| 摘要 |
<p>PURPOSE:To shorten the time necessary to obtain a prescribed N2 purity in the restarting of the operation, by introducing desorbed gas into a product nitrogen holder after the desorbed gas in the desorption and recovery process reaches a prescribed nitrogen purity. CONSTITUTION:The pressure-swing adsorption apparatus for producing high- purity nitrogen is operated according to the following steps. A by-pass line 8 is closed, valves 92, 93 at the inlet and outlet of a circulating N2 holder 9 are closed and a valve 91 of a line 3 for supplying cleaning gas is opened. The valves of the lines 2, 3, 4, 5 are automatically opened and closed while keeping the above state, in such a manner as to enable the continuous operation of three absorption columns 1a, 1b and 1c shifted with each other by one step in three steps consisting of a compression, absorption and waste-gas exhaustion step, a pause-cleaning step and a desorption and recovery step. A high-purity N2 component gas is continuously accumulated in the product N2 holder 6 by this process. A part of the gas is taken out through valves 34, 91 as a cleaning gas for a cleaning step and the remaining part of the gas is delivered through a valve 61 as a product N2 gas.</p> |
