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CN-224207758-U - Improvement system for hydrogen chloride tail gas absorption in chlor-alkali production

CN224207758UCN 224207758 UCN224207758 UCN 224207758UCN-224207758-U

Abstract

The utility model discloses an improved system for absorbing hydrogen chloride tail gas in chlor-alkali production, wherein an air outlet at the top of a hydrogen chloride tail gas absorbing tower is connected with a lower side inlet pipeline in a hydraulic ejector, a water outlet pipeline at the bottom of the hydraulic ejector is connected with a gas-liquid separator, a liquid seal overflow water outlet of the gas-liquid separator is connected with a tail gas water absorbing tank, a water outlet at the lower side of the tail gas absorbing tank is connected with an inlet pipeline of an absorbing water pump, and a water outlet connecting pipeline of the absorbing water pump goes to a salt-dissolving water distribution barrel. The utility model solves the problems of poor hydrogen chloride absorption effect, high consumption of raw materials and auxiliary materials and low self-control level in the prior art, ensures that the process index stability reaches the best, ensures that the tail gas emission is lower than the emission standard, and enhances the safety and stability of the system.

Inventors

  • DU MIN
  • GUO FENG
  • Zhou Xiangqiong
  • HU BIN
  • WAN YIMING

Assignees

  • 湖北兴发化工集团股份有限公司

Dates

Publication Date
20260508
Application Date
20250430

Claims (9)

  1. 1. An improved system for absorbing hydrogen chloride tail gas in chlor-alkali production is characterized in that an air outlet at the top of a hydrogen chloride tail gas absorption tower (13) is connected with a middle-lower side air inlet pipeline of a hydraulic ejector (10), The bottom water outlet pipeline of the hydraulic ejector (10) is connected with the gas-liquid separator (11), The liquid seal overflow water outlet of the gas-liquid separator (11) is connected with a tail gas absorption water tank (14), The water outlet at the lower side of the tail gas absorption water tank (14) is connected with the inlet pipeline of the absorption water pump (3), The water outlet of the absorption water pump (3) is connected with a pipeline to lead the water to the salt dissolving water distribution barrel.
  2. 2. The improved system for hydrogen chloride tail gas absorption in chlor-alkali production of claim 1, wherein: The water outlet connecting pipeline of the absorption water pump (3) is connected with the water inlet at the top of the hydraulic ejector (10) through the water inlet connecting pipeline (17) of the absorption water hydraulic ejector, The water outlet connecting pipeline of the absorption water pump (3) is connected with the upper part of the waste gas absorption tower (12) through the water inlet waste gas absorption tower connecting pipeline (18).
  3. 3. The improved system for absorbing tail gas of hydrogen chloride in chlor-alkali production according to claim 2, wherein the top gas outlet of the waste gas absorbing tower (12) is connected with the inlet pipeline of the flame arrester (23), the outlet pipeline of the flame arrester (23) is connected with the atmosphere, and the nitrogen pipeline and the steam pipeline are connected with the atmosphere pipeline behind the flame arrester.
  4. 4. The improved system for absorbing hydrogen chloride tail gas in chlor-alkali production according to claim 1, wherein the top of the tail gas absorbing water tank (14) is connected with 7 independent pipelines in the tank, namely a nitrogen pipeline, a production water pipeline, a sodium hydroxide solution pipeline, a hydrogen washing tower condensate water pipeline, a hydrogen system water removal device condensate water pipeline, a gas-liquid separator overflow water pipeline and an exhaust gas absorbing tower overflow water pipeline.
  5. 5. The improved system for absorbing hydrogen chloride tail gas in chlor-alkali production according to claim 4, wherein a flowmeter (9) and a sodium hydroxide regulating valve (8) are arranged on a sodium hydroxide pipeline, a liquid level meter (1) is arranged on a tail gas absorption water tank, an absorption water thermometer (2) is arranged on an absorption water pump inlet pipeline, and an absorption water pump outlet pressure meter (4) is arranged on an outlet pipeline.
  6. 6. The improved system for absorbing hydrogen chloride tail gas in chlor-alkali production according to claim 5, wherein an absorption water pH meter (7) is arranged on a connection pipeline (17) of an absorption water inlet hydraulic ejector, a pressure meter (6) is arranged at the top of a gas-liquid separator (11), a tail gas absorption water tank liquid level regulating valve (5) is arranged on a pipeline of an absorption water pump outlet to a salt dissolving water distribution barrel, a hydrogen chloride tail gas analyzer (24) is arranged at an exhaust gas absorption tower outlet, a thermometer (21) is arranged on a pipeline of a flame arrester outlet, a nitrogen gas switch valve (20) is arranged on a nitrogen gas pipeline, and a steam switch valve (22) is arranged on a steam pipeline.
  7. 7. The improved system for absorbing tail gas of hydrogen chloride in chlor-alkali production according to claim 6, wherein a sodium hydroxide regulating valve (8) on a sodium hydroxide pipeline and an absorption water pH meter (7) form a PID self-control loop.
  8. 8. The improved system for absorbing hydrogen chloride tail gas in chlor-alkali production according to claim 6, wherein the tail gas absorption water tank liquid level regulating valve (5) on the pipeline of the absorption water pump outlet de-salified water distribution barrel and the tail gas absorption water tank liquid level meter (1) form a PID self-control loop.
  9. 9. The improved system for absorbing hydrogen chloride tail gas in chlor-alkali production according to claim 2, wherein the top air outlet of the tail gas absorbing water tank (14) is connected with the middle and lower pipelines of the waste gas absorbing tower (12), and the top air outlet of the gas-liquid separator (11) is connected with the middle and lower pipelines of the waste gas absorbing tower (12).

Description

Improvement system for hydrogen chloride tail gas absorption in chlor-alkali production Technical Field The utility model relates to the technical field of chlor-alkali production, in particular to an improved system for absorbing hydrogen chloride tail gas in chlor-alkali production. Background The hydrogen chloride tail gas has strong acidity, irritation, toxicity and corrosiveness, and can react with water vapor to form acid rain, which is harmful to the environment and the ecological system. The hydrogen chloride tail gas absorption flow generally comprises four steps, namely tail gas introduction, absorption process, purified gas discharge and absorption liquid treatment, and is also generally in countercurrent contact with water or alkaline solution in an absorption tower, the hydrogen chloride gas is absorbed by the absorption liquid, the absorbed gas is discharged from the top of the tower, and the hydrogen chloride discharge limit value of the chlor-alkali industry is required to be lower than 5mg/m < 3 >, so that the method is particularly important for process control in the hydrogen chloride tail gas absorption process. In the existing system process flow, the equipment and control system are considered to increase initial investment and maintenance cost, the design of the absorption system is simple, the process flow is short, only the most basic absorption process and control level are finished, for high-concentration or large-amount hydrogen chloride tail gas treatment, emergency treatment is often delayed, the tail gas intermittence exceeds the emission limit value, process control deviation is easy to cause explosion-proof membrane rupture caused by high furnace pressure of a synthetic furnace, peripheral equipment corrosion caused by environmental pollution, better automatic control and remote monitoring system are adopted, the production efficiency is greatly improved, the on-site production environment is improved, the intrinsic safety is enhanced, alkaline solution in chlor-alkali production is fully applied to absorb the tail gas, and the absorption liquid is conveyed by a variable frequency pump to be recycled to a salt-dissolving water distribution barrel for recycling, so that the energy consumption is greatly reduced. Disclosure of utility model The utility model aims at the problems and provides an improved system for absorbing hydrogen chloride tail gas in chlor-alkali production. The full-flow on-line monitoring, the remote automatic control and the emergency treatment of the tail gas absorption system are realized, manual intervention is not needed, the on-site production environment can be greatly improved, and the intrinsic safety is enhanced. The utility model aims to solve the technical problems, and adopts the technical scheme that the improved system for absorbing the hydrogen chloride tail gas in the chlor-alkali production comprises a gas outlet at the upper side of a hydrogen chloride tail gas absorption tower of the synthetic furnace, which is connected with a gas inlet pipeline at the middle and lower sides of a hydraulic ejector, a water inlet at the upper side of the hydraulic ejector is connected with a water outlet pipeline of an absorption water pump, and a water outlet pipeline at the lower side of the hydraulic ejector is connected with the hydraulic ejector. The liquid seal overflow water outlet of the gas-liquid separator is connected with a tail gas water absorption tank, the water outlet at the lower side of the tail gas water absorption tank is connected with an inlet pipeline of an absorption water pump, a water outlet pipe of the absorption water pump is connected with three independent pipelines, one pipeline is connected to a salt dissolving water distribution barrel, the second pipeline is connected with the top of a hydraulic ejector, and the third pipeline is connected with the upper part of a waste gas absorption tower. Seven pipelines which enter the tail gas absorption water tank are respectively connected to the top of the tail gas absorption water tank, and are respectively nitrogen, production water, sodium hydroxide, hydrogen washing tower condensate water, hydrogen system water removal device condensate water, overflow water of a gas-liquid separator and overflow water of an exhaust gas absorption tower, and an air outlet at the top of the tail gas absorption water tank is connected to the middle-lower pipeline of the exhaust gas absorption tower. The gas outlet at the top of the waste gas absorption tower is connected with the inlet pipeline of the flame arrester, the outlet pipeline of the flame arrester is connected with the atmosphere, and the nitrogen and steam pipelines are connected with the rear atmosphere pipeline of the flame arrester. The device is characterized in that a flowmeter and a regulating valve are arranged on the sodium hydroxide pipeline, a liquid level meter is arranged on the tail gas absorption water tank, an absor