| 摘要 |
PROBLEM TO BE SOLVED: To provide a more efficient method of removing gaseous NOx, particularly, NO<SB>2</SB>and/or N<SB>2</SB>O<SB>4</SB>from a phosphate chemical conversion treatment reaction system. SOLUTION: Nitrogen oxide produced by the decomposition of nitric acid ions in a phosphate chemical conversion treatment bath is removed from a phosphate chemical conversion treatment reaction system. For this purpose, in addition to an electrolytic treatment cell where chemical conversion treatment reaction is performed, a preliminary cell where chemical conversion treatment is not performed is provided, and the space therebetween is provided with the main circulation piping system where pressure is applied with a liquid feed pump, and the solution in the treatment bath is transported, so that the solution is circulated. In the middle of the main circulation piping system, a capture means of capturing nitrogen oxide is provided, and also, a removal means of removing the captured nitrogen oxide to the outside of the main circulation piping system is provided. In the removal, after the temporary stop of the main circulation piping system, the solution separated from the electrolytic treatment cell, retained in the preliminary cell and freed from the nitrogen oxide is fed to the capture means, so that the solution in the capture means is replaced with the solution fed from the preliminary cell. COPYRIGHT: (C)2004,JPO&NCIPI
|
