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:
Sep. 25, 1984
Filed:
Mar. 22, 1982
James W Hobbs, Sweeny, TX (US);
Phillips Petroleum Company, Bartlesville, OK (US);
Abstract
In a fractional distillation process in which first (light key) and second (heavy key) components contained in a feed stream are separated with the major portion of the light key component being removed in an overhead product stream and the major portion of the heavy key component being removed in a bottoms product stream, a signal which is responsive to the concentration of the light key component in the bottoms product stream is summed with a signal which is responsive to the concentration of the heavy key component in the overhead product stream to derive a signal which is utilized to manipulate the flow rate of the external reflux (sigma control). Also, the difference between a signal which is responsive to the concentration of the light key component in the bottoms product stream and a signal which is responsive to the concentration of the heavy key component in the overhead product stream is utilized to control the flow rate of the bottoms product stream (delta control). The sigma-delta control results in decoupling of the overhead product composition control and bottoms product composition control, improved recovery from disturbances and increased stability of the process.