阅读说明：本技术 一种高效热泵真空低温蒸发冷冻干燥工艺及设备 (High-efficiency heat pump vacuum low-temperature evaporation freeze drying process and equipment ) 是由 项光武 项文远 项一帆 项亚飞 阳章 林永绍 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种高效热泵真空低温蒸发冷冻干燥工艺及设备,属于真空浓缩与冷冻干燥二合一技术领域,通过电子节流阀出来的低温低压饱和制冷剂在I级冷凝器中吸收了低温二次蒸汽热源的热量变成了低温饱和制冷剂蒸汽,然后经过涡旋压缩式热泵的压缩、增温、增焓后,再进入蒸发器放热,放热后又经II级工质冷凝器冷凝成高压的制冷剂饱和液体,通过电子节流阀节流后继续吸热蒸发,再经升华干燥器干燥成固态物料,并输送到二次干燥器中配合刮板搅拌装置再次干燥,使破碎齿在转动离心作用配合两个弧形磁铁块的相互排斥来回滑动,粉碎固态物料,增大传热面K值,同时振动球体的摆动敲击使物料不残留,出料彻底,实现冷热源双向利用,节能环保。(The invention discloses a high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment, belonging to the technical field of vacuum concentration and freeze-drying, wherein low-temperature low-pressure saturated refrigerant from an electronic throttle valve absorbs the heat of a low-temperature secondary steam heat source in a I-stage condenser to become low-temperature saturated refrigerant steam, then enters an evaporator to release heat after being compressed, heated and enthalpy-increased by a scroll compression type heat pump, is condensed into high-pressure refrigerant saturated liquid by a II-stage working medium condenser after releasing heat, continues to absorb heat and evaporate after being throttled by the electronic throttle valve, is dried into solid material by a sublimation dryer, is conveyed into a secondary dryer to be matched with a scraper stirring device to be dried again, so that crushing teeth are matched with the mutual repulsion of two arc-shaped magnet blocks to slide back and forth under the rotating centrifugal action, the solid material is crushed, the K value of a heat transfer surface is increased, meanwhile, the swinging and knocking of the vibrating ball body enables the materials not to be remained, the discharging is thorough, the bidirectional utilization of cold and heat sources is realized, and the energy conservation and the environmental protection are realized.)

1. A high-efficiency heat pump vacuum low-temperature evaporation freeze drying process and equipment are characterized in that: the method comprises the following steps:

s1, firstly, converting low-pressure refrigerant steam into high-pressure saturated refrigerant steam, conveying the high-pressure saturated refrigerant steam to the evaporator (1) to exchange heat with feed liquid to the feed liquid, improving the concentration of the feed liquid, and conveying the feed liquid to the concentrate pre-cooling tank (2) through the concentrate pump (6) to exchange heat with the low-pressure and low-temperature refrigerant liquid throttled by the electronic throttle valve (7);

s2, automatically feeding the concentrated solution in the concentrated solution pre-cooling tank (2) into the sublimation dryer (3) through negative pressure, and continuously cooling and freezing the concentrated solution by the concentrated solution in the sublimation dryer (3) and the low-pressure and low-temperature refrigerant liquid throttled by the electronic throttle valve (7);

s3, when the concentrated solution begins to separate out crystals (the material temperature is lower than the eutectic point), opening a third control valve (15) to carry out a vacuum sublimation drying process, allowing low-temperature secondary steam generated in sublimation to enter a class I condenser (4) to exchange heat with high-temperature secondary steam generated by an evaporator (1), allowing the low-temperature secondary steam to be condensed into condensed water and the high-temperature secondary steam to simultaneously enter a class II working medium condenser (5), and continuously providing heat for a low-pressure refrigerant;

s4, in the first stage of vacuum sublimation drying, after about 90% of moisture in the frozen material is removed, the material is in a solid state, and is conveyed into a secondary dryer (8) under the stirring of a sublimation dryer (3), at the moment, the solid material exchanges heat with the high-pressure refrigerant saturated liquid, the solid material absorbs the sensible heat of the high-pressure refrigerant saturated liquid, and is continuously heated and dried to remove the residual moisture;

s5, opening a fourth control valve (16), vacuumizing by a vacuum pump (11), enabling secondary steam generated by vaporization of residual moisture to enter a II-level working medium condenser (5), opening a scraper stirring device in a secondary dryer (8) for continuous stirring, closing the fourth control valve (16) when solid materials in the secondary dryer reach required concentration (the water content of dry powder is lower than 1-3%), opening a dry powder discharging bin below the secondary dryer (8), and discharging the dry powder out of the bin.

2. The high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment as claimed in claim 1, wherein the process comprises the following steps: the step of converting the low-pressure refrigerant vapor into the high-pressure saturated refrigerant vapor in S1 includes: the low-pressure refrigerant vapor is sent into a scroll compression heat pump (9), and the temperature, the pressure and the enthalpy are increased to become high-pressure saturated refrigerant vapor.

3. The high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment as claimed in claim 1, wherein the process comprises the following steps: the step of heat exchange between the feed liquid in the S1 and the low-pressure and low-temperature refrigerant liquid comprises the following steps: when the temperature of the concentrated solution in the concentrated solution pre-cooling tank (2) is reduced to be close to the freezing point, the first control valve (13) is automatically closed, the second control valve (14) is automatically opened, and the feed liquid is stopped being cooled.

4. The high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment as claimed in claim 1, wherein the process comprises the following steps: the step of feeding the concentrated solution in the S2 to a sublimation dryer (3) comprises the following steps: when the concentrated solution in the sublimation dryer (3) reaches a set liquid level, the third control valve (15) is automatically closed, vacuum pumping is carried out through the vacuum pump (11), and feeding is stopped.

5. The high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment as claimed in claim 1, wherein the process comprises the following steps: the condensing step of the high-temperature secondary steam in the S3 entering the II-grade working medium condenser (5) comprises the following steps: after high-temperature secondary steam enters the II-grade condenser (5), latent heat of the steam is absorbed by low-pressure and low-temperature refrigerants to become condensed water, and the condensed water is introduced into a condensed water tank (10) and then discharged by a condensed water pump (12).

6. The high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment as claimed in claim 5, wherein the process comprises the following steps: the vacuum pump (11) is respectively communicated with the condensed water tank (10), the II-level working medium condenser (5), the I-level condenser (4), the sublimation dryer (3), the secondary dryer (8) and the evaporator (1).

7. The high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment as claimed in claim 1, wherein the process comprises the following steps: the scraper stirring device in the S5 comprises a stirring cavity (801), the inner top end of the stirring cavity (801) is rotatably connected with a rotating rod (802), a motor (803) is installed at the upper end of the stirring cavity (801), the output end of the motor (803) is fixedly connected with the upper end of the rotating rod (802), the outer end of the rotating rod (802) is fixedly connected with a plurality of uniformly distributed stirring blades (804), one end, far away from the rotating rod (802), of each stirring blade (804) is fixedly connected with a repelling sphere (805), two scraper bodies (806) are arranged in the stirring cavity (801), one ends, far away from each scraper body (806) are both contacted with the inner side wall of the stirring cavity (801), one ends, close to each scraper body (806), of the two scraper bodies are both fixedly connected with the repelling spheres (805), the outer ends of the stirring blades (804) are slidably connected with a sliding plate (807), the outer end of the sliding plate (807) is fixedly connected with a plurality of uniformly distributed crushing teeth (808), the outer end of the sliding plate (807) and the inner side wall of the repelling sphere (805) are fixedly connected with arc-shaped magnet blocks (809), one ends of the two arc-shaped magnet blocks (809) close to each other are S poles, one end, close to the sliding plate (807), of the repelling sphere (805) is provided with a through hole, an extruding sphere (8010) is arranged in the through hole, an elastic diaphragm (8015) is fixedly connected between the outer end of the extruding sphere (8010) and the inner side wall of the through hole, an extruding film (8011) is fixedly connected between the inner walls of the repelling sphere (805), the extruding film (8011) is in contact with the extruding sphere (8010), an elastic magnetism isolating capsule (8012) is fixedly connected between the inner walls of the repelling sphere (805), and the elastic magnetism isolating capsule (8012) is located between the arc-shaped magnet blocks (809) and the extruding film (8011), Fe-Ni alloy powder is filled in the elastic magnetism isolating capsule body (8012), the Ni content is 80%, a plurality of air holes are uniformly distributed at the outer end of the elastic magnetism isolating capsule body (8012), and air permeable films (8016) are fixedly connected to the inner walls of the air holes.

8. The high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment as claimed in claim 7, wherein the process comprises the following steps: the inside of broken tooth (808) is hollow setting, the inside of broken tooth (808) is equipped with a plurality of evenly distributed's activity sacculus (8013), activity sacculus (8013) intussuseption is filled with carbon dioxide gas.

9. The high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment as claimed in claim 7, wherein the process comprises the following steps: the scraper body (806) is hollow, a plurality of vibrating balls (8017) are fixedly connected between the inner walls of the scraper body (806), a tension rope (8018) is fixedly connected to the top end of the inner wall of the vibrating ball (8017), and an elastic swinging ball (8019) is fixedly connected to the lower end of the tension rope (8018).

10. The high-efficiency heat pump vacuum low-temperature evaporation freeze-drying process and equipment as claimed in claim 7, wherein the process comprises the following steps: the outer end of the stirring blade (804) is provided with two sliding grooves in a chiseled mode, the inner side wall of the sliding plate (807) is fixedly connected with two sliding blocks, the sliding blocks are located in the sliding grooves and are in sliding connection with the sliding blocks, and an extension spring (8014) is fixedly connected between the outer end of each sliding block and the inner wall of each sliding groove.

Technical Field

The invention relates to the technical field of integration of vacuum concentration and freeze drying, in particular to a vacuum low-temperature evaporation freeze drying process and equipment for a high-efficiency heat pump.

Background

In the industries of food, fruit juice, tea polyphenol, health products, biochemical engineering, pharmacy, organic solvent extract, fermentation liquor, chemical engineering, waste liquor, wastewater, electroplating, high-salinity wastewater and the like, the processes of material evaporation, concentration, solvent recovery, freeze drying and the like are important process flows in material treatment, and play an important role in the quality of materials.

At present, single technology is progressively less treatment effeciency, the feature of environmental protection is poor, and the energy consumption is high, along with scientific and technological's rapid development, people begin to pursue the equipment of collecting multiple technological effect in an organic whole, realize material evaporation, concentration, solvent recovery, the function of freeze drying quadruple effect is integrative, but the material concentration of prior art is not comprehensive enough with the stirring in the dry treatment process, the heat is not fully utilized, easily lead to the material caking, reduce drying efficiency, and the ejection of compact is easily left, high in production cost, cause the waste of material resource.

Disclosure of Invention

1. Technical problem to be solved

The invention aims to solve the problems in the prior art, and provides a high-efficiency heat pump vacuum low-temperature evaporation freeze drying process and equipment, which can realize that low-temperature low-pressure saturated refrigerant discharged from an electronic throttle valve enters a concentrated solution pre-cooling tank, enters a II-level condenser after being released heat in a sublimation dryer to absorb latent heat of a low-temperature secondary steam heat source to become low-temperature saturated refrigerant steam, then enters an evaporator after being compressed, heated and enthalpy-increased by a scroll compression heat pump to generate primary heat, releases heat and releases secondary sensible heat through a secondary dryer after being released heat, is condensed into high-pressure saturated refrigerant liquid, continues to absorb heat and evaporate after being throttled by the electronic throttle valve, is dried into solid material through the sublimation dryer, and is conveyed into the secondary dryer to be dried again by matching with a scraper stirring device, so that broken teeth slide back and forth under the action of rotation and centrifugation and in cooperation with mutual repulsion of two arc-shaped blocks, the solid material is crushed, the K value of a heat transfer surface is increased, the material is not left due to the swinging and knocking of the vibrating ball body, the discharging is thorough, the bidirectional utilization of cold and heat sources is realized, and the energy conservation and the environmental protection are realized.

2. Technical scheme

In order to solve the above problems, the present invention adopts the following technical solutions.

A high-efficiency heat pump vacuum low-temperature evaporation freeze drying process and equipment comprise the following steps:

s1, firstly, converting low-pressure refrigerant steam into high-pressure saturated refrigerant steam, conveying the high-pressure saturated refrigerant steam to an evaporator to exchange heat with feed liquid, and conveying the high-pressure saturated refrigerant steam to a concentrated liquid pre-cooling tank through a concentrated liquid pump to exchange heat with low-pressure and low-temperature refrigerant liquid throttled by an electronic throttle valve;

s2, automatically feeding the concentrated solution in the concentrated solution precooling tank into the sublimation dryer through negative pressure, and continuously cooling and freezing the concentrated solution by the concentrated solution in the sublimation dryer and the low-pressure and low-temperature refrigerant liquid after the electronic throttle valve is throttled;

s3, when the concentrated solution begins to precipitate crystals, opening a third control valve to perform a vacuum sublimation drying process, allowing low-temperature secondary steam generated in sublimation to enter a class I condenser to exchange heat with high-temperature secondary steam generated by an evaporator, condensing the low-temperature secondary steam into condensed water, allowing the condensed water and the high-temperature secondary steam to simultaneously enter a class II working medium condenser, and continuously providing heat for the low-pressure refrigerant;

s4, in the first stage of vacuum sublimation drying, after about 90% of moisture in the frozen material is removed, the material is in a solid state, and is conveyed into a secondary dryer under the stirring of a sublimation dryer, at the moment, the solid material exchanges heat with the high-pressure refrigerant saturated liquid, the solid material absorbs the sensible heat of the high-pressure refrigerant saturated liquid, and is continuously heated and dried to remove the residual moisture;

and S5, opening a fourth control valve, vacuumizing by a vacuum pump, introducing secondary steam generated by vaporization of residual moisture into a II-grade working medium condenser, opening a scraper stirring device in a secondary dryer for continuous stirring, closing the fourth control valve when solid materials in the secondary dryer reach required concentration, opening a dry powder discharging bin below the secondary dryer, and discharging the dry powder out of the bin.

Further, the step of converting the low-pressure refrigerant vapor into the high-pressure saturated refrigerant vapor in S1 includes: the low-pressure refrigerant steam is sent into the scroll compression heat pump, the temperature, the pressure and the enthalpy are increased, and the high-pressure saturated refrigerant steam is obtained.

Further, the step of exchanging heat and cold between the feed liquid in S1 and the low-pressure and low-temperature refrigerant liquid includes: when the temperature of the concentrated liquid in the concentrated liquid precooling tank is reduced to be close to the freezing point, the first control valve is automatically closed, the second control valve is automatically opened, and the liquid is stopped to be cooled.

Further, the step of feeding the concentrated solution in S2 to a sublimation dryer includes: and when the concentrated solution in the sublimation dryer reaches a set liquid level, automatically closing the third control valve, vacuumizing through a vacuum pump, and stopping feeding.

Further, the step of condensing the high-temperature secondary steam in the S3 into the II-level working medium condenser comprises the following steps: after the high-temperature secondary steam enters the II-level condenser, the latent heat of the steam is absorbed by the low-pressure and low-temperature refrigerant and then is changed into condensed water, and the condensed water enters a condensed water tank and is discharged by a condensed water pump.

Furthermore, the vacuum pump is respectively communicated with the condensed water tank, the II-level working medium condenser, the I-level condenser, the sublimation dryer, the secondary dryer and the evaporator, so that the internal pressure of the container can be reduced, the vacuum degree can be improved, the boiling point of liquid can be reduced, and the evaporation speed of the liquid can be further improved.

Further, the scraper blade stirring device in S5 includes a stirring cavity, the inner top of the stirring cavity is rotatably connected with a rotating rod, the upper end of the stirring cavity is mounted with a motor, the output end of the motor is fixedly connected with the upper end of the rotating rod, the outer end of the rotating rod is fixedly connected with a plurality of uniformly distributed stirring blades, the end of the stirring blade far from the rotating rod is fixedly connected with a repelling sphere, two scraper plates are arranged in the stirring cavity, the far ends of the two scraper plates are both contacted with the inner side wall of the stirring cavity, the near ends of the two scraper plates are both fixedly connected with the repelling sphere, the outer end of the stirring blade is slidably connected with a sliding plate, the outer end of the sliding plate is fixedly connected with a plurality of uniformly distributed crushing teeth, the outer end of the sliding plate and the inner side wall of the repelling sphere are both fixedly connected with arc-shaped magnet blocks, and the ends of the two arc-shaped magnet blocks, which are close to each other, are S poles, a through hole is cut at the end of the repelling sphere, which is close to the sliding plate, an extruding sphere is arranged in the through hole, an elastic diaphragm is fixedly connected between the outer end of the extruding sphere and the inner side wall of the through hole, an extruding film is fixedly connected between the inner walls of the repelling sphere, the extruding film is contacted with the extruding sphere, an elastic magnet isolating sac body is fixedly connected between the inner walls of the repelling sphere, the elastic magnet isolating sac body is positioned between the arc-shaped magnet blocks and the extruding film, Fe-Ni alloy powder is filled in the elastic magnet isolating sac body, the content of Ni is 80%, a plurality of air vents which are uniformly distributed are cut at the outer end of the elastic magnet isolating sac body, and the inner walls of the air vents are fixedly connected with a breathable film, so that the rotating rod can be driven by a motor to rotate, and the stirring blades and the scraper body are driven to rotate, in the rotating process of the stirring blade, due to the centrifugal action, the sliding plate and the crushing teeth are far away from the rotating rod to slide, the arc-shaped magnet blocks are contacted with the extrusion ball body along with the sliding of the sliding plate and the crushing teeth, and the extrusion ball body moves towards the interior of the repulsion ball body to drive the extrusion film to extrude the air in the repulsion ball body, so that the air enters the elastic magnet-insulating capsule body through the air-permeable film to drive the elastic magnet-insulating capsule body to expand, and Fe-Ni alloy powder is dispersed along with the expansion of the elastic magnet-insulating capsule body to generate gaps which can not be tightly gathered together and can not isolate the magnetic influence between the two arc-shaped magnet blocks, so that the sliding plate and the crushing teeth slide towards the rotating rod direction under the action of the repulsion force of the two arc-shaped magnet blocks, the extrusion ball body and the extrusion film start to be restored to the original positions after the extrusion is lost, and the elastic magnet-insulating capsule body is restored to the original state, and the Fe-Ni alloy powder is tightly gathered together, realize magnetic isolation, and sliding plate and broken tooth are after losing the repulsive force effect of two arc magnet pieces, through rotating centrifugal influence, are close to the repulsion spheroid once more, realize making a round trip to slide, make broken tooth and solid state material contact breakage, avoid the massive formation of solid state material, can increase the heat transfer surface K value in the secondary drying ware again, and the scraper blade body scrapes remaining solid state material on the stirring cavity inside wall along with rotating, avoids the wasting of resources.

Further, the inside of broken tooth is hollow setting, the inside of broken tooth is equipped with a plurality of evenly distributed's movable sacculus, the activity sacculus intussuseption is filled with carbon dioxide gas, and carbon dioxide gas has the heat absorption effect, and at broken tooth and the broken in-process of solid material contact, the movable sacculus takes place to move and contacts the collision with broken tooth to give solid material with heat transfer, reinforcing drying effect.

Further, scrape the inside of plate body and be hollow setting, scrape a plurality of vibration spheroids of fixedly connected with between the inner wall of plate body, vibration spheroid's interior top fixedly connected with pulling force rope, the lower extreme fixedly connected with elasticity pendulum ball of pulling force rope is rotated at the scraper blade body and is scraped solid-state material in-process, receives to rotate the centrifugal action influence, and elasticity pendulum ball carries out the swing back and forth striking to vibration spheroid's inside wall under the assistance of pulling force rope, produces the vibration to give the stirring cavity with the vibration influence transmission, the cooperation is scraped scraping of plate body, makes the solid-state material who remains on its inside wall drop, avoids causing the wasting of resources, makes the ejection of compact more thorough.

Furthermore, two chutes are formed in the outer ends of the stirring blades, two sliding blocks are fixedly connected to the inner side walls of the sliding plates, the sliding blocks are located in the chutes and are connected with the chutes in a sliding mode, extension springs are fixedly connected between the outer ends of the sliding blocks and the inner walls of the chutes, and the sliding blocks are matched with the sliding blocks and the chutes to achieve elastic effects, so that the sliding plates can move back and forth conveniently.

3. Advantageous effects

Compared with the prior art, the invention has the advantages that:

the scheme includes that low-temperature low-pressure saturated refrigerant coming out of an electronic throttle valve absorbs heat of a low-temperature secondary steam heat source in an I-level condenser to become low-temperature saturated refrigerant steam, then is compressed, heated and enthalpy-increased by a scroll compression heat pump, then enters an evaporator to release heat, and is condensed into high-pressure refrigerant saturated liquid by a II-level working medium condenser after releasing heat, the high-pressure refrigerant saturated liquid is throttled by the electronic throttle valve to continue heat absorption and evaporation, and is dried into solid material by a sublimation dryer and conveyed into a secondary dryer to be dried again by matching with a scraper stirring device, so that crushing teeth are matched with mutual repulsion of two arc magnet blocks to slide back and forth under the action of rotation and centrifugation, the solid material is crushed, the K value of a heat transfer surface is increased, meanwhile, the material is not remained by swinging and knocking of a vibrating ball body, discharging is thorough, bidirectional utilization of cold and heat sources is realized, energy is saved, and environment is protected.

Drawings

FIG. 1 is a schematic flow diagram of an evaporative drying process of the present invention;

FIG. 2 is a schematic view of the overall structure of the stirring blade device of the present invention;

FIG. 3 is a schematic cross-sectional view of the repelling sphere of FIG. 2;

FIG. 4 is a schematic side sectional view of the stirring blade of FIG. 2;

FIG. 5 is a schematic top view of the chute of FIG. 4;

fig. 6 is a schematic cross-sectional view of the scraper body of fig. 2.

The reference numbers in the figures illustrate:

1. an evaporator; 2. a concentrated solution pre-cooling tank; 3. a sublimation dryer; 4. a stage I condenser; 5. a II-grade working medium condenser; 6. a concentrate pump; 7. an electronic throttle valve; 8. a secondary dryer; 801. a stirring cavity; 802. rotating the rod; 803. a motor; 804. a stirring blade; 805. repelling the spheres; 806. a scraper body; 807. a sliding plate; 808. crushing teeth; 809. an arc-shaped magnet block; 8010. extruding the ball body; 8011. extruding the film; 8012. an elastic magnetic isolation capsule body; 8013. a movable balloon; 8014. an extension spring; 8015. an elastic diaphragm; 8016. a gas permeable membrane; 8017. vibrating the ball; 8018. a tension rope; 8019. elastic pendulum ball; 9. a scroll compression heat pump; 10. a condensate tank; 11. a vacuum pump; 12. a condensate pump; 13. a first control valve; 14. a second control valve; 15. a third control valve; 16. a fourth control valve.

Detailed Description

The drawings in the embodiments of the invention will be combined; the technical scheme in the embodiment of the invention is clearly and completely described; obviously; the described embodiments are only some of the embodiments of the invention; but not all embodiments, are based on the embodiments of the invention; all other embodiments obtained by a person skilled in the art without making any inventive step; all fall within the scope of protection of the present invention.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top/bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "disposed," "sleeved/connected," "connected," and the like are to be construed broadly, e.g., "connected," which may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example (b):

referring to fig. 1, a high-efficiency heat pump vacuum low-temperature evaporation freeze drying process and apparatus includes the following steps:

s1, firstly, converting low-pressure refrigerant steam into high-pressure saturated refrigerant steam, conveying the high-pressure saturated refrigerant steam to the evaporator 1 to exchange heat with feed liquid, and conveying the high-pressure saturated refrigerant steam to the concentrated liquid pre-cooling tank 2 through the concentrated liquid pump 6 to exchange heat with low-pressure and low-temperature refrigerant liquid throttled by the electronic throttle valve 7;

s2, automatically feeding the concentrated solution in the concentrated solution precooling tank 2 into the sublimation dryer 3 through negative pressure, and continuously cooling and freezing the concentrated solution by the concentrated solution in the sublimation dryer 3 and the low-pressure and low-temperature refrigerant liquid throttled by the electronic throttle valve 7;

s3, when the concentrated solution begins to separate out crystals, opening a third control valve 15 to carry out a vacuum sublimation drying process, allowing low-temperature secondary steam generated in sublimation to enter a class I condenser 4 to exchange heat with high-temperature secondary steam generated by an evaporator 1, condensing the low-temperature secondary steam into condensed water, allowing the condensed water and the high-temperature secondary steam to simultaneously enter a class II working medium condenser 5, and continuously providing heat for a low-pressure refrigerant;

s4, in the first stage of vacuum sublimation drying, after about 90% of moisture in the frozen material is removed, the material is in a solid state, and is conveyed into a secondary dryer 8 under the stirring of a sublimation dryer 3, at the moment, the solid material exchanges heat with the high-pressure refrigerant saturated liquid, the solid material absorbs the sensible heat of the high-pressure refrigerant saturated liquid, and is continuously heated and dried to remove the residual moisture;

s5, opening a fourth control valve 16, vacuumizing by a vacuum pump 11, enabling secondary steam generated by vaporization of residual moisture to enter a II-level working medium condenser 5, opening a scraper stirring device in a secondary dryer 8 for continuous stirring, closing the fourth control valve 16 when solid materials in the secondary dryer reach required concentration, opening a dry powder discharging bin below the secondary dryer 8, and discharging dry powder out of the bin.

Referring to fig. 1, the step of converting the low-pressure refrigerant vapor into the high-pressure saturated refrigerant vapor in S1 includes: the low-pressure refrigerant steam is sent into the scroll compression type heat pump 9, the temperature, the pressure and the enthalpy are increased, the high-pressure saturated refrigerant steam is obtained, and the cold and heat exchange step of the feed liquid and the low-pressure and low-temperature refrigerant liquid in S1 comprises the following steps: when the temperature of the concentrated solution in the concentrated solution pre-cooling tank 2 is reduced to be close to the freezing point, the first control valve 13 is automatically closed, the second control valve 14 is automatically opened, the temperature reduction of the feed liquid is stopped, the evaporation drying process adopts the most advanced heat pump process technology combined with low-temperature and negative-pressure evaporation drying processes, the maintenance cost is extremely low, wherein the heat pump process can be combined with film rising type, external circulation type, forced circulation type, falling film type and film scraping type evaporation processes for the optional selection of customers, the requirements of material characteristics are met, in the process, an evaporator 1 is made of SS304-316L-2205-TA1-TA2 and other materials, parts of the evaporator 1, which are contacted with the liquid, are made of SAF-2507, SANICRO-28 or titanium alloy and other special corrosion-resistant materials and used for the treatment of sewage containing high chloride or fluoride, a refrigerant is made of R22 or R410a, the evaporation device is injected once and recycled permanently, an automatic cleaning system is arranged in the evaporation process, the evaporation device is automatically and circularly started by a PLC program, the GMP standard requirement is met, and the evaporation device has the advantages of horizontal tube falling film evaporation, high efficiency, short retention time, low possibility of scaling, mild evaporation and suitability for evaporation and concentration of thermosensitive materials.

Referring to fig. 1, the step of feeding the concentrated solution in S2 to the sublimation dryer 3 includes: when the concentrated solution in the sublimation dryer 3 reaches the set liquid level, the third control valve 15 is automatically closed, the vacuum pump 11 is used for vacuumizing, the feeding is stopped, and the condensation step that the high-temperature secondary steam enters the II-level working medium condenser 5 in the S3 comprises the following steps: after high-temperature secondary steam gets into II level condenser 5, the latent heat of steam becomes the comdenstion water by low pressure, after the low temperature refrigerant absorbs, get into condensate water pitcher 10, then discharge by condensate water pump 12, this equipment is the modularization all-in-one, compact structure, occupation of land space is little, can realize sled dress formula work, need not the periphery and provide the cooling water, steam, input power does automatic operation also, adopt siemens PLC control and touch man-machine interface, realize continuous feeding, the continuous ejection of compact, all unit parts are automated control, a key operation, and is simple and reliable, but remote control regulator, realize the thing networking, the cell-phone is visual and alarming function.

Referring to fig. 1, a vacuum pump 11 is respectively connected to a condensate tank 10, a II-stage working medium condenser 5, an I-stage condenser 4, a sublimation dryer 3, a secondary dryer 8 and an evaporator 1, so as to reduce the pressure inside the container, improve the vacuum degree, reduce the boiling point of the liquid, and further improve the evaporation speed of the liquid.

Referring to fig. 2-6, the scraper stirring device in S5 includes a stirring cavity 801, a rotating rod 802 is rotatably connected to the top end of the stirring cavity 801, a motor 803 is installed at the upper end of the stirring cavity 801, an output end of the motor 803 is fixedly connected to the upper end of the rotating rod 802, a plurality of uniformly distributed stirring blades 804 are fixedly connected to the outer end of the rotating rod 802, a repelling sphere 805 is fixedly connected to one end of the stirring blade 804 away from the rotating rod 802, two scraper bodies 806 are disposed in the stirring cavity 801, the ends of the two scraper bodies 806 away from each other are both in contact with the inner side wall of the stirring cavity 801, the ends of the two scraper bodies 806 close to each other are both fixedly connected to the repelling spheres 805, a sliding plate is slidably connected to the outer end of the stirring blade 804, a plurality of uniformly distributed crushing teeth 808 are fixedly connected to the outer end of the sliding plate 807, and arc blocks 809 are both fixedly connected to the outer end of the sliding plate 807 and the inner side wall of the repelling sphere 805, the ends of the two arc-shaped magnets 809 adjacent to each other are S-poles, a through hole is cut at one end of the repelling sphere 805 adjacent to the sliding plate 807, an extruding sphere 8010 is arranged in the through hole, an elastic diaphragm 8015 is fixedly connected between the outer end of the extruding sphere 8010 and the inner side wall of the through hole, an extruding film 8011 is fixedly connected between the inner walls of the repelling sphere 805, the extruding film 8011 is in contact with the extruding sphere 8010, an elastic magnetism isolating capsule 8012 is fixedly connected between the inner walls of the repelling sphere 805, the elastic magnetism isolating capsule 8012 is located between the arc-shaped magnets 809 and the extruding film 8011, Fe-Ni alloy powder is filled in the elastic magnetism isolating capsule 8012, the content of Ni is 80%, a plurality of air vents are uniformly distributed at the outer end of the elastic magnetism isolating capsule 8012, and the inner walls of the air vents are fixedly connected with 8016, so that the motor 803 can drive 802 to rotate, so as to drive the stirring blade 804 and the scraping plate 806 to rotate, in the rotating process of the stirring vane 804, due to the centrifugal action, the sliding plate 807 and the crushing teeth 808 are made to slide away from the rotating rod 802, the arc-shaped magnet blocks 809 are made to contact with the pressing sphere 8010 along with the sliding of the sliding plate 807 and the crushing teeth 808, and are pressed to move towards the interior of the repulsion sphere 805, the pressing film 8011 is driven to press the air in the repulsion sphere 805, the air enters the elastic magnetic capsule 8012 through the air permeable film 8016, the elastic magnetic capsule 8012 is driven to expand, the Fe-Ni alloy powder is dispersed along with the expansion of the elastic magnetic capsule 8012, gaps are generated, the two arc-shaped magnet blocks 809 cannot be closely combined, the magnetic influence between the two arc-shaped magnet blocks 809 cannot be isolated, the sliding plate 807 and the crushing teeth 808 slide towards the direction 802 under the repulsive force of the two arc-shaped magnet blocks 809, and the pressing sphere 8010 and the pressing film 8011 start to return to the original position after losing the pressing, meanwhile, the elastic magnetism isolating capsule 8012 is restored to the original state, Fe-Ni alloy powder is close together to realize magnetism isolating action, the sliding plate 807 and the crushing teeth 808 are close to the repulsion sphere 805 again through rotating centrifugal influence after the repulsion action of the two arc-shaped magnet blocks 809 is lost, so that the reciprocating sliding is realized, the crushing teeth 808 are in contact crushing with solid materials, the formation of large solid material blocks is avoided, the K value of a heat transfer surface in the secondary dryer 8 can be increased, the scraping plate body 806 scrapes off the solid materials remained on the inner side wall of the stirring cavity 801 along with the rotation, and the resource waste is avoided, wherein the model of the motor 803 is Y2/YE 2-132M-4.

Referring to fig. 4-5, the crushing teeth 808 are hollow, a plurality of movable balloons 8013 are uniformly distributed inside the crushing teeth 808, carbon dioxide gas is filled in the movable balloons 8013, the carbon dioxide gas has a heat absorption effect, during the crushing process when the crushing teeth 808 contact with the solid material, the movable balloons 8013 move to contact and collide with the crushing teeth 808, and transfer heat to the solid material, so as to enhance the drying effect, two sliding grooves are formed in the outer ends of the stirring blades 804, two sliding blocks are fixedly connected to the inner side walls of the sliding plates 807, the sliding blocks are located in the sliding grooves and slidably connected with the sliding grooves, and the extension springs 8014 are fixedly connected between the outer ends of the sliding blocks and the inner walls of the sliding grooves, and the sliding blocks and the sliding grooves are arranged to cooperate with the elastic effect of the extension springs 8014, so as to facilitate the sliding plates 807 to move back and forth.

Referring to fig. 6, the scraping plate body 806 is hollow, a plurality of vibrating balls 8017 are fixedly connected between inner walls of the scraping plate body 806, a tension rope 8018 is fixedly connected to an inner top end of the vibrating balls 8017, an elastic swinging ball 8019 is fixedly connected to a lower end of the tension rope 8018, the elastic swinging ball 8019 is influenced by a rotating centrifugal effect in a process of scraping solid materials by the rotation of the scraping plate body 806, the elastic swinging ball 8019 swings and impacts inner side walls of the vibrating balls 8017 back and forth with the aid of the tension rope 8018 to generate vibration, the vibration influence is transmitted to the stirring cavity 801, and the solid materials remained on the inner side walls fall down by the scraping of the scraping plate body 806, so that resource waste is avoided, and discharging is more thorough.

In the invention, when a related technician uses the device, firstly, the driving motor 803 drives the rotating rod 802 to rotate, so that the rotating rod 802 drives the stirring blade 804 and the scraper blade body 806 to rotate, in the rotating process of the stirring blade 804, due to centrifugal action, the sliding plate 807 and the crushing teeth 808 are enabled to slide away from the rotating rod 802, along with the sliding of the sliding plate 807 and the crushing teeth 808, the arc-shaped magnet blocks 809 are enabled to be in contact with the extrusion sphere 8010 and to be extruded to move towards the interior of the repulsion sphere 805, the extrusion film 8011 is enabled to be extruded to the air in the repulsion sphere 805, so that the air enters the elastic magnetism-insulating capsule 8012 through the air-permeable film 8016, the elastic magnetism-insulating capsule 8012 is enabled to expand, along with the expansion of the elastic magnetism-insulating capsule 8012, Fe-Ni alloy powder is dispersed to generate gaps, the gaps can not be gathered together, the magnetic influence between the two arc-shaped magnet blocks 809 can not be isolated, so that the sliding plate 807 and the crushing teeth 808 slide towards the direction of the repulsion force of the two arc-shaped magnet blocks 809 under the action of the rotating rod 809, the pressing sphere 8010 and the pressing film 8011 start to restore to the original position after losing the pressing, meanwhile, the elastic magnetism isolating capsule 8012 also restores to the original state, the Fe-Ni alloy powder is dense together to realize the magnetism isolating function, and the sliding plate 807 and the crushing teeth 808 approach to the repelling sphere 805 again through the rotating centrifugal effect after losing the repulsive force of the two arc magnet blocks 809 to realize the back and forth sliding, so that the crushing teeth 808 are contacted and crushed with the solid material to avoid the formation of large blocks of the solid material, during the contact and crushing process of the crushing teeth 808 and the solid material, the movable balloon 8013 moves to be contacted and collided with the crushing teeth 808, and the heat is transferred to the solid material, while the scraping plate body 806 scrapes the solid material remained on the inner side wall of the stirring cavity 801 along with the rotation, and is influenced by the rotating centrifugal effect during the scraping process, the elastic pendulum ball 8019 is assisted by the tensile rope 8018, the vibrating ball 8017 oscillates and impacts the inner side wall of the vibrating ball 8017 to generate vibration, and the vibration is transmitted to the stirring cavity 801, so that the solid material remained on the inner side wall falls off in cooperation with the scraping of the scraping plate 806.

The above; but are merely preferred embodiments of the invention; the scope of the invention is not limited thereto; any person skilled in the art is within the technical scope of the present disclosure; the technical scheme and the improved concept of the invention are equally replaced or changed; are intended to be covered by the scope of the present invention.