Tail gas absorption tower

Abstract

A tail gas absorption tower comprises a gas-liquid separator, a first-stage absorption tower body and a second-stage absorption tower body, liquid storage tanks are arranged at the bottoms of the first-stage absorption tower body and the second-stage absorption tower body, a water inlet is formed in the side wall of each liquid storage tank and connected with a water source, opening and closing are controlled through a floating ball valve, an alkali feeding opening is formed in the top of each liquid storage tank, and a liquid discharging valve is arranged at the bottom of each liquid storage tank. An exhaust port of the first-stage absorption tower body supplies gas to the second-stage absorption tower body through a pipeline, a feeding port of the gas-liquid separator is connected with a tail gas source, a liquid phase outlet is connected with a tail gas condensate collecting tank, the tail gas condensate collecting tank is connected with a drain valve of each liquid storage tank through a waste liquid pipe, and a gas phase outlet supplies gas to the first-stage absorption tower body through a fan; the liquid storage tanks are connected with the waste liquid pipe through overflow pipes, the overflow pipes are not higher than the water inlets of the corresponding liquid storage tanks, and the downstream ends of the overflow pipes are located on the downstream portions of the corresponding liquid drainage valves. The device is simple in structure and convenient to operate, can automatically discharge and absorb rich liquid and automatically replenish water, and ensures that low-COD (Chemical Oxygen Demand)-value absorption liquid is always utilized to absorb tail gas.

Description

Technical Field

[0001] The utility model relates to the field of chemical industry, in particular to a tail gas absorption tower. Background Art

[0002] The tail gas generated during the production process of chemical enterprises needs to be discharged to the outside after passing through the tail gas treatment system, such as absorption by lean liquid, incineration treatment by incineration tower, etc. At present, the tail gas absorption tower absorption method is to regularly absorb the tail gas passing through the tail gas absorption tower by artificial water replenishment and adding caustic soda flakes on site to prepare alkali solution. It is necessary to frequently sample and test the absorption liquid to ensure that the tail gas absorption tower always uses low COD absorption liquid to absorb the tail gas, resulting in high labor intensity. In addition, the absorption amount of the absorption liquid varies during the sampling process, and it is difficult to accurately determine the COD value of the absorption liquid.

[0003] Therefore, how to design a tail gas absorption tower that can maintain a low COD value absorption liquid and ensure absorption efficiency is a problem that needs to be solved urgently by technical personnel in this field. Summary of the invention

[0004] The utility model aims to provide a tail gas absorption tower in view of the deficiencies in the prior art, which has a simple structure and is easy to operate. It can automatically discharge the rich absorption liquid and automatically replenish water, ensuring that the low COD value absorption liquid is always used to absorb the tail gas, thus meeting environmental protection requirements.

[0005] The technical scheme of the utility model is: a tail gas absorption tower, including a gas-liquid separator, a primary absorption tower body, a secondary absorption tower body, and a circulation pipeline. The tower bottoms of the primary absorption tower body and the secondary absorption tower body are both provided with liquid storage tanks. The side walls of the liquid storage tanks are provided with water inlets connected to a water source, and the opening and closing are controlled by a float valve. The top of each liquid storage tank is provided with an alkali injection port, and the bottom is provided with a drain valve. The downstream end of the circulation pipeline is connected to the inlet of the sprayer of the corresponding absorption tower body, and the upstream end extends into the corresponding liquid storage tank and is located below the liquid level. A circulation pump is provided on each circulation pipeline. The exhaust port of the absorption tower body supplies gas to the secondary absorption tower body through a pipeline, and the exhaust port of the secondary absorption tower body is connected to the atmosphere. The feed port of the gas-liquid separator is connected to the tail gas source, and the liquid phase outlet of the gas-liquid separator is connected to a tail gas condensate collection tank, which is connected to the drain valve of each liquid storage tank through a waste liquid pipe. The gas phase outlet of the gas-liquid separator supplies gas to the primary absorption tower body through a fan, and each liquid storage tank is connected to the waste liquid pipe through an overflow pipe, and the upstream end of the overflow pipe is not higher than the height of the water inlet of the corresponding liquid storage tank, and the downstream end is located downstream of the corresponding drain valve.

[0006] It also includes a heat exchanger, and the feed port of the gas-liquid separator is connected to the tail gas source through the process medium channel of the heat exchanger.

[0007] A waste liquid pipe is provided at the bottom of the tail gas condensate collection tank for connecting to a sewage treatment station.

[0008] The water source is production water and / or fire fighting water.

[0009] The above technical solution has the following beneficial effects:

[0010] 1. The tail gas absorption tower includes a gas-liquid separator, a primary absorption tower body, a secondary absorption tower body, and a circulation pipeline. The bottom of the primary absorption tower body and the secondary absorption tower body are both provided with a liquid storage tank. The side wall of each liquid storage tank is provided with a water inlet connected to a water source, and the opening and closing are controlled by a float valve. The opening of the float valve is determined by the liquid level in the corresponding liquid storage tank. When the liquid level is low, the opening of the float valve is large, and when the liquid level is high, the opening of the float valve is small or even closed. The top of each liquid storage tank is provided with an alkali injection port and the bottom is provided with a drain valve. Alkali is uniformly injected into the liquid storage tank through the alkali injection port to obtain alkali solution as the absorption liquid. The downstream end of the circulation pipeline is connected to the sprayer inlet of the corresponding absorption tower body, and the upstream end extends into the corresponding liquid storage tank, which is located below the liquid level. A circulation pump is provided on each circulation pipeline, and the absorption liquid in the liquid storage tank is circulated in the absorption tower body through the circulation pipeline. The exhaust port of the primary absorption tower body supplies gas to the secondary absorption tower through a pipeline, and the exhaust port of the secondary absorption tower body is connected to the atmosphere, and the tail gas after secondary absorption is discharged from the high point of the exhaust port of the secondary absorption tower body. The feed port of the gas-liquid separator is connected to the tail gas source, and the liquid phase outlet of the gas-liquid separator is connected to a tail gas condensate collection tank, which is connected to the drain valve of each liquid storage tank through a waste liquid pipe. The gas phase outlet of the gas-liquid separator supplies gas to the primary absorption tower body through a fan, that is, the generated tail gas is first separated by the gas-liquid separator, and then the liquid phase therein is separated to reduce corrosion to the fan. Each liquid storage tank is connected to the waste liquid pipe through an overflow pipe, and the upstream end of the overflow pipe is not higher than the height of the water inlet of the corresponding liquid storage tank, and the downstream end is located downstream of the corresponding drain valve. Under normal circumstances, after the absorption liquid level in each liquid storage tank reaches a certain height, it is discharged by the corresponding overflow pipe and sent to the exhaust gas condensate collection tank through the waste liquid pipe for centralized treatment, thereby realizing automatic water replenishment and automatic drainage of the liquid storage tank, stably maintaining a low COD value, and thus ensuring the absorption effect of the exhaust gas.

[0011] 2. It also includes a heat exchanger. The feed port of the gas-liquid separator is connected to the exhaust gas source through the process medium channel of the heat exchanger to cool the exhaust gas, ensure the absorption effect of the absorption liquid on the exhaust gas, and improve the gas-liquid separation effect of the downstream gas-liquid separator, effectively ensuring the service life of the fan.

[0012] Further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a connection diagram of the utility model.

[0014] In the accompanying drawings, 1 is a primary absorption tower body, 2 is a secondary absorption tower body, 3 is a gas-liquid separator, 4 is a circulation pipeline, 5 is a liquid storage tank, 6 is a float valve, 7 is an alkali injection port, 8 is a drain valve, 9 is a circulation pump, 10 is a tail gas condensate collection tank, 11 is a waste liquid pipe, 12 is a fan, 13 is an overflow pipe, 14 is a heat exchanger, and 15 is a waste liquid pipe. DETAILED DESCRIPTION

[0015] See also Figure 1 , which is a specific embodiment of a tail gas absorption tower. The tail gas absorption tower includes a gas-liquid separator 3, a primary absorption tower body 1, a secondary absorption tower body 2, and a circulation pipeline 4. A liquid storage tank 5 is provided at the bottom of the primary absorption tower body 1 and the secondary absorption tower body 2. The side wall of each liquid storage tank 5 is provided with a water inlet connected to a water source, and the opening and closing is controlled by a float valve 6. The water source can be production water and / or fire water, and production water is usually used as the water source. An alkali injection port 7 is provided at the top of each liquid storage tank 5, and a drain valve 8 is provided at the bottom. The downstream end of the circulation pipeline 4 is connected to the sprinkler inlet of the corresponding absorption tower body, and the upstream end extends into the corresponding liquid storage tank, which is located below the liquid level. A circulation pump 9 is provided on each circulation pipeline 4. The exhaust port of the primary absorption tower body 1 supplies gas to the secondary absorption tower body 2 through a pipeline, and the exhaust port of the secondary absorption tower body 2 is connected to the atmosphere, and is usually emptied at a high point. The feed port of the gas-liquid separator 3 is connected to the tail gas source. In this embodiment, a heat exchanger 14 is also provided. The feed port of the gas-liquid separator 3 is connected to the tail gas source through the process medium channel of the heat exchanger. Circulating water flows through the heat exchange medium channel of the heat exchanger to cool the tail gas. The liquid phase outlet of the gas-liquid separator 3 is connected to the tail gas condensate collection tank 10. A waste liquid pipe 15 is provided at the bottom of the tail gas condensate collection tank 10 for connecting to a sewage treatment station. The tail gas condensate collection tank 10 is connected to the drain valve 8 of each liquid storage tank through the waste liquid pipe 11. The gas phase outlet of the gas-liquid separator 3 supplies gas to the primary absorption tower body 1 through the fan 12. Each liquid storage tank 5 is connected to the waste liquid pipe 11 through an overflow pipe 13, and the upstream end of the overflow pipe 13 is not higher than the height of the corresponding liquid storage tank water inlet, and the downstream end is located downstream of the corresponding drain valve 8.

[0016] The working principle of the utility model is as follows: the tail gas is first cooled by the heat exchanger and then enters the gas-liquid separator, the liquid phase is separated and enters the tail gas condensate collection tank for temporary storage, and the gas phase is separated and sent to the primary absorption tower body through the fan. The production water and / or fire water enters the corresponding liquid storage tank through the float valve, and alkali is continuously added through the alkali injection port. The circulation pump is turned on to circulate the alkali solution in the primary absorption tower body and the secondary absorption tower body, and the tail gas passing through the tower body is subjected to primary and secondary absorption and then emptied at the high point. When the absorption liquid level in the liquid storage tank exceeds the specified height, it overflows from the corresponding overflow pipe to the waste liquid pipe, enters the tail gas condensate collection tank, and is finally discharged from the waste liquid pipe to the sewage station for centralized treatment.

Claims

1. A tail gas absorption tower, characterized in that: It comprises a gas-liquid separator (3), a primary absorption tower body (1), a secondary absorption tower body (2), and a circulation pipeline (4). A liquid storage tank (5) is provided at the bottom of each primary absorption tower body (1) and a secondary absorption tower body (2). A water inlet is provided on the side wall of each liquid storage tank (5) and is connected to a water source. The water inlet is controlled to be opened and closed by a float valve (6). An alkali injection port (7) is provided at the top of each liquid storage tank (5), and a liquid discharge valve (8) is provided at the bottom. The downstream end of the circulation pipeline (4) is connected to the inlet of the sprayer of the corresponding absorption tower body, and the upstream end extends into the corresponding liquid storage tank and is located below the liquid level. A circulation pump (9) is provided on each circulation pipeline (4). The exhaust port of the primary absorption tower body (1) supplies air to the secondary absorption tower body (2) through a pipeline, and the exhaust port of the secondary absorption tower body (2) is connected to the atmosphere. The feed port of the gas-liquid separator (3) is connected to the tail gas source, the liquid phase outlet of the gas-liquid separator (3) is connected to a tail gas condensate collection tank (10), the tail gas condensate collection tank (10) is connected to the drain valve (8) of each liquid storage tank through a waste liquid pipe (11), and the gas phase outlet of the gas-liquid separator (3) supplies gas to the primary absorption tower body (1) through a fan (12). Each liquid storage tank (5) is connected to the waste liquid pipe (11) via an overflow pipe (13), and the upstream end of the overflow pipe (13) is not higher than the height of the water inlet of the corresponding liquid storage tank, and the downstream end is located downstream of the corresponding drain valve (8).

2. The tail gas absorption tower according to claim 1, characterized in that: It also includes a heat exchanger (14), and the feed port of the gas-liquid separator (3) is connected to the tail gas source through a process medium channel of the heat exchanger.

3. The tail gas absorption tower according to claim 1, characterized in that: A waste liquid pipe (15) is provided at the bottom of the tail gas condensate collection tank (10) for connecting to a sewage treatment station.

4. The tail gas absorption tower according to claim 1, characterized in that: The water source is production water and / or fire fighting water.

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