Patent · US Expired

Cryogenic rectification process for producing ultra high purity nitrogen

US4902321A · kind A · utility

15Cited by
8References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 16, 1989
Grant dateFeb 20, 1990
Priority date
Expiry dateMar 16, 2009

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF25J2270/02
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A process for producing ultra high purity nitrogen from nitrogen produced by the cryogenic rectification of air wherein superatomospheric nitrogen is progressively condensed and revaporized to effect rejection of lower boiling impurities without need for additional energy beyond that contained in the nitrogen input.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.