Nitric acid production device by virtue of double pressurized method

Abstract

The invention provides a nitric acid production device by virtue of a double pressurized method. The device comprises an ammonia gas feeding assembly, an air feeding assembly an ammonia gas and air mixer and a tail gas separator, wherein the ammonia gas feeding assembly comprises an ammonia evaporator, an ammonia superheater and an ammonia filter which are sequentially connected through an ammonia delivery pipeline; the output end of the ammonia filter is communicated with an ammonia inlet of the ammonia gas and air mixer through the ammonia delivery pipeline; an ammonia adjusting valve and an ammonia emptying valve are sequentially arranged on the ammonia delivery pipeline between the ammonia superheater and the ammonia filter along the ammonia gas delivery direction; the air feeding assembly comprises an air compressor and an air delivery pipeline; the nitric acid production device by virtue of the double pressurized method further comprises a gas delivery pipeline, one end of which is connected with a gas outlet of the tail gas separator while the other end of which is connected to the ammonia delivery pipeline between the ammonia adjusting valve and the ammonia superheater. By adopting the device provided by the invention, tail gas before nitric acid production is connected back to the ammonia delivery pipeline to replace ammonia gas for an ammonia-air ratio test, so that the ammonia gas cost in a debugging stage is greatly lowered.

Description

technical field [0001] The invention belongs to the technical field of nitric acid production, and in particular relates to a double-pressurization nitric acid production device. Background technique [0002] At present, the most common method in the production of dilute nitric acid in industry is to adopt the double pressurization method. Firstly, the two raw material gases, namely 0.45MPa air and 0.52MPa ammonia gas, are pressurized once under the platinum mesh catalyst in a certain proportion. Oxidation produces NOx, and then NOx and secondary air are again pressurized to 1.1MPa by the nitrogen oxide compressor, and then absorbed in the absorption tower to generate dilute nitric acid. [0003] Among them, the most important thing in the whole production process is the mixing ratio control of raw gas air and ammonia, because ammonia is a Class B hazardous substance, the ignition temperature is 651 degrees, and the explosion limit is 15.5-27.0% volume fraction, once ammonia...

AI Technical Summary

Problems solved by technology

And when above-mentioned each operation is carried out, the ammonia gas in the pipeline after the last operation must be emptied, just can guarantee the accuracy of next operation, therefore caused a large amount of waste of raw material ammonia after the above-mentioned process is repeated, and direct test The discharged ammonia gas causes bad smell and environmental pollution

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