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:
Mar. 16, 2004
Filed:
Jul. 20, 2001
Applicant:
Inventor:
Francis M. Stone, Jr., League City, TX (US);
Assignee:
Shell Oil Company, Houston, TX (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 3/02 ; F16K 4/900 ; E03B 7/12 ;
U.S. Cl.
CPC ...
H05B 3/02 ; F16K 4/900 ; E03B 7/12 ;
Abstract
A power supply system for electrically heated pipelines is provided. A variable frequency drive supplies power to the pipeline from an external source of electrical power. An isolation transformer and a contactor or isolating switch may be used between the variable frequency drive and the pipeline. A controller may be used in the system to control special sequences of power level and other needs for heating a pipeline.