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:
Jan. 17, 1978
Filed:
Sep. 28, 1976
John D Karna, Renton, WA (US);
Gregory K Brock, Kelso, WA (US);
Daniel M Shellhammer, Longview, WA (US);
Weyerhaeuser Company, Tacoma, WA (US);
Abstract
Monitoring of the recirculated atmosphere of an oxygen pulping reactor to determine when the inflammability level of combustible gases in the reactor atmosphere has reached a predetermined percentage of the lower explosive limit (LEL) of the reactor atmosphere in terms of combustible organic vapors and carbon monoxide is disclosed. Continuous or discrete samples of the reactor atmosphere are taken at spaced regions, and the samples are applied to: (1) flame ionization detectors, which determine the concentration of combustible organic vapors (e.g., aliphatic, olefinic, aromatic, acetylenic, alcohols, aldehydes, ketones, etc.) in the samples; and, (2) carbon monoxide analyzers, which determine the concentration of carbon monoxide in the samples. The outputs of the flame ionization detectors are calibrated in terms of percent LEL for the contributing combustible organic vapors and, thus, provide percent combustible organic vapor LEL information. The outputs of the carbon monoxide analyzers are calibrated in terms of percent LEL based on the carbon monoxide in the samples. The outputs of the flame ionization detectors are compared and the highest percent output is applied to an alarm and recording subsystem. These outputs are also compared to determine if they are close to one another. If the comparison indicates that a substantial difference exists, a differential sensor activates a further alarm to denote a wide variance that may indicate a faulty detector channel. Similarly, the outputs of the two carbon monoxide analyzers are compared and the highest percent output is applied to an alarm and recording subsystem. Also, if the outputs are substantially different a differential indicator is activated. In addition, in an alternate embodiment, the highest flame ionization output is summed with the highest carbon monoxide analyzer output and the result applied to a controller that continuously controls the position of a vent valve, as well as to an alarm and recording subsystem. Finally, an oxygen analyzer is provided for measuring the oxygen concentration of at least one of the reactor atmosphere samples.