Acid-system tail gas spraying clear-water-recycling and alkaline-water-draining washing tower and automatic control washing technology thereof

Abstract

The invention discloses an acid-system tail gas spraying clear-water-recycling and alkaline-water-draining washing tower and an automatic control washing technology thereof. The washing tower comprises an alkali liquor packing region, a desalted water packing region, a liquor storage vent tank and an alkali liquor storage region, wherein the liquor storage vent tank and the alkali liquor storage region are located between the two washing packing regions. The bottom of the alkali liquor storage region is connected with an inlet pipe of an alkali liquor spraying circulating pump, and an outlet pipe of the alkali liquor spraying circulating pump is connected with a pipe mixer to be connected to an alkali liquor nozzle at the upper portion of the alkali liquor packing region. The liquor storage vent tank is composed of a middle vent cylinder and a liquor storage tank, the lateral side of the liquor storage tank is connected with a desalted water spraying circulating pump through a pipe to be connected to a desalted water nozzle at the upper portion of the desalted water packing region. A tail gas inlet and a tail gas outlet are formed in the lateral side of the bottom and the top of the washing tower respectively. According to the technology, a substance-separating circulating washing circulating path is formed by an upper spraying circulating system and a lower spraying circulating system, and liquid-phase substance-separating washing of exhaust gas is achieved in one washing tower. By means of the washing tower and the technology, washing liquor is not mixed, and recycling of desalted water and draining of alkaline water are guaranteed.

Description

technical field [0001] The invention relates to the technical field of steel rolling waste acid solution regeneration system, in particular to an acid system tail gas spray purification water reuse and alkaline water discharge washing tower and its automatic control washing process. Background technique [0002] The waste acid produced by pickling strip steel in cold rolling mills is extremely corrosive. If it is not treated, it will cause serious pollution to the environment. At the same time, due to the large amount of hydrochloric acid discharge, it will also increase the cost of pickling. Nowadays, most of the treatment of pickling waste liquid adopts the spray roasting process, and the tail gas scrubbing system is one of the core subsystems in the spray roasting process. [0003] In the waste acid regeneration process of the spray roasting method, the waste acid undergoes a chemical reaction, and the free HCl produced is absorbed by the primary scrubber (absorption tow...

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Problems solved by technology

[0004] In the actual engineering design, in the past, the two layers of packing in the last stage of the washing tower were set up, and then the desalted water and NaOH, Na 2 SO 3 After spraying and washing with alkaline solution, the washed liquid is collected together in the bottom liquid storage tank and cannot be separated, and this solution mixed with alkaline substances cannot be reused in the acid regeneration system and can only be discharged into wastewater stand, causing waste

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