| 摘要 |
Method for sealing the NO compressor (3) and the residual gas expander (11) in a plant for producing nitric acid by the dual pressure process, containing a low-pressure part (1), an NO compressor (3), wherein the shafts of the NO compressor (14, 15) are sealed from the gas-bearing parts by means of at least 2 sealing chambers, a high-pressure part with oxidation and absorption (5), at least one heat exchanger (7), a residual gas expander (11), wherein the shafts of the residual gas expander (12, 13) are sealed from the gas-bearing parts by means of at least 2 sealing chambers, and the sealing chambers all have labyrinth seals. In this method ammonia and compressed air are passed into the low-pressure part (3) of the nitric acid plant and there ammonia is oxidized to NO and water by means of a catalyst, and the resultant NO is in part oxidized to NO. The resultant NO-and NO-saturated gas (2) is passed into the NO compressor (3), the compressed NO-and NO-saturated gas (4) is passed into the high-pressure part (5) of the nitric acid plant where an oxidation of the remaining NO to NOproceeds, followed by an absorption of nitrogen dioxide to give nitric acid, the residual gas of the high-pressure part (6) is passed via at least one heat exchanger (7) into the residual gas expander (11), wherein the |
