A complete set of negative pressure defrosting and water recovery system for freeze dryer

Abstract

The present invention belongs to a complete set of negative pressure defrosting and water recovery system for freeze dryers, including a water storage tank in the negative pressure defrosting and water recovery system, characterized in that the pipe interface 1 of the negative pressure steam generator is connected to one end of the heating valve of the heating plate group in the heating system, the pipe interface 1 of the freeze drying chamber, the pipe interface 3 of the heat exchanger, the outlet of the heat medium pump and one end of the heating valve of the negative pressure generator by a four-way pipe and a three-way pipe respectively, the pipe interface 2 of the freeze drying chamber is connected to the other end of the heating valve of the heating plate group by a pipe: the pipe interface 1 of the heat exchanger is connected to one end of the steam regulating valve by a pipe, the vacuum unit is composed of a Roots vacuum pump and a rotary vane vacuum pump connected in series by a pipe, the upper end of the cold trap is connected to one end of the liquid separation head, and the other end of the liquid separation head is connected to the pipe interface 8 of the freeze drying chamber. The invention improves the efficiency of the equipment, saves water and energy for defrosting, reduces the pollution of waste water and waste gas emissions to the environment, and especially enables a large amount of condensed water generated by vacuum freeze drying to be recovered and utilized.

Description

Technical Field

[0001] The invention belongs to a water recovery system, and in particular relates to a complete set of negative pressure defrosting and water recovery systems for a freeze dryer. Background Art

[0002] With the development of society, the progress of the times and the improvement of people's living standards, the food industry is moving towards nutrition, health, function, convenience and easy preservation. In recent years, vacuum freeze drying technology (hereinafter referred to as FDP) has been widely used in the food industry, which can be said to be in the ascendant.

[0003] Freeze-dried food (hereinafter referred to as FDF) technology is to first rapidly freeze the water-containing food material to below its eutectic point temperature, so that the water in it freezes into ice, and then at a suitable temperature and vacuum degree, the ice is sublimated into gas and escapes from the material, and then the ice vapor is condensed into ice using a cold trap (ice vapor trap) to obtain the technology of dry food. After each FDF process is completed, a large amount of ice will condense on the cold trap, and the ice needs to be completely removed before the next work. At present, most freeze dryers use water to remove ice, and occasionally use boiler steam to remove ice, but it consumes a lot of water and energy, and also produces a large amount of wastewater and exhaust gas emissions, causing environmental pollution. What's more regrettable is that a large amount of condensed water is wasted in vain. Summary of the invention

[0004] The object of the present invention is to solve the above technical problems and provide a complete set of negative pressure defrosting and water recovery system for freeze dryers, which is composed of a negative pressure defrosting and water recovery system, a freeze dryer heating system, a vacuum system and a refrigeration system, completes FDP negative pressure defrosting and sublimation water recovery, and realizes single-bin or multi-bin shared freeze dryer negative pressure defrosting and water recovery system.

[0005] The technical solution adopted by the present invention to solve the problem is: a complete set of negative pressure defrosting and water recovery system for freeze dryers, including a water storage tank in a negative pressure defrosting and water recovery system 1, characterized in that the pipe interface 1 of the negative pressure steam generator is connected to the pipe interface 3 of the heat exchanger in the heating system and the pipe interface 1 of the freeze drying bin by a pipeline tee; the outlet of the heat medium pump is connected to one end of the negative pressure evaporator heating valve and one end of the heating valve of the heating plate group by a pipeline and a tee respectively; the pipe interface 2 is connected to one end of the negative pressure steam valve by a pipeline, and the other end of the negative pressure steam valve is connected to the freeze drying bin pipe interface 9; the pipe interface 3 is connected to the negative pressure steam water replenishment valve by a pipeline The other end of the negative pressure steam water replenishment valve is connected with one end of the water inlet valve of the water storage tank and the outlet of the drainage pump respectively by a pipeline and a tee; the other end of the water inlet valve of the water storage tank is connected with the pipe interface 1 of the water storage tank by a pipeline; the inlet of the drainage pump is connected with one end of the flow switch by a pipeline; the other end of the flow switch is connected with the multi-bin system, one end of the drainage valve and one end of the sewage valve by a pipeline and a tee respectively, the other end of the drainage valve is connected with the freeze-drying bin pipe interface 10, and the other end of the sewage valve discharges water; the pipe interface 2 of the water storage tank is connected with one end of the water outlet valve of the water storage tank; the other end of the water outlet valve of the water storage tank is connected with the pipe interface 1 of the water storage tank The end is connected to the purified water system; the heating system is composed of the heating plate group in the freeze-drying warehouse, the heat exchanger, the steam regulating valve, the heat medium pump and the heating valve of the heating plate group; the freeze-drying warehouse pipe interface 2 is connected to the other end of the heating valve of the heating plate group by a pipeline; the pipe interface 1 of the heat exchanger is connected to one end of the steam regulating valve by a pipeline, the pipe interface 2 is connected to the return boiler outlet by a pipeline, and the pipe interface 4 is connected to the heat medium pump inlet by a pipeline; the other end of the steam regulating valve is connected to the boiler steam; the vacuum system is composed of a vacuum unit, a vacuum valve, a vacuum breaking valve, a Roots vacuum pump and a rotary vane vacuum pump; the vacuum unit is connected to the Roots vacuum pump and the rotary vane vacuum pump by a pipe The inlet of the Roots vacuum pump is connected with one end of the vacuum valve by a pipeline; the other end of the vacuum valve is connected with the pipe interface 6 of the freeze-drying chamber; one end of the vacuum breaking valve is vented, and the other end is connected with the pipe interface 5 of the freeze-drying chamber; the refrigeration system is composed of a cold trap in the freeze-drying chamber, a liquid separation head, an electronic expansion valve, a liquid supply port of a refrigerator, and a return air port of a refrigerator; the upper end of the cold trap is connected with one end of the liquid separation head, and the other end of the liquid separation head is connected with the pipe interface 8 of the freeze-drying chamber, the pipe interface 8 is connected with one end of the electronic expansion valve, and the other end of the electronic expansion valve is connected with the liquid supply port of the refrigerator; the pipe interface 7, that is, the lower end interface of the cold trap, is connected with the return air port of the refrigerator.

[0006] The beneficial effects of the present invention are as follows: the present invention gives full play to the functions of the freeze-drying chamber, vacuum, heating and refrigeration systems of the vacuum freeze-drying equipment, improves the equipment efficiency, saves water and energy for defrosting, reduces the pollution to the environment caused by wastewater and waste gas emissions, and especially enables a large amount of sublimation water produced by vacuum freeze-drying to be recycled and utilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The following is a detailed description of the embodiments with reference to the accompanying drawings.

[0008] Figure 1 It is a schematic diagram of a complete set of negative pressure defrosting and water recovery system for a freeze dryer.

[0009] In the figure: 1-negative pressure defrosting and water recovery system; 1-1-negative pressure steam generator; 1-2-water storage tank; 1-3-drainage pump; 1-4-flow switch; 1-5-drainage valve; 1-6-drainage valve; 1-7-negative pressure evaporator water supply valve; 1-8-negative pressure evaporator heating valve; 1-9-water storage tank inlet valve; 1-10-negative pressure steam valve; 1-11-water storage tank outlet valve; 1-12-freeze drying chamber; 2-heating system; 2-1-heating plate group; 2-2-heat exchanger ; 2-3-steam regulating valve; 2-4-boiler steam; 2-5-return to boiler; 2-6 heat medium pump; 2-7-heating valve of heating plate group; 3-vacuum system; 3-1-vacuum unit; 3-2-Roots vacuum pump; 3-3-rotary vane vacuum pump; 3-4-vacuum extraction valve; 3-5-vacuum breaking valve; 4-refrigeration system; 4-1-electronic expansion valve; 4-2-refrigeration machine liquid supply port; 4-3-liquid distributor; 4-4-refrigeration machine return air port; 4-5-cold trap; 5-multi-bin system. DETAILED DESCRIPTION

[0010] Embodiment, with reference to the accompanying drawings, includes a water storage tank 1-2 in a negative pressure defrosting and water recovery system 1, characterized in that the pipe interface 1 of the negative pressure steam generator 1-1 is connected to the pipe interface 3 of the heat exchanger 2-2 in the heating system 2 and the pipe interface 1 of the freeze-drying bin 1-12 by a pipeline tee; the outlet of the heat medium pump 2-6 is connected to one end of the negative pressure evaporator heating valve 1-8 and one end of the heating plate group heating valve 2-7 by a pipeline and a tee respectively; the pipe interface 2 is connected to one end of the negative pressure steam valve 1-10 by a pipeline, and the other end of the negative pressure steam valve 1-10 is connected to the pipe interface 9 of the freeze-drying bin 1-12; the pipe interface 3 is connected to one end of the negative pressure steam water replenishment valve 1-7 by a pipeline; the pipe interface 4 is connected to the other end of the negative pressure evaporator heating valve 1-8 by a pipeline; the other end of the negative pressure steam water replenishment valve 1-7 is connected to one end of the water tank inlet valve 1-9 and the drainage pump 1-3 by a pipeline and a tee respectively. The outlet is connected; the other end of the water tank inlet valve 1-9 is connected to the pipe interface 1 of the water tank 1-2 by a pipeline; the inlet of the drainage pump 1-3 is connected to one end of the flow switch 1-4 by a pipeline; the other end of the flow switch 1-4 is connected to the multi-bin system 5, one end of the drainage valve 1-5 and one end of the sewage valve 1-6 by a pipeline and a tee, the other end of the drainage valve 1-5 is connected to the freeze-drying bin 1-12 pipe interface 10, and the other end of the sewage valve 1-6 discharges water; the pipe interface 2 of the water tank 1-2 is connected to one end of the water tank outlet valve 1-11; the other end of the water tank outlet valve 1-11 is connected to the purified water system; the heating system 2, which is composed of the heating plate group 2-1 in the freeze-drying bin 1-12, the heat exchanger 2-2, the steam regulating valve 2-3, the heat medium pump 2-6 and the heating valve 2-7 of the heating plate group; the pipe interface 2 (4) of the freeze-drying bin 1-12 is connected to the heating valve 2- 7; the pipe interface 1 of the heat exchanger 2-2 is connected to one end of the steam regulating valve 2-3 by a pipeline, the pipe interface 2 is connected to the outlet of the return boiler 2-5 by a pipeline, and the pipe interface 4 is connected to the inlet of the heat medium pump 2-6 by a pipeline; the other end of the steam regulating valve 2-3 is connected to the boiler steam 2-4.The device connected to the pipe interface 1 of the freeze-drying chamber 1-12 can also be connected to the pipe interface 3, and the device connected to the pipe interface 2 of the freeze-drying chamber 1-12 can also be connected to the pipe interface 4; the vacuum system 3 is composed of a vacuum unit 3-1, a vacuum valve 3-4, a vacuum breaking valve 3-5, a Roots vacuum pump 3-2 and a rotary vane vacuum pump 3-3; the vacuum unit 3-1 is composed of a Roots vacuum pump 3-2 and a rotary vane vacuum pump 3-3 connected in series by pipelines; the inlet of the Roots vacuum pump 3-2 is connected to one end of the vacuum valve 3-4 by a pipeline; the other end of the vacuum valve 3-4 is connected to the freeze-drying chamber 1-12 The pipe interface 6 is connected; one end of the vacuum breaking valve 3-5 is vented, and the other end is connected to the pipe interface 5 of the freeze-drying chamber 1-12; the refrigeration system 4 is composed of a cold trap 4-5 in the freeze-drying chamber 1-12, a liquid separation head 4-3, an electronic expansion valve 4-1, a refrigerator liquid supply port 4-2, and a refrigerator return air port 4-4; the upper end of the cold trap 4-5 is connected to one end of the liquid separation head 4-3, and the other end of the liquid separation head 4-3 is connected to the pipe interface 8 of the freeze-drying chamber 1-12, and the pipe interface 8 is connected to one end of the electronic expansion valve 4-1, and the other end of the electronic expansion valve 4-1 is connected to the refrigerator liquid supply port 4-2; the pipe interface 7, that is, the lower end interface of the cold trap 4-5, is connected to the refrigerator return air port 4-4.

[0011] A process method for a complete set of negative pressure defrosting and water recovery system for a freeze dryer, comprising the following steps:

[0012] a. After the FDF process is completed, the dry material is discharged from the freeze-drying bin 1-12, and the freeze-drying bin door is reset, the negative pressure defrosting and water recovery system 1 is turned on. The vacuum degree of the negative pressure defrosting is pre-set to 3000Pa on the vacuum film gauge digital display, and the PLC temperature module digital display is pre-set: the heating temperature of the negative pressure steam generator 1-1 is 90°C, and the negative pressure defrosting time is 30 ~ 60min. Under the premise, the negative pressure defrosting and water recovery system 1 automatically starts the vacuum system 3: that is, the vacuum breaking valve 3-5 is closed, the freeze-drying bin door 1-12 is locked, the vacuum unit 3-1 and the vacuum valve 3-4 are turned on, and the freeze-drying bin 1-12 system is evacuated;

[0013] b. Start the heating system 2 at the same time: that is, close the heating valve 2-7 of the heating plate group, start the heat medium pump 2-6, open the steam regulating valve 100%, open the negative pressure evaporator heating valve 1-8, and heat the negative pressure steam generator 1-1; when the freeze-drying bin 1-12 system reaches the set negative pressure defrosting vacuum degree of 3000Pa, the PLC temperature module digital display: real-time value 3000Pa, the heating temperature of the negative pressure steam generator 1-1 is 90℃, and the PLC temperature module digital display: real-time value 90℃, the negative pressure defrosting and water recovery system 1 automatically closes the vacuum unit 3-1 and the vacuum valve 3-4 of the vacuum system 3, and opens the negative pressure steam valve 1-10. At the same time, the heating of the negative pressure steam generator 1-1 and the heating system 2 enter the automatic temperature control mode, and the negative pressure defrosting and water recovery system 1 starts to count down for 30~60 minutes, and the PLC control module digital display: real-time value 30~60 minutes to reduce negative pressure defrosting;

[0014] c. When the negative pressure defrosting time is reduced to 0 min and the PLC control module digital display shows: real-time value 0 min, defrosting is completed, and the negative pressure defrosting and water recovery system 1 automatically shuts down the heating system 2: that is, the steam regulating valve opening is 0%, the heat medium pump 2-6 is shut down, and at the same time, the negative pressure evaporator heating valve 1-8 is closed and the vacuum breaking valve 3-5 is opened;

[0015] d. When the system pressure reaches the specified pressure of the drainage pump 1-3 of 60~90kPa, the negative pressure defrost and water recovery system 1 automatically starts the drainage valve 1-5, the drainage pump 1-3 and the negative pressure evaporator water supply valve 1-7 to supply water to the negative pressure steam generator 1-1; when the replenished water reaches the set liquid level, the electronic water level sensor: green light, the negative pressure defrost and water recovery system 1 automatically closes the negative pressure evaporator water supply valve 1-7, opens the water storage tank inlet valve 1-9, and discharges all the remaining sublimation water into the water storage tank 1-2; when the sublimation water drainage flow is lower than the specified value of the flow switch 1-4, the negative pressure defrost and water recovery system 1 automatically closes the drainage pump 1-3, the water storage tank inlet valve 1-9, the negative pressure steam valve 1-10, opens the sewage valve 1-6, and releases the lock of the freeze-drying chamber 1-12. At this point, the FDP negative pressure defrost and sublimation water recovery process ends.

[0016] In this embodiment, the freeze-drying bins 1-12 are single bins, and multiple bins can also be connected in parallel. When the multi-bin system 5 is connected in parallel, the drainage pipe drain valve of the multi-bin system 5 is merged into the drainage pipe of the negative pressure defrosting and water recovery system 1. The heating plate group 2-1 uses an existing patented device (ZL20 1620 1385248 .5); the negative pressure steam generator 1-1 uses an existing patented device (ZL 20 16 20676267.7); and the cold trap 4-5 uses an existing patented device (ZL 2016 2 0676268.1).

[0017] The design principle of the invention: no matter what kind of freeze-drying equipment is used, after the freeze-drying of the material is completed, a thick layer of ice will form on the cold trap 4-5 (sublimation water collector). Since the freeze-drying bin 1-12 works periodically, all the ice on the cold trap 4-5 must be removed before the next work. The current common practice is to use water combined with the water spray system equipped with the freeze-drying bin 1-12 for spray defrosting, and then drain the sublimation water and the spray water together. Since the spray heads are arranged above the cold trap 4-5, it is difficult to spray evenly. For the cold trap 4-5 bundle full of ice, the spray water can only gradually melt the ice layer on the upper surface, and the melting of the ice layer in the lower part and inside the cold trap 4-5 bundle is a slow process, the work efficiency is very low, and a large amount of spray water and sublimation water is wasted.

[0018] The present invention utilizes the necessary freeze-drying bin, vacuum system, heating system, refrigeration system of the FDF equipment itself, and is attached with a negative pressure defrosting and water recovery system 1. After optimized design, a negative pressure environment suitable for negative pressure defrosting is created, so that when the negative pressure steam generated by the negative pressure steam generator 1-1 is passed into the freeze-drying bin 1-12, the latent heat and sensible heat of the negative pressure steam dispersed around the cold trap tube 4-5 bundle are utilized to quickly melt the ice layer of the cold trap 4-5 without dead ends. Then, the condensed water is completely recovered through the water recovery device, which not only improves the defrosting efficiency, saves energy, and reduces emissions, but more importantly, does not involve any external water source and completely recovers the condensed water in a pure state.

[0019] The system control of the present invention is achieved by programming and applying PLC + configuration host computer + Internet, and by using special sensors and execution components at each control point, effectively controlling each system after optimization design, completing the process of FDP negative pressure defrosting and sublimation water recovery; it can realize single-bin and multi-bin shared negative pressure defrosting and water recovery system; it can also be remotely controlled.

Claims

1. A complete set of negative pressure defrosting and water recovery system for a freeze dryer, comprising a water storage tank (1-2) in a negative pressure defrosting and water recovery system (1), characterized in that The pipe interface 1 of the negative pressure steam generator (1-1) is connected to the pipe interface 3 of the heat exchanger (2-2) in the heating system (2) and the pipe interface 1 (3) of the freeze-drying bin (1-12) through a pipe tee; the outlet of the heat medium pump (2-6) is connected to the negative pressure evaporator heating valve (1-8) and one end of the heating plate group heating valve (2-7) through a pipe and a tee respectively; the pipe interface 2 is connected to one end of the negative pressure steam valve (1-10) through a pipe, and the other end of the negative pressure steam valve (1-10) is connected to the freeze-drying bin pipe interface 9; the pipe interface 3 is connected to one end of the negative pressure steam water replenishment valve (1-7) through a pipe; the pipe interface 4 is connected to the other end of the negative pressure evaporator heating valve (1-8) through a pipe; the negative pressure steam water replenishment valve (1-7) The other end of the water tank inlet valve (1-9) is connected to one end of the water tank inlet valve (1-9) and the outlet of the drainage pump (1-3) by a pipeline and a tee respectively; the other end of the water tank inlet valve (1-9) is connected to the pipe interface 1 of the water tank (1-2) by a pipeline; the inlet of the drainage pump (1-3) is connected to one end of the flow switch (1-4) by a pipeline; the other end of the flow switch (1-4) is connected to the multi-bin system (5), one end of the drainage valve (1-5) and one end of the sewage valve (1-6) by a pipeline and a tee respectively, and the other end of the drainage valve (1-5) is connected to the pipe interface 10 of the freeze-drying bin (1-12); the other end of the sewage valve (1-6) discharges water; the pipe interface 2 of the water tank (1-2) is connected to one end of the water tank outlet valve (1-11); the water tank The other end of the water outlet valve (1-11) of the freeze-drying chamber is connected to the purified water system; the heating system (2) is composed of a heating plate group (2-1), a heat exchanger (2-2), a steam regulating valve (2-3), a heat medium pump (2-6) and a heating valve (2-7) of the heating plate group in the freeze-drying chamber (1-12); the pipe interface 2 of the freeze-drying chamber (1-12) is connected to the other end of the heating valve (2-7) of the heating plate group by a pipeline; the pipe interface 1 of the heat exchanger (2-2) is connected to one end of the steam regulating valve (2-3) by a pipeline, the pipe interface 2 is connected to the outlet of the return boiler (2-5) by a pipeline, and the pipe interface 4 is connected to the inlet of the heat medium pump (2-6) by a pipeline; the other end of the steam regulating valve (2-3) is connected to the boiler steam (2-4); The device connected to the pipe interface 1 of the freeze-drying bin (1-12) can also be connected to the pipe interface 3, and the device connected to the pipe interface 2 of the freeze-drying bin (1-12) can also be connected to the pipe interface 4; the refrigeration system (4) is composed of a cold trap (4-5) in the freeze-drying bin (1-12), a liquid separation head (4-3), an electronic expansion valve (4-1), a refrigerator liquid supply port (4-2), and a refrigerator air return port (4-4); the upper end of the cold trap (4-5) is connected to one end of the liquid separation head (4-3), the other end of the liquid separation head (4-3) is connected to the pipe interface 8 of the freeze-drying bin (1-12), the pipe interface 8 is connected to one end of the electronic expansion valve (4-1), and the other end of the electronic expansion valve (4-1) is connected to the refrigerator liquid supply port (4-2);The pipe interface 9 of the freeze-drying chamber (1-12) is connected to the other end of the negative pressure steam valve (1-10), the pipe interface 10 is connected to the other end of the drain valve (1-5), the pipe interface 7 is the lower end interface of the cold trap 4-5, and the pipe interface 7 is connected to the return air port (4-4) of the refrigerator. ; 2. A complete set of negative pressure defrosting and water recovery system for freeze dryer according to claim 1, characterized in that The vacuum system (3) is composed of a vacuum unit (3-1), a vacuum extraction valve (3-4), a vacuum breaking valve (3-5), a Roots vacuum pump (3-2) and a rotary vane vacuum pump (3-3); the vacuum unit (3-1) is composed of a Roots vacuum pump (3-2) and a rotary vane vacuum pump (3-3) connected in series by a pipeline; the inlet of the Roots vacuum pump (3-2) is connected to one end of the vacuum extraction valve (3-4) by a pipeline; the other end of the vacuum extraction valve (3-4) is connected to a pipe interface 6 of a freeze-drying chamber (1-12); one end of the vacuum breaking valve (3-5) is vented, and the other end is connected to a pipe interface 5 of the freeze-drying chamber (1-12).

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