Method and device for treating converted gas in production of sodium nitrate

Abstract

The invention relates to a method and a device for treating converted gas in the production of sodium nitrate. The device comprises a conversion tower, a pre-conversion tower, an electric deentrainment tower, a gas-liquid separator, an acid-seal device and an absorption tower, wherein the electric deentrainment tower is provided with a constant-current high-pressure direct-current electric field for conversion. The gas outlet on the top of the conversion tower is connected with the converted gas inlet of the pre-conversion tower. The converted gas outlet of the pre-conversion tower is connected with the converted gas inlet, the converted gas outlet is connected with the absorption tower, and the separation liquid outlet is connected with the acid-seal device. Sodium nitrite mother solution and dilute nitric acid are subjected to conversion reaction in the conversion tower to produce sodium nitrate solution and converted gas, the sodium nitrate solution is sent to a nitrate work section to produce sodium nitrate product, and the converted gas enters into the pre-conversion tower to be subjected to pre-conversion reaction with the mother solution. The converted gas departing from the pre-conversion tower enters an alkali absorption system after the acid mist and liquid drops of nitric acid and fine foams of nitrate solution are removed by passing though the constant-current high-pressure direct-current electric field of the electric deentrainment tower. According to the method and the device for treating converted gas in the production of sodium nitrate, the high-voltage direct-current electric field is utilized to capture impurities in the converted gas so as to purify the converted gas, the use ratio of converted gas is increased, and the quality of sodium nitrite product and sodium nitrate product are improved.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and relates to a method and a device for treating converted gas in sodium nitrate production. Background technique [0002] In the nitrate production process, the conversion process is the process of reacting sodium nitrite mother liquor and dilute nitric acid in the conversion tower to form sodium nitrate solution and nitric oxide gas (ie, conversion gas). The sodium nitrate solution is sent to the nitrate The workshop section carries out operations such as evaporation, crystallization, centrifugation, and drying to produce sodium nitrate products. After the reformed gas is purified, it is mixed into the alkali absorption system, and continues to react with soda ash to prepare a qualified neutralizing solution for the production of sodium nitrite. [0003] Impurities such as nitric acid mist, liquid droplets, and fine foam of nitrate solution brought out when the reformed gas leaves...

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Problems solved by technology

The separated reformed gas still contains some liquid foam of nitrate salt solution. If it cannot be discharged in time, sodium nitrate and sodium nitrate in the liquid foam will crystallize and precipitate, which will block the separator, reduce the separation effect or even fail to achieve the separation effect. Furthermore, the acid mist entrained by the conversion gas is brought into the alkali absorption system, which affects the absorption rate of nitrogen oxides and the concentration of sodium nitrite in the neutralization solution

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