| 摘要 |
<p>PURPOSE:To effectively recover and utilize OFF-gas by a method wherein the evaporated gas (OFF-gas) in a low temp. storage tank is allowed to meet with exhaust gas to recover cold gas in a heat exchanger and the cold gas is used as either one of the regeneration or cooling gas of a pretreatment process. CONSTITUTION:A liquid nitrogen storage tank 21 is a low pressure and low temp. storage tank having a heat insulating layer 21a arranged to the periphery thereof and liquid nitrogen LN is supplied to a user from the pipeline 40 of the bottom part of the storage tank 21 through a valve 41. An OFF-gas recovery system 42 recovering OFF-gas OG is provided to the top part of the liquid nitrogen storage tank 21. The OFF-gas recovery system 42 is constituted of the pipeline 43 communicating with the top part of the storage tank, the check valve 44 provided to the pipeline 43 and a flow rate control valve 46 and the terminal of the pipeline 43 is connected to the pipeline 25 discharging the waste gas WG evaporated in a condenser 18. The OFF-gas OG evaporated in the liquid nitrogen gas storage tank 21 is passed through the OFF-gas recovery system 42 to be allowed to meet with an exhaust gas system and cold gas is recovered in a main heat exchanger 13 to be used as the regeneration gas RG of adsorbing equipment 8.</p> |
