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:
Apr. 19, 1977
Filed:
Dec. 10, 1975
Nicholas Daviduk, Pennington, NJ (US);
David W Lewis, Lawrenceville, NJ (US);
Michael T Siuta, Torrance, CA (US);
Mobil Oil Corporation, New York City, NY (US);
Abstract
A process for in situ retorting of oil shale wherein an externally heated gas is circulated through a first retort zone. Surface retorting units comprised of compressors and furnaces are used to start the retorting process and to continue same until the off gas being recovered from the first retort zone reaches a temperature condition which is indicative that adequate heat is available in the retort zone to complete the retorting process without further external heating of the retorting gas. The surface retorting units are then replaced with frontal advance units comprised of low head fans which are capable of circulating the required volume of retorting gas but which require substantially less power to operate than the compressors. Also, when the units are interchanged the off gas from the first retort zone is diverted through a second retort zone to cool the off gas and to preheat the second zone.