Patent ID: 6827842
Filing Date: 2004-12-07
Classification: G01N

Abstract:
A solvent dewaxing process comprises:(a) contacting a waxy oil with cold dewaxing solvent to form a dewaxed oil and wax, both of which contain said dewaxing solvent; (b) heating said solvent containing dewaxed oil and wax and then passing same to separate solvent recovery fractionaters to separate and recover said solvent; (c) passing said hot recovered dewaxing solvent produced in (b) into a solvent line that passes it to solvent chillers downstream of said fractionaters and wherein said hot solvent is cooled back down to the cold dewaxing temperature in said chillers and recycled back to solvent dewax more waxy oil; (d) passing a slipstream of said hot recovered solvent from said line upstream of said chillers into a solvent loop containing a sample chamber and into said chamber without exposing said sample to the ambient, wherein said chamber contains wax crystal detecting means comprising a laser beam that is reflected by wax crystals focused at a point in said sample in said chamber, wherein wax crystals forming in said sample that pass through said focal point reflect said beam, and wherein said reflections are detected and recorded as indicating the presence of said wax crystals in said sample, and (e) cooling said sample in said chamber under conditions of relative motion between said beam and sample down to a predetermined temperature or until wax crystals form and are detected, and recording the temperature at which they form under conditions that provide relative movement between said beam and sample.