Novel freeze dryer utilizing residual heat recovery rotary wheel for dehumidification

Abstract

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 utility model relates to a new type of freeze dryer utilizing waste heat recovery rotary dehumidification belongs to refrigeration technical field. BACKGROUND

[0002] With the wide application of freeze drying technology in biological products, pharmaceutical products and high-end food field, higher requirements are put forward for the performance of freeze drying equipment. These materials usually have strict requirements for low temperature environment and humidity control, and the traditional freeze drying equipment has significant shortcomings in deep cooling capacity, energy utilization efficiency and temperature and humidity control. Single-stage refrigeration system is difficult to provide sufficient deep cooling capacity, resulting in low freezing efficiency of the material; the waste heat of the condenser is usually not effectively recycled and utilized, relying on the traditional heating mode, which not only causes energy waste, but also significantly increases the operation cost. In addition, the traditional temperature regulation mode is realized by switching between refrigeration and heating, which has slow response speed and large temperature fluctuation, affecting the stability of the drying process. At the same time, the evaporator or refrigerant of the traditional cold trap or water supplement device needs to capture the removed water, which requires a lower temperature, and the corresponding evaporation temperature is relatively low, reducing the efficiency of the entire refrigeration. At the same time, the water captured by the cold trap or water supplement device adheres to its surface, and after the drying is completed, it needs to wait for the water to melt or be heated to promote melting, and the defrosting process can be carried out for the next batch of drying, which prolongs the drying cycle. Therefore, the industry urgently needs an innovative freeze drying equipment that can break through the bottleneck of traditional technology to meet the stringent requirements of high-end material freeze drying. SUMMARY

[0003] The utility model discloses a new type of freeze dryer utilizing waste heat recovery rotary dehumidification.

[0004] The utility model discloses a technical scheme as follows: a new type of freeze dryer utilizing waste heat recovery rotary dehumidification, characterized in that it comprises a refrigeration system, a waste heat collection system, a vacuum pumping system and a rotary dehumidification system.

[0005] The refrigeration system comprises a low-pressure stage compressor, a high-pressure stage compressor, a condenser, an intermediate cooler, a throttle valve, an auxiliary throttle valve, a main throttle valve, an auxiliary electromagnetic valve, a main electromagnetic valve, an auxiliary evaporator and a main evaporator.

[0006] The waste heat collection system comprises 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.

[0007] The vacuum pumping system comprises an oil pump, a drying box, a rotary dehumidification box, a valve and a vacuum pump.

[0008] The rotary dehumidification system comprises a rotary dehumidification box, a dehumidification runner, a vacuum pump, a fan and a regeneration heater.

[0009] The low-pressure stage compressor outlet is connected with the high-pressure stage compressor inlet, the high-pressure stage compressor outlet is connected with one-way inlet of the condenser, one-way outlet of the condenser is connected with one-way inlet of the intermediate cooler, one-way outlet of the intermediate cooler is connected with inlet of the main electromagnetic valve and inlet of the auxiliary electromagnetic valve respectively, outlet of the main electromagnetic valve is connected with inlet of the main throttle valve, outlet of the main throttle valve is connected with one-way inlet of the main evaporator, one-way outlet of the main evaporator is connected with the low-pressure stage compressor inlet; outlet of the auxiliary electromagnetic valve is connected with inlet of the auxiliary throttle valve, outlet of the auxiliary throttle valve is connected with inlet of the auxiliary evaporator, outlet of the auxiliary evaporator is connected with the low-pressure stage compressor inlet; inlet of the throttle valve is connected with one-way outlet of the condenser, outlet of the throttle valve is connected with two-way inlet of the intermediate cooler, two-way outlet of the intermediate cooler is connected with the high-pressure stage compressor inlet; inlet of the oil cooler is connected with two-way outlet of the main evaporator, outlet of the oil cooler is connected with one-way inlet of the oil tank, one-way outlet of the oil tank is connected with two-way inlet of the main evaporator; inlet of the hot oil pump is connected with two-way outlet of the condenser, outlet of the hot oil pump is connected with inlet of the second regulating valve, outlet of the second regulating valve is connected with two-way inlet of the oil tank, two-way outlet of the oil tank is connected with inlet of the first regulating valve, outlet of the first regulating valve is connected with two-way inlet of the condenser; inlet of the third regulating valve is connected with outlet of the hot oil pump, outlet of the third regulating valve is connected with one-way inlet of the heat exchanger, one-way outlet of the heat exchanger is connected with inlet of the fourth regulating valve, outlet of the fourth regulating valve is connected with two-way inlet of the condenser; inlet of the oil pump is connected with three-way outlet of the oil tank, outlet of the oil pump is connected with upper side inlet of the drying tank, upper side outlet of the drying tank is connected with three-way inlet of the oil tank; inlet of the valve is connected with right lower side outlet of the drying tank, outlet of the valve is connected with inlet of the dehumidification area of the lower side of the rotary dehumidification tank through a pipeline, the rotary dehumidification tank is internally provided with a dehumidification rotary wheel, the dehumidification rotary wheel is provided with a regeneration area and / or a dehumidification area, outlet of the dehumidification area of the lower side of the rotary dehumidification tank is connected with inlet of the vacuum pump, outlet of the vacuum pump directly enters air; two-way outlet of the heat exchanger is connected with inlet of the fan through a pipeline, outlet of the fan is connected with inlet of the regeneration area of the upper side of the rotary dehumidification tank through a pipeline, outlet of the regeneration area of the upper side of the rotary dehumidification tank directly enters air; two-way inlet of the heat exchanger is connected with air through the regeneration heater.

[0010] The double-stage refrigeration system composed of the low-pressure stage compressor, the high-pressure stage compressor, the condenser, the intermediate cooler, the throttle valve, the auxiliary throttle valve, the main throttle valve, the auxiliary electromagnetic valve, the main electromagnetic valve, the auxiliary evaporator and the main evaporator can provide deep cooling capacity with lower temperature for the drying tank, can quickly freeze materials and reduce sublimation temperature of water in the drying process, and improves drying efficiency.

[0011] The utility model discloses set up condenser, hot oil pump, third regulating valve, fourth regulating valve, heat exchanger recycling freeze dryer operation process condenser's residual heat, use it as the heat source of rotary dehumidification system regenerative air, when the heat is insufficient, open regenerative heater and heat regenerative air. This design avoids the dependence of traditional heating mode to external energy, significantly improves the energy utilization rate of system, reduces energy waste, reduces operating cost.

[0012] The utility model discloses through setting oil tank, regulating valve and oil circuit, with oil as cold carrier and heat carrier, realize the adjustment of drying box temperature through the mixture of hot and cold oil. Compared with the traditional mode of realizing temperature adjustment by switching refrigeration and heating alternately, the target temperature can be reached quickly without waiting for equipment switching, and the drying efficiency is improved significantly.

[0013] The utility model discloses set up the rotary dehumidification system of dehumidification box, dehumidification runner, vacuum pump, fan, regenerative heater composition, can through dehumidification runner continuous adsorption and regenerative moisture, solved traditional cold trap dehumidification efficiency is low, while the problem of unit not using low evaporation temperature operation, ensure the high efficiency controllable of freeze drying process.

[0014] The dehumidification runner in the dehumidification box of the utility model absorbs the moisture in the air continuously through the adsorption material, and the regenerated air heated by the heat exchanger is used to heat the regenerative dehumidification runner, so that the cold trap is no longer needed, and after the freeze drying is completed, the drying efficiency is improved, and the drying period is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is the structural schematic diagram of the utility model.

[0016] Note: the thick solid line represents the refrigerant circulation path;

[0017] The thin solid line represents the circulation path of the oil;

[0018] In the figure: 1, low-pressure stage compressor; 2, high-pressure stage compressor; 3, condenser; 4, intermediate cooler; 5-1, throttle valve; 5-2, auxiliary throttle valve; 5-3, main throttle valve; 6-1, auxiliary electromagnetic valve; 6-2, main electromagnetic valve; 7, auxiliary evaporator; 8, main evaporator; 9, cold oil pump; 10, regenerative 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 runner; 19, vacuum pump; 20, heat exchanger; 21, fan. DETAILED DESCRIPTION

[0019] The specific embodiments of the utility model will be further explained in detail below with reference to the drawings.

[0020] As shown in Figure 1 A novel freeze dryer using waste heat recovery rotary dehumidification includes a refrigeration system, a waste heat collection system, a vacuum pumping system, and a rotary dehumidification system.

[0021] The refrigeration system includes a low-pressure stage compressor 1, a high-pressure stage compressor 2, a condenser 3, an intermediate cooler 4, a throttling valve 5-1, an auxiliary throttling valve 5-2, a main throttling valve 5-3, an auxiliary solenoid valve 6-1, a main solenoid valve 6-2, an auxiliary evaporator 7, and a main evaporator 8.

[0022] The waste heat collection system includes the main evaporator 8, a cold oil pump 9, the 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.

[0023] The vacuum pumping system includes an oil pump 11, a drying tank 13, a rotary dehumidification tank 17, a valve 16, and a vacuum pump 19.

[0024] The rotary dehumidification system includes the rotary dehumidification tank 17, a dehumidification rotor 18, the vacuum pump 19, a fan 21, and a regeneration heater 10.

[0025] The outlet of low-pressure compressor 1 is connected to the inlet of high-pressure compressor 2. The outlet of high-pressure 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 the inlet of main solenoid valve 6-2 and the inlet of auxiliary solenoid valve 6-1, respectively. 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 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 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. Two outlets of intercooler 4 are connected to the inlet of high-pressure compressor 2. The inlet of the cold oil pump 9 is connected to the second outlet of the main evaporator 8, and the outlet of the cold oil pump 9 is connected to the first inlet of the oil tank 12, and the first outlet of the oil tank 12 is connected to the second inlet of the main evaporator 8. The inlet of the hot oil pump 15 is connected to the second 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 second inlet of the oil tank 12, and the second 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 second 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 first inlet of the heat exchanger 20, and the first 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 second inlet of the condenser 3. The inlet of oil pump 11 is connected to the three-way outlet of oil tank 12. The outlet of oil pump 11 is connected to the upper inlet of drying box 13, and the upper outlet of drying box 13 is connected to the three-way inlet of oil tank 12. The inlet of valve 16 is connected to the lower right outlet of drying box 13. The outlet of valve 16 is connected via a pipeline to the dehumidification zone inlet on the lower side of rotary dehumidification box 17. Rotary dehumidification box 17 contains dehumidification wheel 18, which has a 1 / 4 regeneration zone 18-1 and a 3 / 4 dehumidification zone 18-2. The dehumidification zone outlet on the lower side of rotary dehumidification box 17 is connected to the inlet of vacuum pump 19, and the outlet of vacuum pump 19 directly enters the air. The two-way outlet of heat exchanger 20 is connected via a pipeline to the inlet of fan 21. The outlet of fan 21 is connected via a pipeline to the regeneration zone inlet on the upper side of rotary dehumidification box 17, and the regeneration zone outlet on the upper side of rotary dehumidification box 17 directly enters the air. The second inlet of the heat exchanger 20 is connected to the air through the regeneration heater 10 .

[0026] The specific operation mode is:

[0027] The working operation of the novel freeze dryer is divided into three stages of pre-freezing, sublimation drying and desorption drying.

[0028] 1. Pre-freezing stage

[0029] The main role of the pre-freezing stage is to freeze the water in the drying box material into solid ice, thereby creating conditions for the subsequent sublimation drying stage. At this time, the throttle valve 5-1, the main electromagnetic 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 opened. The auxiliary electromagnetic 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 opened to preheat the dehumidification runner, and the regenerative heater 10 is closed.

[0030] Pre-freezing stage fluid circuit:

[0031] Pre-freezing stage refrigerant circuit:

[0032] The low-pressure stage compressor 1 outputs the evaporated refrigerant vapor at intermediate pressure, which is mixed with the intermediate pressure refrigerant vapor from the two-way outlet of the intermediate cooler 4, enters the high-pressure stage compressor 2, and is compressed by the high-pressure stage compressor 2 to output high-pressure high-temperature refrigerant vapor. The high-pressure high-temperature refrigerant vapor enters the condenser 3 through the one-way inlet of the condenser 3, and is condensed and heat-released to become high-pressure high-temperature refrigerant liquid. The high-pressure high-temperature refrigerant liquid is divided into two parts through the one-way inlet and outlet of the condenser 3. One part is throttled and pressure-reduced to intermediate pressure by the throttle valve 5-1, enters the intermediate cooler 4 through the two-way inlet of the intermediate cooler 4, and evaporates in the intermediate cooler 4. The other part enters the coil 4-1 of the intermediate cooler 4 through the one-way inlet of the intermediate cooler 4, evaporates by exchanging heat with the intermediate pressure refrigerant outside the coil 4-1, and then enters the high-pressure stage compressor 2 by mixing with the low-pressure stage compressor exhaust. The refrigerant in the coil 4-1 flows back to the low-pressure stage compressor 1 through the one-way outlet of the intermediate cooler 4, the main electromagnetic 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 pressure-reduced to become low-temperature low-pressure liquid. The refrigerant enters the main evaporator 8 through the one-way inlet of the main evaporator 8, evaporates, and becomes low-temperature low-pressure refrigerant gas after absorbing heat. The low-temperature low-pressure refrigerant gas flows back to the low-pressure stage compressor 1 through the one-way outlet of the main evaporator 8, is compressed by the low-pressure stage compressor 1 to become refrigerant vapor at intermediate pressure, and repeats the above cycle.

[0033] Pre-freezing stage oil circuit: The hot oil in the condenser 3 flows out from the two-way outlet of the condenser 3, is driven by the hot oil pump 15, enters the heat exchanger 20 through the third regulating valve 14-3, exchanges heat, and then flows back to the condenser 3 through the fourth regulating valve 14-4 from the two-way inlet of the condenser 3.

[0034] The oil in the oil tank 12 enters the main evaporator 8 from the two-way inlet of the main evaporator 8 through the one-way outlet of the oil tank 12, and the temperature decreases after the heat absorption of the refrigerant. The cooled oil flows out from the two-way outlet of the main evaporator 8, and under the drive of the cold oil pump 9, the heat-exchanged cold oil enters the oil tank 12 through the one-way inlet of the oil tank 12. The cold oil from the three-way outlet of the oil tank 12 is driven by the oil pump 11 to enter the drying tank 13 through the upper inlet of the drying tank 13, exchanges heat with the environment in the tank, reduces the temperature of the environment in the drying tank 13, realizes the pre-freezing of the material, and the temperature of the heat-exchanged oil rises. The oil flows into the three-way inlet of the oil tank 12 from the upper outlet of the drying tank 13 and returns to the oil tank 13, and the above cycle is repeated.

[0035] 2. Sublimation drying stage

[0036] The sublimation drying stage needs to be vacuumized in a low-temperature environment, and then heated. After the temperature rises to the target temperature of the sublimation drying stage (usually 5-10°C 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 the hot oil in the oil tank 12, so that the temperature in the drying tank 2 reaches the target temperature of the sublimation drying stage after heat exchange. 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 adjusting valve 14-1, the second adjusting valve 14-2, the third adjusting valve 14-3, the fourth adjusting valve 14-4, the hot oil pump 15, the valve 16, the vacuum pump 19 and the fan 21 are opened.

[0037] The opening and closing of the auxiliary solenoid valve 6-1 and the auxiliary throttle valve 5-2 depend on the temperature of the drying tank 13. When the temperature in the drying tank 13 cannot reach the target temperature of the sublimation drying stage after the oil pump 11 works for 10 minutes, it means that the cold energy is too much. At this time, the auxiliary solenoid valve 6-1 and the auxiliary throttle valve 5-2 are opened, and the cold energy is released to the outside through the auxiliary evaporator 7.

[0038] When running, the vacuum pump 19 first works to draw the runner dehumidification box 17 to a certain vacuum degree (the vacuum degree set value depends on the type of the material to be dried, ranging from 20 to 200 Pa). The solid ice frozen in the material sublimates into water vapor directly by absorbing heat in the low-pressure and low-temperature vacuum environment. The water vapor enters the runner dehumidification box 17 through the lower right outlet of the drying box 13 and the pipeline, and then enters the dehumidification zone 18-2 of the runner dehumidification box 17. The water in the air is adsorbed onto the surface of the runner, and the dehumidified air is directly discharged into the atmosphere through the dehumidification zone outlet at the lower side of the runner dehumidification box 17 and the vacuum pump 19. The fresh air is first heated in the heat exchanger 20 (usually 60-120°C), and when the preheating temperature of the fresh air cannot be reached, the regenerative heater 10 is turned on to heat. Under the drive of the fan 21, the air enters the regeneration zone 18-1 of the runner through the upper side of the runner dehumidification box 17, and carries away the water adsorbed on the surface of the runner. The air is discharged into the atmosphere through the regeneration zone outlet at the upper side of the runner dehumidification box 17.

[0039] Refrigerant circuit of the sublimation drying stage and the heating stage:

[0040] The intermediate-pressure evaporated refrigerant vapor output by the low-pressure stage compressor 1 is mixed with the intermediate-pressure refrigerant vapor from the two-way outlet of the intermediate cooler 4, and then enters the high-pressure stage compressor 2. After being compressed by the high-pressure stage compressor 2, the high-pressure and high-temperature refrigerant vapor enters the condenser 3 through the one-way inlet of the condenser 3. The condenser 3 is divided into two parts by the one-way inlet and outlet of the condenser 3. One part is throttled to the intermediate pressure by the throttling valve 5-1, and then enters the intermediate cooler 4 through the two-way inlet of the intermediate cooler 4 to evaporate. The other part enters the coil 4-1 of the intermediate cooler 4 through the one-way inlet of the intermediate cooler 4. The refrigerant in the coil 4-1 evaporates by exchanging heat with the intermediate-pressure refrigerant outside the coil 4-1. The refrigerant outside the coil 4-1 enters the high-pressure stage compressor 2 after being mixed with the exhaust gas of the low-pressure stage compressor. The refrigerant in the coil 4-1 flows back to the low-pressure stage compressor 1 through the one-way outlet of the intermediate cooler 4, the main electromagnetic valve 6-2, and the main throttling valve 5-3. The refrigerant liquid is cooled and decompressed to a low-temperature and low-pressure state by the throttling action of the main throttling valve 5-3. The refrigerant enters the main evaporator 8 through the one-way inlet of the main evaporator 8, evaporates, and becomes a low-temperature and low-pressure refrigerant gas. The refrigerant gas flows back to the low-pressure stage compressor 1 through the one-way outlet of the main evaporator 8.

[0041] 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 the cooling capacity is excessive. At this time, the auxiliary electromagnetic valve 6-1 and the auxiliary throttle valve 5-2 are opened, and part of the refrigerant coming out of the coil 4-1 in the intermediate cooler 4 passes through the auxiliary electromagnetic 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 decompressed to become low-temperature and low-pressure liquid. The refrigerant enters the auxiliary evaporator 7 to evaporate and become low-temperature and low-pressure refrigerant gas after absorbing heat. The refrigerant gas is mixed with the gas coming out of the main evaporator 8 and flows back to the low-pressure stage compressor 1 to be compressed into refrigerant vapor at intermediate pressure.

[0042] The oil in the oil tank 12 enters the main evaporator 8 from the two-way inlet of the main evaporator 8 through the one-way outlet of the oil tank 12. After absorbing heat from the refrigerant, the temperature of the oil is reduced. The cooled oil flows out of the two-way outlet of the main evaporator 8. Under the drive of the cold oil pump 9, the heat-exchanged cold oil enters the oil tank 12 through the one-way inlet of the oil tank 12. Part of the oil in the oil tank 12 flows out of the two-way outlet of the oil tank 12, enters the condenser 3 through the two-way inlet of the condenser 3 via the first regulating valve 14-1, and its temperature rises after releasing heat from the refrigerant. The heat-exchanged hot oil flows out of the two-way outlet of the condenser 3. Under the drive of the hot oil pump 15, the heat-exchanged hot oil enters the oil tank 12 through the two-way inlet of the oil tank 12 via 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, the oil temperature reaches the target temperature of the sublimation drying stage. Then, the oil enters the drying box 13 through the upper inlet of the drying box 13 via the oil pump 11, exchanges heat with the environment in the drying box 13, and its temperature rises. The heat-exchanged oil 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. When the temperature of the oil tank 12 is higher than the target temperature of the sublimation drying stage, the opening degrees of the third regulating valve 14-3 and the fourth regulating valve 14-4 increase, and the opening degrees of the first regulating valve 14-1 and the second regulating valve 14-2 decrease. The amount of hot oil entering the oil tank 12 decreases, the mixed oil temperature in the oil tank 12 decreases, and the target temperature of the sublimation drying stage is reached. The above cycle is repeated.

[0043] 3. Desorption drying stage

[0044] In the desorption drying stage, the material needs to be further heated under vacuum conditions and maintained at a certain temperature (the target temperature of the desorption drying stage is above 30°C, and the maximum can reach 100°C) to cause the bound water in the material to be desorbed. The refrigerant circuit and oil circuit in the desorption drying stage are the same as those in the sublimation drying stage.

[0045] The refrigerant circuit of the heating stage of the desorption drying stage: the intermediate pressure evaporated refrigerant vapor output by the low pressure stage compressor 1 is mixed with the intermediate pressure refrigerant vapor from the two-way outlet of the intermediate cooler 4, enters the high pressure stage compressor 2, and after being compressed by the high pressure stage compressor 2, outputs high pressure and high temperature refrigerant vapor which enters the condenser 3 through the one-way inlet of the condenser 3, and is condensed and released to become high pressure and high temperature refrigerant liquid which is divided into two parts by the one-way inlet and outlet of the condenser 3, one part is throttled and decompressed to intermediate pressure by the throttle valve 5-1, enters the intermediate cooler 4 through the two-way inlet of the intermediate cooler 4, and evaporates in the intermediate cooler 4, and the other part enters the coil 4-1 of the intermediate cooler 4 through the one-way inlet of the intermediate cooler 4, evaporates by exchanging heat with the intermediate pressure refrigerant outside the coil 4-1, and the outside refrigerant enters the high pressure stage compressor 2 after being mixed with the low pressure stage compressor exhaust through the two-way outlet of the intermediate cooler 4. The refrigerant in the coil 4-1 enters the one-way outlet of the intermediate cooler 4, passes through the main electromagnetic valve 6-2 and the main throttle valve 5-3, and under the action of the main throttle valve 5-3, the refrigerant liquid is cooled and decompressed to become low temperature and low pressure liquid by throttling, and the refrigerant enters the main evaporator 8 through the one-way inlet of the main evaporator 8, evaporates, and becomes low temperature and low pressure refrigerant gas after absorbing heat, and flows back to the low pressure stage compressor 1 after passing through the one-way outlet of the main evaporator 8. The refrigerant is compressed to intermediate pressure vapor by the low pressure stage compressor 1.

[0046] When the temperature in the drying box 13 cannot reach the target temperature of the desorption drying stage after the oil pump 11 works for 10 minutes, it means that the cooling capacity is too much, at this time, the auxiliary electromagnetic valve 6-1 and the auxiliary throttle valve 5-2 are opened, part of the refrigerant from the coil 4-1 of the intermediate cooler 4 passes through the auxiliary electromagnetic valve 6-1 and the auxiliary throttle valve 5-2, and under the action of the auxiliary throttle valve 5-2, the refrigerant liquid is cooled and decompressed to become low temperature and low pressure liquid by throttling, and the refrigerant enters the auxiliary evaporator 7, evaporates, and becomes low temperature and low pressure refrigerant gas after absorbing heat, and mixes with the outlet gas of the main evaporator 8, and flows back to the low pressure stage compressor 1, and is compressed to intermediate pressure vapor by the low pressure stage compressor 1.

[0047] The oil in the oil tank 12 enters the main evaporator 8 from the two-way inlet of the main evaporator 8 through the one-way outlet of the oil tank 12, and the temperature of the oil is reduced after the heat absorption of the refrigerant, and the oil flows out from the two-way outlet of the main evaporator 8. Under the driving of the cold oil pump 9, the heat-exchanged cold oil enters the oil tank 12 through the one-way inlet of the oil tank 12; part of the oil in the oil tank 12 goes out from the two-way outlet of the oil tank 12, enters the condenser 3 through the two-way inlet of the condenser 3 through the first regulating valve 14-1, and the temperature of the oil is increased after the heat release of the refrigerant, and the heat-exchanged hot oil flows out from the two-way outlet of the condenser 3. Under the driving of the hot oil pump 15, the heat-exchanged hot oil enters the oil tank 12 through the two-way inlet of the oil tank 12 through the second regulating valve 14-2. After the hot oil from the condenser 3 and the cold oil from the main evaporator 8 are mixed, the oil temperature reaches the target temperature of the desorption drying stage, and then the oil flows into the drying tank 13 through the upper inlet of the drying tank 13 through the oil pump 11 from the three-way outlet of the oil tank 12. The oil is heated and exchanged with the environment in the tank, and the temperature of the heat-exchanged oil is increased, and the oil flows into the three-way inlet of the oil tank 12 from the upper outlet of the drying tank 13 and returns to the oil tank 13. When the temperature of the oil tank 12 is higher than the target temperature of the desorption drying stage, the opening degrees of the third regulating valve 14-3 and the fourth regulating valve 14-4 are increased, the opening degrees of the first regulating valve 14-1 and the second regulating valve 14-2 are decreased, the amount of hot oil entering the oil tank 12 is decreased, the temperature of the mixed oil in the oil tank 12 is decreased, and the target temperature of the desorption drying stage is reached. Repeat the above cycle.

[0048] It should be understood that parts not described in detail in the specification are part of the prior art. The above examples only describe the preferred embodiments of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements of the technical scheme of the present application made by ordinary engineering technicians in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A novel freeze dryer utilizing residual heat recovery and 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 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 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 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, and 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 stage 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 stage 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 second inlet of the oil tank is connected, the second outlet of the oil tank is connected to the inlet of the first regulating valve, the outlet of the first regulating valve is connected to the second 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 inlet of the heat exchanger, the one outlet of the heat exchanger is connected to the inlet of the fourth regulating valve, the outlet of the fourth regulating valve is connected to the two 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, 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 drying box The lower right outlet of the box is connected, and the outlet of the valve is connected to 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, and there are / regeneration zone and / dehumidification zone on the dehumidification wheel. The outlet of the dehumidification zone on the lower side of the rotary dehumidification box is connected to the inlet of the vacuum pump, and the outlet of the vacuum pump directly enters the air; the second outlet of the heat exchanger is connected to the inlet of the fan through a pipeline, and the outlet of the fan is connected to the inlet of the regeneration zone on the upper side of the rotary dehumidification box through a pipeline, and the outlet of the regeneration zone on the upper side of the rotary dehumidification box directly enters the air; the second inlet of the heat exchanger is connected to the air through the regeneration heater.

Images