The preparation equipment for high-purity nitrogen contains a liquid nitrogen tank connected with the rectifying tower and a condenser. The air compressor leads air into the rectifying tower through pipeline. The air is cooled by the latent heat of evaporating the liquid nitrogen from the tank. Nitrogen and oxygen are separated owing to the boiling-point difference, and the nitrogen gas is taken out through the exhaust pipe. In the rectifying tower, there are a bell-shaped dome and a gas collector. The nitrogen gas to the upper part of the rectifying tower together with that out of the exhaust pipe rotates to exhaust. The gas impurities, helium and hydrogen, in the nitrogen product is collected by means of centrifugal force and exhausted to atmosphere. |