Abstract: An apparatus for treating in counter current of suspended particles with a liquid, whereby the particles and the liquid are transferred in opposite directions through a contact zone which, at some places, spaced in axial direction, is stirred in planes perpendicular to the centre line of the contact zone, in which the contact zone is one continuous space and that the volume fraction of the solid matter in the contact zone is maintained at a value between 0.20 and 0.55.

Abstract: An apparatus for concentrating a suspension consisting of a hollow cylinder in which one or more tubes of a constant outward diameter extend in axial direction, in the wall of each tube at least one filter being mounted forming the only direct connection between the interior of the tube and the interior of the cylinder. Two or more of such apparatus can be connected in series in order to form a cascade.

Abstract: An apparatus for concentrating a suspension consisting of a hollow cylinder in which one or more tubes of a constant outward diameter extend in axial direction, in the wall of each tube at least one filter being mounted forming the only direct connection between the interior of the tube and the interior of the cylinder. Two or more of such apparatus can be connected in series in order to form a cascade.

Abstract: Process for continuous crystallization of a liquid mixture in which the mixture is led through a cascade of cooling sections. The temperature in the first section is such that a part of the mixture crystallizes, the temperature in each succeeding section is lower than in the preceding section. The temperature in the last section is such that not the whole of the liquid mixture solidifies. The crystals kept suspended in the liquid are led through the cascade. In one section, not being the last one, the crystal and liquid flow is divided in two flows. One flow mainly formed by the crystals, the other by the liquid. A portion of the divided flow is recycled to the dividing section to keep the crystal volume fraction at a desired value.

Abstract: A method for treating in counter current of suspended particles with a liquid, whereby the particles and the liquid are transferred in opposite directions through a contact zone which, at some places, spaced in axial direction, is stirred in planes perpendicular to the center line of the contact zone, in which the contact zone is one continuous space and that the volume fraction of the solid matter in the contact zone is maintained at a value between 0.20 and 0.55.

Abstract: In a multistage countercurrent crystallization apparatus for multistage crystallization by adiabatic recrystallization and extractive washing comprising a vertical column containing a feed line, a waste material discharge, a purified product discharge, a crystallization zone or chamber at one end and a melter or dissolver at the other end, said vertical column containing a crystallizing liquid, a number of perforated plates subdividing said column into multistages, substantially spherical bodies contacting said perforated plates of a size larger than said perforations and designed to cooperate with the perforations of said perforated plates while in motion with respect to said perforated plates, means for vibrating said perforated plates whereby said substantially spherical bodies vehemently vibrate against said perforated plates, the improvement consisting essentially of reciprocating means to move said crystallizing liquid slowly and periodically with respect to said perforated plates in said column where s

Abstract: A process for the operation of a counter current crystallization column is described in which perforated plates or screens are positioned at spaced intervals. Movable objects such as steel balls or plastic balls are inserted in the column on each of the plates or screens and set into vibration by some kind of distance effect such as vibration of the entire column. The vibrating objects promote the passage of the crystals through the plate in that they have a milling effect on the crystals and are drumming against the plates. When said effect is wanted at the under side of the plates, supporting screens are mounted just below the plates and provided with the movable objects.