Processing method of waste nitric acid fume and device thereof

Abstract

The invention discloses a processing method of waste nitric acid fume, comprising the following steps: 1) introducing waste nitric acid fume into a main absorbing tower so as to perform first integrated reaction between the waste nitric acid fume and an introduced medicine, wherein the medicine is sprayed in the motion direction of the waste nitric acid fume through spray equipment when the integrated reaction is performed, and during the first integrated reaction, a filter pack is used for deceleration of the waste gas, uniform distribution of the sprayed medicine and complete reaction; 2) arranging a hollow layer in the main absorbing tower, allowing the waste gas to pass through the hollow layer, and performing a second integrated reaction between the waste gas and the medicine introduced in the main absorbing tower; and 3) introducing the waste gas from the main absorbing tower into an auxiliary absorbing tower so as to perform reaction and absorption again in the auxiliary absorbing tower, and discharging into the atmosphere through a chimney. The invention also discloses a treatment device. By the adoption of the treatment device provided by the invention, acid fog and acid gas in the waste gas can be rapidly and thoroughly absorbed through reactions. The device has a simple structure, and is energy saving and environmentally friendly.

Description

technical field [0001] The invention relates to the technical field of acid mist treatment in a surface treatment workshop, in particular to a nitric acid mist waste gas treatment method and a device technology thereof. Background technique [0002] In aluminum rod casting, profile extrusion, surface treatment, and deep processing, the acid mist generated by its surface treatment (anodizing) is generally neutralized by ammonia gas, and then discharged into the atmosphere after repeated spraying and neutralization of acid and alkali solutions . Although this process can handle most of the acid mist, when the amount of flue gas is large, the neutralization reaction is not sufficient, some yellow acid mist still emerges intermittently, and the pungent smell inherent in ammonia gas is also It pollutes the air during periods of low air pressure. According to the actual production analysis, this acid mist mainly contains acid mist formed by mixing sulfuric acid, phosphoric acid,...

AI Technical Summary

Problems solved by technology

Although this process can handle most of the acid mist, when the amount of flue gas is large, the neutralization reaction is not sufficient, some yellow acid mist still emerges intermittently, and the pungent smell inherent in ammonia gas is also pollutes the air during periods of low air pressure

According to the actual production analysis, this acid mist mainly contains acid mist formed by mixing sulfuric acid, phosphoric acid, nitric acid, nitrous acid and water, and a certain amount of nitrogen oxides (NO, NO2, etc.). Ammonia gas, ammonia water, liquid caustic soda (sodium hydroxide aqueous solution), or a mixture of ammonia water and liquid caustic soda can be used, and a spray tower or packed tower can be used, because the acid gas to be processed can be processed in a short time (about 3 seconds) It is relatively difficult to completely react and absorb completely. In the existing technology, the main equipment for removing acid mist and acid gas includes spray towers, plate towers, and packed towers. All types of equipment can reach 80-90% when the parameters are designed reasonably. The removal efficiency is high, but it still does not meet the requirements of environmental protection, and although the structure of the spray tower is simple, the cost is low, the pressure loss is small, the energy consumption of the required fan is low, the operation flexibility is large, and the operation is stable, but the gas-liquid ratio needs to be large ;The operating efficiency of the plate tower is high, but the operating flexibility is small, and it is not suitable for occasions where the air volume changes greatly; the processing efficiency of the packed tower is higher than that of the spray tower, but the cost of the filler is expensive, and it is generally suitable for small air volume projects

Images