Process for separating a solid substance from a liquid mixture of substances

Claim 1

Process for recovering a powder by separating a liquid mixture of substances comprised of a dissolved solid substance and liquid substances, in which the liquid substances are separated from the solid substance by countercurrent extraction in an extraction chamber with a solvent to form a solvent phase which is loaded with the liquid substances and an extraction phase comprising said solid substance and solvent, the solvent, during the countercurrent extraction, is in a liquid or supercritical state and under standard conditions, is gaseous, the solvent phase which is loaded with the liquid substances is removed from the extraction chamber, the solvent phase subsequently is resolved by pressure reduction and/or temperature change into its components to recover gaseous solvent, the recovered gaseous solvent is returned into the extraction chamber, and the solid substance is recovered from said extraction phase in powder form, said process comprising (a) feeding the solvent to a cylindrical extraction chamber at the lowest point of the extraction chamber through nozzles, the extraction chamber having a diameter-to-height ratio of 1:5 to 1:10 and not having any internal components, the nozzles being in the form of bores and forming an angle of 0 to 60° with the axis of the extraction chamber, and (b) controlling the flow of the solvent through the extraction chamber by selecting the number and bore-width of the nozzles so that the solvent leaves the nozzles with a Reynolds' number of >40,000 and flows upwards in the extraction chamber with a Reynolds' number of 2,700 to 8,000.