Abstract: The incremental solvent dilution chilling of 600N waxy oils in a staged agitated chilling tower using cold solvent injection is improved in terms of feed filter rate with respect to a 600N waxy oil having a final boiling point of >600.degree. C. and a mean boiling point of about 500.degree. C. when the solvent dewaxing process is practiced under conditions of cold solvent injection such that there is an equal chilling rate/stage profile as compared to an equal temperature drop/stage profile in the chilling tower and with respect to a 600N waxy oil having a final boiling point of 600.degree. C. and a mean boiling point of about 500.degree. C. when the solvent dewaxing process is practiced under conditions of cold solvent injection such that there is an equal temperature drop/stage profile as compared to an equal chilling rate/stage profile in the chilling tower.

Abstract: A method is disclosed for the in-situ repair of damaged filter cloths in solvent dewaxing filters. The damage that can be repaired can be either or both of tears or holes. The method comprises thoroughly washing the filter cloth in the area of the damage to remove wax and oil, applying a quantity of solvent resistant adhesive to the damaged area such that the area of treatment extends beyond the hole or tear and adhesive overlays onto undamaged cloth, inserting pre-cut portions of filter cloth into the damage so as to completely fill the hole or tear but not create a bulge or cloth buildup in the face of the filter cloth where required and, finally, and optimally applying a final coating of adhesive over the repaired area.

Abstract: This invention relates to solvent dewaxing processes, for dewaxing waxy hydrocarbon oils using a dewaxing aid, which dewaxing aid comprises a mixture of (A) polyalkyl arcylate having alkyl group side chain length of from 10-26 carbons (excluding branching) and (B) an n-alkyl methacrylate polymer having alkyl group side chain length of from 10-20 carbons (excluding branching). Component (A) typically has a number average molecular weight of from 3,000 to 500,000 while component (B) typically has a number average molecular weight of from 5,000 to 200,000. The combination (A) plus (B) may be employed in a weight ratio within the range from about 1/100 to 100/1, preferably about 1/6 to 2/1 and at an aid does level ranging from about 0.01 wt % to 1 wt %, preferably 0.02 to 0.2 wt % active ingredient.