DEWAXING PROCESS USING AGITATED HEAT EXCHANGER TO CHILL SOLVENT-OIL AND WAX SLURRY TO WAX FILTRATION TEMPERATURE

摘要

ABSTRACT OF THE DISCLOSUREAn improved process for dewaxing waxy hydro-carbon oils, wherein said waxy oil is introduced at atemperature above its cloud point into a direct chill-ing zone divided into a plurality of stages, passingsaid waxy oil from stage-to-stage of said chillingzone, introducing a cold dewaxing solvent into atleast a portion of said stages, maintaining a highdegree of agitation in at least a portion of thestages containing solvent and waxy oil, thereby ef-fecting substantially instantaneous mixing thereofwhile cooling said solvent-waxy oil mixture, to atemperature greater than the wax separation tempera-ture, whereby a substantial portion of the wax isprecipitated from said waxy oil and forming a sol-ventoil mixture containing precipitated wax (slurryI), withdrawing said slurry I from said direct chill-ing zone and cooling same to the wax separation tem-perature in an indirect chilling zone thereby preci-pitating a further portion of wax from said waxy oiland separating said precipitated wax from the wax-oil-solvent mixture in solid-liquid separation means, theimprovement comprising using as the indirect chillingzone an indirect heat exchanger means operated at ahigh level of agitation. Expressed in terms ofImpeller Reynolds Number the agitation is on the orderof about 1,000 to 1,000,000.Alternatively, the staged, agitated, directchilling zone is totally replaced by the high agita-tion indirect heat exchanger means.