Method and device for preventing the nox emissions at the end of the interruptions of an emergency in the preparation of nitric acid.

摘要

The invention is aimed at preventing the no.sub.x emissions during interruptions of an emergency in the production of nitric acid. It is interrupted at 2a, 36, 37 the arrival of nitrous gases of the suction side of the compressor of nitrous gases 7; the nitrous gases which are situated on the dimension of the suction as 4, 5, 27 through the compressor 7 towards the delivery side; it is blocked by 10, 11, the gas which is located on the side outlet of the compressor is relaxes by 14 towards the suction side of the compressor, the gas present in the compressor, and it draws in a system under vacuum, the gas which is then of the dimension of the suction.