Vinyl chloride deacidification device capable of reducing alkali consumption

Abstract

The utility model relates to the technical field of chloroethylene deacidification, and discloses a chloroethylene deacidification device capable of reducing alkali consumption, which comprises a combined acid absorption tower, a gas-liquid separation tank and an alkali absorption tower, the top of the gas-liquid separation tank is provided with a gas inlet and a gas outlet, and the combined acid absorption tower is connected with the gas inlet of the gas-liquid separation tank through an exhaust pipe; a gas outlet of the gas-liquid separation tank is connected with a gas phase inlet of the alkali absorption tower through a communicating pipe, and an acid discharge port is formed in the bottom of the gas-liquid separation tank and is connected with the combined acid absorption tower through an acid discharge pipe. The gas-liquid separation device has the beneficial effects that the gas-liquid separation tank is arranged between the combined acid absorption tower and the alkali absorption tower, and acid mist in gas discharged from the combined acid absorption tower can be removed, so that the alkali consumption of the alkali absorption tower is greatly reduced, and the load of the alkali absorption tower is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of vinyl chloride deacidification, in particular to a vinyl chloride deacidification device with reduced alkali consumption. Background Art

[0002] In the synthetic chemical production process of vinyl chloride, the generated vinyl chloride contains hydrogen chloride. To remove the hydrogen chloride, a multi-stage foam deacidification tower, a combined absorption tower, a water washing tower, or a combination of several towers is usually used. The purified gas after absorption also needs to be absorbed by an alkali tower to remove the remaining acid gas. Before the alkali tower absorbs, the gas coming out of each absorption tower contains a certain amount of acid mist, which will increase the load of the alkali tower and increase the alkali consumption.

[0003] The Chinese utility model patent with the authorization announcement number CN201147645Y discloses an intelligent temperature-controlled acid mist condensation purification device. The environmental protection equipment consists of an acid mist collection cover, a corrosion-resistant pipe, a corrosion-resistant fan, an acid mist condensation tower, an acid mist neutralization tower, a gas-liquid separation tower, and an intelligent temperature-controlled refrigerator. The intelligent temperature-controlled refrigerator controls the temperature in the acid mist condensation tower, so that the acid mist condenses on a relatively low-temperature corrosion-resistant heat exchanger and a multi-faceted hollow ball, and then neutralizes the remaining acid mist, thereby recovering the acid mist, reducing the amount of alkali used to neutralize the acid mist, and improving the acid mist treatment capacity. In this application, an intelligent temperature-controlled refrigerator is required for cooling, which consumes a lot of energy and has a high equipment cost. Utility Model Content

[0004] The utility model aims to remove excess hydrogen chloride in vinyl chloride and reduce the consumption of caustic soda. In view of the above-mentioned shortcomings of the prior art, a vinyl chloride deacidification device with reduced caustic soda consumption is proposed.

[0005] A vinyl chloride deacidification device for reducing alkali consumption comprises a combined acid absorption tower, a gas-liquid separation tank and an alkali absorption tower, wherein an air inlet and an air outlet are arranged on the top of the gas-liquid separation tank, the combined acid absorption tower is connected to the air inlet of the gas-liquid separation tank through an exhaust pipe, the air outlet of the gas-liquid separation tank is connected to the gas phase inlet of the alkali absorption tower through a connecting pipe, an acid discharge port is arranged at the bottom of the gas-liquid separation tank, and the acid discharge port is connected to the combined acid absorption tower through an acid discharge pipe.

[0006] By adopting the above technical scheme: the vinyl chloride gas containing hydrogen chloride passes through the combined acid absorption tower to remove hydrogen chloride, and the primary purified gas discharged from the exhaust pipe of the combined acid absorption tower also contains some hydrogen chloride acid mist. The hydrogen chloride acid mist is separated from the purified gas by a gas-liquid separation tank to obtain a secondary purified gas, and then the secondary purified gas enters the alkali absorption tower to remove the remaining acid gas, and the acid liquid collected at the bottom of the gas-liquid separation tank is refluxed to the combined acid absorption tower through the acid discharge pipe for reuse. The gas-liquid separation tank is arranged between the combined acid absorption tower and the alkali absorption tower to remove the acid mist in the outlet gas of the combined acid absorption tower, thereby greatly reducing the alkali consumption of the alkali absorption tower and reducing the load of the alkali absorption tower.

[0007] The above technical scheme is further configured as follows: the gas-liquid separation tank includes a tank body, a plurality of partition one, a plurality of partition two and a wire mesh demister, a plurality of partition one and partition two are alternately arranged in the tank body, the top of the partition one is fixedly connected to the top surface of the tank body, the two sides are fixedly connected to the side walls of the tank body, and a bottom flow channel is formed between the bottom and the bottom surface of the tank body; the two sides of the partition two are fixedly connected to the side walls of the tank body, a top flow channel is formed between the top of the partition two and the top surface of the tank body, the bottom of the partition two is lower than the bottom of the partition one, and the liquid level in the tank body is located between the bottom of the partition one and the bottom of the partition two.

[0008] The above technical solution is further configured as follows: the wire mesh demister is located between the adjacent partition plate 1 and partition plate 2.

[0009] By adopting the above technical solution: partition one and partition two divide the gas-liquid separation tank into a baffle channel, a wire mesh demister is provided in the baffle channel, and the gas discharged from the combined acid absorption tower flows along the baffle channel in the tank body, which can increase the residence time of the gas in the gas-liquid separation tank, so that the gas in the gas-liquid separator tank is fully in contact with the wire mesh demister, thereby enhancing the gas-liquid separation effect.

[0010] The above technical solution is further configured as follows: the combined acid absorption tower includes a foam deacidification tower, a concentrated acid deacidification mechanism, a dilute acid deacidification mechanism and a water washing tower which are connected in sequence.

[0011] The above technical solution is further configured as follows: the exhaust pipe is arranged at the top of the water washing tower.

[0012] By adopting the above technical solution: most of the hydrogen chloride gas can be removed from the vinyl chloride gas after being treated in the combined acid absorption tower, and the last stage of purified gas is discharged from the top of the water washing tower. The first stage purified gas also contains a certain amount of acid mist.

[0013] The above technical solution is further configured as follows: an acid return port is provided on the dilute acid deacidification mechanism, and the water outlet end of the acid discharge pipe is connected to the acid return port.

[0014] By adopting the above technical solution, the acid liquid collected at the bottom of the gas-liquid separation tank is discharged from the acid discharge pipe into the dilute acid deacidification mechanism and can be used for the subsequent deacidification of vinyl chloride gas.

[0015] The above technical solution is further configured as follows: the acid discharge port is higher than the acid return port.

[0016] By adopting the above technical solution: the height of the acid discharge port of the gas-liquid separation tank is higher than the acid return port, so that the acid liquid in the gas-liquid separation tank can flow into the dilute acid deacidification mechanism by means of the potential difference.

[0017] The above technical solution is further configured as follows: a U-shaped bend is provided in the middle of the acid discharge pipe, and the top height of the U-shaped bend is higher than the acid discharge port.

[0018] By adopting the above technical solution: the U-shaped elbow is a liquid sealing device, which can prevent the gas in the gas-liquid separation tank from flowing back to the dilute acid deacidification mechanism.

[0019] The beneficial effects of the utility model are:

[0020] 1. The vinyl chloride gas containing hydrogen chloride passes through the combined acid absorption tower to remove hydrogen chloride. The first-level purified gas discharged from the exhaust pipe of the combined acid absorption tower also contains some hydrogen chloride acid mist. The hydrogen chloride acid mist is separated from the purified gas by a gas-liquid separation tank to obtain a secondary purified gas. The secondary purified gas then enters the alkali absorption tower to remove the remaining acid gas. The acid liquid collected at the bottom of the gas-liquid separation tank flows back to the combined acid absorption tower through the acid discharge pipe for reuse. The gas-liquid separation tank is set between the combined acid absorption tower and the alkali absorption tower to remove the acid mist in the outlet gas of the combined acid absorption tower, thereby greatly reducing the alkali consumption of the alkali absorption tower and reducing the load of the alkali absorption tower.

[0021] 2. Partition 1 and partition 2 divide the gas-liquid separation tank into a baffle channel, and a wire mesh demister is provided in the baffle channel. The gas discharged from the combined acid absorption tower flows along the baffle channel in the tank body, which can increase the residence time of the gas in the gas-liquid separation tank, so that the gas in the gas-liquid separator tank is fully in contact with the wire mesh demister, thereby enhancing the gas-liquid separation effect.

[0022] 3. A U-shaped elbow is provided on the acid discharge pipe. The U-shaped elbow is a liquid sealing device, which can prevent the gas in the gas-liquid separation tank from flowing back to the dilute acid deacidification mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the utility model.

[0024] In the figure, 1. combined acid absorption tower; 101. foam deacidification tower; 102. concentrated acid deacidification mechanism; 103. dilute acid deacidification mechanism; 104. water washing tower; 105. exhaust pipe; 106. acid return port; 2. gas-liquid separation tank; 201. acid discharge port; 202. acid discharge pipe; 203. connecting pipe; 204. tank body; 205. partition one; 206. partition two; 207. wire mesh demister; 208. air inlet; 209. air outlet; 3. alkali absorption tower; 301. gas phase inlet; 302. air outlet pipe; 4. U-shaped bend pipe. DETAILED DESCRIPTION

[0025] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0026] Example 1

[0027] A chloroacetic acid deacidification device with reduced alkali consumption, such as Figure 1 As shown, it includes a combined acid absorption tower 1, a gas-liquid separation tank 2 and an alkali absorption tower 3. The combined acid absorption tower 1 includes a foam deacidification tower 101, a concentrated acid deacidification mechanism 102, a dilute acid deacidification mechanism 103 and a water scrubber 104 which are connected in sequence. The vinyl chloride gas containing hydrogen chloride enters from the foam deacidification tower 101 and is finally discharged from the water scrubber 104. An exhaust pipe 105 is provided on the top of the water scrubber 104. The vinyl chloride gas containing hydrogen chloride passes through the combined acid absorption tower 1 to remove hydrogen chloride, and the primary purified gas discharged from the exhaust pipe 105 of the water scrubber 104 also contains part of the hydrogen chloride acid mist.

[0028] like Figure 1 As shown, the top of the gas-liquid separation tank 2 is provided with an air inlet 208 and an air outlet 209, the bottom of the gas-liquid separation tank 2 is provided with an acid discharge pipe 202, the exhaust pipe 105 is connected to the top air inlet 208 of the gas-liquid separation tank 2, the top air outlet 209 of the gas-liquid separation tank 2 is connected to the gas phase inlet 301 of the alkali absorption tower 3 through a connecting pipe 203, and the top of the alkali absorption tower 3 is provided with an air outlet pipe 302. The gas-liquid separation tank 2 is used to separate the hydrochloric acid mist from the primary purified gas to obtain the secondary purified gas, and the secondary purified gas also contains a small amount of hydrogen chloride gas. The secondary purified gas enters the alkali absorption tower 3 through the connecting pipe 203, and finally the vinyl chloride gas without hydrogen chloride is discharged from the air outlet pipe 302 of the alkali absorption tower 3. The gas-liquid separation tank 2 is arranged between the combined acid absorption tower 1 and the alkali absorption tower 3, so as to remove the acid mist in the outlet gas of the combined acid absorption tower 1, thereby greatly reducing the alkali consumption of the alkali absorption tower 3 and reducing the load of the alkali absorption tower 3.

[0029] like Figure 1As shown, an acid discharge port 201 is provided at the bottom of the gas-liquid separation tank 2, an acid discharge pipe 202 is fixedly connected to the acid discharge port 201, an acid return port 106 is provided on the dilute acid deacidification mechanism 103, a water outlet end of the acid discharge pipe 202 is connected to the acid return port 106, and the height of the acid discharge port 201 is higher than the acid return port 106. The acid liquid collected at the bottom of the gas-liquid separation tank 2 is discharged from the acid discharge pipe 202 into the dilute acid deacidification mechanism 103, and can be used for the subsequent deacidification of vinyl chloride gas.

[0030] Example 2

[0031] like Figure 1 As shown, the gas-liquid separation tank 2 includes a tank body 204, a plurality of partition plates 205, a plurality of partition plates 206 and a wire mesh demister 207. The plurality of partition plates 205 and the plurality of partition plates 206 are alternately arranged in the tank body 204, and the wire mesh demister 207 is located between the adjacent partition plates 205 and 206. A plurality of support rods are fixedly connected in the horizontal direction in the tank body 204, and the wire mesh demister 207 is installed on the support rods. The top of partition 1 205 is fixedly connected to the top surface of the tank body 204, the two sides are fixedly connected to the side walls of the tank body 204, and a bottom flow channel is formed between the bottom and the bottom surface of the tank body 204; the two sides of partition 206 are fixedly connected to the side walls of the tank body 204, and a top flow channel is formed between the top of partition 206 and the top surface of the tank body 204, the bottom of partition 206 is lower than the bottom of partition 1 205, and the liquid level in the tank body 204 is located between the bottom of partition 1 205 and the bottom of partition 2 206.

[0032] like Figure 1 As shown, partition 1 205 and partition 2 206 divide the gas-liquid separation tank 2 into a baffle channel, in which a wire mesh demister is provided. The gas discharged from the combined acid absorption tower 1 flows along the baffle channel in the tank body 204, which can increase the residence time of the gas in the gas-liquid separation tank 2, so that the gas can fully contact with the wire mesh demister in the gas-liquid separator tank, thereby enhancing the gas-liquid separation effect.

[0033] Example 3

[0034] like Figure 1 As shown, a U-shaped elbow 4 is provided in the middle of the acid discharge pipe 202, and the top of the U-shaped elbow 4 is higher than the acid discharge port 201. The U-shaped elbow 4 is a liquid sealing device, which can prevent the gas in the gas-liquid separation tank 2 from flowing back to the dilute acid deacidification mechanism 103.

[0035] For matters not mentioned above, the prior art applies.

[0036] Although some specific embodiments of the utility model have been described in detail through examples, those skilled in the art should understand that the above examples are only for illustration, not for limiting the scope of the utility model. Those skilled in the art of the utility model can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, but they will not deviate from the direction of the utility model or exceed the scope defined by the attached claims. Those skilled in the art should understand that any modification, equivalent replacement, improvement, etc. made to the above implementation methods based on the technical essence of the utility model should be included in the protection scope of the utility model.

Claims

1. A vinyl chloride deacidification device for reducing alkali consumption, characterized in that: The invention comprises a combined acid absorption tower (1), a gas-liquid separation tank (2) and an alkali absorption tower (3); the top of the gas-liquid separation tank (2) is provided with an air inlet (208) and an air outlet (209); the combined acid absorption tower (1) is connected to the air inlet (208) of the gas-liquid separation tank (2) via an exhaust pipe (105); the air outlet (209) of the gas-liquid separation tank (2) is connected to the gas phase inlet (301) of the alkali absorption tower (3) via a connecting pipe (203); the bottom of the gas-liquid separation tank (2) is provided with an acid discharge port (201); the acid discharge port (201) is connected to the combined acid absorption tower (1) via an acid discharge pipe (202).

2. The vinyl chloride deacidification device for reducing alkali consumption according to claim 1, characterized in that: The gas-liquid separation tank (2) comprises a tank body (204), a plurality of partition plates 1 (205), a plurality of partition plates 2 (206) and a wire mesh demister (207); the plurality of partition plates 1 (205) and partition plates 2 (206) are alternately arranged in the tank body (204); the top of the partition plate 1 (205) is fixedly connected to the top surface of the tank body (204), the two sides are fixedly connected to the side walls of the tank body (204), and a bottom flow passage is formed between the bottom and the bottom surface of the tank body (204); the two sides of the partition plate 2 (206) are fixedly connected to the side walls of the tank body (204), a top flow passage is formed between the top of the partition plate 2 (206) and the top surface of the tank body (204), the bottom of the partition plate 2 (206) is lower than the bottom of the partition plate 1 (205), and the liquid level in the tank body (204) is located between the bottom of the partition plate 1 (205) and the bottom of the partition plate 2 (206).

3. The vinyl chloride deacidification device for reducing alkali consumption according to claim 2, characterized in that: The wire mesh demister (207) is located between the adjacent partition plate 1 (205) and partition plate 2 (206).

4. The vinyl chloride deacidification device for reducing alkali consumption according to claim 1, characterized in that: The combined acid absorption tower (1) comprises a foam deacidification tower (101), a concentrated acid deacidification mechanism (102), a dilute acid deacidification mechanism (103) and a water washing tower (104) which are connected in sequence.

5. The vinyl chloride deacidification device for reducing alkali consumption according to claim 4, characterized in that: The exhaust pipe (105) is arranged at the top of the water washing tower (104).

6. The vinyl chloride deacidification device for reducing alkali consumption according to claim 4, characterized in that: The dilute acid deacidification mechanism (103) is provided with an acid return port (106), and the water outlet end of the acid discharge pipe (202) is connected to the acid return port (106).

7. The vinyl chloride deacidification device for reducing alkali consumption according to claim 6, characterized in that: The acid discharge port (201) is higher than the acid return port (106).

8. The vinyl chloride deacidification device for reducing alkali consumption according to claim 6, characterized in that: A U-shaped curved pipe (4) is provided in the middle of the acid discharge pipe (202), and the top of the U-shaped curved pipe (4) is higher than the acid discharge port (201).

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