercooler, a throttle valve, an auxiliary throttle valve, a main throttle valve, an auxiliary solenoid valve, a main solenoid valve, an auxiliary evaporator, and a main evaporator; The residual heat collection system includes a main evaporator, a cold oil pump, a condenser, a hot oil pump, a third regulating valve, a first regulating valve, a second regulating valve, an oil tank, a fourth regulating valve, and a heat exchanger; The vacuum system includes an oil pump, a drying box, a rotary dehumidification box, a valve, and a vacuum pump; The rotary dehumidification system includes a rotary dehumidification box, a dehumidification rotary wheel, a vacuum pump, a fan, and a regeneration heater; The outlet of the low-pressure compressor is connected to the inlet of the high-pressure compressor, the outlet of the high-pressure compressor is connected to one inlet of the condenser, one outlet of the condenser is connected to one inlet of the intercooler, one outlet of the intercooler is respectively connected to the inlet of the main solenoid valve and the inlet of the auxiliary solenoid valve, the outlet of the main solenoid valve is connected to the inlet of the main throttle valve, the outlet of the main throttle valve is connected to one inlet of the main evaporator, one outlet of the main evaporator is connected to the inlet of the low-pressure compressor; the outlet of the auxiliary solenoid valve is connected to the inlet of the auxiliary throttle valve, the outlet of the auxiliary throttle valve is connected to the inlet of the auxiliary evaporator, The inlet of the auxiliary evaporator is connected to the inlet of the low-pressure compressor; the inlet of the throttle valve is connected to the first outlet of the condenser, the outlet of the throttle valve is connected to the second inlet of the intercooler, and the second outlet of the intercooler is connected to the inlet of the high-pressure compressor; the inlet of the cold oil pump is connected to the second outlet of the main evaporator, the outlet of the cold oil pump is connected to the first inlet of the oil tank, and the first outlet of the oil tank is connected to the second inlet of the main evaporator; the inlet of the hot oil pump is connected to the second outlet of the condenser, the outlet of the hot oil pump is connected to the inlet of the second regulating valve, and the outlet of the second regulating valve is connected to The two-way inlet of the oil tank is connected, the two-way outlet of the oil tank is connected to the inlet of the first regulating valve, and the outlet of the first regulating valve is connected to the two-way inlet of the condenser; the inlet of the third regulating valve is connected to the outlet of the hot oil pump, the outlet of the third regulating valve is connected to the one-way inlet of the heat exchanger, the one-way outlet of the heat exchanger is connected to the inlet of the fourth regulating valve, and the outlet of the fourth regulating valve is connected to the two-way inlet of the condenser; the inlet of the oil pump is connected to the three-way outlet of the oil tank, the outlet of the oil pump is connected to the upper inlet of the drying box, and the upper outlet of the drying box is connected to the three-way inlet of the oil tank; the inlet of the valve is connected to the dry box The lower right outlet of the box is connected, the outlet of the valve is connected with the inlet of the dehumidification zone on the lower side of the rotary dehumidification box through a pipeline, there is a dehumidification wheel in the rotary dehumidification box, there are / regeneration zone and / dehumidification zone on the dehumidification wheel, the dehumidification zone outlet on the lower side of the rotary dehumidification box is connected with the inlet of the vacuum pump, and the outlet of the vacuum pump directly enters the air; the two-way outlet of the heat exchanger is connected with the inlet of the fan through a pipeline, the outlet of the fan is connected with the inlet of the regeneration zone on the upper side of the rotary dehumidification box through a pipeline, and the regeneration zone outlet on the upper side of the rotary dehumidification box directly enters the air; the two-way inlet of the heat exchanger is connected to the air through the regeneration heater.

[0005] An operating method of a novel freeze dryer utilizing residual heat recovery rotary dehumidification, characterized in that it specifically comprises: The working operation is divided into three stages: pre-freezing, sublimation drying, and analytical drying; 1) Pre-freezing stage At this time, the throttle valve, main solenoid valve, main throttle valve, cold oil pump, oil pump, third regulating valve, fourth regulating valve, and hot oil pump are turned on; the auxiliary solenoid valve, auxiliary throttle valve, first regulating valve, second regulating valve, valve, and vacuum pump are turned off; Fluid circuit during the pre-freezing phase: Refrigerant circuit in the pre-freezing stage: The refrigerant vapor evaporated under the intermediate pressure output by the low-pressure compressor is mixed with the intermediate pressure refrigerant vapor output from the second outlet of the intercooler and enters the high-pressure compressor. After being compressed by the high-pressure compressor, the high-pressure and high-temperature refrigerant vapor output enters the condenser through the first inlet of the condenser, condenses and releases heat to become high-pressure and high-temperature refrigerant liquid. The refrigerant liquid is divided into two parts through the first inlet of the condenser. One part is throttled and reduced to the intermediate pressure through the throttle valve and enters the intercooler through the second inlet of the intercooler to evaporate. The other part enters the coil of the intercooler through the first inlet of the intercooler and passes through the coil. The refrigerant exchanges heat with the refrigerant under the intermediate pressure outside the tube to evaporate. The refrigerant outside the tube then enters the high-pressure compressor after mixing with the exhaust gas of the low-pressure compressor through the two-way outlet of the intercooler. The refrigerant in the coil passes through the main solenoid valve and the main throttle valve through the one-way outlet of the intercooler. Under the action of the main throttle valve, the refrigerant liquid is cooled and reduced in temperature and pressure through the throttling effect to become a low-temperature and low-pressure liquid. The refrigerant enters the main evaporator through the one-way inlet of the main evaporator to evaporate. After absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas. It flows back to the low-pressure compressor through the one-way outlet of the main evaporator. It is compressed into a refrigerant vapor under the intermediate pressure in the high-pressure compressor, and the above cycle is repeated. Oil circuit in the pre-freezing stage: The hot oil in the condenser flows out from the second outlet of the condenser, and under the drive of the hot oil pump, enters the heat exchanger through the third regulating valve for heat exchange. After the heat exchange, the oil flows back to the condenser from the second inlet of the condenser through the fourth regulating valve; The oil in the oil tank enters the main evaporator from the second inlet of the main evaporator through the first outlet of the oil tank. After absorbing heat from the refrigerant, the temperature is reduced and flows out from the second outlet of the main evaporator. Driven by the cold oil pump, the cold oil after heat exchange enters the oil tank through the first inlet of the oil tank. The cold oil enters the drying box through the upper inlet of the drying box from the third outlet of the oil tank driven by the oil pump, exchanges heat with the environment in the drying box, reduces the ambient temperature in the drying box, and realizes pre-freezing of materials. The temperature of the oil after heat exchange increases and flows from the upper outlet of the drying box into the three-way inlet of the oil tank and returns to the oil tank, repeating the above cycle. 2) Sublimation drying stage The sublimation drying stage needs to be vacuumed in a low temperature environment, and then heated up to the target temperature of the sublimation drying stage: after it is 5℃~10℃ lower than the eutectic point of the material, the cold oil temperature is adjusted by adjusting the auxiliary solenoid valve switch to adjust the mixed temperature of the cold oil and hot oil in the oil tank, ensuring that after entering the drying box for heat exchange, the temperature in the drying box reaches the target temperature of the sublimation drying stage; at this time, the throttle valve, main solenoid valve, main throttle valve, cold oil pump, oil pump, first regulating valve, second regulating valve, third regulating valve, fourth regulating valve, hot oil pump, valve, vacuum pump, and fan are turned on; The switch of the auxiliary solenoid valve and the auxiliary throttle valve depends on the temperature of the drying box. When the temperature in the drying box does not reach the target temperature of the sublimation drying stage after the oil pump has been working for 10 minutes, the switch of the auxiliary solenoid valve and the auxiliary throttle valve is opened to release the cold capacity to the outside through the auxiliary evaporator. During operation, the vacuum pump works first to pump the rotary dehumidifier box to a vacuum range of 20 to 200Pa; the solid ice frozen in the material directly sublimates into water vapor by absorbing heat under a low-pressure and low-temperature vacuum environment, and the water vapor enters the rotary dehumidifier box from the drying box through the lower right outlet of the drying box and the pipeline through the dehumidification zone inlet on the lower side of the rotary dehumidifier box, dehumidifies in the dehumidification zone in the rotary dehumidifier box, contacts with the hygroscopic material, and the moisture in the air is adsorbed onto the surface of the rotor. The dehumidified air is directly discharged into the atmosphere through the dehumidification zone outlet on the lower side of the rotary dehumidifier box and the vacuum pump; the fresh air is first heated in the heat exchanger, and the preheating temperature is 60℃ to 120℃. When the fresh air preheating temperature is not reached, the regeneration heater is turned on for heating, and driven by the fan, it enters the regeneration zone of the rotary wheel through the regeneration zone inlet on the upper side of the rotary dehumidifier box, takes away the moisture adsorbed on the surface of the rotary wheel, and discharges into the atmosphere through the regeneration zone outlet on the upper side of the rotary dehumidifier box; Refrigerant circuit in the heating stage of the sublimation drying stage: The refrigerant vapor evaporated under the intermediate pressure output by the low-pressure compressor is mixed with the intermediate-pressure refrigerant vapor output from the second outlet of the intercooler and enters the high-pressure compressor. After being compressed by the high-pressure compressor, the high-pressure and high-temperature refrigerant vapor output enters the condenser through the first inlet of the condenser, condenses and releases heat to become high-pressure and high-temperature refrigerant liquid. The refrigerant is divided into two parts through the first inlet of the condenser. One part is throttled and reduced to the intermediate pressure through the throttle valve and enters the intercooler through the second inlet of the intercooler to evaporate. The other part enters the coil of the intercooler through the first inlet of the intercooler and passes through the coil and the tube. The refrigerant at the external intermediate pressure is heat exchanged to evaporate. The refrigerant outside the tube is mixed with the exhaust gas of the low-pressure compressor through the two-way outlet of the intermediate cooler and then enters the high-pressure compressor. The refrigerant in the coil passes through the main solenoid valve and the main throttle valve through the one-way outlet of the intermediate cooler. Under the action of the main throttle valve, the refrigerant liquid is throttled to reduce temperature and pressure and become a low-temperature and low-pressure liquid. The refrigerant enters the main evaporator through the one-way inlet of the main evaporator to evaporate. After absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas. It flows back to the low-pressure compressor through the one-way outlet of the main evaporator and is compressed into a refrigerant vapor under the intermediate pressure in the high-pressure compressor. When the temperature in the drying box fails to reach the target temperature of the sublimation drying stage after the oil pump has been working for 10 minutes, the auxiliary solenoid valve and the auxiliary throttle valve are turned on at this time, and part of the refrigerant coming out of the coil in the intercooler passes through the auxiliary solenoid valve and the auxiliary throttle valve. Under the action of the auxiliary throttle valve, the refrigerant liquid is cooled and depressurized by the throttling action to become a low-temperature and low-pressure liquid. The refrigerant enters the auxiliary evaporator for evaporation, and after absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas that mixes with the outlet gas of the main evaporator and flows back to the low-pressure compressor, where it is compressed into refrigerant vapor at an intermediate pressure. The oil in the oil tank enters the main evaporator from the second inlet of the main evaporator through the first outlet of the oil tank. After absorbing heat from the refrigerant, the temperature drops and flows out from the second outlet of the main evaporator. Driven by the cold oil pump, the cold oil after heat exchange enters the oil tank through the first inlet of the oil tank; part of the oil in the oil tank goes out from the second outlet of the oil tank, passes through the second inlet of the condenser through the first regulating valve, enters the condenser, and after releasing heat from the refrigerant, the temperature rises and flows out from the second outlet of the condenser. Driven by the hot oil pump, the hot oil after heat exchange enters the oil tank through the second inlet of the oil tank through the second regulating valve; the hot oil from the condenser and After the cold oil from the main evaporator is mixed, when the oil temperature reaches the target temperature of the sublimation drying stage, it enters the drying box through the upper inlet of the drying box through the three-way outlet of the oil tank driven by the oil pump, and exchanges heat with the environment in the box. After the heat exchange, the oil temperature rises, and flows from the upper outlet of the drying box into the three-way inlet of the oil tank and returns to the oil tank; when the temperature of the oil tank is higher than the target temperature of the sublimation drying stage, the openings of the third regulating valve and the fourth regulating valve become larger, and the openings of the first regulating valve and the second regulating valve become smaller, the amount of hot oil entering the oil tank becomes less, and the temperature of the mixed oil in the oil tank decreases, reaching the target temperature of the sublimation drying stage, and the above cycle is repeated; 3) Analysis and drying stage During the analytical drying stage, the material needs to be further heated under vacuum conditions and the target temperature of the analytical drying stage should be maintained at 30°C to 100°C to precipitate the bound water in the material. Analysis of the refrigerant circuit in the heating phase of the drying phase: The refrigerant vapor evaporated under the intermediate pressure output by the low-pressure compressor is mixed with the intermediate-pressure refrigerant vapor output from the second outlet of the intercooler and enters the high-pressure compressor. After being compressed by the high-pressure compressor, the high-pressure and high-temperature refrigerant vapor output enters the condenser through the first inlet of the condenser, condenses and releases heat to become high-pressure and high-temperature refrigerant liquid. The refrigerant is divided into two parts through the first inlet of the condenser. One part is throttled and reduced to the intermediate pressure through the throttle valve and enters the intercooler through the second inlet of the intercooler to evaporate. The other part enters the coil of the intercooler through the first inlet of the intercooler and passes through the coil and the tube. The refrigerant at the external intermediate pressure is heat exchanged to evaporate. The refrigerant outside the tube is mixed with the exhaust gas of the low-pressure compressor through the two-way outlet of the intermediate cooler and then enters the high-pressure compressor. The refrigerant in the coil passes through the main solenoid valve and the main throttle valve through the one-way outlet of the intermediate cooler. Under the action of the main throttle valve, the refrigerant liquid is throttled to reduce temperature and pressure and become a low-temperature and low-pressure liquid. The refrigerant enters the main evaporator through the one-way inlet of the main evaporator to evaporate. After absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas. It flows back to the low-pressure compressor through the one-way outlet of the main evaporator and is compressed into a refrigerant vapor under the intermediate pressure in the high-pressure compressor. When the temperature in the drying box fails to reach the target temperature of the analytical drying stage after the oil pump has been working for 10 minutes, the auxiliary solenoid valve and the auxiliary throttle valve are turned on, and part of the refrigerant coming out of the coil in the intercooler passes through the auxiliary solenoid valve and the auxiliary throttle valve. Under the action of the auxiliary throttle valve, the refrigerant liquid is cooled and depressurized by the throttling action to become a low-temperature and low-pressure liquid. The refrigerant enters the auxiliary evaporator for evaporation, and after absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas that mixes with the outlet gas of the main evaporator and flows back to the low-pressure compressor, where it is compressed into refrigerant vapor at an intermediate pressure. The oil in the oil tank enters the main evaporator from the second inlet of the main evaporator through the first outlet of the oil tank. After absorbing heat from the refrigerant, the temperature drops and flows out from the second outlet of the main evaporator. Driven by the cold oil pump, the cold oil after heat exchange enters the oil tank through the first inlet of the oil tank; part of the oil in the oil tank goes out from the second outlet of the oil tank, passes through the second inlet of the condenser through the first regulating valve, enters the condenser, and after releasing heat from the refrigerant, the temperature rises and flows out from the second outlet of the condenser. Driven by the hot oil pump, the hot oil after heat exchange enters the oil tank through the second inlet of the oil tank through the second regulating valve; the hot oil from the condenser and After the cold oil from the main evaporator is mixed, when the oil temperature reaches the target temperature of the analysis and drying stage, it enters the drying box from the three-way outlet of the oil tank through the upper inlet of the drying box driven by the oil pump, exchanges heat with the environment in the box, and the oil temperature after the heat exchange increases, and flows from the upper outlet of the drying box into the three-way inlet of the oil tank and returns to the oil tank; when the temperature of the oil tank is higher than the target temperature of the analysis and drying stage, the openings of the third and fourth regulating valves become larger, and the openings of the first and second regulating valves become smaller, the amount of hot oil entering the oil tank decreases, the temperature of the mixed oil in the oil tank decreases, and reaches the target temperature of the analysis and drying stage, and the above cycle is repeated.

[0006] The beneficial effects of the present invention are as follows: the present invention is provided with a two-stage refrigeration system consisting of a low-pressure compressor, a high-pressure compressor, a condenser, an intermediate cooler, a throttle valve, an auxiliary throttle valve, a main throttle valve, an auxiliary solenoid valve, a main solenoid valve, an auxiliary evaporator, and a main evaporator, which can provide a lower temperature deep cooling capacity for the drying box, can quickly freeze the material, reduce the sublimation temperature of the water in the drying process, and improve the drying efficiency. At the same time, it is widely applicable to materials, and is suitable for freeze-drying materials that have strict requirements on low-temperature environments, such as biological products, pharmaceutical products, and high-end foods.

[0007] The present invention is provided with a condenser, a hot oil pump, a third regulating valve, a fourth regulating valve, and a heat exchanger to recover the residual heat of the condenser during the operation of the freeze dryer, and use it as a heat source for the regeneration air of the rotary dehumidification system. At the same time, a regeneration heater is provided. When the heat is insufficient, the regeneration heater is turned on to heat the regeneration air. This design avoids the dependence of the traditional heating method on external energy, significantly improves the energy utilization rate of the system, reduces energy waste, and reduces the operating cost.

[0008] The present invention uses oil as a cooling and heating medium by setting an oil tank, a regulating valve and an oil circuit, and adjusts the temperature of the drying box by mixing cold and hot oil. Compared with the traditional method of temperature adjustment by alternately switching between cooling and heating, the target temperature can be quickly reached without waiting for the equipment to switch, which significantly improves the drying efficiency.

[0009] The present invention is provided with a rotary dehumidification system consisting of a dehumidification box, a dehumidification wheel, a vacuum pump, a fan, and a regeneration heater. The dehumidification wheel can continuously adsorb and regenerate moisture, thereby solving the problem of low dehumidification efficiency of traditional cold traps and the problem that the unit does not need to operate at a low evaporation temperature, thereby ensuring high efficiency and controllability in the freeze-drying process.

[0010] The dehumidification wheel in the dehumidification box of the present invention continuously absorbs moisture in the air through the adsorption material, and uses the regenerated air heated by the heat exchanger to heat the regenerated dehumidification wheel. A cold trap is no longer required. After freeze-drying is completed, there is no need to wait for the cold trap to capture moisture to melt and discharge, thereby improving the drying efficiency and reducing the drying cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the present invention.

[0012] Note: The thick solid line represents the refrigerant circulation path; The thin solid line represents the oil circulation path; In the figure: 1. low-pressure compressor; 2. high-pressure compressor; 3. condenser; 4. intercooler; 5-1. throttle valve; 5-2. auxiliary throttle valve; 5-3. main throttle valve; 6-1. auxiliary solenoid valve; 6-2. main solenoid valve; 7. auxiliary evaporator; 8. main evaporator; 9. cold oil pump; 10. regeneration heater; 11. oil pump; 12. oil tank; 13. drying box; 14-1. first regulating valve; 14-2. second regulating valve; 14-3. third regulating valve; 14-4. fourth regulating valve; 15. hot oil pump; 16. valve; 17. rotary dehumidification box; 18. dehumidification rotary wheel; 19. vacuum pump; 20. heat exchanger; 21. fan. DETAILED DESCRIPTION

[0013] The specific implementation of the present invention is further described in detail below with reference to the accompanying drawings: like Figure 1 As shown, a new type of freeze dryer using residual heat recovery and rotary dehumidification includes four parts: a refrigeration system, a residual heat collection system, a vacuum system, and a rotary dehumidification system.

[0014] The refrigeration system includes a low-pressure compressor 1, a high-pressure compressor 2, a condenser 3, an intercooler 4, a throttle valve 5-1, an auxiliary throttle valve 5-2, a main throttle valve 5-3, an auxiliary solenoid valve 6-1, a main solenoid valve 6-2, an auxiliary evaporator 7, and a main evaporator 8.

[0015] The residual heat collection system includes a main evaporator 8, a cold oil pump 9, a condenser 3, a hot oil pump 15, a third regulating valve 14-3, a first regulating valve 14-1, a second regulating valve 14-2, an oil tank 12, a fourth regulating valve 14-4, and a heat exchanger 20.

[0016] The vacuum system includes an oil pump 11 , a drying box 13 , a rotary dehumidification box 17 , a valve 16 , and a vacuum pump 19 .

[0017] The rotary dehumidification system includes a rotary dehumidification box 17 , a dehumidification rotary wheel 18 , a vacuum pump 19 , a fan 21 , and a regeneration heater 10 .

[0018] The outlet of the low-pressure compressor 1 is connected to the inlet of the high-pressure compressor 2, the outlet of the high-pressure compressor 2 is connected to one inlet of the condenser 3, one outlet of the condenser 3 is connected to one inlet of the intercooler 4, one outlet of the intercooler 4 is respectively connected to the inlet of the main electromagnetic valve 6-2 and the inlet of the auxiliary electromagnetic valve 6-1, the outlet of the main electromagnetic valve 6-2 is connected to the inlet of the main throttle valve 5-3, the outlet of the main throttle valve 5-3 is connected to one inlet of the main evaporator 8, and one outlet of the main evaporator 8 is connected to the inlet of the low-pressure compressor 1. The outlet of the auxiliary electromagnetic valve 6-1 is connected to the inlet of the auxiliary throttle valve 5-2, the outlet of the auxiliary throttle valve 5-2 is connected to the inlet of the auxiliary evaporator 7, and the outlet of the auxiliary evaporator 7 is connected to the inlet of the low-pressure compressor 1. The inlet of the throttle valve 5-1 is connected to one outlet of the condenser 3, the outlet of the throttle valve 5-1 is connected to two inlets of the intercooler 4, and the two outlets of the intercooler 4 are connected to the inlet of the high-pressure compressor 2. The inlet of the cold oil pump 9 is connected to the two-way outlet of the main evaporator 8, and the outlet of the cold oil pump 9 is connected to the one-way inlet of the oil tank 12, and the one-way outlet of the oil tank 12 is connected to the two-way inlet of the main evaporator 8. The inlet of the hot oil pump 15 is connected to the two-way outlet of the condenser 3, and the outlet of the hot oil pump 15 is connected to the inlet of the second regulating valve 14-2, and the outlet of the second regulating valve 14-2 is connected to the two-way inlet of the oil tank 12, and the two-way outlet of the oil tank 12 is connected to the inlet of the first regulating valve 14-1, and the outlet of the first regulating valve 14-1 is connected to the two-way inlet of the condenser 3. The inlet of the third regulating valve 14-3 is connected to the outlet of the hot oil pump 15, and the outlet of the third regulating valve 14-3 is connected to the one-way inlet of the heat exchanger 20, and the one-way outlet of the heat exchanger 20 is connected to the inlet of the fourth regulating valve 14-4, and the outlet of the fourth regulating valve 14-4 is connected to the two-way inlet of the condenser 3. The inlet of the oil pump 11 is connected to the three-way outlet of the oil tank 12, and the outlet of the oil pump 11 is connected to the upper inlet of the drying box 13, and the upper outlet of the drying box 13 is connected to the three-way inlet of the oil tank 12. The inlet of the valve 16 is connected to the lower right outlet of the drying box 13, and the outlet of the valve 16 is connected to the dehumidification zone inlet at the lower side of the rotary dehumidification box 17 through a pipeline. The rotary dehumidification box 17 has a dehumidification wheel 18, and the dehumidification wheel 18 has a 1 / 4 regeneration zone 18-1 and a 3 / 4 dehumidification zone 18-2. The dehumidification zone outlet at the lower side of the rotary dehumidification box 17 is connected to the inlet of the vacuum pump 19, and the outlet of the vacuum pump 19 directly enters the air. The two-way outlet of the heat exchanger 20 is connected to the inlet of the fan 21 through a pipeline, and the outlet of the fan 21 is connected to the regeneration zone inlet at the upper side of the rotary dehumidification box 17 through a pipeline, and the regeneration zone outlet at the upper side of the rotary dehumidification box 17 directly enters the air. The second inlet of the heat exchanger 20 is connected to air through the regeneration heater 10 .

[0019] The specific operation mode is: The working operation of the novel freeze dryer of the present invention is divided into three stages: pre-freezing, sublimation drying and analytical drying.

[0020] 1. Pre-freezing stage The main function of the pre-freezing stage is to freeze the moisture in the drying box material into solid ice, creating conditions for the subsequent sublimation drying stage. At this time, the throttle valve 5-1, the main solenoid valve 6-2, the main throttle valve 5-3, the cold oil pump 9, the oil pump 11, the third regulating valve 14-3, the fourth regulating valve 14-4, and the hot oil pump 15 are turned on. The auxiliary solenoid valve 6-1, the auxiliary throttle valve 5-2, the first regulating valve 14-1, the second regulating valve 14-2, the valve 16, and the vacuum pump 19 are closed. The fan 21 is turned on to preheat the dehumidification wheel, and the regeneration heater 10 is turned off.

[0021] Fluid circuit during the pre-freezing phase: Refrigerant circuit in the pre-freezing stage: The refrigerant vapor evaporated under the intermediate pressure output by the low-pressure compressor 1 is mixed with the intermediate pressure refrigerant vapor output from the second outlet of the intercooler 4 and enters the high-pressure compressor 2. After being compressed by the high-pressure compressor 2, the high-pressure and high-temperature refrigerant vapor output enters the condenser 3 through the first inlet of the condenser 3, condenses and releases heat to become a high-pressure and high-temperature refrigerant liquid, which is divided into two parts through the first inlet of the condenser 3. One part is throttled and reduced to the intermediate pressure through the throttle valve 5-1 and enters the intercooler 4 through the second inlet of the intercooler 4 to evaporate. The other part enters the coil 4-1 of the intercooler 4 through the first inlet of the intercooler 4 and is connected to the intermediate pressure outside the tube through the coil 4-1. The refrigerant is evaporated by heat exchange under the pressure, and the refrigerant outside the tube is mixed with the exhaust gas of the low-pressure compressor through the two-way outlet of the intermediate cooler 4 and then enters the high-pressure compressor 2. The refrigerant in the coil 4-1 passes through the one-way outlet of the intermediate cooler 4 through the main solenoid valve 6-2 and the main throttle valve 5-3. Under the action of the main throttle valve 5-3, the refrigerant liquid is cooled and reduced in pressure by throttling to become a low-temperature and low-pressure liquid. The refrigerant enters the main evaporator 8 through the one-way inlet of the main evaporator 8 to evaporate, and becomes a low-temperature and low-pressure refrigerant gas after absorbing heat. It flows back to the low-pressure compressor 1 through the one-way outlet of the main evaporator 8, and is compressed into refrigerant vapor under intermediate pressure in the high-pressure compressor 1, and the above cycle is repeated.

[0022] Oil circuit in the pre-freezing stage: the hot oil in the condenser 3 flows out from the second outlet of the condenser 3, and under the drive of the hot oil pump 15, enters the heat exchanger 20 for heat exchange through the third regulating valve 14-3. After the heat exchange, the oil flows back to the condenser 3 from the second inlet of the condenser 3 through the fourth regulating valve 14-4.

[0023] The oil in the oil tank 12 enters the main evaporator 8 from the second inlet of the main evaporator 8 through the first outlet of the oil tank 12, and its temperature is reduced after the refrigerant absorbs heat, and it flows out from the second outlet of the main evaporator 8. Driven by the cold oil pump 9, the cold oil after heat exchange enters the oil tank 12 through the first inlet of the oil tank 12, and the cold oil enters the drying box 13 through the upper inlet of the drying box 13 driven by the oil pump 11 from the three-way outlet of the oil tank 12, exchanges heat with the environment in the box, reduces the ambient temperature in the drying box 13, and realizes pre-freezing of materials. The temperature of the oil after heat exchange increases, and flows into the three-way inlet of the oil tank 12 from the upper outlet of the drying box 13 and returns to the oil tank 13, and the above cycle is repeated.

[0024] 2. Sublimation drying stage The sublimation drying stage needs to be vacuumed in a low temperature environment, and then heated. After the temperature reaches the target temperature of the sublimation drying stage (usually 5℃~10℃ lower than the eutectic point of the material), the cold oil temperature is adjusted by adjusting the auxiliary solenoid valve 6-1 switch to adjust the mixed temperature of the cold oil and hot oil in the oil tank 12, ensuring that after entering the drying box 12 for heat exchange, the temperature in the drying box 2 reaches the target temperature of the sublimation drying stage. At this time, the throttle valve 5-1, the main solenoid valve 6-2, the main throttle valve 5-3, the cold oil pump 9, the oil pump 11, the first regulating valve 14-1, the second regulating valve 14-2, the third regulating valve 14-3, the fourth regulating valve 14-4, the hot oil pump 15, the valve 16, the vacuum pump 19, and the fan 21 are turned on.

[0025] The switch of the auxiliary solenoid valve 6-1 and the auxiliary throttle valve 5-2 depends on the temperature of the drying box 13. When the temperature in the drying box 13 does not reach the target temperature of the sublimation drying stage after the oil pump 11 has been working for 10 minutes, it means that there is too much cold energy. At this time, the switch of the auxiliary solenoid valve 6-1 and the auxiliary throttle valve 5-2 is opened to release the cold energy to the outside through the auxiliary evaporator 7.

[0026] During operation, the vacuum pump 19 works first to draw the rotary dehumidification box 17 to a certain vacuum degree (the vacuum degree setting value depends on the type of material to be dried, and the range is 20-200Pa). Solid ice frozen in the material is directly sublimated into water vapor by absorbing heat in a vacuum environment of low pressure and low temperature. The water vapor enters the dehumidifier box 17 from the drying box 13 through the lower right outlet of the drying box 13 and the pipeline through the dehumidification zone inlet on the lower side of the rotary dehumidifier box 17, and is dehumidified in the dehumidification zone 18-2 in the rotary dehumidifier box 17. It contacts with the hygroscopic material, and the moisture in the air is adsorbed onto the surface of the rotor. The dehumidified air is directly discharged into the atmosphere through the dehumidification zone outlet on the lower side of the rotary dehumidifier box 17 and the vacuum pump 19; the fresh air is first heated in the heat exchanger 20 (usually 60°C to 120°C). When the fresh air preheating temperature cannot be reached, the regeneration heater 10 is turned on for heating. Driven by the fan 21, the fresh air enters the regeneration zone 18-1 of the rotor through the regeneration zone inlet on the upper side of the rotary dehumidifier box 17, takes away the moisture adsorbed on the surface of the rotor, and is discharged into the atmosphere through the regeneration zone outlet on the upper side of the rotary dehumidifier box 17.

[0027] Refrigerant circuit in the heating stage of the sublimation drying stage: The refrigerant vapor evaporated under the intermediate pressure output by the low-pressure compressor 1 is mixed with the intermediate-pressure refrigerant vapor output from the second outlet of the intercooler 4 and enters the high-pressure compressor 2. After being compressed by the high-pressure compressor 2, the high-pressure and high-temperature refrigerant vapor output enters the condenser 3 through the first inlet of the condenser 3, condenses and releases heat to become a high-pressure and high-temperature refrigerant liquid, which is divided into two parts through the first inlet of the condenser 3. One part is throttled and reduced in pressure to the intermediate pressure through the throttle valve 5-1 and enters the intercooler 4 through the second inlet of the intercooler 4 to evaporate, and the other part enters the coil 4-1 of the intercooler 4 through the first inlet of the intercooler 4, and is connected to the pipe through the coil 4-1. The refrigerant at the external intermediate pressure is heat exchanged to evaporate, and the refrigerant outside the tube is then mixed with the exhaust gas of the low-pressure compressor through the two-way outlet of the intermediate cooler 4 and then enters the high-pressure compressor 2. The refrigerant in the coil 4-1 passes through the one-way outlet of the intermediate cooler 4 through the main solenoid valve 6-2 and the main throttle valve 5-3. Under the action of the main throttle valve 5-3, the refrigerant liquid is cooled and reduced in pressure by throttling to become a low-temperature and low-pressure liquid. The refrigerant enters the main evaporator 8 through the one-way inlet of the main evaporator 8 to evaporate, and becomes a low-temperature and low-pressure refrigerant gas after absorbing heat, and flows back to the low-pressure compressor 1 through the one-way outlet of the main evaporator 8, and is compressed into refrigerant vapor under the intermediate pressure in the high-pressure compressor 1.

[0028] When the temperature in the drying box 13 still fails to reach the target temperature of the sublimation drying stage after the oil pump 11 has been working for 10 minutes, it means that there is too much cooling capacity. At this time, open the switches of the auxiliary solenoid valve 6-1 and the auxiliary throttle valve 5-2, and a part of the refrigerant coming out of the coil 4-1 in the intercooler 4 passes through the auxiliary solenoid valve 6-1 and the auxiliary throttle valve 5-2. Under the action of the auxiliary throttle valve 5-2, the refrigerant liquid is cooled and reduced in temperature and pressure through the throttling effect to become a low-temperature and low-pressure liquid. The refrigerant enters the auxiliary evaporator 7 for evaporation, and after absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas, which mixes with the outlet gas of the main evaporator 8, and flows back to the low-pressure stage compressor 1, where it is compressed into refrigerant vapor under intermediate pressure.

[0029] The oil in the oil tank 12 enters the main evaporator 8 from the second inlet of the main evaporator 8 through the first outlet of the oil tank 12, and its temperature decreases after the refrigerant absorbs heat, and it flows out from the second outlet of the main evaporator 8. Driven by the cold oil pump 9, the cold oil after heat exchange enters the oil tank 12 through the first inlet of the oil tank 12; a part of the oil in the oil tank 12 goes out from the second outlet of the oil tank 12, enters the condenser 3 through the second inlet of the condenser 3 through the first regulating valve 14-1, and its temperature increases after the refrigerant releases heat, and flows out from the second outlet of the condenser 3. Driven by the hot oil pump 15, the hot oil after heat exchange enters the oil tank 12 through the second inlet of the oil tank 12 through the second regulating valve 14-2. After the hot oil from the condenser 3 is mixed with the cold oil from the main evaporator 8, when the oil temperature reaches the target temperature of the sublimation drying stage, it enters the drying box 13 through the upper inlet of the drying box 13 from the three-way outlet of the oil tank 12 driven by the oil pump 11, and exchanges heat with the environment in the box. After the heat exchange, the oil temperature rises, and flows from the upper outlet of the drying box 13 into the three-way inlet of the oil tank 12 and returns to the oil tank 13. When the temperature of the oil tank 12 is higher than the target temperature of the sublimation drying stage, the opening of the third regulating valve 14-3 and the fourth regulating valve 14-4 becomes larger, and the opening of the first regulating valve 14-1 and the second regulating valve 14-2 becomes smaller, the amount of hot oil entering the oil tank 12 becomes less, and the temperature of the mixed oil in the oil tank 12 decreases, reaching the target temperature of the sublimation drying stage, and the above cycle is repeated.

[0030] 3. Drying stage During the analytical drying stage, the material needs to be further heated under vacuum conditions and maintained at a certain temperature (the target temperature of the analytical drying stage is above 30°C, and the maximum temperature can reach 100°C) to precipitate the bound water in the material. The refrigerant circuit and oil circuit flow in the analytical drying stage are the same as those in the sublimation drying stage.

[0031] Analysis of the refrigerant circuit in the heating stage of the drying stage: the refrigerant vapor evaporated under the intermediate pressure output by the low-pressure compressor 1 is mixed with the intermediate pressure refrigerant vapor output from the second outlet of the intercooler 4 and enters the high-pressure compressor 2. After being compressed by the high-pressure compressor 2, the high-pressure and high-temperature refrigerant vapor output enters the condenser 3 through the first inlet of the condenser 3, condenses and releases heat to become a high-pressure and high-temperature refrigerant liquid, which is divided into two parts through the first inlet of the condenser 3. One part is throttled and reduced to the intermediate pressure through the throttle valve 5-1 and enters the intercooler 4 through the second inlet of the intercooler 4 to evaporate, and the other part enters the coil 4-1 of the intercooler 4 through the first inlet of the intercooler 4. , the refrigerant at the intermediate pressure outside the tube is evaporated by heat exchange with the coil 4-1, and the refrigerant outside the tube is then mixed with the exhaust gas of the low-pressure compressor through the two-way outlet of the intermediate cooler 4 and enters the high-pressure compressor 2. The refrigerant in the coil 4-1 passes through the one-way outlet of the intermediate cooler 4 through the main solenoid valve 6-2 and the main throttle valve 5-3. Under the action of the main throttle valve 5-3, the refrigerant liquid is cooled and reduced in temperature and pressure through the throttling effect to become a low-temperature and low-pressure liquid. The refrigerant enters the main evaporator 8 through the one-way inlet of the main evaporator 8 to evaporate, and becomes a low-temperature and low-pressure refrigerant gas after absorbing heat. It flows back to the low-pressure compressor 1 through the one-way outlet of the main evaporator 8, and is compressed into a refrigerant vapor under the intermediate pressure in the high-pressure compressor 1.

[0032] When the temperature in the drying box 13 does not reach the target temperature of the analytical drying stage after the oil pump 11 has been working for 10 minutes, it means that the cooling capacity is too much. At this time, the auxiliary solenoid valve 6-1 and the auxiliary throttle valve 5-2 are turned on, and a part of the refrigerant coming out of the coil 4-1 in the intercooler 4 passes through the auxiliary solenoid valve 6-1 and the auxiliary throttle valve 5-2. Under the action of the auxiliary throttle valve 5-2, the refrigerant liquid is cooled and reduced in temperature and pressure through the throttling effect to become a low-temperature and low-pressure liquid. The refrigerant enters the auxiliary evaporator 7 for evaporation, and after absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas, which mixes with the outlet gas of the main evaporator 8 and flows back to the low-pressure stage compressor 1, where it is compressed into refrigerant vapor under intermediate pressure.

[0033] The oil in the oil tank 12 enters the main evaporator 8 from the second inlet of the main evaporator 8 through the first outlet of the oil tank 12, and its temperature decreases after the refrigerant absorbs heat, and it flows out from the second outlet of the main evaporator 8. Driven by the cold oil pump 9, the cold oil after heat exchange enters the oil tank 12 through the first inlet of the oil tank 12; a part of the oil in the oil tank 12 goes out from the second outlet of the oil tank 12, enters the condenser 3 through the second inlet of the condenser 3 through the first regulating valve 14-1, and its temperature increases after the refrigerant releases heat, and flows out from the second outlet of the condenser 3. Driven by the hot oil pump 15, the hot oil after heat exchange enters the oil tank 12 through the second inlet of the oil tank 12 through the second regulating valve 14-2. After the hot oil from the condenser 3 is mixed with the cold oil from the main evaporator 8, when the oil temperature reaches the target temperature of the analytical drying stage, it enters the drying box 13 through the upper inlet of the drying box 13 from the three-way outlet of the oil tank 12 driven by the oil pump 11, and exchanges heat with the environment in the box. After the heat exchange, the oil temperature rises, and flows from the upper outlet of the drying box 13 into the three-way inlet of the oil tank 12 and returns to the oil tank 13. When the temperature of the oil tank 12 is higher than the target temperature of the analytical drying stage, the opening of the third regulating valve 14-3 and the fourth regulating valve 14-4 becomes larger, and the opening of the first regulating valve 14-1 and the second regulating valve 14-2 becomes smaller, the amount of hot oil entering the oil tank 12 becomes less, and the temperature of the mixed oil in the oil tank 12 decreases, reaching the target temperature of the analytical drying stage, and the above cycle is repeated.

[0034] It should be understood that the parts not elaborated in detail in this specification belong to the prior art. The above embodiments are only descriptions of the preferred implementation methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made by ordinary engineers and technicians in this field to the technical solution of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A novel freeze dryer utilizing residual heat recovery rotary dehumidification, characterized in that: It includes refrigeration system, residual heat collection system, vacuum system, and rotary dehumidification system; The refrigeration system includes a low-pressure compressor, a high-pressure compressor, a condenser, an intercooler, a throttle valve, an auxiliary throttle valve, a main throttle valve, an auxiliary solenoid valve, a main solenoid valve, an auxiliary evaporator, and a main evaporator; The residual heat collection system includes a main evaporator, a cold oil pump, a condenser, a hot oil pump, a third regulating valve, a first regulating valve, a second regulating valve, an oil tank, a fourth regulating valve, and a heat exchanger; The vacuum system includes an oil pump, a drying box, a rotary dehumidification box, a valve, and a vacuum pump; The rotary dehumidification system includes a rotary dehumidification box, a dehumidification rotary wheel, a vacuum pump, a fan, and a regeneration heater; The outlet of the low-pressure compressor is connected to the inlet of the high-pressure compressor, the outlet of the high-pressure compressor is connected to one inlet of the condenser, one outlet of the condenser is connected to one inlet of the intercooler, one outlet of the intercooler is respectively connected to the inlet of the main solenoid valve and the inlet of the auxiliary solenoid valve, the outlet of the main solenoid valve is connected to the inlet of the main throttle valve, the outlet of the main throttle valve is connected to one inlet of the main evaporator, one outlet of the main evaporator is connected to the inlet of the low-pressure compressor; the outlet of the auxiliary solenoid valve is connected to the inlet of the auxiliary throttle valve, the outlet of the auxiliary throttle valve is connected to the inlet of the auxiliary evaporator, The inlet of the auxiliary evaporator is connected to the inlet of the low-pressure compressor; the inlet of the throttle valve is connected to the first outlet of the condenser, the outlet of the throttle valve is connected to the second inlet of the intercooler, and the second outlet of the intercooler is connected to the inlet of the high-pressure compressor; the inlet of the cold oil pump is connected to the second outlet of the main evaporator, the outlet of the cold oil pump is connected to the first inlet of the oil tank, and the first outlet of the oil tank is connected to the second inlet of the main evaporator; the inlet of the hot oil pump is connected to the second outlet of the condenser, the outlet of the hot oil pump is connected to the inlet of the second regulating valve, and the outlet of the second regulating valve is connected to The two-way inlet of the oil tank is connected, the two-way outlet of the oil tank is connected to the inlet of the first regulating valve, and the outlet of the first regulating valve is connected to the two-way inlet of the condenser; the inlet of the third regulating valve is connected to the outlet of the hot oil pump, the outlet of the third regulating valve is connected to the one-way inlet of the heat exchanger, the one-way outlet of the heat exchanger is connected to the inlet of the fourth regulating valve, and the outlet of the fourth regulating valve is connected to the two-way inlet of the condenser; the inlet of the oil pump is connected to the three-way outlet of the oil tank, the outlet of the oil pump is connected to the upper inlet of the drying box, and the upper outlet of the drying box is connected to the three-way inlet of the oil tank; the inlet of the valve is connected to the dry box The lower right outlet of the box is connected, the outlet of the valve is connected with the inlet of the dehumidification zone on the lower side of the rotary dehumidification box through a pipeline, there is a dehumidification wheel in the rotary dehumidification box, there are / regeneration zone and / dehumidification zone on the dehumidification wheel, the dehumidification zone outlet on the lower side of the rotary dehumidification box is connected with the inlet of the vacuum pump, and the outlet of the vacuum pump directly enters the air; the two-way outlet of the heat exchanger is connected with the inlet of the fan through a pipeline, the outlet of the fan is connected with the inlet of the regeneration zone on the upper side of the rotary dehumidification box through a pipeline, and the regeneration zone outlet on the upper side of the rotary dehumidification box directly enters the air; the two-way inlet of the heat exchanger is connected to the air through the regeneration heater.

2. A method for operating a novel freeze dryer utilizing residual heat recovery rotary dehumidification, characterized in that: Specifically include: The working operation is divided into three stages: pre-freezing, sublimation drying, and analytical drying; 1) Pre-freezing stage At this time, the throttle valve, main solenoid valve, main throttle valve, cold oil pump, oil pump, third regulating valve, fourth regulating valve, and hot oil pump are turned on; the auxiliary solenoid valve, auxiliary throttle valve, first regulating valve, second regulating valve, valve, and vacuum pump are turned off; Fluid circuit during the pre-freezing phase: Refrigerant circuit in the pre-freezing stage: The refrigerant vapor evaporated under the intermediate pressure output by the low-pressure compressor is mixed with the intermediate pressure refrigerant vapor output from the second outlet of the intercooler and enters the high-pressure compressor. After being compressed by the high-pressure compressor, the high-pressure and high-temperature refrigerant vapor output enters the condenser through the first inlet of the condenser, condenses and releases heat to become high-pressure and high-temperature refrigerant liquid. The refrigerant liquid is divided into two parts through the first inlet of the condenser. One part is throttled and reduced to the intermediate pressure through the throttle valve and enters the intercooler through the second inlet of the intercooler to evaporate. The other part enters the coil of the intercooler through the first inlet of the intercooler and passes through the coil. The refrigerant exchanges heat with the refrigerant under the intermediate pressure outside the tube to evaporate. The refrigerant outside the tube then enters the high-pressure compressor after mixing with the exhaust gas of the low-pressure compressor through the two-way outlet of the intercooler. The refrigerant in the coil passes through the main solenoid valve and the main throttle valve through the one-way outlet of the intercooler. Under the action of the main throttle valve, the refrigerant liquid is cooled and reduced in temperature and pressure through the throttling effect to become a low-temperature and low-pressure liquid. The refrigerant enters the main evaporator through the one-way inlet of the main evaporator to evaporate. After absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas. It flows back to the low-pressure compressor through the one-way outlet of the main evaporator. It is compressed into a refrigerant vapor under the intermediate pressure in the high-pressure compressor, and the above cycle is repeated. Oil circuit in the pre-freezing stage: The hot oil in the condenser flows out from the second outlet of the condenser, and under the drive of the hot oil pump, enters the heat exchanger through the third regulating valve for heat exchange. After the heat exchange, the oil flows back to the condenser from the second inlet of the condenser through the fourth regulating valve; The oil in the oil tank enters the main evaporator from the second inlet of the main evaporator through the first outlet of the oil tank. After absorbing heat from the refrigerant, the temperature is reduced and flows out from the second outlet of the main evaporator. Driven by the cold oil pump, the cold oil after heat exchange enters the oil tank through the first inlet of the oil tank. The cold oil enters the drying box through the upper inlet of the drying box from the third outlet of the oil tank driven by the oil pump, exchanges heat with the environment in the drying box, reduces the ambient temperature in the drying box, and realizes pre-freezing of materials. The temperature of the oil after heat exchange increases and flows from the upper outlet of the drying box into the three-way inlet of the oil tank and returns to the oil tank, repeating the above cycle. 2) Sublimation drying stage The sublimation drying stage needs to be vacuumed in a low temperature environment, and then heated up to the target temperature of the sublimation drying stage: after it is 5℃~10℃ lower than the eutectic point of the material, the cold oil temperature is adjusted by adjusting the auxiliary solenoid valve switch to adjust the mixed temperature of the cold oil and hot oil in the oil tank, ensuring that after entering the drying box for heat exchange, the temperature in the drying box reaches the target temperature of the sublimation drying stage; at this time, the throttle valve, main solenoid valve, main throttle valve, cold oil pump, oil pump, first regulating valve, second regulating valve, third regulating valve, fourth regulating valve, hot oil pump, valve, vacuum pump, and fan are turned on; The switch of the auxiliary solenoid valve and the auxiliary throttle valve depends on the temperature of the drying box. When the temperature in the drying box does not reach the target temperature of the sublimation drying stage after the oil pump has been working for 10 minutes, the switch of the auxiliary solenoid valve and the auxiliary throttle valve is opened to release the cold capacity to the outside through the auxiliary evaporator. During operation, the vacuum pump works first to pump the rotary dehumidifier box to a vacuum range of 20 to 200Pa; the solid ice frozen in the material directly sublimates into water vapor by absorbing heat under a low-pressure and low-temperature vacuum environment, and the water vapor enters the rotary dehumidifier box from the drying box through the lower right outlet of the drying box and the pipeline through the dehumidification zone inlet on the lower side of the rotary dehumidifier box, dehumidifies in the dehumidification zone in the rotary dehumidifier box, contacts with the hygroscopic material, and the moisture in the air is adsorbed onto the surface of the rotor. The dehumidified air is directly discharged into the atmosphere through the dehumidification zone outlet on the lower side of the rotary dehumidifier box and the vacuum pump; the fresh air is first heated in the heat exchanger, and the preheating temperature is 60℃ to 120℃. When the fresh air preheating temperature is not reached, the regeneration heater is turned on for heating, and driven by the fan, it enters the regeneration zone of the rotary wheel through the regeneration zone inlet on the upper side of the rotary dehumidifier box, takes away the moisture adsorbed on the surface of the rotary wheel, and discharges into the atmosphere through the regeneration zone outlet on the upper side of the rotary dehumidifier box; Refrigerant circuit in the heating stage of the sublimation drying stage: The refrigerant vapor evaporated under the intermediate pressure output by the low-pressure compressor is mixed with the intermediate-pressure refrigerant vapor output from the second outlet of the intercooler and enters the high-pressure compressor. After being compressed by the high-pressure compressor, the high-pressure and high-temperature refrigerant vapor output enters the condenser through the first inlet of the condenser, condenses and releases heat to become high-pressure and high-temperature refrigerant liquid. The refrigerant is divided into two parts through the first inlet of the condenser. One part is throttled and reduced to the intermediate pressure through the throttle valve and enters the intercooler through the second inlet of the intercooler to evaporate. The other part enters the coil of the intercooler through the first inlet of the intercooler and passes through the coil and the tube. The refrigerant at the external intermediate pressure is heat exchanged to evaporate. The refrigerant outside the tube is mixed with the exhaust gas of the low-pressure compressor through the two-way outlet of the intermediate cooler and then enters the high-pressure compressor. The refrigerant in the coil passes through the main solenoid valve and the main throttle valve through the one-way outlet of the intermediate cooler. Under the action of the main throttle valve, the refrigerant liquid is throttled to reduce temperature and pressure and become a low-temperature and low-pressure liquid. The refrigerant enters the main evaporator through the one-way inlet of the main evaporator to evaporate. After absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas. It flows back to the low-pressure compressor through the one-way outlet of the main evaporator and is compressed into a refrigerant vapor under the intermediate pressure in the high-pressure compressor. When the temperature in the drying box fails to reach the target temperature of the sublimation drying stage after the oil pump has been working for 10 minutes, the auxiliary solenoid valve and the auxiliary throttle valve are turned on at this time, and part of the refrigerant coming out of the coil in the intercooler passes through the auxiliary solenoid valve and the auxiliary throttle valve. Under the action of the auxiliary throttle valve, the refrigerant liquid is cooled and depressurized by the throttling action to become a low-temperature and low-pressure liquid. The refrigerant enters the auxiliary evaporator for evaporation, and after absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas that mixes with the outlet gas of the main evaporator and flows back to the low-pressure compressor, where it is compressed into refrigerant vapor at an intermediate pressure. The oil in the oil tank enters the main evaporator from the second inlet of the main evaporator through the first outlet of the oil tank. After absorbing heat from the refrigerant, the temperature drops and flows out from the second outlet of the main evaporator. Driven by the cold oil pump, the cold oil after heat exchange enters the oil tank through the first inlet of the oil tank; part of the oil in the oil tank goes out from the second outlet of the oil tank, passes through the second inlet of the condenser through the first regulating valve, enters the condenser, and after releasing heat from the refrigerant, the temperature rises and flows out from the second outlet of the condenser. Driven by the hot oil pump, the hot oil after heat exchange enters the oil tank through the second inlet of the oil tank through the second regulating valve; the hot oil from the condenser and After the cold oil from the main evaporator is mixed, when the oil temperature reaches the target temperature of the sublimation drying stage, it enters the drying box through the upper inlet of the drying box through the three-way outlet of the oil tank driven by the oil pump, and exchanges heat with the environment in the box. After the heat exchange, the oil temperature rises, and flows from the upper outlet of the drying box into the three-way inlet of the oil tank and returns to the oil tank; when the temperature of the oil tank is higher than the target temperature of the sublimation drying stage, the openings of the third regulating valve and the fourth regulating valve become larger, and the openings of the first regulating valve and the second regulating valve become smaller, the amount of hot oil entering the oil tank becomes less, and the temperature of the mixed oil in the oil tank decreases, reaching the target temperature of the sublimation drying stage, and the above cycle is repeated; 3) Analysis and drying stage During the analytical drying stage, the material needs to be further heated under vacuum conditions and the target temperature of the analytical drying stage should be maintained at 30°C to 100°C to precipitate the bound water in the material. Analysis of the refrigerant circuit in the heating phase of the drying phase: The refrigerant vapor evaporated under the intermediate pressure output by the low-pressure compressor is mixed with the intermediate-pressure refrigerant vapor output from the second outlet of the intercooler and enters the high-pressure compressor. After being compressed by the high-pressure compressor, the high-pressure and high-temperature refrigerant vapor output enters the condenser through the first inlet of the condenser, condenses and releases heat to become high-pressure and high-temperature refrigerant liquid. The refrigerant is divided into two parts through the first inlet of the condenser. One part is throttled and reduced to the intermediate pressure through the throttle valve and enters the intercooler through the second inlet of the intercooler to evaporate. The other part enters the coil of the intercooler through the first inlet of the intercooler and passes through the coil and the tube. The refrigerant at the external intermediate pressure is heat exchanged to evaporate. The refrigerant outside the tube is mixed with the exhaust gas of the low-pressure compressor through the two-way outlet of the intermediate cooler and then enters the high-pressure compressor. The refrigerant in the coil passes through the main solenoid valve and the main throttle valve through the one-way outlet of the intermediate cooler. Under the action of the main throttle valve, the refrigerant liquid is throttled to reduce temperature and pressure and become a low-temperature and low-pressure liquid. The refrigerant enters the main evaporator through the one-way inlet of the main evaporator to evaporate. After absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas. It flows back to the low-pressure compressor through the one-way outlet of the main evaporator and is compressed into a refrigerant vapor under the intermediate pressure in the high-pressure compressor. When the temperature in the drying box fails to reach the target temperature of the analytical drying stage after the oil pump has been working for 10 minutes, the auxiliary solenoid valve and the auxiliary throttle valve are turned on, and part of the refrigerant coming out of the coil in the intercooler passes through the auxiliary solenoid valve and the auxiliary throttle valve. Under the action of the auxiliary throttle valve, the refrigerant liquid is cooled and depressurized by the throttling action to become a low-temperature and low-pressure liquid. The refrigerant enters the auxiliary evaporator for evaporation, and after absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas that mixes with the outlet gas of the main evaporator and flows back to the low-pressure compressor, where it is compressed into refrigerant vapor at an intermediate pressure. The oil in the oil tank enters the main evaporator from the second inlet of the main evaporator through the first outlet of the oil tank. After absorbing heat from the refrigerant, the temperature drops and flows out from the second outlet of the main evaporator. Driven by the cold oil pump, the cold oil after heat exchange enters the oil tank through the first inlet of the oil tank; part of the oil in the oil tank goes out from the second outlet of the oil tank, passes through the second inlet of the condenser through the first regulating valve, enters the condenser, and after releasing heat from the refrigerant, the temperature rises and flows out from the second outlet of the condenser. Driven by the hot oil pump, the hot oil after heat exchange enters the oil tank through the second inlet of the oil tank through the second regulating valve; the hot oil from the condenser and After the cold oil from the main evaporator is mixed, when the oil temperature reaches the target temperature of the analytical drying stage, it enters the drying box through the upper inlet of the drying box through the three-way outlet of the oil tank driven by the oil pump, and exchanges heat with the environment in the box. After the heat exchange, the oil temperature rises, and flows from the upper outlet of the drying box into the three-way inlet of the oil tank and returns to the oil tank; when the temperature of the oil tank is higher than the target temperature of the analytical drying stage, the opening of the third regulating valve and the fourth regulating valve becomes larger, and the opening of the first regulating valve and the second regulating valve becomes smaller, the amount of hot oil entering the oil tank becomes less, and the temperature of the mixed oil in the oil tank decreases, reaching the target temperature of the analytical drying stage, and repeating the above cycle. .

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