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:
Aug. 05, 1980
Filed:
Dec. 28, 1978
Douglas G Ryan, Rockaway, NJ (US);
Other;
Abstract
A continuous, combination ketone-autorefrigerant solvent dewaxing process is disclosed wherein a waxy oil is partially solvent dewaxed to within from about 30.degree. to 110.degree. F. of the final wax filtration temperature in a first chilling zone, preferably comprising a plurality of agitated stages in the presence of a ketone dewaxing solvent to form a slurry containing solid wax particles, partially dewaxed oil and solvent. This ketone-containing slurry is passed to a second chilling zone, which is an autorefrigerant chilling zone, preferably employing liquid propylene operates on a continuous basis, and comprises a vertical, multi-staged tower, operating at constant pressure, wherein additional wax is precipitated from the slurry. In the second chilling zone the slurry is chilled down to the wax filtration temperature by stagewise contact with liquid propylene which is injected into a plurality of said stages and evaporated therein so as to cool the waxy slurry at an average rate of between about 0.1.degree. to 20.degree. F. per minute with an average temperature drop across each stage of between about 2.degree. and 20.degree. F. Some of the propylene remains in the oil which serves to further dilute and reduce the viscosity of the slurry. The dewaxed oil-containing slurry may then be fed directly to wax filters without having to pass through scraped-surface chillers and filter feed drum.