The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 12, 2002
Filed:
Jul. 06, 2000
Tsutomu Kikuchi, Tokyo, JP;
Tetsuya Satou, Tokyo, JP;
Akira Nishina, Tokyo, JP;
Tetsuya Kimijima, Tokyo, JP;
Nippon Sanso Corporation, Tokyo, JP;
Abstract
Gas supplying apparatus and gas substitution method where machinery and parts constituting the gas system are not damaged, and where gas substitution in the gas system is carried out in a short time with good efficiency. The gas substitution, method for substituting a gas after switching into a gas supplying passage by switching the kind of gases to be supplied includes carrying out an operation for fluctuating a pressure in the gas supplying passage within a range of pressure limitation of component parts thereof until a concentration of a gas before switching remaining in the gas supplying passage becomes parts per billion (ppb) level while the gas after switching is made to flow in the gas supplying passage; setting the pressure to a predetermined pressure; and carrying out an operation for increasing a flow rate of the gas after switching in the gas supplying passage under a flow rate limitation of the component parts thereof until the concentration of the gas is before switching remaining in the gas supplying passage becomes sub-ppb level.