between about 1 10 and about 1 200 in general the chilling tower of the present invention will be operated at a pressure sufficient to prevent flashing of the solvent atmospheric pressure is sufficient when the ketones are employed as solvents however superatmospheric pressures are required when low molecular weight autorefrigerant hydrocarbons such as propane are used in some cases it is more advantageous to operate the tower under elevated pressure even when the dewaxing solvent does not contain an autorefrigerant in order to provide flow of the waxy oil solvent slurry to an elevated location and or wax filters etc without having to pump the slurry the invention will be more apparent from the working examples set forth below in this example experiments were run utilizing a single stage dilchill dewaxing laboratory batch unit which while not completely duplicating continuous multistage operation has been found to give results approximately equivalent to those obtained with continuous commercial multistage operations the batch unit contained a flat bladed impeller and a solvent injection tube experiments were conducted by filling the unit with the waxy oil to be chilled at just above its cloud point after the unit was filled with the waxy oil the impeller was started along with simultaneous injection of chilled solvent into the waxy oil at the impeller tip the rate of solvent injection was varied as the run progressed to simulate conditions in successive stages of a 17 stage continuously operated tower excess.