Sodium and potassium salt separation device

Abstract

The utility model relates to a sodium and potassium salt separation device which comprises a feeding pump, a crystallization separator, a crystallizer circulating pipe, a salt discharge slurry pump, a mother liquor transfer pump and an enamel kettle, the crystallizer circulating pipe and the crystallization separator are connected to form a circulating loop, and the crystallizer circulating pipe is sequentially provided with a solid-liquid separator, a densimeter, a circulating pump and a heater in the flow direction of feed liquid. The feeding pump is used for feeding materials to the crystallizer circulating pipe; the solid-liquid separator is provided with a conductivity meter for detecting the conductivity of the clarified mother liquor separated by the solid-liquid separator; the salt slurry discharging pump is connected with a salt leg of the crystallization separator; and the mother liquor transfer pump conveys the clarified mother liquor separated by the solid-liquid separator to the enamel kettle. The solid content of an evaporative crystallization material is monitored through the densimeter, the solid content of a circulating liquid in the crystallization separator is maintained through starting and stopping of the salt discharge slurry pump, the TDS of the evaporative crystallization material is detected through the conductivity meter, and the TDS of the circulating liquid in the crystallization separator is maintained through starting and stopping of the mother liquor transfer pump. And the operation stability of the sodium-potassium salt separation device is effectively improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of fly ash water washing sodium and potassium salt separation, and particularly relates to a sodium and potassium salt separation device. Background Art

[0002] Existing technologies for separating sodium chloride and potassium chloride from fly ash from municipal solid waste incineration ("fly ash") involve water-washing and separation. The process involves evaporation and crystallization to extract sodium chloride. This separation of sodium chloride yields a potassium-rich mother liquor, which is then cooled to crystallize and extract potassium chloride. Currently, the evaporation and crystallization process is primarily manual, which can easily lead to agglomeration and a high failure rate. Furthermore, it's difficult to fully automate the sodium-potassium salt separation process. Utility Model Content

[0003] Based on the above-mentioned shortcomings and deficiencies in the prior art, one of the purposes of the present invention is to at least solve one or more of the above-mentioned problems in the prior art. In other words, one of the purposes of the present invention is to provide a sodium-potassium salt separation device that meets one or more of the above-mentioned needs.

[0004] In order to achieve the above-mentioned purpose of the utility model, the utility model adopts the following technical solutions:

[0005] A sodium-potassium salt separation device includes a feed pump, a crystallizer separator, a crystallizer circulation pipe, a salt slurry pump, a mother liquor transfer pump, and an enamel kettle. The crystallizer circulation pipe is connected to the crystallizer separator to form a circulation loop. The crystallizer circulation pipe is sequentially provided with a solid-liquid separator, a density meter, a circulation pump, and a heater along the flow direction of the feed liquid. The feed pump is used to feed the crystallizer circulation pipe. The solid-liquid separator is provided with a conductivity meter for detecting the conductivity of the clarified mother liquor separated by the solid-liquid separator.

[0006] The salt slurry pump is connected to the salt leg of the crystallizer;

[0007] The mother liquor transfer pump is used to transport the clarified mother liquor separated by the solid-liquid separator to the enamel kettle.

[0008] As a preferred solution, the crystallizer circulation pipe has a vertical pipe section, and the density meter is located in the vertical pipe section.

[0009] As a preferred solution, the feed pump is connected between the vertical pipe section of the crystallizer circulation pipe and the heater.

[0010] As a preferred solution, the crystallization separator is provided with a double-flange differential pressure level gauge.

[0011] As a preferred solution, the crystallization separator is provided with a liquid level window.

[0012] As a preferred embodiment, the solid-liquid separator includes a shell and a straight pipe installed in the shell, one end of the straight pipe is connected to the crystallizer circulation pipe, and the other end of the straight pipe is located in the middle of the shell. The shell has a liquid outlet connected to the crystallizer circulation pipe, so that the liquid upstream of the crystallizer circulation pipe enters the shell through the straight pipe and enters the downstream of the crystallizer circulation pipe through the liquid outlet of the shell.

[0013] As a preferred solution, the space between the upper portion of the shell and the straight pipe constitutes a clarified mother liquor storage chamber, and the conductivity meter is arranged in the clarified mother liquor storage chamber.

[0014] As a preferred solution, the heater is a heat exchanger.

[0015] As a preferred solution, the heat source of the heat exchanger is steam.

[0016] As a preferred solution, the densitometer is a vibration densitometer or a static pressure densitometer.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The utility model monitors the solid content of the evaporation crystallization material through a density meter, and maintains the solid content of the circulating liquid inside the crystallization separator by starting and stopping the salt slurry pump, thereby reducing the risk of agglomeration, solving the problem of low thermal energy utilization efficiency of the evaporation crystallization system due to excessively high solid content, and making the sodium-potassium salt separation device operate more stably;

[0019] (2) The utility model monitors the liquid level of the crystallizer by coupling a double-flange differential pressure level gauge with a density meter, and automatically controls the start and stop of the feed pump through the accurate feedback of the level gauge. For the sodium-potassium salt separation device that operates continuously and stably, the stable liquid level can maintain the material temperature of the crystallizer to a great extent, making the operation of the sodium-potassium salt separation device more stable, and at the same time can reduce the risk of lumps falling from the inner wall of the crystallizer and clogging the pipeline;

[0020] (3) The utility model detects the TDS of the evaporated crystallization material through a conductivity meter, and maintains the TDS of the circulating liquid in the crystallizer by starting and stopping the mother liquor transfer pump; by monitoring the total dissolved solid content of the material in the crystallizer, the concentration of the evaporated crystallized sodium and potassium salt has an end point, namely the sodium-potassium salt co-saturation point. In order to avoid the precipitation of sodium and potassium salts in the crystallizer at the same time, and to ensure that a higher concentration of potassium-rich mother liquor is obtained, it is particularly important to reasonably control the salt separation point. The sodium-potassium salt co-saturation point can be predicted by the online conductivity meter, and the start and stop of the mother liquor transfer pump can be automatically controlled to transfer the mother liquor to the enamel kettle for cooling and potassium precipitation. The degree of automation and the quality and yield of the crystallized salt are effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1This is a schematic structural diagram of a sodium-potassium salt separation device according to Example 1 of the present invention;

[0022] Figure 2 It is a structural schematic diagram of the solid-liquid separator of Example 1 of the present utility model. DETAILED DESCRIPTION

[0023] In order to more clearly illustrate the embodiments of the present invention, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without inventive work.

[0024] Example 1:

[0025] like Figure 1 As shown, the sodium-potassium salt separation device of this embodiment includes a feed pump 1, a crystallizer separator 2, a crystallizer circulation pipe 3, a salt slurry pump 4, a mother liquor transfer pump 5, an enamel kettle 6, a solid-liquid separator 7, an online density meter 8, a forced circulation pump 9, a forced circulation heat exchanger 10 and a conductivity meter 11.

[0026] The crystallizer 2 of this embodiment is provided with a double-flange differential pressure level gauge 20, which is a differential pressure transmitter. The calculation method is: liquid pressure difference = liquid density × gravitational acceleration × height, where the initial density of the differential pressure transmitter is the set value. As the evaporated material gradually concentrates, its density gradually increases, and a deviation occurs between the displayed liquid level and the actual liquid level. After performing compensation calculations with an online density meter, the displayed liquid level will no longer deviate from the actual liquid level.

[0027] In addition, in order to make the liquid level detection of the crystallizer separator 2 more accurate, an on-site liquid level meter is added for auxiliary observation, that is, the crystallizer separator 2 of this embodiment is also provided with a liquid level window. The type of on-site liquid level meter is a high borosilicate glass sight glass, which is in the shape of a long strip and arranged vertically, and can cover the range of 1m above and below the operating liquid level of the crystallizer separator 2.

[0028] In this embodiment, the crystallizer circulation pipe 3 is connected to the crystallizer separator 2 to form a circulation loop for the fly ash water wash. Distributed along the crystallizer circulation pipe along the flow direction of the fly ash water wash are a solid-liquid separator 7, an online density meter 8, a forced circulation pump 9, and a forced circulation heat exchanger 10. The crystallizer circulation pipe 3 has a vertical pipe section 3a, and the online density meter 8 is located in this vertical pipe section to ensure the accuracy of density measurement. Furthermore, the forced circulation heat exchanger 10 uses steam as its heat source and is connected to a steam generator or an external fresh steam pipeline to heat the fly ash water wash.

[0029] The feed pump 1 of this embodiment is used to feed into the crystallizer circulation pipe 3 , and the feed pump 1 is connected between the vertical pipe section 3 a of the crystallizer circulation pipe 3 and the forced circulation pump 9 .

[0030] like Figure 2 As shown, the solid-liquid separator 7 of this embodiment includes a shell 71 and a straight pipe 72 installed in the shell 71, the upper end of the straight pipe 72 is connected to the crystallizer circulation pipe 3, and the lower end of the straight pipe 72 is located in the middle of the shell 71. The bottom of the shell 71 has a liquid outlet connected to the crystallizer circulation pipe 3, so that the feed liquid in the upstream of the crystallizer circulation pipe enters the shell 71 through the straight pipe 72 and enters the downstream of the crystallizer circulation pipe through the liquid outlet of the shell 71; wherein, the feed liquid enters the shell 71 from the straight pipe 72, reduces the flow rate, and provides time for sedimentation to achieve solid-liquid separation; the space between the upper part of the shell 71 and the straight pipe 72 constitutes a clarified mother liquor storage chamber 70, and the conductivity meter 11 is provided in the clarified mother liquor storage chamber 70 for detecting the conductivity of the clarified mother liquor separated by the solid-liquid separator, so as to control the start and stop of the mother liquor transfer pump 5; the mother liquor transfer pump 5 is used to transport the clarified mother liquor separated by the solid-liquid separator 7 to the enamel kettle 6.

[0031] The salt discharge slurry pump 4 of this embodiment is connected to the salt leg of the crystallizer 2. When the feedback value of the online density meter 8 reaches the discharge requirement of the sodium-potassium salt separation device, the start and stop of the salt discharge slurry pump 4 are controlled.

[0032] The online density meter 8 of this embodiment adopts a vibration density meter or a static pressure density meter. The material of the liquid contact part of the instrument needs to meet the requirements of high temperature resistance and corrosion resistance. It can withstand high temperatures of 0 to 200° C. and is made of TA2, 2205, 2507, etc.

[0033] The operation process of the sodium-potassium salt separation device of this embodiment is as follows:

[0034] S1. The fly ash washing liquid is pumped into the crystallizer circulation pipe through the feed pump, and evaporated and crystallized after being heated by the forced circulation heat exchanger. The density of the material is detected by the online density meter. The double-flange differential pressure level gauge calculates the liquid level display value based on the density compensation, and the local liquid level window is used for calibration.

[0035] S2. During the evaporation and crystallization process, a double flange differential pressure level gauge is used to control the start and stop of the feed pump;

[0036] S3. After the material begins to concentrate and crystallize in the crystallizer, the solid content in the circulating liquid gradually increases. Always pay attention to the feedback value of the online density meter and take samples on site to observe the solid content in the circulating liquid;

[0037] S4. When the online density feedback value reaches the discharge requirement, the start and stop of the salt slurry discharge pump is controlled by the online density meter;

[0038] S5. After the material is concentrated to a certain degree in the crystallizer, the total dissolved solids content of the circulating liquid reaches the mother liquor discharge requirement, that is, the sodium-potassium salt separation point, and the mother liquor is discharged from the solid-liquid separator into the enamel kettle for cooling crystallization and potassium precipitation;

[0039] S6. The conductivity meter controls the start and stop of the mother liquor transfer pump.

[0040] Example 2:

[0041] The sodium-potassium salt separation device of this embodiment is different from that of embodiment 1 in that:

[0042] The feed pump can be connected to other locations between the vertical section of the crystallizer circulation pipe and the forced circulation heat exchanger, as long as it is upstream of the forced circulation heat exchanger, to meet the needs of different applications;

[0043] For other structures, please refer to Example 1.

[0044] The above description is only a detailed description of the preferred embodiments and principles of the present invention. For ordinary technicians in this field, based on the ideas provided by the present invention, there will be changes in the specific implementation methods, and these changes should also be regarded as the scope of protection of the present invention.

Claims

1. A sodium-potassium salt separation device, characterized in that: It includes a feed pump, a crystallizer separator, a crystallizer circulation pipe, a salt discharge slurry pump, a mother liquor transfer pump and an enamel kettle. The crystallizer circulation pipe is connected to the crystallization separator to form a circulation loop. The crystallizer circulation pipe is equipped with a solid-liquid separator, a density meter, a circulation pump and a heater along the flow direction of the material and liquid. The feed pump is used to feed material to the crystallizer circulation pipe; among them, the solid-liquid separator is equipped with a conductivity meter for conductivity testing of the clarified mother liquor separated by the solid-liquid separator; The salt slurry pump is connected to the salt leg of the crystallizer; The mother liquor transfer pump is used to transport the clarified mother liquor separated by the solid-liquid separator to the enamel kettle.

2. The sodium-potassium salt separation device according to claim 1, characterized in that The crystallizer circulation pipe has a vertical pipe section, and the density meter is located in the vertical pipe section.

3. The sodium-potassium salt separation device according to claim 2, characterized in that: The feed pump is connected between the vertical pipe section of the crystallizer circulation pipe and the heater.

4. The sodium-potassium salt separation device according to claim 2, characterized in that: The crystallization separator is provided with a double-flange differential pressure level gauge.

5. The sodium-potassium salt separation device according to claim 4, characterized in that: The crystallization separator is provided with a liquid level window.

6. The sodium-potassium salt separation device according to any one of claims 1 to 5, characterized in that: The solid-liquid separator includes a shell and a straight pipe installed in the shell, one end of the straight pipe is connected to the crystallizer circulation pipe, and the other end of the straight pipe is located in the middle of the shell. The shell has a liquid outlet connected to the crystallizer circulation pipe, so that the material liquid upstream of the crystallizer circulation pipe enters the shell through the straight pipe and enters the downstream of the crystallizer circulation pipe through the liquid outlet of the shell.

7. The sodium-potassium salt separation device according to claim 6, characterized in that: The space between the upper part of the shell and the straight pipe forms a clarified mother liquor storage chamber, and the conductivity meter is arranged in the clarified mother liquor storage chamber.

8. The sodium-potassium salt separation device according to any one of claims 1 to 5, characterized in that: The heater is a heat exchanger.

9. The sodium-potassium salt separation device according to claim 8, characterized in that: The heat source of the heat exchanger is steam.

10. The sodium-potassium salt separation device according to any one of claims 1 to 5, characterized in that: The densitometer is a vibration densitometer or a static pressure densitometer.

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