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:
Jul. 22, 1997
Filed:
Mar. 09, 1995
William A Gast, Jr, Spokane, WA (US);
Nitec, Inc., Spokane, WA (US);
Abstract
A nitrogen generation control system and method are provided for controlling levels of nitrogen and oxygen in a controlled atmosphere within a container for perishable goods. The nitrogen generation control system has a nitrogen generator that controllably generates an amount of nitrogen, while releasing oxygen as an off gas. The nitrogen is injected into the container to create a controlled environment. A sample analyzer subsystem is connected to the container to extract a sample of gases from the controlled environment and analyze the oxygen content. The control system further includes a cascaded, dual control loop controller coupled to the nitrogen generator and sample analyzer subsystem. The controller has a nitrogen generation control loop to control the amount of nitrogen generated by the nitrogen generator in response to variation between the oxygen released during nitrogen generation and a reference amount of oxygen. The controller also has a container atmosphere control loop to control the reference amount of oxygen used as a control input to the nitrogen generation control loop in response to variation between the actual oxygen content in the container and a preselected oxygen level desired to be present in the container.