Device for improving circulating efficiency of ionic liquid

Abstract

The invention discloses a device for improving the circulating efficiency of ionic liquid, which comprises a heat exchanger connected with a barren liquor pipeline of a desulfurization system and used for enabling part of cooled barren liquor to enter the heat exchanger for further heat exchange and cooling; the crystallization kettle is connected with the heat exchanger, so that the cooled barren liquor can enter the crystallization kettle; a cooling water pipeline of the water-cooling screw low-temperature brine unit is communicated with a heat exchange pipe in the crystallization kettle and is used for carrying out heat exchange and cooling on barren liquor in the crystallization kettle; the inlet end of the centrifugal machine is connected with the bottom outlet of the crystallization kettle. The freezing method is used for desalting and producing sodium sulfate, so that the problem of low absorption efficiency is solved, certain economic benefits are achieved, and a scheme is provided for ion liquid desalting treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of smelting equipment, in particular to a device for improving the circulation efficiency of ionic liquid. BACKGROUND

[0002] High-concentration sulfur dioxide flue gas generated in the smelting process is used for acid production, and the treatment method of low-concentration sulfur dioxide flue gas includes the limestone method, the caustic soda method, the activated coke method, the ionic liquid method, the sodium citrate absorption and resolution method, and the ammonia method. The ionic liquid method is used to treat sulfur dioxide flue gas. With the recycling of ionic liquid, the pH value of the lean liquid continuously decreases, the absorption efficiency is low, and the like. Therefore, liquid caustic soda needs to be supplemented to increase the pH value, which causes sodium salt to continuously accumulate, and sodium sulfate needs to be removed in time to ensure the stable operation of the system. In view of this situation, the desalination method is used to produce sodium sulfate, which not only solves the problem of low absorption efficiency, but also has certain economic benefits, and provides a scheme for the desalination treatment of ionic liquid. SUMMARY

[0003] In view of the above technical problems, the present application provides a device for improving the circulation efficiency of ionic liquid.

[0004] In order to achieve the above-mentioned purpose, the technical scheme of the present application is as follows: A device for improving the circulation efficiency of ionic liquid, comprising: A heat exchanger is connected with the lean liquid pipeline of the desulfurization system, so that part of the cooled lean liquid enters the heat exchanger for further heat exchange and cooling; A crystallization kettle is connected with the heat exchanger, so that the cooled lean liquid can enter the crystallization kettle; A water-cooled screw low-temperature brine unit, whose cooling water pipeline is communicated with the heat exchange pipe in the crystallization kettle, is used to heat exchange and cool the lean liquid in the crystallization kettle; A centrifuge, whose inlet end is connected with the bottom outlet of the crystallization kettle.

[0005] The heat exchanger is connected with the lean liquid pipeline of the desulfurization system through a valve.

[0006] The crystallization kettle is provided with a stirrer.

[0007] The present application further comprises: An underground storage tank, whose inlet end is connected with the lean liquid outlet end of the centrifuge; A lean liquid storage tank, whose inlet end is connected with the underground storage tank through a submersible pump; A valve three and a delivery pump are sequentially arranged on the bottom outlet of the lean liquid storage tank, the delivery pump is connected with the lean liquid inlet of the absorption tower of the desulfurization system, and enters the circulation system.

[0008] The beneficial effects of the present application are: when the sodium sulfate is removed, the lean liquid cooled by the lean-liquid rich-liquid heat exchanger enters the heat exchanger for heat exchange and cooling again, enters the crystallization kettle, and the cold water prepared by the water-cooled screw low-temperature brine unit is introduced into the heat exchange pipe in the crystallization kettle to cool and cool the lean liquid in the crystallization kettle. Under the stirring of the stirrer, the sodium sulfate in the lean liquid in the crystallization kettle gradually crystallizes to form sodium sulfate crystals. After the lean liquid is cooled and crystallized in the crystallization kettle, it enters the centrifuge for solid-liquid separation, and the separated sodium sulfate crystals are sold, and the lean liquid is punched into the lean liquid storage tank for standby. The present application deeply removes the sulfate in the lean liquid through the setting of the refrigeration unit, the heat exchanger, the crystallization axe and the centrifuge, and ensures the normal operation of the system. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 The schematic diagram of the present application.

[0010] Among them, 1-absorption tower, 2-lean liquid inlet, 3-smoke gas inlet, 4-laying liquid device one, 5-fume catching device one, 6-gas outlet, 7-rich liquid pump, 8-lean-rich liquid heat exchanger, 9-lean liquid pump, 10-regeneration tower, 11-laying liquid device two, 12-fume catching device two, 13-smoke gas outlet, 14-valve one, 15-valve two, 16-underground storage tank, 17-underground pump, 18-sodium sulfate, 19-centrifuge, 20-water-cooled screw low-temperature brine unit, 21-crystallization kettle, 22-heat exchange pipe, 23-stirrer, 24-heat exchanger, 25-cooling water inlet, 26-cooling water outlet, 27-lean liquid storage tank, 28-valve three, 29-conveying pump. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical scheme and advantages of the present application more clear and obvious, the present application will be further described in detail below in combination with specific embodiments. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present application. In addition, in the following description, the description of the known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0012] As Figure 1As shown, the device for improving the circulation efficiency of ionic liquid includes: a heat exchanger 24 connected with the lean liquid pipeline of the desulfurization system, so that the partially cooled lean liquid enters the heat exchanger 24 for further heat exchange and cooling; a crystallization kettle 21 connected with the heat exchanger 24, so that the cooled lean liquid can enter the crystallization kettle 21; a water-cooled screw low-temperature brine unit 20, the cooling water pipeline of which is communicated with the heat exchange pipe 22 in the crystallization kettle 21 to heat exchange and cool the lean liquid in the crystallization kettle 21; and a centrifugal machine 19, the inlet end of which is connected with the bottom outlet of the crystallization kettle 21. The heat exchanger 24 is connected with the lean liquid pipeline of the desulfurization system through a valve 14. The crystallization kettle 21 is provided with a stirrer 23. The application further includes: a underground storage tank 16, the inlet end of which is connected with the lean liquid outlet end of the centrifugal machine 19; a lean liquid storage tank 27, the inlet end of which is connected with the underground storage tank 16 through a liquid pump 17; a valve 28 and a delivery pump 29 are sequentially arranged on the bottom outlet of the lean liquid storage tank 27, and the delivery pump 29 is connected with the lean liquid inlet 2 of the absorption tower 1 of the desulfurization system to enter the circulation system.

[0013] When the desulfurization system is running, the valve 14 is closed, the valve 15 is opened, the rich liquid pump 7 and the lean liquid pump 9 are started, and the flue gas enters the absorption tower 1 through the flue gas inlet 3. In the absorption tower 1, the flue gas is countercurrently contacted with the ionic liquid lean liquid of the liquid distribution device 4 to absorb the sulfur dioxide in the flue gas. After the sulfur dioxide in the flue gas is absorbed by the ionic liquid lean liquid, the ionic liquid lean liquid is converted into ionic liquid rich liquid and falls into the bottom of the absorption tower 1, and then is pumped into the lean-rich liquid heat exchanger 8 by the rich liquid pump 7. After the heat exchange and temperature rise of the rich liquid in the lean-rich liquid heat exchanger 8, the ionic liquid rich liquid enters the liquid distribution device 11 of the regeneration tower 10. The ionic liquid rich liquid distributed by the liquid distribution device 11 is analyzed in the regeneration tower 10 to release the sulfur dioxide in the ionic liquid rich liquid. After the sulfur dioxide is captured by the foam capturing device 12, it is discharged from the flue gas outlet 13 to enter the next process. The analyzed ionic liquid lean liquid falls into the bottom of the regeneration tower 10 and is pumped into the lean-rich liquid heat exchanger 8 by the lean liquid pump 9. After the heat exchange and cooling in the lean-rich liquid heat exchanger 8, the ionic liquid lean liquid enters the liquid distribution device 4 of the absorption tower 1 to continue the circulation. When the flue gas concentration of the flue gas inlet 3 increases sharply or is too high, the desorption of the regeneration tower 10 is insufficient, the pH value of the lean liquid decreases rapidly, the absorption efficiency decreases, and the system has the risk of exceeding the standard of sulfur dioxide discharge. In order to deal with the situation of sudden increase of the inlet sulfur dioxide concentration, liquid alkali needs to be added to the ionic liquid to quickly increase the pH value of the ionic liquid, so as to ensure that the flue gas meets the standard for discharge. With the circulation of the ionic liquid, the sodium salt in the ionic liquid accumulates continuously, and the sodium sulfate needs to be removed regularly to ensure the stable operation of the system.

[0014] When the sodium sulfate is removed, the valve one 14 and the valve two 15 are adjusted, according to the production process index, the part of the lean liquid after the temperature reduction enters the heat exchanger 24 for further heat exchange and temperature reduction, then enters the crystallization kettle 21, the water-cooled screw low-temperature brine unit 20 is opened, the cold water prepared by the water-cooled screw low-temperature brine unit enters the heat exchange pipe 22 to perform heat exchange and temperature reduction on the lean liquid in the crystallization kettle 21, under the stirring of the stirrer 23, the sodium sulfate in the lean liquid in the crystallization kettle 21 gradually crystallizes to form sodium sulfate crystals. After the temperature reduction and crystallization of the lean liquid in the crystallization kettle 21 are completed, the lean liquid enters the centrifugal machine 19 for solid-liquid separation, the separated sodium sulfate crystals 18 are sold, the lean liquid enters the underground storage tank 16 and is pumped into the lean liquid storage tank 27 by the submersible pump 17 for standby, when the lean liquid needs to be supplemented, the valve three 28 is opened, the delivery pump 29 is started to make the lean liquid enter the absorption tower 1 through the lean liquid inlet 2 to enter the circulation system.

[0015] The cold water prepared by the water-cooled screw low-temperature brine unit 20 enters the crystallization kettle 21 to perform heat exchange and temperature reduction on the lean liquid in the crystallization kettle 21, so that the sodium sulfate in the lean liquid gradually crystallizes to form sodium sulfate crystals.

[0016] It should be understood that the above specific embodiments of the present application are only used for illustrative or explanatory purposes of the principles of the present application, and do not constitute a limitation of the present application. Therefore, any modification, equivalent replacement, improvement, etc. made without departing from the spirit and scope of the present application shall be included in the protection scope of the present application. In addition, the appended claims of the present application are intended to cover all variations and modifications falling within the scope and boundary of the appended claims, or the equivalent forms of such scope and boundary.

Claims

1. A device for improving the efficiency of ion liquid circulation, characterized in that, It comprises: a heat exchanger (24) connected with the lean liquid pipeline of the desulfurization system, so that the partially cooled lean liquid enters the heat exchanger (24) for further heat exchange and cooling; a crystallization kettle (21) connected with the heat exchanger (24), so that the cooled lean liquid can enter the crystallization kettle (21); a water-cooled screw low-temperature brine unit (20), whose cooling water pipeline is in communication with the heat exchange pipe (22) in the crystallization kettle (21), so as to perform heat exchange and cooling on the lean liquid in the crystallization kettle (21); a centrifugal machine (19) with its inlet end connected with the bottom outlet of the crystallization kettle (21).

2. The device for improving the circulation efficiency of ionic liquid according to claim 1, characterized in that, The heat exchanger (24) is connected with the lean liquid pipeline of the desulfurization system through a valve one (14).

3. The device for improving the circulation efficiency of ionic liquid according to claim 1, characterized in that, The crystallization kettle (21) is provided with a stirrer (23).

4. The device for improving the circulation efficiency of ionic liquid according to claim 1, characterized in that, It further comprises: an underground storage tank (16) with its inlet end connected with the lean liquid outlet end of the centrifugal machine (19); a lean liquid storage tank (27) with its inlet end connected with the underground storage tank (16) through a submersible pump (17); a valve three (28) and a delivery pump (29) are sequentially arranged on the bottom outlet of the lean liquid storage tank (27), and the delivery pump (29) is connected with the lean liquid inlet (2) of the absorption tower (1) of the desulfurization system, and enters the circulating system.

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