Negative-pressure ammonia distillation process and equipment for deaminizing ammonia before vacuum pump

Abstract

The invention relates to a negative-pressure ammonia distillation process and equipment for deaminizing ammonia before a vacuum pump. When a gas system adopts a recovery process of ammonia for producing ammonium sulfate, a sulfuric acid is used for absorbing ammonia in an acid pickling tower. The equipment comprises the acid pickling tower, a recycle liquid pump, a recycle liquid cooler, a fixed scale mixer or sulfuric acid metering pump, a concentrated sulfur acid tank and a connecting pipeline; when the gas system adopts the ammonia recovery process of anhydrous ammonia produced through ammonium phosphate ammonia-washing, ammonia or stronger ammonia water, the sulfuric acid or ammonium phosphate absorbs ammonia in the acid pickling tower. Compared with the prior art, the process and the equipment have the benefits that 1), the bad influence of ammonia in negative-pressure ammonia distillation exhaust gas on the performance and the operation of the liquid ring type vacuum pump is avoided, and since the vacuum pump is high in cost, the service life of the vacuum pipe is prolonged, the maintenance quantity of the vacuum pump is reduced, and the economic benefits of enterprises can be improved effectively; 2) the influence of ammonia on the vacuum degree of the vacuum pump is avoided, and the stable operation of a negative-pressure ammonia distillation system is ensured.

Description

technical field [0001] The invention relates to the technical field of recovery of coking chemical products, in particular to a negative pressure ammonia distillation process and equipment for deammonizing ammonia vapor before a vacuum pump. Background technique [0002] At present, there are two processes for residual ammonia distillation in the coking industry: positive pressure ammonia distillation and negative pressure ammonia distillation. Compared with positive pressure ammonia distillation, negative pressure ammonia distillation adopts vacuum distillation, which has the advantages of lower operating temperature, less corrosive medium, lower process requirements for equipment materials, and can use some waste heat as a heat source to reduce energy consumption. More attention has been paid to the coking industry. [0003] Such as figure 1 As shown, it is a negative pressure ammonia distillation process using the waste heat of raw coal gas as a heat source. The ammonia...

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Problems solved by technology

Second, ammonia and CO 2 Soluble in water, forming NH 4 HCO 3 Crystallization can easily cause vacuum pump blockage; salt crystals hang unevenly on the blades of the impeller, causing the impeller to be unbalanced and vibrate during operation; salt crystals enter the gap between the valve seat cover of the pump and the impeller, causing the gap to expand beyond the specified value. The suction chamber of the pump communicates with the exhaust chamber, reducing the performance of the pump

The above factors greatly shorten the maintenance and replacement cycle of the vacuum pump in actual use.

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