Continuous salt separation type high-concentration brine heat exchange process

Abstract

The invention relates to the technical field of waste liquid treatment, and discloses a continuous salt separation type high-concentration brine heat exchange process which comprises the following steps: inputting high-concentration brine into a first evaporation tank through a stock solution pipeline, and concentrating and evaporating the high-concentration brine in the first evaporation tank; when the first monitoring assembly monitors that the monitoring index value of the feed liquid in the first evaporation tank reaches a first threshold value, the feed liquid capable of separating salt is input into the relay barrel; the liquid outlet pipeline is used for inputting salt-separable material liquid in the relay barrel into the second evaporation tank; the salt separation pipeline is used for feeding salt separation feed liquid subjected to heat exchange of the shell-and-tube heat exchanger into the centrifugal assembly for salt separation; intermittent evaporation and concentration and continuous salt separation are synchronously carried out, so that the problem that high-concentration brine cannot be concentrated to a salt separation state during concentration and evaporation so as to cause insufficient treatment of the high-concentration brine can be effectively avoided, and the influence of separated salt and scale on a tank body when the evaporation concentration reaches the salt separation state can be avoided; the service life of the tank body is short; and subsequent evaporation and concentration are influenced.

Description

Technical Field

[0001] The invention relates to the technical field of waste liquid treatment, and in particular to a continuous salt separation type high-concentration brine heat exchange process. Background Art

[0002] After heat pump evaporation and concentration, distilled water that meets the discharge standards can be extracted from the sewage. The distilled water can be discharged directly, and the remaining concentrate can be discharged to the sewage treatment plant for treatment, which can greatly reduce the company's sewage treatment costs.

[0003] The applicant has retrieved some prior art to achieve salt separation treatment of highly concentrated brine, for example, the patent publication number is CN112321048A, the main technical means of which is to adopt a process combining three-stage countercurrent evaporation with opposite steam and material flow directions to precipitate sodium salt + flash evaporation and cooling to precipitate potassium salt, and to control the concentration and temperature of the discharged potassium chloride, so as to completely separate the two salts and improve the purity of the separated product. After analysis by the applicant, the disadvantage of this technical solution is that during the evaporation and concentration process, when the salt separation concentration is reached, scaling will inevitably occur, and the precipitated salt will easily adhere to the side wall of the equipment and cannot be smoothly discharged for collection. After a long period of use, the precipitated salt will be deposited at the bottom of the equipment, resulting in the subsequent evaporation and concentration efficiency being affected. If salt separation and scaling are to be avoided, the concentrated liquid cannot be concentrated to the salt separation concentration during the evaporation process. Based on this, the present invention provides a continuous salt separation high-concentration brine heat exchange process that can achieve evaporation concentration and salt separation synchronously. Summary of the invention

[0004] The purpose of the present invention is to provide a continuous salt separation high-concentration brine heat exchange process to address the deficiencies of the prior art, so as to solve the technical problem that scaling of the concentrated liquid will occur during salt separation and affect the subsequent concentration of the feed liquid.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A continuous salt separation type high-concentration brine heat exchange process, the process comprising the following steps:

[0007] Step S1: Start the first vacuum component to make the first evaporator and the first refrigerant heat exchanger both have negative pressure environments, and start the second vacuum component at the same time to make the second evaporator, the tube-in-tube heat exchanger and the second refrigerant heat exchanger both have negative pressure environments, so that the boiling point of the liquid in the evaporation treatment system is reduced;

[0008] Step S2: Highly concentrated brine is input into the first evaporation tank through the raw liquid pipeline, and hot refrigerant after absorbing the heat of the first compressor is input into the first evaporation tank to concentrate and evaporate the high-concentration brine in the first evaporation tank, and the hot refrigerant undergoes a phase change to become a liquid refrigerant. At the same time, the first monitoring component in the first evaporation tank monitors the feed liquid therein;

[0009] Step S3: the liquid refrigerant is input into the first refrigerant heat exchanger, and after heat exchange, is input into the first compressor to perform work, and then enters the first evaporation tank for concentration and evaporation;

[0010] Step S4: when the first monitoring component detects that the monitoring index value of the feed liquid in the first evaporation tank reaches the first threshold value, the first evaporation tank contains the divisible salt feed liquid, and at this time, the liquid inlet pipeline is opened to input the divisible salt feed liquid into the relay barrel;

[0011] Step S5: the liquid outlet pipeline inputs the divisible salt liquid in the relay barrel into the second evaporation tank, and then the liquid outlet pipeline is closed, and the divisible salt liquid circulates in the circulation pipeline between the second evaporation tank and the shell-and-tube heat exchanger;

[0012] Step S6: inputting the hot refrigerant after absorbing the heat of the second compressor into the shell-and-tube heat exchanger to exchange heat with the divisible salt liquid entering the shell-and-tube heat exchanger, and the hot refrigerant undergoes a phase change to become a liquid refrigerant;

[0013] Step S7: opening the salt separation pipeline, sending the salt separation liquid after heat exchange in the shell-and-tube heat exchanger into the centrifugal assembly for salt separation, while the second monitoring assembly in the second evaporation tank monitors the liquid therein;

[0014] Step S8: When the second monitoring component detects that the monitoring index value of the liquid in the second evaporation tank reaches the second threshold value, the liquid outlet pipeline is opened to input the same amount of divisible liquid as the output of the salt separation pipeline into the second evaporation tank.

[0015] As a further solution of the present invention: the step S2 specifically comprises the following steps:

[0016] Step S21: Open the raw liquid pipeline to input highly concentrated brine into the first evaporation tank;

[0017] Step S22: After the high-concentration brine input is completed, the raw liquid pipeline is closed, and the hot refrigerant that has absorbed the heat of the first compressor is input into the first evaporation tank to concentrate and evaporate the high-concentration brine in the first evaporation tank;

[0018] Step S23: The hot refrigerant undergoes a phase change to become a liquid refrigerant;

[0019] Step S24: the first monitoring component in the first evaporation tank monitors the liquid therein.

[0020] As a further solution of the present invention: in step S4, after the liquid inlet pipeline is opened to input the divisible salt solution into the relay barrel, the raw liquid pipeline is opened to input new high-concentration brine into the first evaporation tank.

[0021] As a further solution of the present invention: the step S8 specifically includes the following steps:

[0022] Step S81: when the salt separation pipeline delivers the salt separation liquid after heat exchange into the centrifugal assembly, when the second detection assembly detects that the monitoring index value of the liquid in the second evaporation tank reaches the second threshold, the external controller calculates the liquid output corresponding to when the monitoring index value of the liquid in the second evaporation tank reaches the second threshold;

[0023] Step S82: Open the liquid outlet pipeline, input the same amount of divisible salt liquid as the liquid output into the second evaporation tank, and then repeat steps S5 to S8.

[0024] As a further solution of the present invention: the first evaporation tank is connected to a de-powder separator, and the steam generated by concentrated evaporation of the first evaporation tank is input into the de-powder separator for de-powder removal, and then input into the first refrigerant heat exchanger.

[0025] As a further solution of the present invention: the first evaporator is connected to the first refrigerant heat exchanger through a first plate heat exchanger, the shell and tube heat exchanger is connected to the second refrigerant heat exchanger through a second plate heat exchanger, and the first plate heat exchanger and the second plate heat exchanger are both connected to the cooling pipeline.

[0026] As a further solution of the present invention: the first compressor and the second compressor are both oil-free compressors.

[0027] As a further solution of the present invention: the first refrigerant heat exchanger and the second refrigerant heat exchanger are both immersion heat exchangers, and steam pipes for flowing steam are provided in the first refrigerant heat exchanger and the second refrigerant heat exchanger, and the steam pipes are immersed in the refrigerant inside the heat exchanger.

[0028] As a further solution of the present invention: a defoaming agent pipeline and a cleaning water pipeline are connected to the second evaporator, and control valves are respectively provided on the defoaming agent pipeline and the cleaning water pipeline.

[0029] Beneficial effects of the present invention:

[0030] (1) In the present invention, the first evaporator performs evaporation and concentration in batches. When the feed liquid is concentrated to a state where salt separation is imminent, the first evaporator stops evaporating and concentrating the feed liquid and inputs the feed liquid into the relay barrel for storage. Meanwhile, the second evaporator inputs the salt-separable feed liquid stored in the relay barrel and continuously performs salt separation. That is, intermittent evaporation and concentration are performed simultaneously with continuous salt separation. This can effectively avoid the problem that the high-concentration brine cannot be concentrated to a salt separation state during concentration and evaporation, resulting in insufficient treatment of the high-concentration brine. It can also avoid the problem that when the evaporation concentration reaches the salt separation state, the precipitated salt and scaling affect the tank body, resulting in a short service life of the tank body and affecting subsequent evaporation and concentration.

[0031] (2) In the present invention, considering that the processing rates during the initial concentration and the salt separation concentration are different, after the initial concentration to the state of being ready for salt separation, all of this part of the salt-separable feed liquid is stored, and the second evaporation tank for salt separation and concentration is intermittently taken out according to the amount, so that the high-concentration brine can have sufficient time to be evaporated and processed, and reach a sufficient concentration, thereby improving the processing effect of the high-concentration brine;

[0032] (3) In the present invention, the first evaporator is used for intermittent concentration, which is the preliminary concentration of the highly concentrated brine. The concentration is stopped when the salt separation is about to occur. This can avoid the problem of salt precipitation in the tank due to one-time concentration, which affects the subsequent concentration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below in conjunction with the accompanying drawings.

[0034] Figure 1 It is a schematic diagram of the overall process flow of the present invention;

[0035] Figure 2 This is a schematic diagram of the preliminary concentration process of the first evaporator in the present invention;

[0036] Figure 3 It is a schematic diagram of the process flow of salt separation and concentration in the second evaporation tank of the present invention.

[0037] In the figure: 1. first evaporator; 2. raw liquid pipeline; 3. first refrigerant heat exchanger; 4. first vacuum assembly; 5. first compressor; 6. first plate heat exchanger; 7. impurity removal separator; 8. liquid inlet pipeline; 9. relay barrel; 10. second evaporator; 11. liquid outlet pipeline; 12. circulation pipeline; 13. shell and tube heat exchanger; 14. circulation pump; 15. salt distribution pipeline; 16. second refrigerant heat exchanger; 17. second compressor; 18. second plate heat exchanger; 19. second vacuum assembly; 20. cooling pipeline; 21. defoaming agent pipeline; 22. cleaning water pipeline. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] See also Figure 1-Figure 3 As shown, the present invention is a continuous salt separation type high-concentration brine heat exchange process, the process comprising the following steps:

[0040] Step S1: Start the first vacuum component 4, so that the first evaporation tank 1 and the first refrigerant heat exchanger 3 are both in a negative pressure environment, and start the second vacuum component 19 at the same time, so that the second evaporation tank 10, the shell and tube heat exchanger 13 and the second refrigerant heat exchanger 16 are all in a negative pressure environment, so that the boiling point of the liquid in the evaporation treatment system is reduced;

[0041] Step S2: Highly concentrated brine is input into the first evaporation tank 1 through the raw liquid pipeline 2, and at the same time, hot refrigerant after absorbing the heat of the first compressor 5 is input into the first evaporation tank 1 to concentrate and evaporate the highly concentrated brine in the first evaporation tank 1, and the hot refrigerant undergoes a phase change to become a liquid refrigerant. At the same time, the first monitoring component in the first evaporation tank 1 monitors the feed liquid therein;

[0042] Step S3: the liquid refrigerant is input into the first refrigerant heat exchanger 3, and after heat exchange, is input into the first compressor 5 to perform work, and then enters the first evaporation tank 1 for concentration and evaporation;

[0043] Step S4: when the first monitoring component detects that the monitoring index value of the liquid in the first evaporation tank 1 reaches the first threshold value, the first evaporation tank 1 contains the divisible salt liquid, and at this time, the liquid inlet pipeline 8 is opened to input the divisible salt liquid into the relay barrel 9;

[0044] Step S5: the liquid outlet pipeline 11 inputs the divisible salt liquid in the relay barrel 9 into the second evaporation tank 10, and then the liquid outlet pipeline 11 is closed, and the divisible salt liquid circulates in the circulation pipeline 12 between the second evaporation tank 10 and the shell-and-tube heat exchanger 13;

[0045] Step S6: inputting the hot refrigerant after absorbing the heat of the second compressor 17 into the shell-and-tube heat exchanger 13 to exchange heat with the divisible salt liquid entering the shell-and-tube heat exchanger 13, and the hot refrigerant undergoes a phase change to become a liquid refrigerant;

[0046] Step S7: opening the salt separation pipeline 15, sending the salt separation liquid after heat exchange in the tube-in-tube heat exchanger 13 to the centrifugal assembly for salt separation, while the second monitoring assembly in the second evaporation tank 10 monitors the liquid therein;

[0047] Step S8: When the second monitoring component detects that the monitoring index value of the liquid in the second evaporation tank 10 reaches the second threshold, the liquid outlet pipeline 11 is opened to input the same amount of divisible liquid as the output of the salt separation pipeline 15 into the second evaporation tank 10 .

[0048] It should be noted that the raw liquid pipeline 2, liquid inlet pipeline 8, liquid outlet pipeline 11, circulation pipeline 12 and salt separation pipeline 15 described in the present application are all provided with control valves, and the control valves are connected to an external controller to control the opening and closing of each pipeline; the circulation pipeline 12 is provided with a circulation pump 14.

[0049] In one case of the present embodiment, the first vacuum component 4 and the second vacuum component 19 can both use vacuum centrifugal pumps or water ring vacuum components, as long as they can achieve a negative pressure environment, and the present embodiment does not make specific limitations here; the first monitoring component can use a current monitor, and when the current monitor detects that the current value of the liquid in the first evaporation tank 1 reaches a first threshold, the liquid in the tank is in a state of about to be desalted; the second monitoring component is a liquid level sensor, and when the salt separation pipeline 15 outputs the desaltable liquid to the second evaporation tank 10, the liquid level height drops to a second threshold, the data processing module included in the external controller calculates the liquid level drop height corresponding to the second evaporation tank 10 The output of the feed liquid is then opened, and the liquid outlet pipeline 11 is opened to input the same amount of separable salt feed liquid as the output of the feed liquid into the second evaporation tank 10. Of course, the first monitoring component and the second monitoring component may also use other modules with monitoring functions, which are not described in detail here; the centrifugal component may use a centrifuge or other equipment capable of salt separation, which is not specifically limited here; the control valve, external controller, vacuum component, monitoring component, circulation pump 14, centrifugal component and other electrical components are all prior art, and this application does not improve them. Therefore, it is not necessary to disclose their specific mechanical structure and circuit structure, and it does not affect the integrity of this application.

[0050] In actual application of this embodiment, the first vacuum component 4 cooperates with the second vacuum component 19 to make the second evaporation tank 10, the tube-in-tube heat exchanger 13 and the second refrigerant heat exchanger 16 all in negative pressure environment, so that the boiling point of the liquid in the entire evaporation treatment system is reduced; the hot refrigerant is input into the first evaporation tank 1 to perform evaporation and concentration treatment with the highly concentrated brine therein, and when the first monitoring component detects that the current value of the feed liquid in the first evaporation tank 1 reaches the first threshold value, the feed liquid in the first evaporation tank 1 is in a state of being ready to be desalted, that is, desalted feed liquid, at this time, the evaporation and concentration in the first evaporation tank 1 is interrupted, and the desalted feed liquid is all input into the relay barrel 9 for storage; the evaporation and concentration treatment in the second evaporation tank 10 is from The divisible salt liquid is input into the relay barrel 9, and the divisible salt liquid circulates in the circulation pipeline 12, and exchanges heat with the hot refrigerant in the shell-and-tube heat exchanger 13 when entering the shell-and-tube heat exchanger 13. When the divisible salt liquid starts to circulate, it quickly reaches the salt separation state. Therefore, while circulating, the salt separation pipeline 15 is opened, and the salt separation liquid after heat exchange in the shell-and-tube heat exchanger 13 is sent to the centrifugal component for salt separation, and the second monitoring component monitors the liquid in the second evaporation tank 10 at all times. When the monitoring index value reaches the second threshold value, the liquid outlet pipeline 11 is opened, and the divisible salt liquid of the same amount as the output of the salt separation pipeline 15 is input to the second evaporation tank 10, and the second evaporation tank 10 continues to evaporate and concentrate; that is, The first evaporation tank 1 performs evaporation and concentration in batches. When the feed liquid is concentrated to a state where salt separation is about to occur, the first evaporation tank 1 stops evaporating and concentrating the feed liquid, and all of the feed liquid is input into the relay barrel 9 for storage. Subsequently, new highly concentrated brine is input into the first evaporation tank 1 for evaporation and concentration. After the second evaporation tank 10 inputs the separable salt feed liquid stored in the relay barrel 9, the evaporation and concentration begins to be circulated, i.e., salt separation begins. At this time, the salt separation pipeline 15 is simultaneously opened to send the salt separation feed liquid after heat exchange in the tube-in-tube heat exchanger 13 into the centrifugal assembly for salt separation. After a certain amount of the separable salt feed liquid is output, the relay barrel 9 again inputs new separable salt feed liquid into the second evaporation tank 10 for heat exchange and output of salt separation, i.e., intermittent evaporation and concentration. The shrinkage and continuous salt separation are carried out simultaneously, which can effectively avoid the problem that the high-concentration brine cannot be concentrated to the salt separation state during concentration and evaporation, resulting in insufficient treatment of the high-concentration brine. It can also avoid the problem that when the evaporation concentration reaches the salt separation state, the precipitated salt and scaling affect the tank body, resulting in a short tank life and subsequent evaporation and concentration. The processing rate during initial concentration and salt separation concentration is different. After the initial concentration is to the state of salt separation, this part of the salt-separable feed liquid is stored in full, and the second evaporation tank 10 for salt separation and concentration is intermittently taken according to the amount, so that the high-concentration brine can have sufficient time to be evaporated and processed, and reach a sufficient concentration, thereby improving the treatment effect of the high-concentration brine.

[0051] like Figure 1-Figure 2 As shown, as a preferred embodiment of the present invention, step S2 specifically includes the following steps:

[0052] Step S21: Open the raw liquid pipeline 2 to input highly concentrated brine into the first evaporation tank 1;

[0053] Step S22: After the high-concentration brine input is completed, the raw liquid pipeline 2 is closed, and the hot refrigerant that has absorbed the heat of the first compressor 5 is input into the first evaporation tank 1 to concentrate and evaporate the high-concentration brine in the first evaporation tank 1;

[0054] Step S23: The hot refrigerant undergoes a phase change to become a liquid refrigerant;

[0055] Step S24: the first monitoring component in the first evaporation tank 1 monitors the liquid therein.

[0056] In one case of this embodiment, in step S4 , after the liquid inlet pipeline 8 is opened to input the divisible salt solution into the relay barrel 9 , the raw liquid pipeline 2 is opened to input new high-concentration brine into the first evaporation tank 1 .

[0057] In actual application of this embodiment, the first evaporation tank 1 performs intermittent concentration, which is the preliminary concentration of highly concentrated brine, and stops concentrating when the salt separation state is about to be reached, which can avoid the problem of salt precipitation deposition in the tank due to one-time concentration affecting subsequent concentration processing.

[0058] like Figure 1-Figure 3 As shown, as a preferred embodiment of the present invention, step S8 specifically includes the following steps:

[0059] Step S81: when the salt separation pipeline 15 delivers the salt separation liquid after heat exchange into the centrifugal assembly, when the second detection assembly detects that the monitoring index value of the liquid in the second evaporation tank 10 reaches the second threshold, the external controller calculates the liquid output corresponding to when the monitoring index value of the liquid in the second evaporation tank 10 reaches the second threshold;

[0060] Step S82: Open the liquid outlet pipeline 11, input the same amount of divisible salt liquid as the liquid output into the second evaporation tank 10, and then repeat steps S5 to S8.

[0061] In one case of the present embodiment, when the second detection component uses a liquid level sensor, the second threshold value is a liquid level height value. The liquid level height value, combined with the size of the second evaporation tank 10, can correspond to a liquid output. In actual application, it is not necessary to use an external sensor for each measurement. The parameters are pre-set, and the liquid output corresponding to the liquid level height value can be pre-calculated. When the liquid level of the divisible salt liquid output from the salt separation pipeline 15 to the second evaporation tank 10 drops to the second threshold value, the liquid outlet pipeline 11 is directly opened to input the divisible salt liquid in an amount equal to the liquid output corresponding to the second threshold value into the second evaporation tank 10.

[0062] like Figure 1-Figure 2As shown, as a preferred embodiment of the present invention, the first evaporation tank 1 is connected to the impurity removal separator 7, and the steam generated by concentrated evaporation of the first evaporation tank 1 is input into the impurity removal separator 7 for impurity removal, and then input into the first refrigerant heat exchanger 3.

[0063] In one case of this embodiment, the impurity removal separator 7 may be a cyclone separator, after which the steam generated by evaporation in the first evaporation tank 1 enters the cyclone separator, and the mixed water droplets are thrown back into the first evaporation tank 1 for further evaporation. Of course, the impurity removal separator 7 may also be other structural components capable of removing impurities, which is not specifically limited in this embodiment.

[0064] like Figure 1-Figure 3 As shown, as a preferred embodiment of the present invention, the first evaporator 1 is connected to the first refrigerant heat exchanger 3 through the first plate heat exchanger 6, the shell and tube heat exchanger 13 is connected to the second refrigerant heat exchanger 16 through the second plate heat exchanger 18, and the first plate heat exchanger 6 and the second plate heat exchanger 18 are both connected to the cooling pipeline 20.

[0065] In actual application of this embodiment, when the temperature of the refrigerant after heat exchange reaches 45°C, the plate heat exchanger is turned on for supercooling. Because the internal pressure of the first evaporator 1 and the shell-and-tube heat exchanger 13 will increase and the heat exchange efficiency will decrease after long-term use, in order to maintain the pressure and ensure that the refrigerant has a certain degree of supercooling, the plate heat exchanger can supercool the refrigerant to avoid the alarm caused by the continuous increase of the compressor pressure when the steam processing is unbalanced, so as to maintain the balance of the system; in addition, when the ambient temperature is too high, the temperature of the chiller connected to the cooling pipeline 20 will also be too high, then the efficiency of generating cold water will decrease, and the efficiency of the system in processing steam will decrease. The plate heat exchanger can increase the degree of supercooling of the system and maintain the balance of the system.

[0066] like Figure 1-Figure 3 As shown, as a preferred embodiment of the present invention, the first compressor 5 and the second compressor 17 are both oil-free compressors; in actual application, the oil-free compressors have no oil return failure.

[0067] like Figure 1-Figure 3 As shown, as a preferred embodiment of the present invention, the first refrigerant heat exchanger 3 and the second refrigerant heat exchanger 16 are both immersion heat exchangers, and steam pipes for flowing steam are provided in the first refrigerant heat exchanger 3 and the second refrigerant heat exchanger 16, and the steam pipes are immersed in the refrigerant inside the heat exchanger.

[0068] In one case of this embodiment, the refrigerant liquid level inside the immersion heat exchanger is located at half the height of its inner cavity, and the height of the steam pipe is lower than the refrigerant liquid level. A sight glass is provided on the immersion heat exchanger.

[0069] In actual application of this embodiment, the steam pipe is immersed in the refrigerant, and the refrigerant liquid level just submerges the steam pipe. The refrigerant liquid level is controlled by a liquid level sensor arranged on the immersion heat exchanger, and the steam pipe is laid to half the height of the inner cavity of the immersion heat exchanger. In this way, the refrigerant just submerges the steam pipe, which can avoid the refrigerant liquid level being too low, resulting in part of the steam in the steam pipe being unable to be fully condensed. At the same time, it can avoid the refrigerant liquid level being too high, and the compressor entraining too much incompletely vaporized liquid refrigerant and steam condensate when sucking in the refrigerant.

[0070] like Figure 1-Figure 3 As shown, as a preferred embodiment of the present invention, a defoaming agent pipeline 21 and a cleaning water pipeline 22 are connected to the second evaporation tank 10, and control valves are respectively provided on the defoaming agent pipeline 21 and the cleaning water pipeline 22.

[0071] In actual application of this embodiment, defoaming agent can be input into the second evaporation tank 10 through the defoaming agent pipeline 21, and washing water can be input into the second evaporation tank 10 in combination with the washing water pipeline 22, so as to clean the second evaporation tank 10, thereby avoiding the problem of a large amount of dirt adhering to the tank wall after long-term use, resulting in a decrease in subsequent wastewater evaporation efficiency.

[0072] Working principle of the present invention: The above embodiment of the present invention provides a continuous salt separation type high-concentration brine heat exchange process, which is carried out in batches by the first evaporation tank 1 for evaporation and concentration. When the feed liquid is concentrated to a state of being about to be salted, the first evaporation tank 1 stops evaporating and concentrating it, and all of it is input into the relay barrel 9 for storage. Then, new high-concentration brine is input into the first evaporation tank 1 for evaporation and concentration, and after the salt-separable feed liquid stored in the relay barrel 9 is input into the second evaporation tank 10, when the circulation of evaporation and concentration begins, the salt separation begins. At this time, the salt separation pipeline 15 is opened synchronously to send the salt-separated feed liquid after heat exchange in the shell-and-tube heat exchanger 13 into the centrifugal assembly for salt separation. After the salt-separable feed liquid is output to a certain amount, the relay barrel 9 again inputs new salt-separable feed liquid into the second evaporation tank 10. The liquid is heat exchanged and salt is output, that is, intermittent evaporation concentration and continuous salt separation are carried out simultaneously, which can effectively avoid the problem that the high-concentration brine cannot be concentrated to the salt separation state during concentration and evaporation, resulting in insufficient treatment of the high-concentration brine. It can also avoid the problem that when the evaporation concentration reaches the salt separation state, the precipitated salt and scaling affect the tank body, resulting in a short service life of the tank body and the subsequent evaporation and concentration being affected. The processing rate during initial concentration and salt separation concentration is different. After the initial concentration is to the state of salt separation, this part of the salt-separable feed liquid is stored in full, and the second evaporation tank 10 for salt separation and concentration is intermittently taken according to the amount, so that the high-concentration brine can have sufficient time to be evaporated and processed, and reach a sufficient concentration, thereby improving the treatment effect of the high-concentration brine.

[0073] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A continuous salt separation high-concentration brine heat exchange process, characterized in that: The process comprises the following steps: Step S1: starting the first vacuum component (4) so ​​that the first evaporation tank (1) and the first refrigerant heat exchanger (3) are both in a negative pressure environment, and simultaneously starting the second vacuum component (19) so that the second evaporation tank (10), the tube-in-tube heat exchanger (13) and the second refrigerant heat exchanger (16) are all in a negative pressure environment, thereby reducing the boiling point of the liquid in the evaporation treatment system; Step S2: Highly concentrated brine is input into the first evaporation tank (1) through the raw liquid pipeline (2), and at the same time, hot refrigerant that has absorbed heat from the first compressor (5) is input into the first evaporation tank (1) to concentrate and evaporate the highly concentrated brine in the first evaporation tank (1), and the hot refrigerant undergoes a phase change to become a liquid refrigerant. At the same time, the first monitoring component in the first evaporation tank (1) monitors the feed liquid therein; Step S3: the liquid refrigerant is input into the first refrigerant heat exchanger (3), and after heat exchange, is input into the first compressor (5) to perform work, and then enters the first evaporation tank (1) for concentration and evaporation; Step S4: when the first monitoring component detects that the monitoring index value of the liquid in the first evaporation tank (1) reaches a first threshold value, the first evaporation tank (1) contains liquid that can be separated into salts, and at this time, the liquid inlet pipeline (8) is opened to input the liquid that can be separated into salts into the relay barrel (9); Step S5: the liquid outlet pipeline (11) inputs the divisible salt liquid in the relay barrel (9) into the second evaporation tank (10), and then the liquid outlet pipeline (11) is closed, and the divisible salt liquid circulates in the circulation pipeline (12) between the second evaporation tank (10) and the shell-and-tube heat exchanger (13); Step S6: inputting the hot refrigerant after absorbing the heat of the second compressor (17) into the shell-and-tube heat exchanger (13) to exchange heat with the divisible salt liquid entering the shell-and-tube heat exchanger (13), and the hot refrigerant undergoes a phase change to become a liquid refrigerant; Step S7: opening the salt separation pipeline (15), sending the salt separation liquid after heat exchange in the tube-in-tube heat exchanger (13) into the centrifugal assembly for salt separation, while the second monitoring assembly in the second evaporation tank (10) monitors the liquid therein; Step S8: When the second monitoring component detects that the monitoring index value of the liquid in the second evaporation tank (10) reaches a second threshold value, the liquid outlet pipeline (11) is opened to input a salt-dispersible liquid in an amount equal to the output amount of the salt-dispersing pipeline (15) into the second evaporation tank (10).

2. A continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that: The step S2 specifically includes the following steps: Step S21: opening the raw liquid pipeline (2) to input highly concentrated brine into the first evaporation tank (1); Step S22: After the high-concentration brine is input, the raw liquid pipeline (2) is closed, and the hot refrigerant that has absorbed the heat of the first compressor (5) is input into the first evaporation tank (1) to concentrate and evaporate the high-concentration brine in the first evaporation tank (1); Step S23: The hot refrigerant undergoes a phase change to become a liquid refrigerant; Step S24: the first monitoring component in the first evaporation tank (1) monitors the liquid therein.

3. A continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that: In step S4, after the liquid inlet pipeline (8) is opened to input the divisible salt solution into the relay barrel (9), the raw liquid pipeline (2) is opened to input new high-concentration salt water into the first evaporation tank (1).

4. A continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that: The step S8 specifically includes the following steps: Step S81: when the salt separation pipeline (15) delivers the salt separation liquid after heat exchange into the centrifugal assembly, when the second detection assembly detects that the monitoring index value of the liquid in the second evaporation tank (10) reaches a second threshold value, the external controller calculates the liquid output corresponding to when the monitoring index value of the liquid in the second evaporation tank (10) reaches the second threshold value; Step S82: Open the liquid outlet pipeline (11) and input a saltable liquid in an amount equal to the liquid output into the second evaporation tank (10), and then repeat steps S5 to S8.

5. A continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that: The first evaporation tank (1) is connected to the impurity removal separator (7), and the steam generated by concentrated evaporation of the first evaporation tank (1) is input into the impurity removal separator (7) for impurity removal, and then input into the first refrigerant heat exchanger (3).

6. A continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that: The first evaporator (1) is connected to the first refrigerant heat exchanger (3) via a first plate heat exchanger (6), the shell-and-tube heat exchanger (13) is connected to the second refrigerant heat exchanger (16) via a second plate heat exchanger (18), and both the first plate heat exchanger (6) and the second plate heat exchanger (18) are connected to a cooling pipeline (20).

7. A continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that: The first compressor (5) and the second compressor (17) are both oil-free compressors.

8. The continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that: The first refrigerant heat exchanger (3) and the second refrigerant heat exchanger (16) are both immersed heat exchangers. Steam pipes for flowing steam are provided in the first refrigerant heat exchanger (3) and the second refrigerant heat exchanger (16), and the steam pipes are immersed in the refrigerant inside the heat exchanger.

9. A continuous salt separation high-concentration brine heat exchange process according to claim 1, characterized in that: The second evaporation tank (10) is connected to a defoaming agent pipeline (21) and a cleaning water pipeline (22), and control valves are respectively provided on the defoaming agent pipeline (21) and the cleaning water pipeline (22).

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