A new freeze dryer using waste heat recovery rotary dehumidifier and its operation method

Abstract

The application discloses a new freeze dryer using residual temperature recovery rotary dehumidification and a running method thereof, wherein the refrigerating system comprises a low-pressure stage compressor, a high-pressure stage compressor, a condenser, an intermediate cooler, a throttle valve, an electromagnetic valve, an auxiliary evaporator and a main evaporator; the residual temperature collection system comprises the main evaporator, a cold oil pump, the condenser, a hot oil pump, a regulating valve, an oil tank and a heat exchanger; the vacuum pumping system comprises an oil pump, a drying box, a rotary dehumidification box, a valve and a vacuum pump; and the rotary dehumidification system comprises the rotary dehumidification box, a dehumidification rotary wheel, the vacuum pump, a fan and a regeneration heater; the application improves the drying efficiency, significantly improves the energy utilization rate of the system, reduces energy waste, reduces the operation cost, ensures that the humidity environment in the freeze drying process is more uniform and controllable, and avoids the frosting phenomenon caused by low temperature in the dehumidification process.

Description

Technical Field

[0001] This invention relates to a novel freeze dryer that utilizes residual heat recovery dehumidification rotor and its operating method, belonging to the field of refrigeration technology. Background Technology

[0002] With the widespread application of freeze-drying technology in biopharmaceuticals, pharmaceuticals, and high-end foods, higher demands are being placed on the performance of freeze-drying equipment. These materials typically have stringent requirements for low-temperature environments and humidity control, while traditional freeze-drying equipment suffers from significant deficiencies in cryogenic capacity, energy efficiency, and temperature and humidity control. Single-stage refrigeration systems struggle to provide sufficient cryogenic capacity, resulting in low material freezing efficiency. Waste heat from the condenser is often not effectively recovered, relying on traditional heating methods, which not only wastes energy but also significantly increases operating costs. Furthermore, traditional temperature control methods, achieved by switching between refrigeration and heating, have slow response times and large temperature fluctuations, affecting the stability of the drying process. Simultaneously, traditional cold traps or water replenishers require evaporators or refrigerants to capture the removed moisture, necessitating low temperatures and correspondingly low evaporation temperatures, reducing overall refrigeration efficiency. Additionally, the moisture captured by the cold trap or water replenisher adheres to its surface; after drying, it requires waiting for the moisture to melt or being heated to induce melting before the next batch can be dried, resulting in a long drying cycle. Therefore, the industry urgently needs an innovative freeze-drying equipment that can break through the bottlenecks of traditional technology to meet the stringent requirements for freeze-drying high-end materials. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a new type of freeze dryer and its operation method that utilizes residual heat recovery dehumidification wheel.

[0004] The technical solution provided by this invention is as follows: a novel freeze dryer that utilizes residual heat recovery dehumidification, characterized in that it includes a refrigeration system, a residual heat collection system, a vacuum system, and a dehumidification system. The refrigeration system includes a low-pressure stage compressor, a high-pressure stage 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 waste 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 chamber, a rotary dehumidifier chamber, valves, and a vacuum pump; The rotary dehumidification system includes a rotary dehumidification box, a dehumidification rotor, a vacuum pump, a fan, and a regeneration heater; The low-pressure stage compressor outlet is connected to the high-pressure stage compressor inlet. The high-pressure stage compressor outlet 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 connected to both 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 low-pressure stage compressor inlet. 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 auxiliary evaporator inlet. The inlet of the main evaporator is connected to the main evaporator, and the outlet of the auxiliary evaporator is connected to the inlet of the low-pressure stage compressor. The inlet of the throttle valve is connected to one outlet of the condenser, and the outlet of the throttle valve is connected to the second inlet of the intercooler. The second outlet of the intercooler is connected to the inlet of the high-pressure stage compressor. The inlet of the cold oil pump is connected to the two outlets of the main evaporator, and the outlet of the cold oil pump is connected to one inlet of the oil tank. 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 two outlets of the condenser, and the outlet of the hot oil pump is connected to the inlet of the second regulating valve. The outlet of the second regulating valve is connected to... The oil tank's two inlets are connected, and its two outlets are connected to the inlet of the first regulating valve, which in turn is connected to the two inlets of the condenser. The inlet of the third regulating valve is connected to the outlet of the hot oil pump, which is also connected to one inlet of the heat exchanger. The heat exchanger's one outlet is connected to the inlet of the fourth regulating valve, which is connected to the two inlets of the condenser. The oil pump's inlet is connected to the three outlets of the oil tank, and its outlet is connected to the upper inlet of the drying chamber. The upper outlet of the drying chamber is connected to the three inlets of the oil tank. The valve's inlet is connected to the drying... The lower right outlet of the chamber is connected, and the valve outlet is connected to the dehumidification zone inlet on the lower side of the rotary dehumidifier via a pipeline. The rotary dehumidifier contains a dehumidification rotor with a regeneration zone and a dehumidification zone. The dehumidification zone outlet on the lower side of the rotary dehumidifier is connected to the vacuum pump inlet, and the vacuum pump outlet directly enters the air. The two outlets of the heat exchanger are connected to the fan inlet via pipelines, and the fan outlet is connected to the regeneration zone inlet on the upper side of the rotary dehumidifier via pipelines. The regeneration zone outlet on the upper side of the rotary dehumidifier directly enters the air. The two inlets of the heat exchanger are connected to the air via a regeneration heater.

[0005] A novel freeze dryer operating method utilizing residual heat recovery dehumidification rotor, characterized in that it specifically includes: The operation is divided into three stages: pre-freezing, sublimation drying, and desorption 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 open; the auxiliary solenoid valve, auxiliary throttle valve, first regulating valve, second regulating valve, valve, and vacuum pump are closed. Fluid circuit during the pre-freezing stage: The refrigerant circuit during the pre-freezing stage: Refrigerant vapor evaporated at intermediate pressure from the low-pressure stage compressor mixes with intermediate-pressure refrigerant vapor from the two outlets of the intercooler, and enters the high-pressure stage compressor. After compression by the high-pressure stage compressor, high-pressure, high-temperature refrigerant vapor is output and enters the condenser through one inlet. It condenses and releases heat to become high-pressure, high-temperature refrigerant liquid. Through one inlet and outlet of the condenser, it is divided into two parts: one part is throttled and depressurized to intermediate pressure by the expansion valve and enters the intercooler through the two inlets to evaporate; the other part enters the intercooler coil through the first inlet and then flows through the coil. The refrigerant outside the pipes exchanges heat with the refrigerant at intermediate pressure, causing it to evaporate. The refrigerant outside the pipes then mixes with the exhaust gas from the low-pressure stage compressor through the two outlets of the intercooler and enters the high-pressure stage compressor. The refrigerant inside the coil passes through one outlet of the intercooler, through the main solenoid valve and the main throttle valve. Under the action of the main throttle valve, the refrigerant liquid is cooled and depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the main evaporator through one inlet to evaporate, and after absorbing heat, it becomes a low-temperature, low-pressure refrigerant gas. It flows back to the low-pressure stage compressor through one outlet of the main evaporator, where it is compressed into refrigerant vapor at intermediate pressure. The above cycle is repeated. Oil circuit during the pre-freezing stage: Hot oil in the condenser flows out from the second outlet of the condenser. Driven by the hot oil pump, it enters the heat exchanger through the third regulating valve for heat exchange. After heat exchange, the oil flows back to the condenser from the second inlet of the condenser through the fourth regulating valve. Oil in the oil tank enters the main evaporator through the second inlet of the main evaporator via the first outlet of the oil tank. After absorbing heat from the refrigerant, the temperature decreases, and the oil flows out from the second outlet of the main evaporator. Driven by the cold oil pump, the cooled oil after heat exchange enters the oil tank through the first inlet of the oil tank. The cooled oil then enters the drying chamber through the upper inlet of the drying chamber via the third outlet of the oil tank, driven by the oil pump. It exchanges heat with the environment inside the drying chamber, lowering the temperature of the environment inside the drying chamber and achieving pre-freezing of the material. After heat exchange, the oil temperature rises and flows back to the oil tank through the third inlet of the oil tank from the upper outlet of the drying chamber, repeating the above cycle. 2) Sublimation drying stage The sublimation drying stage requires vacuuming at a low temperature, followed by heating. Once the temperature reaches the target temperature for the sublimation drying stage (5℃~10℃ below the eutectic point of the material), the temperature of the cold oil is adjusted by regulating the auxiliary solenoid valve switch. This regulates the mixing temperature of the cold and hot oil in the oil tank, ensuring that the temperature inside the drying chamber reaches the target temperature for the sublimation drying stage after heat exchange. 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, valves, vacuum pump, and fan are activated. The opening and closing of the auxiliary solenoid valve and the auxiliary throttle valve depend on the temperature of the drying chamber. When the temperature inside the drying chamber does not reach the target temperature for the sublimation drying stage after the oil pump has been working for 10 minutes, the auxiliary solenoid valve and the auxiliary throttle valve are opened to release the cold energy to the outside through the auxiliary evaporator. During operation, the vacuum pump works first, drawing the rotary dehumidifier to a vacuum level of 20–200 Pa. Solid ice frozen in the material, under low pressure and low temperature vacuum conditions, absorbs heat and sublimates directly into water vapor. This water vapor enters the rotary dehumidifier through the lower right outlet and pipeline of the drying chamber, passing through the dehumidification zone inlet on the lower side. It is dehumidified in the dehumidification zone, coming into contact with the moisture-absorbing material. Moisture in the air is adsorbed onto the surface of the rotor. The dehumidified air is then discharged directly into the atmosphere through the dehumidification zone outlet on the lower side of the rotary dehumidifier and the vacuum pump. Fresh air is first heated in the heat exchanger to a preheating temperature of 60–120°C. If the preheating temperature is insufficient, the regeneration heater is activated. Driven by a fan, the fresh air enters the regeneration zone of the rotor through the regeneration zone inlet on the upper side of the rotary dehumidifier, carrying away the moisture adsorbed on the rotor surface. The moisture is then discharged into the atmosphere through the regeneration zone outlet on the upper side of the rotary dehumidifier. The refrigerant circuit during the heating stage of the sublimation drying phase: The refrigerant vapor evaporated at intermediate pressure from the low-pressure stage compressor mixes with the intermediate-pressure refrigerant vapor from the two outlets of the intercooler and enters the high-pressure stage compressor. After compression by the high-pressure stage compressor, the high-pressure, high-temperature refrigerant vapor enters the condenser through one inlet. It condenses and releases heat to become a high-pressure, high-temperature refrigerant liquid. This liquid is then divided into two parts through one inlet and one outlet of the condenser. One part is throttled and depressurized to intermediate pressure by a throttling valve and enters the intercooler through the two inlets to evaporate. The other part enters the intercooler coil through the first inlet and then... Under external intermediate pressure, the refrigerant undergoes heat exchange to evaporate. The refrigerant outside the pipe then mixes with the exhaust gas from the low-pressure stage compressor through the two outlets of the intercooler and enters the high-pressure stage compressor. The refrigerant inside the coil passes through one outlet of the intercooler, through the main solenoid valve and the main throttle valve. Under the action of the main throttle valve, the refrigerant liquid is cooled and depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the main evaporator through one inlet to evaporate and absorb heat, becoming a low-temperature, low-pressure refrigerant gas. It then flows back to the low-pressure stage compressor through one outlet of the main evaporator, where it is compressed into refrigerant vapor at intermediate pressure. If the temperature inside the drying chamber fails to reach the target temperature for the sublimation drying stage after the oil pump has been running for 10 minutes, the auxiliary solenoid valve and auxiliary throttle valve are opened. A portion of the refrigerant coming out of the coil in the intercooler passes through the auxiliary solenoid valve and auxiliary throttle valve. Under the action of the auxiliary throttle valve, the refrigerant liquid is cooled and depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the auxiliary evaporator to evaporate, absorbs heat, and becomes a low-temperature, low-pressure refrigerant gas. It mixes with the gas from the main evaporator and flows back to the low-pressure stage compressor, where it is compressed into refrigerant vapor at an intermediate pressure. Oil in the oil tank enters the main evaporator through the second inlet of the main evaporator via the first outlet of the oil tank. After absorbing heat from the refrigerant, its temperature decreases, and it flows out from the second outlet of the main evaporator. Driven by the cold oil pump, the cooled oil, after heat exchange, enters the oil tank through the first inlet of the oil tank. Part of the oil in the oil tank exits through the second outlet of the oil tank, passes through the first regulating valve, and enters the condenser through the second inlet. After releasing heat from the refrigerant, its temperature increases, and it flows out from the second outlet of the condenser. Driven by the hot oil pump, the heated oil, after heat exchange, enters the oil tank through the second regulating valve and the second inlet of the oil tank. The hot oil from the condenser and... After the cold oil from the main evaporator mixes with the oil, and the oil temperature reaches the target temperature for the sublimation drying stage, it enters the drying chamber from the three outlets of the oil tank via the oil pump through the upper inlet of the drying chamber. It exchanges heat with the environment inside the chamber, and the oil temperature rises after heat exchange. It then flows back into the oil tank from the upper outlet of the drying chamber through the three inlets of the oil tank. When the temperature of the oil tank is higher than the target temperature for the sublimation drying stage, the opening of the third and fourth regulating valves increases, while the opening of the first and second regulating valves decreases. The amount of hot oil entering the oil tank decreases, and the temperature of the mixed oil in the oil tank decreases until the target temperature for the sublimation drying stage is reached. The above cycle is repeated. 3) Analysis and drying stage During the desorption drying stage, the material needs to be further heated under vacuum conditions, and the target temperature of the desorption drying stage should be maintained at 30℃~100℃ to allow the bound water in the material to be precipitated. Analysis of the refrigerant circuit during the heating phase of the drying stage: The refrigerant vapor evaporated at intermediate pressure from the low-pressure stage compressor mixes with the intermediate-pressure refrigerant vapor from the two outlets of the intercooler and enters the high-pressure stage compressor. After compression by the high-pressure stage compressor, the high-pressure, high-temperature refrigerant vapor enters the condenser through one inlet. It condenses and releases heat to become a high-pressure, high-temperature refrigerant liquid. This liquid is then divided into two parts through one inlet and one outlet of the condenser. One part is throttled and depressurized to intermediate pressure by a throttling valve and enters the intercooler through the two inlets to evaporate. The other part enters the intercooler coil through the first inlet and then... Under external intermediate pressure, the refrigerant undergoes heat exchange to evaporate. The refrigerant outside the pipe then mixes with the exhaust gas from the low-pressure stage compressor through the two outlets of the intercooler and enters the high-pressure stage compressor. The refrigerant inside the coil passes through one outlet of the intercooler, through the main solenoid valve and the main throttle valve. Under the action of the main throttle valve, the refrigerant liquid is cooled and depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the main evaporator through one inlet to evaporate and absorb heat, becoming a low-temperature, low-pressure refrigerant gas. It then flows back to the low-pressure stage compressor through one outlet of the main evaporator, where it is compressed into refrigerant vapor at intermediate pressure. If the temperature inside the drying chamber fails to reach the target temperature for the desorption and drying stage after the oil pump has been running for 10 minutes, the auxiliary solenoid valve and auxiliary throttle valve are opened. A portion of the refrigerant coming out of the coil in the intercooler passes through the auxiliary solenoid valve and auxiliary throttle valve. Under the action of the auxiliary throttle valve, the refrigerant liquid is cooled and depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the auxiliary evaporator to evaporate, absorbs heat, and becomes a low-temperature, low-pressure refrigerant gas. It mixes with the gas from the main evaporator and flows back to the low-pressure stage compressor, where it is compressed into refrigerant vapor at an intermediate pressure. Oil in the oil tank enters the main evaporator through the second inlet of the main evaporator via the first outlet of the oil tank. After absorbing heat from the refrigerant, its temperature decreases, and it flows out from the second outlet of the main evaporator. Driven by the cold oil pump, the cooled oil, after heat exchange, enters the oil tank through the first inlet of the oil tank. Part of the oil in the oil tank exits through the second outlet of the oil tank, passes through the first regulating valve, and enters the condenser through the second inlet. After releasing heat from the refrigerant, its temperature increases, and it flows out from the second outlet of the condenser. Driven by the hot oil pump, the heated oil, after heat exchange, enters the oil tank through the second regulating valve and the second inlet of the oil tank. The hot oil from the condenser and... After the cold oil from the main evaporator mixes with the target temperature of the desorption and drying stage, it enters the drying chamber from the three outlets of the oil tank via the oil pump and the upper inlet of the drying chamber. It exchanges heat with the environment inside the chamber, and the oil temperature rises after heat exchange. It then flows back into the oil tank from the upper outlet of the drying chamber through the three inlets of the oil tank. When the temperature of the oil tank is higher than the target temperature of the desorption and drying stage, the opening of the third and fourth regulating valves increases, while the opening of the first and second regulating valves decreases. The amount of hot oil entering the oil tank decreases, and the temperature of the mixed oil in the oil tank decreases until the target temperature of the desorption and drying stage is reached. The above cycle is repeated.

[0006] The beneficial effects of this invention are as follows: This invention employs a two-stage refrigeration system consisting of a low-pressure stage compressor, a high-pressure stage compressor, a condenser, an intercooler, a throttling valve, an auxiliary throttling valve, a main throttling valve, an auxiliary solenoid valve, a main solenoid valve, an auxiliary evaporator, and a main evaporator. This system provides the drying oven with a deeper cryogenic capability, enabling rapid freezing of materials, reducing the sublimation temperature of moisture during the drying process, and improving drying efficiency. It is also widely applicable to materials requiring harsh low-temperature environments for freeze-drying, such as biological products, pharmaceutical products, and high-end foods.

[0007] This invention incorporates a condenser, a hot oil pump, a third regulating valve, a fourth regulating valve, and a heat exchanger to recover the residual heat from the condenser during the operation of the freeze dryer. This residual heat is used as a heat source for the regenerated air in the rotary dehumidification system. A regeneration heater is also included; when the heat is insufficient, the regeneration heater is activated to heat the regenerated air. This design avoids the dependence on external energy sources found in traditional heating methods, significantly improving the system's energy utilization rate, reducing energy waste, and lowering operating costs.

[0008] This invention utilizes an oil tank, regulating valves, and oil circuits, employing oil as both a cooling and heating medium. Temperature regulation of the drying chamber is achieved through the mixing of hot and cold oil. Compared to traditional methods that rely on alternating switching between cooling and heating for temperature control, this invention rapidly reaches the target temperature without waiting for equipment switching, significantly improving drying efficiency.

[0009] This invention features a rotary dehumidification system consisting of a dehumidification chamber, a dehumidification wheel, a vacuum pump, a fan, and a regeneration heater. This system continuously adsorbs and regenerates moisture through the dehumidification wheel, solving the problems of low dehumidification efficiency in traditional cold traps and the inability of the unit to operate at low evaporation temperatures. This ensures high efficiency and controllability during the freeze-drying process.

[0010] The dehumidification rotor in the dehumidification box of this invention continuously absorbs moisture from the air through adsorption material, and uses regenerated air heated by a heat exchanger to regenerate the dehumidification rotor. The cold trap is no longer needed, and after freeze-drying, there is no need to wait for the cold trap to capture moisture to melt and drain, which improves drying efficiency and reduces the drying cycle. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure 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 diagram: 1. Low-pressure stage compressor; 2. High-pressure stage compressor; 3. Condenser; 4. Intercooler; 5-1. Throttling valve; 5-2. Auxiliary throttling valve; 5-3. Main throttling 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 chamber; 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 dehumidifier box; 18. Dehumidifier rotor; 19. Vacuum pump; 20. Heat exchanger; 21. Fan. Detailed Implementation

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

[0014] The refrigeration system includes a low-pressure stage compressor 1, a high-pressure stage 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 chamber 13, a rotary dehumidifier chamber 17, a valve 16, and a vacuum pump 19.

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

[0018] The outlet of low-pressure stage compressor 1 is connected to the inlet of high-pressure stage compressor 2. The outlet of high-pressure stage compressor 2 is connected to one inlet of condenser 3. One outlet of condenser 3 is connected to one inlet of intercooler 4. One outlet of intercooler 4 is connected to both the inlet of main solenoid valve 6-2 and the inlet of auxiliary solenoid valve 6-1. The outlet of main solenoid valve 6-2 is connected to the inlet of main throttle valve 5-3. The outlet of main throttle valve 5-3 is connected to one inlet of main evaporator 8. One outlet of main evaporator 8 is connected to the inlet of low-pressure stage compressor 1. The outlet of auxiliary solenoid valve 6-1 is connected to the inlet of auxiliary throttle valve 5-2. The outlet of auxiliary throttle valve 5-2 is connected to the inlet of auxiliary evaporator 7. The outlet of auxiliary evaporator 7 is connected to the inlet of low-pressure stage compressor 1. The inlet of throttle valve 5-1 is connected to one outlet of condenser 3. The outlet of throttle valve 5-1 is connected to two inlets of intercooler 4. The two outlets of intercooler 4 are connected to the inlet of high-pressure stage compressor 2. The inlet of the cold oil pump 9 is connected to the two outlets of the main evaporator 8, and the outlet of the cold oil pump 9 is connected to one inlet of the oil tank 12. One outlet of the oil tank 12 is connected to the two inlets of the main evaporator 8. The inlet of the hot oil pump 15 is connected to the two outlets 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. The outlet of the second regulating valve 14-2 is connected to the two inlets of the oil tank 12, and the two outlets of the oil tank 12 are connected to the inlet of the first regulating valve 14-1. The outlet of the first regulating valve 14-1 is connected to the two inlets 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 one inlet of the heat exchanger 20. One 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 inlets of the condenser 3. The inlet of oil pump 11 is connected to the three outlets of oil tank 12, and the outlet of oil pump 11 is connected to the upper inlet of drying chamber 13. The upper outlet of drying chamber 13 is connected to the three inlets of oil tank 12. The inlet of valve 16 is connected to the lower right outlet of drying chamber 13, and the outlet of valve 16 is connected to the dehumidification zone inlet of rotary dehumidifier 17 via a pipeline. Rotary dehumidifier 17 contains a dehumidification rotor 18 with a 1 / 4 regeneration zone 18-1 and a 3 / 4 dehumidification zone 18-2. The dehumidification zone outlet of rotary dehumidifier 17 is connected to the inlet of vacuum pump 19, and the outlet of vacuum pump 19 directly enters the air. The two outlets of heat exchanger 20 are connected to the inlet of fan 21 via a pipeline, and the outlet of fan 21 is connected to the upper regeneration zone inlet of rotary dehumidifier 17 via a pipeline. The upper regeneration zone outlet of rotary dehumidifier 17 directly enters the air. The two inlets of heat exchanger 20 are connected to air via regeneration heater 10.

[0019] The specific operating method is as follows: The operation of the novel freeze dryer of this invention is divided into three stages: pre-freezing, sublimation drying, and desorption drying.

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

[0021] Fluid circuit during the pre-freezing stage: Refrigerant circuit during pre-freezing stage: The refrigerant vapor evaporated at the intermediate pressure output by the low-pressure stage compressor 1 mixes with the intermediate-pressure refrigerant vapor exiting from the two outlets of the intercooler 4 and enters the high-pressure stage compressor 2. After being compressed by the high-pressure stage compressor 2, the high-pressure, high-temperature refrigerant vapor output enters the condenser 3 through one inlet. It condenses and releases heat to become a high-pressure, high-temperature refrigerant liquid. It is then divided into two parts through one inlet and one outlet of the condenser 3. One part is throttled and depressurized to the intermediate pressure by the throttling valve 5-1 and enters the intercooler 4 through the two inlets to evaporate. The other part enters the coil 4-1 of the intercooler 4 through one inlet. The coil 4-1 then mixes with the intermediate-pressure refrigerant vapor outside the coil. The refrigerant evaporates due to heat exchange under pressure. The refrigerant outside the pipe mixes with the exhaust gas from the low-pressure stage compressor through the two outlets of the intercooler 4 and then enters the high-pressure stage compressor 2. The refrigerant in the coil 4-1 passes through one outlet of the intercooler 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 depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the main evaporator 8 through one inlet to evaporate and absorb heat, becoming a low-temperature, low-pressure refrigerant gas. It then flows back to the low-pressure stage compressor 1 through one outlet of the main evaporator 8, where it is compressed into refrigerant vapor at an intermediate pressure. The above cycle is repeated.

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

[0023] Oil in oil tank 12 enters the main evaporator 8 through the second inlet of the main evaporator 8 via the first outlet of oil tank 12. After absorbing heat from the refrigerant, the temperature decreases and it flows out from the second outlet of the main evaporator 8. Driven by the cold oil pump 9, the cooled oil after heat exchange enters oil tank 12 through the first inlet of oil tank 12. The cooled oil then enters the drying chamber 13 through the upper inlet of the drying chamber 13 via the third outlet of oil tank 12 driven by the oil pump 11. It exchanges heat with the environment inside the chamber, lowering the temperature of the environment inside the drying chamber 13 and achieving pre-freezing of the material. After heat exchange, the oil temperature rises and flows back from the upper outlet of the drying chamber 13 into the third inlet of oil tank 12, returning to oil tank 13, repeating the above cycle.

[0024] 2. Sublimation and drying stage The sublimation drying stage requires vacuuming at a low temperature, followed by heating. Once the temperature reaches the target temperature for sublimation drying (usually 5℃~10℃ below the eutectic point of the material), the temperature of the cold oil is adjusted by regulating the auxiliary solenoid valve 6-1. This regulates the mixing temperature of the cold and hot oil in the oil tank 12, ensuring that the temperature inside the drying chamber 2 reaches the target temperature for sublimation drying after heat exchange. At this time, the following valves are activated: throttle valve 5-1, main solenoid valve 6-2, main throttle valve 5-3, cold oil pump 9, oil pump 11, first regulating valve 14-1, second regulating valve 14-2, third regulating valve 14-3, fourth regulating valve 14-4, hot oil pump 15, valve 16, vacuum pump 19, and fan 21.

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

[0026] During operation, the vacuum pump 19 works first to evacuate the rotary dehumidifier 17 to a certain vacuum level (the vacuum level setting depends on the type of material to be dried, and ranges from 20 to 200 Pa). Solid ice frozen in the material sublimates directly into water vapor by absorbing heat under a low-pressure, low-temperature vacuum environment. The water vapor enters the dehumidification chamber 17 through the lower right outlet and pipeline of the drying chamber 13 and the dehumidification zone inlet on the lower side of the dehumidification chamber 17. It is dehumidified in the dehumidification zone 18-2 of the dehumidification chamber 17 and comes into contact with the moisture-absorbing material. The moisture in the air is adsorbed onto the surface of the dehumidifier. The dehumidified air is directly discharged into the atmosphere through the dehumidification zone outlet on the lower side of the dehumidification chamber 17 and the vacuum pump 19. Fresh air is first heated in the heat exchanger 20 (usually 60℃~120℃). When the fresh air preheating temperature is not reached, the regeneration heater 10 is turned on to heat the air. Driven by the fan 21, the fresh air enters the regeneration zone 18-1 of the dehumidifier through the regeneration zone inlet on the upper side of the dehumidification chamber 17, carrying away the moisture adsorbed on the surface of the dehumidifier. The fresh air is discharged into the atmosphere through the regeneration zone outlet on the upper side of the dehumidification chamber 17.

[0027] The refrigerant circuit during the heating stage of the sublimation drying phase: The refrigerant vapor evaporated at intermediate pressure from the low-pressure stage compressor 1 mixes with the intermediate-pressure refrigerant vapor from the two outlets of the intercooler 4 and enters the high-pressure stage compressor 2. After compression by the high-pressure stage compressor 2, the high-pressure, high-temperature refrigerant vapor enters the condenser 3 through one inlet. It condenses and releases heat to become high-pressure, high-temperature refrigerant liquid, which is then divided into two parts through one inlet and one outlet of the condenser 3. One part is throttled and depressurized to intermediate pressure by the expansion valve 5-1 and enters the intercooler 4 through the two inlets to evaporate. The other part enters the coil 4-1 of the intercooler 4 through one inlet, and then... Under external intermediate pressure, the refrigerant undergoes heat exchange to evaporate. The refrigerant outside the pipe then mixes with the exhaust gas from the low-pressure stage compressor through the two outlets of the intercooler 4 and enters the high-pressure stage compressor 2. The refrigerant inside the coil 4-1 passes through one outlet of the intercooler 4, then 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 depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the main evaporator 8 through one inlet to evaporate and absorb heat, becoming a low-temperature, low-pressure refrigerant gas. It then flows back to the low-pressure stage compressor 1 through one outlet of the main evaporator 8, where it is compressed into refrigerant vapor at intermediate pressure.

[0028] If the temperature inside the drying chamber 13 fails to reach the target temperature for the sublimation drying stage after the oil pump 11 has been working for 10 minutes, it indicates that there is too much cooling capacity. At this time, the auxiliary solenoid valve 6-1 and the auxiliary throttling valve 5-2 are opened. 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 throttling valve 5-2. Under the action of the auxiliary throttling valve 5-2, the refrigerant liquid is cooled and depressurized by the throttling effect, becoming a low-temperature and low-pressure liquid. The refrigerant enters the auxiliary evaporator 7 for evaporation. After absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas, which mixes with the gas from the main evaporator 8 and flows back to the low-pressure stage compressor 1. The low-pressure stage compressor 1 compresses it into refrigerant vapor at an intermediate pressure.

[0029] Oil in oil tank 12 enters the main evaporator 8 through the second inlet of the main evaporator 8 via one outlet of oil tank 12. After absorbing heat from the refrigerant, the oil temperature decreases and flows out from the second outlet of the main evaporator 8. Driven by the cold oil pump 9, the cooled oil after heat exchange enters oil tank 12 through one inlet of oil tank 12. Part of the oil in oil tank 12 exits through the second outlet of oil tank 12, enters the condenser 3 through the second inlet of the condenser 3 via the first regulating valve 14-1. After releasing heat from the refrigerant, the oil temperature increases and flows out from the second outlet of the condenser 3. Driven by the hot oil pump 15, the heated oil after heat exchange enters oil tank 12 through the second regulating valve 14-2 via the second inlet of oil tank 12. After the hot oil from condenser 3 mixes with the cold oil from the main evaporator 8, and the oil temperature reaches the target temperature for the sublimation drying stage, it flows from the three outlets of oil tank 12 through oil pump 11 and into the upper inlet of drying chamber 13. There, it exchanges heat with the environment inside the chamber, increasing its temperature. The oil then flows back into oil tank 13 from the upper outlet of drying chamber 13 through the three inlets. When the temperature of oil tank 12 exceeds the target temperature for the sublimation drying stage, the openings of the third regulating valve 14-3 and the fourth regulating valve 14-4 increase, while the openings of the first regulating valve 14-1 and the second regulating valve 14-2 decrease. This reduces the amount of hot oil entering oil tank 12, lowering the temperature of the mixed oil inside, until the target temperature for the sublimation drying stage is reached. This cycle repeats.

[0030] 3. Analysis and Drying Stage During the desorption drying stage, the material needs to be further heated under vacuum conditions and maintained at a certain temperature (the target temperature for the desorption drying stage is above 30℃, and can reach up to 100℃) to allow the bound water in the material to precipitate out. The refrigerant circuit and oil circuit flow are the same in the desorption drying stage and the sublimation drying stage.

[0031] Analysis of the refrigerant circuit in the heating stage of the drying phase: The refrigerant vapor evaporated at the intermediate pressure output by the low-pressure stage compressor 1 mixes with the intermediate-pressure refrigerant vapor from the two outlets of the intercooler 4, and enters the high-pressure stage compressor 2. After being compressed by the high-pressure stage compressor 2, the high-pressure, high-temperature refrigerant vapor output enters the condenser 3 through one inlet. It condenses and releases heat to become a high-pressure, high-temperature refrigerant liquid. It is divided into two parts through one inlet and one outlet of the condenser 3. One part is throttled and depressurized to the intermediate pressure by the throttling valve 5-1 and enters the intercooler 4 through the two inlets to evaporate. The other part enters the coil 4-1 of the intercooler 4 through one inlet. The refrigerant in coil 4-1 evaporates due to heat exchange with the refrigerant under intermediate pressure outside the coil. The refrigerant outside the coil then mixes with the exhaust gas from the low-pressure stage compressor through the two outlets of the intercooler 4 and enters the high-pressure stage compressor 2. The refrigerant in coil 4-1 passes through the main solenoid valve 6-2 and the main throttle valve 5-3 through one outlet of the intercooler 4. Under the action of the main throttle valve 5-3, the refrigerant liquid is cooled and depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the main evaporator 8 through one inlet to evaporate and absorb heat, becoming a low-temperature, low-pressure refrigerant gas. It then flows back to the low-pressure stage compressor 1 through one outlet of the main evaporator 8, where it is compressed into refrigerant vapor under intermediate pressure.

[0032] If the temperature inside the drying chamber 13 fails to reach the target temperature for the desorption and drying stage after the oil pump 11 has been working for 10 minutes, it indicates that there is too much cooling capacity. At this time, the auxiliary solenoid valve 6-1 and the auxiliary throttling valve 5-2 are opened. 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 throttling valve 5-2. Under the action of the auxiliary throttling valve 5-2, the refrigerant liquid is cooled and depressurized by the throttling effect, becoming a low-temperature and low-pressure liquid. The refrigerant enters the auxiliary evaporator 7 to evaporate, and after absorbing heat, it becomes a low-temperature and low-pressure refrigerant gas that mixes with the gas output from the main evaporator 8 and flows back to the low-pressure stage compressor 1. The low-pressure stage compressor 1 compresses it into refrigerant vapor at an intermediate pressure.

[0033] Oil in oil tank 12 enters the main evaporator 8 through the second inlet of the main evaporator 8 via one outlet of oil tank 12. After absorbing heat from the refrigerant, the oil temperature decreases and flows out from the second outlet of the main evaporator 8. Driven by the cold oil pump 9, the cooled oil after heat exchange enters oil tank 12 through one inlet of oil tank 12. Part of the oil in oil tank 12 exits through the second outlet of oil tank 12, enters the condenser 3 through the second inlet of the condenser 3 via the first regulating valve 14-1. After releasing heat from the refrigerant, the oil temperature increases and flows out from the second outlet of the condenser 3. Driven by the hot oil pump 15, the heated oil after heat exchange enters oil tank 12 through the second regulating valve 14-2 via the second inlet of oil tank 12. After the hot oil from condenser 3 mixes with the cold oil from main evaporator 8, and the oil temperature reaches the target temperature for the desorption and drying stage, it flows from the three outlets of oil tank 12 through oil pump 11 and into the upper inlet of drying chamber 13. There, it exchanges heat with the environment inside the chamber, increasing its temperature. The oil then flows back into oil tank 13 from the upper outlet of drying chamber 13 through the three inlets. When the temperature of oil tank 12 exceeds the target temperature for the desorption and drying stage, the openings of the third regulating valve 14-3 and the fourth regulating valve 14-4 increase, while the openings of the first regulating valve 14-1 and the second regulating valve 14-2 decrease. This reduces the amount of hot oil entering oil tank 12, lowering the temperature of the mixed oil inside, thus reaching the target temperature for the desorption and drying stage. This cycle repeats.

[0034] It should be understood that any parts not described in detail in this specification belong to the prior art. The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements to the technical solutions of the present invention made by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A novel freeze dryer utilizing residual heat recovery dehumidification rotor, characterized in that, It includes a refrigeration system, a residual heat collection system, a vacuum system, and a rotary dehumidification system; The refrigeration system includes a low-pressure stage compressor, a high-pressure stage 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 waste 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 chamber, a rotary dehumidifier chamber, valves, and a vacuum pump; The rotary dehumidification system includes a rotary dehumidification box, a dehumidification rotor, a vacuum pump, a fan, and a regeneration heater; The low-pressure stage compressor outlet is connected to the high-pressure stage compressor inlet. The high-pressure stage compressor outlet 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 connected to both 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 low-pressure stage compressor inlet. 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 auxiliary evaporator inlet. The inlet of the main evaporator is connected to the main evaporator, and the outlet of the auxiliary evaporator is connected to the inlet of the low-pressure stage compressor. The inlet of the throttle valve is connected to one outlet of the condenser, and the outlet of the throttle valve is connected to the second inlet of the intercooler. The second outlet of the intercooler is connected to the inlet of the high-pressure stage compressor. The inlet of the cold oil pump is connected to the two outlets of the main evaporator, and the outlet of the cold oil pump is connected to one inlet of the oil tank. 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 two outlets of the condenser, and the outlet of the hot oil pump is connected to the inlet of the second regulating valve. The outlet of the second regulating valve is connected to... The oil tank's two inlets are connected, and its two outlets are connected to the inlet of the first regulating valve, which in turn is connected to the two inlets of the condenser. The inlet of the third regulating valve is connected to the outlet of the hot oil pump, which is also connected to one inlet of the heat exchanger. The heat exchanger's one outlet is connected to the inlet of the fourth regulating valve, which is connected to the two inlets of the condenser. The oil pump's inlet is connected to the three outlets of the oil tank, and its outlet is connected to the upper inlet of the drying chamber. The upper outlet of the drying chamber is connected to the three inlets of the oil tank. The valve's inlet is connected to the drying... The lower right outlet of the chamber is connected, and the valve outlet is connected to the dehumidification zone inlet on the lower side of the rotary dehumidifier via a pipeline. The rotary dehumidifier contains a dehumidification rotor with a regeneration zone and a dehumidification zone. The dehumidification zone outlet on the lower side of the rotary dehumidifier is connected to the vacuum pump inlet, and the vacuum pump outlet directly enters the air. The two outlets of the heat exchanger are connected to the fan inlet via pipelines, and the fan outlet is connected to the regeneration zone inlet on the upper side of the rotary dehumidifier via pipelines. The regeneration zone outlet on the upper side of the rotary dehumidifier directly enters the air. The two inlets of the heat exchanger are connected to the air via a regeneration heater.

2. The operating method of the novel freeze dryer utilizing residual heat recovery dehumidification as described in claim 1, characterized in that, Specifically, it includes: The operation is divided into three stages: pre-freezing, sublimation drying, and desorption 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 open; the auxiliary solenoid valve, auxiliary throttle valve, first regulating valve, second regulating valve, valve, and vacuum pump are closed. 2) Sublimation drying stage The sublimation drying stage requires vacuuming at a low temperature, followed by heating. Once the temperature reaches the target temperature for the sublimation drying stage (5℃~10℃ below the eutectic point of the material), the temperature of the cold oil is adjusted by regulating the auxiliary solenoid valve switch. This regulates the mixing temperature of the cold and hot oil in the oil tank, ensuring that the temperature inside the drying chamber reaches the target temperature for the sublimation drying stage after heat exchange. 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, valves, vacuum pump, and fan are activated. The opening and closing of the auxiliary solenoid valve and the auxiliary throttle valve depend on the temperature of the drying chamber. When the temperature inside the drying chamber does not reach the target temperature for the sublimation drying stage after the oil pump has been working for 10 minutes, the auxiliary solenoid valve and the auxiliary throttle valve are opened to release the cold energy to the outside through the auxiliary evaporator. If the temperature inside the drying chamber fails to reach the target temperature for the sublimation drying stage after the oil pump has been running for 10 minutes, the auxiliary solenoid valve and auxiliary throttle valve are opened. A portion of the refrigerant coming out of the coil in the intercooler passes through the auxiliary solenoid valve and auxiliary throttle valve. Under the action of the auxiliary throttle valve, the refrigerant liquid is cooled and depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the auxiliary evaporator to evaporate, absorbs heat, and becomes a low-temperature, low-pressure refrigerant gas. It mixes with the gas from the main evaporator and flows back to the low-pressure stage compressor, where it is compressed into refrigerant vapor at an intermediate pressure. 3) Analysis and drying stage During the desorption drying stage, the material needs to be further heated under vacuum conditions, and the target temperature of the desorption drying stage should be maintained at 30℃~100℃ to allow the bound water in the material to be precipitated. If the temperature inside the drying chamber fails to reach the target temperature for the desorption and drying stage after the oil pump has been running for 10 minutes, the auxiliary solenoid valve and auxiliary throttle valve are opened. A portion of the refrigerant coming out of the coil in the intercooler passes through the auxiliary solenoid valve and auxiliary throttle valve. Under the action of the auxiliary throttle valve, the refrigerant liquid is cooled and depressurized to become a low-temperature, low-pressure liquid. The refrigerant enters the auxiliary evaporator to evaporate, absorbs heat, and becomes a low-temperature, low-pressure refrigerant gas. It mixes with the gas from the main evaporator and flows back to the low-pressure stage compressor, where it is compressed into refrigerant vapor at an intermediate pressure.

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