Coke oven gas purification system

Abstract

The invention discloses a coke oven gas purification system, comprising: a saturator, a soft water storage tank, a final cooling tower, a crude benzene distillation and separation water storage tank, an ammonia distillation device and a sewage treatment device, the soft water storage tank is connected to the saturator, and the saturator is connected to the final cooling tower. The air inlet of the lower section of the cooling tower is connected, the water outlet of the lower section of the final cooling tower is connected with the first delivery pump, the first delivery pump is connected with the first heat exchanger, and the first heat exchanger is connected with the water inlet of the lower section of the final cooling tower , the upper water outlet of the final cooling tower is connected to the second delivery pump, the second delivery pump is connected to the second heat exchanger, and the second heat exchanger is connected to the upper water inlet of the final cooling tower; the fourth pipeline is connected to the ammonia distillation device , the ammonia distillation unit is connected to the sewage treatment unit, the crude benzene distillation and separation water storage tank is connected with the sixth pipeline through the eleventh pipeline equipped with a submerged pump and the third valve, and the fourth pipeline is also connected with the sixth pipeline through a The twelfth pipeline of the fourth valve is communicated with the water supply main pipe. The invention has the advantage of low production and use cost for enterprises.

Description

technical field [0001] The invention relates to a coke oven gas purification system for reuse of waste water such as final cooling water in a coking plant and distilled and separated water in a crude benzene process. Background technique [0002] The current coke oven gas purification system (such as figure 1 shown) includes: saturator 40, soft water storage tank 41, final cooling tower 42, crude benzene distillation and separation water storage tank 43, ammonia distillation device 44 and sewage treatment device 45, soft water storage tank 41 passes through the first valve 46 The first pipeline 47 is connected with the water supply port of the saturator 40, and the gas outlet of the saturator 40 is connected with the lower section air inlet of the final cooling tower 42 through the second pipeline 48, and the lower section water outlet of the final cooling tower 42 passes through the second pipeline 48. The three pipelines 49 communicate with the water inlet of the first de...

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Problems solved by technology

[0003] The disadvantages of the above-mentioned coke oven gas purification system are: (1) Since the working principle of the saturator is to remove ammonia in the dry gas by reacting dilute sulfuric acid with ammonia in the dry gas to produce ammonium sulfate, when the concentration of ammonium sulfate in the saturator exceeds When saturated, a large number of ammonium sulfate crystal particles will be produced in the mother liquor, and part of the ammonium sulfate crystals will be attached to the inner wall of the saturator, reducing the gas flow section in the saturator and increasing the gas resistance. When it is over 2000Pa, it will bring safety hazards to the entire coke oven gas purification system. Therefore, when the gas resistance of the saturator exceeds 2000Pa, it is necessary to add soft water to the saturator to dilute the mother liquor, so that the ammonium sulfate mother liquor is from a supersaturated state. It becomes an unsaturated state, so that the ammonium sulfate crystals attached to the inner wall of the saturator are dissolved in the unsaturated mother liquor to achieve the purpose of reducing the gas resistance in the saturator; therefore, in order to ensure that the gas resistance in the saturator meets the normal production requirements, It is necessary to replenish soft water in the saturator regularly, resulting in a large amount of soft water used, not only high production and use costs of the enterprise, but also a lot of waste water, which makes the waste water treatment capacity of the terminal sewage treatment device large and increases the cost of sewage treatment; (2 ) Since the crude benzene distillation separation water produced in the crude benzene distillation process and stored in the crude benzene distillation separation water storage tank and the excess final cooling water generated by the final cooling tower also directly enter the sewage treatment device through the ammonia distillation device, further increasing the terminal The wastewater treatment capacity of the sewage treatment plant further increases the cost of sewage treatment and further increases the cost of production and use of enterprises

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