DEVELOPING A HIGH-EFFICIENCY WASH COLUMN.

A new type of wash column for the industrial purification of solid particles from a suspension, is being developed, called the TNO-Thijssen wash column. The innovative aspects of the process are formed by the design and operation of the unit. Process and equipment have been demonstrated on a 100kg product per hour scale. Purities up to 99. 95% have been obtained for separation of para-xylene crystals from the mother liquor and a washing efficiency of 99% has been demonstrated when separating sodium chloride crystals from the saturated solution using only 21 of washing liquid per 100kg sodium chloride crystals. A theoretical model for the description of the transport in the wash column has been developed. Experimental results are in good agreement with the model calculations. On the basis of the model calculations, preliminary data can be given on the technical and economical feasibility of new applications of the wash column.