阅读说明：本技术 一种热泵蒸发浓缩系统 (Heat pump evaporation concentration system ) 是由 陈�峰 刘洪涛 于 2020-04-27 设计创作，主要内容包括：本发明公开一种热泵蒸发浓缩系统,以提高有机溶剂的回收利用率及系统的能源利用率。热泵蒸发浓缩系统,用于蒸发浓缩含有机溶剂原料液,热泵蒸发浓缩系统包括：有机溶剂水蒸汽发生系统以及含有机溶剂原料液浓缩系统,有机溶剂水蒸汽发生系统包括第一换热器,以及与第一换热器连通的生蒸汽管道和原料液输入管道；含有机溶剂原料液浓缩系统包括依次连通的蒸汽喷射器、第二换热器以及蒸发器,其中：第一换热器与蒸汽喷射器通过一次蒸汽管道连通；蒸汽喷射器与第二换热器通过蒸汽喷射管道连通；第二换热器与有机溶剂提取取管道连通,且第二换热器与蒸发器通过汽液混合管道和液体管道连通；蒸发器与蒸汽喷射器通过二次蒸汽管道连通。(The invention discloses a heat pump evaporation and concentration system, which aims to improve the recovery utilization rate of an organic solvent and the energy utilization rate of the system. The heat pump evaporation concentration system is used for evaporating and concentrating the raw material liquid containing the organic solvent, and comprises: the organic solvent steam generating system comprises a first heat exchanger, a raw steam pipeline and a raw material liquid input pipeline, wherein the raw steam pipeline and the raw material liquid input pipeline are communicated with the first heat exchanger; contain organic solvent feed solution concentrated system including steam ejector, second heat exchanger and the evaporimeter that communicates in proper order, wherein: the first heat exchanger is communicated with the steam ejector through a primary steam pipeline; the steam ejector is communicated with the second heat exchanger through a steam injection pipeline; the second heat exchanger is communicated with the organic solvent extraction pipeline, and the second heat exchanger is communicated with the evaporator through a vapor-liquid mixing pipeline and a liquid pipeline; the evaporator is communicated with the steam ejector through a secondary steam pipeline.)

1. A heat pump evaporative concentration system for evaporative concentration of an organic solvent-containing feed solution, the heat pump evaporative concentration system comprising: the organic solvent steam generating system comprises a first heat exchanger, a raw steam pipeline and a raw material liquid input pipeline, wherein the raw steam pipeline and the raw material liquid input pipeline are communicated with the first heat exchanger; the organic solvent-containing raw material liquid concentration system comprises a steam ejector, a second heat exchanger and an evaporator which are sequentially communicated, wherein:

the first heat exchanger is communicated with the steam ejector through a primary steam pipeline; the steam ejector is communicated with the second heat exchanger through a steam injection pipeline; the second heat exchanger is communicated with an organic solvent extraction pipeline, and the second heat exchanger is communicated with the evaporator through a vapor-liquid mixing pipeline and a liquid pipeline; the evaporator is communicated with the steam ejector through a secondary steam pipeline.

2. The heat pump evaporative concentration system of claim 1, wherein the organic solvent-containing feed solution concentration system further comprises a vapor-liquid separator and a pressure boosting device disposed between the first heat exchanger and the steam ejector, the first heat exchanger and the vapor-liquid separator being in communication via a vapor-liquid mixing conduit; the steam-liquid separator, the supercharging device and the steam ejector are sequentially communicated through a primary steam pipeline, and the steam-liquid separator is communicated with the second heat exchanger through a liquid pipeline.

3. The heat pump evaporative concentration system of claim 1, wherein the pressure boosting device is a throttle valve.

4. The heat pump evaporative concentration system of claim 2, wherein said vapor ejector is one, said second heat exchanger is one, and said evaporator is one;

the second heat exchanger comprises a first raw material liquid inlet and a first raw material liquid outlet, and the evaporator comprises a second raw material liquid inlet and a second raw material liquid outlet; the first raw material liquid inlet is communicated with the gas-liquid separator and the second raw material liquid outlet through liquid pipelines respectively, and the first raw material liquid outlet is communicated with the second raw material liquid inlet through a gas-liquid mixing pipeline.

5. The heat pump evaporative concentration system of claim 2, wherein the steam ejector is one, the number of the second heat exchangers is at least two, the number of the evaporators is the same as the number of the second heat exchangers, and the second heat exchangers are arranged alternately with the evaporators, wherein:

the steam ejector is communicated with a second heat exchanger at the head end through a steam ejection pipeline, and the second heat exchanger and the evaporator which are sequentially communicated form an evaporation concentration group; aiming at two adjacent evaporation concentration groups, the evaporator of the last evaporation concentration group is communicated with the second heat exchanger of the next evaporation concentration group through a secondary steam pipeline;

the end evaporator is communicated with the steam ejector through a secondary steam pipeline.

6. The heat pump evaporative concentration system of claim 5, wherein the second heat exchanger includes a first feed liquid inlet and a first feed liquid outlet, and the evaporator includes a second feed liquid inlet and a second feed liquid outlet; aiming at each evaporation concentration group, the first raw material liquid inlet is respectively communicated with the vapor-liquid separator and the second raw material liquid outlet through liquid pipelines, and the first raw material liquid outlet is communicated with the second raw material liquid inlet through a vapor-liquid mixing pipeline.

7. The heat pump evaporative concentration system of claim 2, wherein the number of the second heat exchangers is at least two, the number of the evaporators is the same as the number of the second heat exchangers, the number of the steam ejectors is the same as the number of the second heat exchangers, the second heat exchangers are arranged alternately with the evaporators, the steam ejectors are in one-to-one communication with the second heat exchangers, and wherein:

the booster device is communicated with the head-end steam ejector through a primary steam pipeline, and the evaporator is communicated with the adjacent steam ejector through a secondary steam pipeline.

8. The heat pump evaporative concentration system of claim 7, wherein the second heat exchanger includes a first feed liquid inlet and a first feed liquid outlet, and the evaporator includes a second feed liquid inlet and a second feed liquid outlet;

the steam ejector, the second heat exchanger and the evaporator which are sequentially communicated are evaporation concentration groups, for each evaporation concentration group, the first raw material liquid inlet is respectively communicated with the vapor-liquid separator and the second raw material liquid outlet through liquid pipelines, and the first raw material liquid outlet is communicated with the second raw material liquid inlet through a vapor-liquid mixing pipeline.

9. The heat pump evaporative concentration system of claim 4, 6 or 8, wherein the second feed solution outlet is in communication with a feed solution collection conduit.

10. The heat pump evaporative concentration system of claim 9, further comprising a concentration detection device disposed in the second heat exchanger, the concentration detection device being configured to detect a concentration of the feed solution at the second feed solution outlet.

11. The heat pump evaporative concentration system of claim 1, further comprising a condensate drain conduit in communication with the first heat exchanger.

12. A method for preparing a concentrated solution by using the heat pump evaporation concentration system of any one of claims 1 to 11, comprising an organic solvent steam generation process and a raw material solution concentration process, wherein the method comprises:

the raw material liquid exchanges heat with raw steam through a first heat exchanger to generate a first concentrated liquid and organic solvent water azeotrope steam;

the organic solvent water azeotrope steam enters an ejector to inject first organic solvent steam into a second heat exchanger;

the first concentrated solution enters a second heat exchanger;

the first organic solvent steam and the first concentrated solution are subjected to heat exchange in a second heat exchanger and then condensed into an organic solvent solution, and the organic solvent solution enters an organic solvent extraction pipeline;

the first concentrated solution enters an evaporator after heat exchange in a second heat exchanger to form concentrated raw material solution and second ethanol steam;

the second organic solvent steam enters the ejector and is ejected;

and the concentrated raw material liquid flows back to the second heat exchanger for repeated evaporation and concentration, and is collected when the concentration meets the requirement.

Technical Field

The invention relates to the technical field of evaporation equipment, in particular to a heat pump evaporation concentration system.

Background

The evaporation concentration is a very typical chemical unit operation in industrial production, and is widely applied to industrial production processes of chemical industry, light industry, food, pharmacy, seawater desalination, sewage treatment and the like.

The material which is often evaporated in industrial production is an aqueous solution. Saturated steam is commonly used as a heating source, and the 'secondary steam' evaporated from the solution is not beneficial to transportation due to low pressure and low quality, so that the gas using condition is basically not achieved. Therefore, the secondary steam is directly discharged to the atmosphere, condensed by a cooling system or used in some low-pressure steam equipment, so that pollution and energy waste are caused.

Currently, there are three main processes in the field of evaporative concentration: conventional Multiple Effect Evaporation (MEE), Thermal Vapor Recompression (TVR), Mechanical Vapor Recompression (MVR). The multiple-effect evaporation process needs to spend an external heat source to provide heat, the materials are heated, so that secondary organic solvent steam generated by the evaporation of the previous effect is used as a heating source of the next effect, and devices such as a cooling tower and the like are used for producing cooling water to cool the secondary organic solvent steam of the last effect evaporation. And the thermal steam recompression is additionally provided with an injection pump on the basis of the traditional process, a part of external heat sources are spent to inject part of secondary organic solvent steam generated by the materials, and the steam is used as a heat source for heating the materials after temperature rise and pressure rise.

At present, the traditional Chinese medicine is concentrated by a thermal steam recompression process, and an ejector is needed to eject the organic solvent in the traditional Chinese medicine by raw steam in the concentration process, so that the concentration and quality of the organic solvent can be reduced, and the organic solvent is not favorably recycled.

Disclosure of Invention

The embodiment of the invention aims to provide a heat pump evaporation and concentration system to improve the recovery utilization rate of an organic solvent and the energy utilization rate of the system.

The embodiment of the invention provides a heat pump evaporation and concentration system, which is used for evaporating and concentrating organic solvent-containing raw material liquid, and comprises: the organic solvent steam generating system comprises a first heat exchanger, a raw steam pipeline and a raw material liquid input pipeline, wherein the raw steam pipeline and the raw material liquid input pipeline are communicated with the first heat exchanger; the organic solvent-containing raw material liquid concentration system comprises a steam ejector, a second heat exchanger and an evaporator which are sequentially communicated, wherein:

the first heat exchanger is communicated with the steam ejector through a primary steam pipeline; the steam ejector is communicated with the second heat exchanger through a steam injection pipeline; the second heat exchanger is communicated with the organic solvent extraction pipeline, and the second heat exchanger is communicated with the evaporator through a vapor-liquid mixing pipeline and a liquid pipeline; the evaporator is communicated with the steam ejector through a secondary steam pipeline.

In any embodiment of the present technical solution, optionally, the organic solvent-containing raw material solution concentration system further includes a vapor-liquid separator and a pressure boosting device, which are disposed between the first heat exchanger and the steam ejector, and the first heat exchanger is communicated with the vapor-liquid separator through a vapor-liquid mixing pipeline; the steam-liquid separator, the supercharging device and the steam ejector are sequentially communicated through a primary steam pipeline, and the steam-liquid separator is communicated with the second heat exchanger through a liquid pipeline.

In this embodiment, optionally, the pressure boosting device is a throttle valve.

In any embodiment of the present disclosure, optionally, there is one steam ejector, one second heat exchanger, and one evaporator;

the second heat exchanger comprises a first raw material liquid inlet and a first raw material liquid outlet, and the evaporator comprises a second raw material liquid inlet and a second raw material liquid outlet; the first raw material liquid inlet is communicated with the gas-liquid separator and the second raw material liquid outlet through liquid pipelines respectively, and the first raw material liquid outlet is communicated with the second raw material liquid inlet through a gas-liquid mixing pipeline.

In this embodiment, optionally, the number of the steam ejector is one, the number of the second heat exchangers is at least two, the number of the evaporators is the same as that of the second heat exchangers, and the second heat exchangers and the evaporators are alternately arranged, wherein:

the steam ejector is communicated with a second heat exchanger at the head end through a steam ejection pipeline, and the second heat exchanger and the evaporator which are sequentially communicated form an evaporation concentration group; aiming at two adjacent evaporation concentration groups, the evaporator of the last evaporation concentration group is communicated with the second heat exchanger of the next evaporation concentration group through a secondary steam pipeline;

the end evaporator is communicated with the steam ejector through a secondary steam pipeline.

In any embodiment of the present disclosure, optionally, the second heat exchanger includes a first raw material liquid inlet and a first raw material liquid outlet, and the evaporator includes a second raw material liquid inlet and a second raw material liquid outlet; aiming at each evaporation concentration group, the first raw material liquid inlet is respectively communicated with the vapor-liquid separator and the second raw material liquid outlet through liquid pipelines, and the first raw material liquid outlet is communicated with the second raw material liquid inlet through a vapor-liquid mixing pipeline.

In this embodiment of the technical solution, optionally, the number of the second heat exchangers is at least two, the number of the evaporators is the same as that of the second heat exchangers, the number of the steam ejectors is the same as that of the second heat exchangers, the second heat exchangers and the evaporators are alternately arranged, and the steam ejectors and the second heat exchangers are in one-to-one correspondence communication, where:

the booster device is communicated with the head-end steam ejector through a primary steam pipeline, and the evaporator is communicated with the adjacent steam ejector through a secondary steam pipeline.

In any embodiment of the present disclosure, optionally, the second heat exchanger includes a first raw material liquid inlet and a first raw material liquid outlet, and the evaporator includes a second raw material liquid inlet and a second raw material liquid outlet;

the steam ejector, the second heat exchanger and the evaporator which are sequentially communicated are evaporation concentration groups, for each evaporation concentration group, the first raw material liquid inlet is respectively communicated with the vapor-liquid separator and the second raw material liquid outlet through liquid pipelines, and the first raw material liquid outlet is communicated with the second raw material liquid inlet through a vapor-liquid mixing pipeline.

In this embodiment, optionally, the second raw material liquid outlet is communicated with the raw material liquid collecting pipeline.

In any embodiment of the present technical solution, optionally, the heat pump evaporation and concentration system further includes a concentration detection device disposed in the second heat exchanger, where the concentration detection device is configured to detect a concentration of the raw material liquid at the second raw material liquid outlet.

In this embodiment, optionally, the heat pump evaporative concentration system further includes a condensed water discharge conduit communicated with the first heat exchanger.

According to the heat pump evaporation concentration system adopting the technical scheme, firstly, raw steam enters a first heat exchanger through a raw steam pipeline, raw material liquid containing an organic solvent enters the first heat exchanger through a raw material liquid input pipeline, and the raw steam and the raw material liquid containing the organic solvent exchange heat in the first heat exchanger to form organic solvent water azeotrope steam and a first concentrated solution; then, spraying organic solvent water azeotrope steam into a second heat exchanger through a steam sprayer, allowing the organic solvent-containing raw material liquid and the first concentrated solution to flow into the second heat exchanger, allowing the organic solvent water azeotrope steam in the second heat exchanger to exchange heat with the organic solvent-containing raw material liquid and the first concentrated solution, evaporating the organic solvent in the organic solvent-containing raw material liquid and the first concentrated solution to form organic solvent steam, cooling the organic solvent water azeotrope steam to form organic solvent water condensate, and allowing the organic solvent water condensate to enter an organic solvent extraction system through an organic solvent extraction pipeline; then, the organic solvent vapor carries the raw material liquid to enter an evaporator to form secondary organic solvent vapor and concentrated raw material liquid; and finally, introducing the secondary organic solvent steam into a steam ejector to be introduced into a second heat exchanger by the organic solvent water azeotrope steam, and allowing the concentrated raw material liquid to flow into the second heat exchanger to be continuously evaporated and concentrated.

In the heat pump evaporation and concentration system of the technical scheme, the organic solvent-containing raw material liquid is evaporated to form organic solvent water azeotrope steam by arranging the first heat exchanger, and the organic solvent water azeotrope steam is used for ejecting secondary organic solvent steam, so that the waste of the secondary organic solvent steam is avoided, and the energy utilization rate of the heat pump evaporation and concentration system is effectively improved; and the organic solvent water condensate formed after the organic solvent water azeotrope steam is cooled can directly enter the organic solvent extraction system through the organic solvent extraction pipeline, so that the organic solvent extraction process of the organic solvent water condensate is simplified, and the organic solvent after the organic solvent extraction has better quality and can be continuously used because the concentration of the organic solvent in the organic solvent water condensate is higher, therefore, the heat pump evaporation concentration system adopting the technical scheme can effectively improve the recovery utilization rate of the organic solvent.

Based on the same inventive concept, the technical scheme also provides a method for preparing a concentrated solution by using the heat pump evaporation concentration system, which comprises an organic solvent steam generation process and a raw material solution concentration process, wherein the method comprises the following steps:

the raw material liquid exchanges heat with raw steam through a first heat exchanger to generate a first concentrated liquid and organic solvent water azeotrope steam;

the organic solvent water azeotrope steam enters an ejector to inject first organic solvent steam into a second heat exchanger;

the first concentrated solution enters a second heat exchanger;

the first organic solvent steam and the first concentrated solution are subjected to heat exchange in a second heat exchanger and then condensed into an organic solvent solution, and the organic solvent solution enters an organic solvent extraction pipeline;

the first concentrated solution enters an evaporator after heat exchange in a second heat exchanger to form concentrated raw material solution and second organic solvent steam;

the second organic solvent steam enters the ejector and is ejected;

and the concentrated raw material liquid flows back to the second heat exchanger for repeated evaporation and concentration, and is collected when the concentration meets the requirement.

The method for preparing the concentrated solution in the technical scheme is used for evaporating and concentrating the organic solvent-containing raw material solution, so that waste of secondary organic solvent steam is avoided on the basis of meeting the concentration requirement, and the energy utilization rate of a heat pump evaporation and concentration system is effectively improved; in addition, an organic solvent solution with higher concentration and better quality can be obtained, and the recovery rate of the organic solvent is improved.

Drawings

FIG. 1 is a schematic diagram of a heat pump evaporative concentration system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a heat pump evaporative concentration system according to another embodiment of the present invention;

FIG. 3 is a schematic diagram of a heat pump evaporative concentration system according to yet another embodiment of the present invention;

FIG. 4 is a schematic diagram of a heat pump evaporative concentration system according to an embodiment of the present invention;

FIG. 5 is a flow chart of a method of preparing a concentrate according to an embodiment of the present invention.

Reference numerals:

1-ethyl acetate steam generation system;

101-a first heat exchanger;

102-a raw steam pipeline;

103-raw material liquid input pipeline;

2-ethyl acetate-containing raw material liquid concentration system;

201-a vapor-liquid separator;

202-a pressure boosting device;

203-steam ejector;

2031 — head end steam injector;

2032-end steam injector;

204-a second heat exchanger;

2041 — a head end second heat exchanger;

2042-end second heat exchanger;

2043-first feed solution inlet;

2044-first feed solution outlet;

205-an evaporator;

2051-head end evaporator;

2052-end evaporator;

2053-second raw material liquid inlet;

2054-second raw material liquid outlet;

206-evaporation concentration group;

3-a vapor-liquid mixing pipeline;

4-primary steam pipeline;

5-a liquid conduit;

6-steam injection pipeline;

7-organic solvent extraction line;

8-secondary steam pipeline;

9-a raw material liquid collecting pipeline;

10-condensed water discharge pipe.

Detailed Description

In order to improve the recovery utilization rate of ethyl acetate and the energy utilization rate of the system, the embodiment of the invention provides a heat pump evaporation and concentration system. In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail by referring to the following examples.

As shown in fig. 1 to 4, an embodiment of the present invention provides a heat pump evaporation and concentration system for evaporation and concentration of a raw material liquid containing ethyl acetate, the heat pump evaporation and concentration system including: the ethyl acetate water vapor generation system 1 comprises a first heat exchanger 101, a raw vapor pipeline 102 and a raw material liquid input pipeline 103, wherein the raw vapor pipeline 102 and the raw material liquid input pipeline 103 are communicated with the first heat exchanger 101; the ethyl acetate-containing raw material liquid concentration system 2 comprises a steam ejector 203, a second heat exchanger 204 and an evaporator 205 which are communicated in sequence, wherein:

the first heat exchanger 101 is communicated with the steam ejector 203 through a primary steam pipeline 4; the steam injector 203 is communicated with the second heat exchanger 204 through the steam injection pipeline 6; the second heat exchanger 204 is communicated with the organic solvent extraction pipeline 7, and the second heat exchanger 204 is communicated with the evaporator 205 through a vapor-liquid mixing pipeline 3 and a liquid pipeline 5; the evaporator 205 communicates with the steam ejector 203 through the secondary steam pipe 8.

By adopting the heat pump evaporation concentration system of the technical scheme, firstly, raw steam enters the first heat exchanger 101 through a raw steam pipeline 102, raw material liquid containing ethyl acetate enters the first heat exchanger 101 through a raw material liquid input pipeline 103, and thus the raw steam and the raw material liquid containing ethyl acetate exchange heat in the first heat exchanger 101 to form ethyl acetate water azeotrope steam and a first concentrated solution; then, the ethyl acetate water azeotrope steam is sprayed into a second heat exchanger 204 through a steam sprayer 203, the ethyl acetate-containing raw material liquid and the first concentrated solution flow into the second heat exchanger 204 through a liquid pipeline 5, the ethyl acetate water azeotrope steam in the second heat exchanger 204 exchanges heat with the first concentrated solution, ethyl acetate in the first concentrated solution is evaporated to form ethyl acetate steam, the ethyl acetate water azeotrope steam is cooled to form ethyl acetate water condensate, and the ethyl acetate water condensate enters an organic solvent extraction system through an organic solvent extraction pipeline 7; then, the ethyl acetate vapor carries with the raw material liquid and enters the evaporator 205 through the vapor-liquid mixing pipeline 3 to form secondary ethyl acetate vapor and concentrated raw material liquid; finally, the secondary ethyl acetate steam enters the steam ejector 203 and is introduced into the second heat exchanger 204 by the ethanol water azeotrope steam, and the concentrated raw material liquid flows into the second heat exchanger 204 through the liquid pipeline 5 to be continuously evaporated and concentrated.

In the heat pump evaporative concentration system of this technical scheme, through setting up first heat exchanger 101 so that contain ethyl acetate raw material liquid evaporation and form ethyl acetate water azeotrope steam for draw and penetrate secondary ethyl acetate steam, its waste of having avoided secondary ethyl acetate steam, thereby the effectual energy utilization who improves heat pump evaporative concentration system is rateed. And the ethyl acetate water condensate formed after the ethyl acetate water azeotrope vapor is cooled can directly enter the organic solvent extraction system through the organic solvent extraction pipeline 7, so that the organic solvent extraction process of the ethyl acetate water condensate is simplified, and the ethyl acetate water condensate has high concentration and high quality after the organic solvent is extracted, and can be continuously used, so that the heat pump evaporation concentration system adopting the technical scheme can effectively improve the recovery utilization rate of the ethyl acetate.

As shown in fig. 1, in any embodiment of the present technical solution, optionally, the ethyl acetate-containing raw material liquid concentration system further includes a vapor-liquid separator 201 and a pressure boosting device 202, which are disposed between the first heat exchanger 101 and the steam ejector 203, and the first heat exchanger 101 is communicated with the vapor-liquid separator 201 through a vapor-liquid mixing pipeline 3; the vapor-liquid separator 201, the pressure increasing device 202, and the steam ejector 203 are sequentially communicated through the primary steam pipe 4, and the vapor-liquid separator 201 and the second heat exchanger 204 are communicated through the liquid pipe 5.

In this embodiment, the raw steam and the raw material liquid containing ethyl acetate are subjected to heat exchange in a first heat exchanger 101 to form ethyl acetate water azeotrope steam and a first concentrated solution; then, the ethyl acetate water azeotrope steam is separated from the liquid raw material liquid in the gas-liquid separator 201, the separated ethyl acetate water azeotrope steam is pressurized by the pressurizing device 202 and then is sprayed into the second heat exchanger 204 through the steam sprayer 203, the ethyl acetate-containing raw material liquid and the first concentrated solution flow into the second heat exchanger 204 through the liquid pipeline 5, and the ethyl acetate water azeotrope steam in the second heat exchanger 204 exchanges heat with the first concentrated solution.

Can get into second heat exchanger 204 respectively after passing through vapour and liquid separator 201 separation with ethyl acetate water azeotrope steam and the first concentrated solution that forms in first heat exchanger 101 like this to through supercharging device 202 after to ethyl acetate water azeotrope steam pressure boost, can improve its entering efficiency, and the effect of penetrating ethyl acetate steam can be drawn in better realization.

As shown in fig. 2, in one embodiment of the present solution, there is one steam ejector 203, one second heat exchanger 204, and one evaporator 205;

the second heat exchanger 204 comprises a first feedstock inlet 2043 and a first feedstock outlet 2044, and the evaporator 205 comprises a second feedstock inlet 2053 and a second feedstock outlet 2054; the first raw material liquid inlet 2043 is respectively communicated with the vapor-liquid separator 201 and the second raw material liquid outlet 2054 through a liquid pipeline 5, and the first raw material liquid outlet 2044 is communicated with the second raw material liquid inlet 2053 through a vapor-liquid mixing pipeline 3.

In the present embodiment, the boosting device 202 is optionally a throttle valve.

In this embodiment, the second raw material liquid outlet 2054 is optionally in communication with the raw material liquid collecting conduit 9.

Further, in this embodiment, optionally, the heat pump evaporation and concentration system further includes a concentration detection device (not shown in the figure) disposed in the second heat exchanger 205, and the concentration detection device is configured to detect the concentration of the raw material liquid at the second raw material liquid outlet 2054.

Further, in this embodiment, optionally, the heat pump evaporative concentration system further includes a condensed water discharge conduit 10 communicating with the first heat exchanger 101.

In the embodiment of the present invention, the pressure increasing device 202 is a throttle valve, but may be other increasing devices that can increase the pressure of the gas. The throttle valve is the closed state at the beginning, when adopting the heat pump evaporation concentration system of this technical scheme to evaporating concentration to containing ethyl acetate raw material liquid, at first, raw steam enters into first heat exchanger 101 through raw steam pipeline 102, contains ethyl acetate raw material liquid and enters into first heat exchanger 101 through raw material liquid input pipeline 103, and raw steam and containing ethyl acetate raw material liquid carry out the heat transfer evaporation in first heat exchanger 101 like this and form ethyl acetate water azeotrope steam and first concentrate.

Then, ethyl acetate water azeotrope steam is separated from the first concentrated solution in the vapor-liquid separator 201, the throttle valve is opened after the vapor pressure of the separated ethyl acetate water azeotrope is increased, the ethyl acetate water azeotrope steam is sprayed into the second heat exchanger 204 through the vapor ejector 203, the ethyl acetate-containing raw material liquid and the separated first concentrated solution flow into the second heat exchanger 204 through the liquid pipeline 5, the ethyl acetate water azeotrope steam in the second heat exchanger 204 exchanges heat with the ethyl acetate-containing raw material liquid and the first concentrated solution, a certain vacuum state is maintained in the second heat exchanger 204, ethanol in the ethyl acetate-containing raw material liquid and the first concentrated solution is evaporated to form ethyl acetate steam, the ethyl acetate water azeotrope steam is cooled to form ethyl acetate water condensate, and the ethyl acetate water condensate enters the organic solvent extraction system through the organic solvent extraction pipeline 7.

The ethyl acetate vapor then carries the feed solution through vapor-liquid mixing line 3 into evaporator 205, forming a secondary ethyl acetate vapor and a concentrated feed solution.

Finally, the secondary ethyl acetate vapor enters the vapor ejector 203 and is introduced into the second heat exchanger 204 by the ethyl acetate water azeotrope vapor, and the concentrated raw material liquid flows into the second heat exchanger 204 through the liquid pipeline 5 to be continuously evaporated and concentrated.

In the later stage of evaporation and concentration, the ethyl acetate in the raw material liquid is evaporated, the temperature of the first heat exchanger 101 rises under continuous heating, the water in the raw material liquid is evaporated and cooled to form condensed water, and the condensed water flows into the waste liquid collecting system through a condensed water discharge pipeline 10 communicated with the first heat exchanger 101. And the concentrated raw material liquid in the evaporator 205 flows back to the second heat exchanger 204 to be subjected to repeated evaporation concentration, and when the concentration detection device provided in the second heat exchanger 204 detects that the raw material liquid concentration at the second raw material liquid outlet 2054 of the evaporator 205 reaches a certain value, the concentrated raw material liquid can be discharged and collected through the raw material liquid collection pipe 9 communicated with the second raw material liquid outlet 2054, and at this time, the evaporation concentration process is completed.

By adopting the heat pump evaporation and concentration system of the embodiment of the technical scheme, the energy utilization rate of the heat pump evaporation and concentration system can be effectively improved. And moreover, the extraction process of the organic solvent of the ethyl acetate water condensate can be simplified, and the ethyl acetate in the ethyl acetate water condensate has high concentration, so that the quality of the ethyl acetate after the organic solvent is extracted is high, and the ethyl acetate can be continuously used, and therefore, the heat pump evaporation concentration system adopting the technical scheme can effectively improve the recovery utilization rate of the ethyl acetate.

As shown in fig. 3, in another specific embodiment of the present invention, there is one steam ejector 203, there are at least two second heat exchangers 204, the number of evaporators 205 is the same as that of the second heat exchangers 204, and the second heat exchangers 204 and the evaporators 205 are alternately arranged, wherein:

the steam ejector 203 is communicated with the head-end second heat exchanger 2041 through the steam ejection pipeline 6, and the second heat exchanger 204 and the evaporator 205 which are sequentially communicated form an evaporation concentration group 206; for two adjacent evaporation concentration groups 206, the evaporator 205 of the previous evaporation concentration group is communicated with the second heat exchanger 205 of the next evaporation concentration group through a secondary steam pipeline 8;

the end evaporator 2052 communicates with the steam injector 203 via a secondary steam line 8.

In this embodiment, optionally, the second heat exchanger 204 includes a first raw material liquid inlet 2043 and a first raw material liquid outlet 2044, and the evaporator 205 includes a second raw material liquid inlet 2053 and a second raw material liquid outlet 2054; for each evaporation concentration group 206, the first raw material liquid inlet 2043 is respectively communicated with the vapor-liquid separator 201 and the second raw material liquid outlet 2054 through a liquid pipeline 5, and the first raw material liquid outlet 2044 is communicated with the second raw material liquid inlet 2053 through a vapor-liquid mixing pipeline 3.

In the present embodiment, the boosting device 202 is optionally a throttle valve.

In this embodiment, the second raw material liquid outlet 2054 is optionally in communication with the raw material liquid collecting conduit 9.

Further, in this embodiment, optionally, the heat pump evaporation and concentration system further includes a concentration detection device disposed in the second heat exchanger 204, and the concentration detection device is configured to detect the concentration of the raw material liquid at the second raw material liquid outlet 2054.

Further, in this embodiment, optionally, the heat pump evaporative concentration system further includes a condensed water discharge conduit 10 communicating with the first heat exchanger 101.

The present embodiment will be described in detail by taking an example in which one steam ejector 203 is provided, two second heat exchangers 204 are provided, and two evaporators 205 are provided, and the embodiment is similar to that in the case where a plurality of second heat exchangers 204 and evaporators 205 are provided.

In the embodiment of the present invention, the pressure increasing device 202 is a throttle valve, but may be other increasing devices that can increase the pressure of the gas. As shown in fig. 2, the throttle valve is initially closed, and when the heat pump evaporation concentration system according to the present embodiment is used to perform evaporation concentration on a raw material liquid containing ethyl acetate, raw steam firstly enters the first heat exchanger 101 through the raw steam pipeline 102, and the raw material liquid containing ethyl acetate enters the first heat exchanger 101 through the raw material liquid input pipeline 103, so that the raw steam and the raw material liquid containing ethyl acetate undergo heat exchange evaporation in the first heat exchanger 101 to form an ethyl acetate water azeotrope steam and a first concentrated solution.

Then, the ethyl acetate water azeotrope steam is separated from the first concentrated solution in the vapor-liquid separator 201, the throttle valve is opened after the vapor pressure of the separated ethyl acetate water azeotrope is increased, the ethyl acetate water azeotrope steam is injected into the first-end second heat exchanger 2041 through the vapor injector 203, the ethyl acetate-containing raw material liquid and the separated first concentrated solution flow into the first-end second heat exchanger 2041 and the tail-end second heat exchanger 2042 through the liquid pipeline 5, the ethyl acetate water azeotrope steam in the first-end second heat exchanger 2041 exchanges heat with the ethyl acetate-containing raw material liquid and the first concentrated solution, a certain vacuum state is maintained in the first-end second heat exchanger 2041, the ethyl acetate-containing raw material liquid and the ethyl acetate in the first concentrated solution are evaporated to form ethyl acetate steam, the ethyl acetate water azeotrope steam is cooled to form an ethyl acetate water condensate, and the ethyl acetate water condensate enters the organic solvent extraction system through the organic solvent extraction pipeline 7.

Then, the ethyl acetate vapor carries with the raw material liquid and enters the head-end evaporator 2051 through the vapor-liquid mixing pipeline 3 to form secondary ethyl acetate vapor and concentrated raw material liquid, the secondary ethyl acetate vapor enters the tail-end second heat exchanger 2042, a higher vacuum state is maintained in the tail-end second heat exchanger 2042, the secondary ethyl acetate vapor exchanges heat with the ethyl acetate-containing raw material liquid in the tail-end second heat exchanger 2042 to evaporate to form ethyl acetate vapor, and the ethyl acetate vapor carries with the raw material liquid and enters the tail-end evaporator 2052 through the vapor-liquid mixing pipeline 3 to form the secondary ethyl acetate vapor and the concentrated raw material liquid again.

Finally, the secondary ethyl acetate vapor formed in the final evaporator 2052 enters the vapor ejector 203 and is introduced into the first-end second heat exchanger 2041 by the ethyl acetate water azeotrope vapor, and the concentrated raw material liquid flows into the final second heat exchanger 2042 through the liquid pipe 5 to be continuously evaporated and concentrated.

In the later stage of evaporation and concentration, the ethyl acetate in the raw material liquid is evaporated, the temperature of the first heat exchanger 101 rises under continuous heating, the water in the raw material liquid is evaporated and cooled to form condensed water, and the condensed water flows into the waste liquid collecting system through a condensed water discharge pipeline 10 communicated with the first heat exchanger 101. The concentrated raw material liquid in the first-end evaporator 2051 is returned to the first-end second heat exchanger 2041 through the liquid pipe 5, and the concentrated raw material liquid in the last evaporator 2052 is returned to the last second heat exchanger through the liquid pipe 5, so that repeated evaporation and concentration are performed. When the concentration detection device disposed in the second heat exchanger 204 detects that the concentration of the concentrated raw material solution at the second raw material solution outlet 2054 of the corresponding evaporator 205 reaches a certain value, the concentrated raw material solution can be made to flow out and be collected through the raw material solution collection pipeline 9 communicated with the second raw material solution outlet 2054, and at this time, the evaporation and concentration process is completed.

By adopting the heat pump evaporation and concentration system of the embodiment of the technical scheme, as the heat pump evaporation and concentration system is provided with the plurality of second heat exchangers 204 and the plurality of evaporators 205, the secondary ethyl acetate steam can be more fully utilized, and the energy utilization rate of the heat pump evaporation and concentration system is further improved. And moreover, the extraction process of the organic solvent of the ethyl acetate water condensate can be simplified, and the ethyl acetate in the ethyl acetate water condensate has high concentration, so that the quality of the ethyl acetate after the organic solvent is extracted is high, and the ethyl acetate can be continuously used, and therefore, the heat pump evaporation concentration system adopting the technical scheme can effectively improve the recovery utilization rate of the ethyl acetate.

As shown in fig. 4, in another specific embodiment of the present technical solution, optionally, there are at least two second heat exchangers 204, the number of evaporators 205 is the same as that of the second heat exchangers 204, the number of steam injectors 203 is the same as that of the second heat exchangers 204, the second heat exchangers 204 and the evaporators 205 are alternately arranged, the steam injectors 203 are in one-to-one correspondence with the second heat exchangers 204, where:

the booster 202 communicates with the head end steam injector 2031 via a primary steam line 4, and the evaporator 205 communicates with the adjacent steam injector 203 via a secondary steam line 8.

In this embodiment, optionally, the second heat exchanger 204 includes a first raw material liquid inlet 2043 and a first raw material liquid outlet 2044, and the evaporator 205 includes a second raw material liquid inlet 2053 and a second raw material liquid outlet 2054;

the steam ejector 203, the second heat exchanger 204, and the evaporator 205, which are sequentially connected, are one evaporation concentration group 206, and for each evaporation concentration group 206, the first raw material liquid inlet 2043 is respectively connected to the vapor-liquid separator 201 and the second raw material liquid outlet 2054 via the liquid pipe 5, and the first raw material liquid outlet 2044 is connected to the second raw material liquid inlet 2053 via the vapor-liquid mixing pipe 3.

In the present embodiment, the boosting device 202 is optionally a throttle valve.

In this embodiment, the second raw material liquid outlet 2054 is optionally in communication with the raw material liquid collecting conduit 9.

Further, in this embodiment, optionally, the heat pump evaporation and concentration system further includes a concentration detection device disposed in the second heat exchanger 204, and the concentration detection device is configured to detect the concentration of the raw material liquid at the second raw material liquid outlet 2054.

Further, in this embodiment, optionally, the heat pump evaporative concentration system further includes a condensed water discharge conduit 10 communicating with the first heat exchanger 201.

The present embodiment will be described in detail by taking an example in which two steam ejectors 203 are provided, two second heat exchangers 204 are provided, and two evaporators 205 are provided, and the embodiment is similar to the case in which a plurality of second heat exchangers 204, evaporators 205, and steam ejectors 203 are provided.

In the embodiment of the present invention, the pressure increasing device 202 is a throttle valve, but may be other increasing devices that can increase the pressure of the gas. As shown in fig. 4, the throttle valve is initially closed, and when the heat pump evaporation concentration system according to the present embodiment is used to perform evaporation concentration on a raw material liquid containing ethyl acetate, raw steam firstly enters the first heat exchanger 101 through the raw steam pipeline 102, and the raw material liquid containing ethyl acetate enters the first heat exchanger 101 through the raw material liquid input pipeline 103, so that the raw steam and the raw material liquid containing ethyl acetate perform heat exchange evaporation in the first heat exchanger 101 to form an ethyl acetate water azeotrope steam and a first concentrated solution.

Then, the ethyl acetate water azeotrope steam is separated from the first concentrated solution in the vapor-liquid separator 201, the throttle valve is opened after the vapor pressure of the separated ethyl acetate water azeotrope is increased, the ethyl acetate water azeotrope steam is injected 2031 through the head-end vapor injector and enters the head-end second heat exchanger 2041, the ethyl acetate water azeotrope steam containing the ethyl acetate raw material liquid and the separated first concentrated solution flow into the head-end second heat exchanger 2041 and the tail-end second heat exchanger 2042 through the liquid pipeline 5, the heat exchange is performed between the ethyl acetate water azeotrope steam in the head-end second heat exchanger 2041 and the ethyl acetate water azeotrope containing raw material liquid and the first concentrated solution, the head end of the second heat exchanger 2041 keeps a certain vacuum state, the ethyl acetate containing the ethyl acetate raw material liquid and the ethyl acetate in the first concentrated solution are evaporated to form ethyl acetate steam, the ethyl acetate water azeotrope steam is cooled to form an ethyl acetate water condensate, and the ethyl acetate water condensate enters the organic solvent.

Then, the ethyl acetate vapor carries the raw material liquid and enters the head-end evaporator 2051 through the vapor-liquid mixing pipeline 3 to form secondary ethyl acetate vapor and concentrated raw material liquid, the secondary ethyl acetate vapor is divided into two paths, one path enters the head-end vapor ejector 2031, the ethyl acetate water azeotrope vapor is introduced into the head-end second heat exchanger 2041, and evaporation and concentration are continuously performed; the other path enters the end second heat exchanger 2042 through the end steam ejector 2032, a higher vacuum state is maintained in the end second heat exchanger 2042, the ethyl diacetate steam exchanges heat with the ethyl acetate-containing raw material liquid in the end second heat exchanger 2042 to evaporate to form ethyl acetate steam, and the ethyl acetate steam carries the raw material liquid to enter the end evaporator 2052 through the vapor-liquid mixing pipeline 3 to form ethyl diacetate steam and concentrated raw material liquid again.

Finally, the ethyl diacetate vapor formed in the end evaporator 2052 enters the end vapor injector 2032 and is introduced into the end second heat exchanger 2042 by the ethyl diacetate vapor formed in the head-end second heat exchanger 2041, and the concentrated raw material liquid flows into the end second heat exchanger 2042 through the liquid pipe 5 to be further subjected to evaporation concentration.

In the later stage of evaporation and concentration, the ethyl acetate in the raw material liquid is evaporated, the temperature of the first heat exchanger 101 rises under continuous heating, the water in the raw material liquid is evaporated and cooled to form condensed water, and the condensed water flows into the waste liquid collecting system through a condensed water discharge pipeline 10 communicated with the first heat exchanger 101. The concentrated raw material liquid in the first-end evaporator 2051 flows back to the first-end second heat exchanger 2041 through the liquid pipe 5, and the concentrated raw material liquid in the last evaporator 2052 flows back to the last second heat exchanger 2042 through the liquid pipe 5, so that repeated evaporation and concentration are performed. When the concentration detection device disposed in the second heat exchanger 204 detects that the concentration of the concentrated raw material solution at the second raw material solution outlet 2054 of the corresponding evaporator 205 reaches a certain value, the concentrated raw material solution can be made to flow out and be collected through the raw material solution collection pipeline 9 communicated with the second raw material solution outlet 2054, and at this time, the evaporation and concentration process is completed.

By adopting the heat pump evaporation and concentration system of the embodiment of the technical scheme, as the heat pump evaporation and concentration system is provided with the plurality of second heat exchangers 204 and the plurality of evaporators 205, the secondary ethyl acetate steam can be more fully utilized, and the energy utilization rate of the heat pump evaporation and concentration system is further improved. And the extraction process of the ethyl acetate water condensate can be simplified, and the ethyl acetate concentration in the ethyl acetate water condensate is high, so that the ethyl acetate after the organic solvent is extracted has high quality and can be continuously used, and therefore, the heat pump evaporation and concentration system adopting the technical scheme can effectively improve the recovery utilization rate of the ethyl acetate.

As shown in fig. 5, based on the same inventive concept, the present invention further provides a method for preparing a concentrated solution by using the heat pump evaporation concentration system as described above, including an ethyl acetate steam generation process and a raw material solution concentration process, the method including:

step 001: the raw material liquid exchanges heat with raw steam through a first heat exchanger to generate a first concentrated liquid and ethyl acetate water azeotrope steam;

step 002: the ethyl acetate water azeotrope steam enters an ejector to inject first ethyl acetate steam into a second heat exchanger;

step 003: the first concentrated solution enters a second heat exchanger;

step 004: exchanging heat between the first ethyl acetate steam and the first concentrated solution in a second heat exchanger, condensing the first ethyl acetate steam and the first concentrated solution into an ethyl acetate solution, and feeding the ethyl acetate solution into an organic solvent extraction pipeline;

step 005: the first concentrated solution enters an evaporator after heat exchange in a second heat exchanger to form concentrated raw material solution and second ethyl diacetate steam;

step 006: the second ethyl acetate steam enters the ejector and is ejected;

step 007: and the concentrated raw material liquid flows back to the second heat exchanger for repeated evaporation and concentration, and is collected when the concentration meets the requirement.

According to the method for preparing the concentrated solution, the raw material solution containing ethyl acetate is evaporated and concentrated, and waste of secondary ethyl acetate steam is avoided on the basis of meeting the concentration requirement, so that the energy utilization rate of a heat pump evaporation and concentration system is effectively improved; in addition, the ethyl acetate solution with higher concentration and better quality can be obtained, and the recovery rate of the ethyl acetate is improved.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.