METHOD OF AND DEVICE FOR PRODUCING NITROGEN OF HIGH PURITY.
摘要
<p>Material gas in a cooled state is fed into a main fractionating column so as to be rectified, liquid nitrogen is taken out at a position lower than the uppermost step in the main fractionating column, the liquid nitrogen thus taken out is fed into the sub-rectifier to be rectified, and nitrogen as a product is taken out from the sub-rectifier at a position lower than the position at which liquid nitrogen is introduced. <IMAGE></p>
