DRYING WATER-CONTAINING VALUABLE SUBSTANCES OR MIXTURES THEREOF WITH SUPERHEATED STEAM

摘要

PCT No. PCT/EP94/01987 Sec. 371 Date Feb. 23, 1996 Sec. 102(e) Date Feb. 23, 1996 PCT Filed Jun. 18, 1994 PCT Pub. No. WO95/00222 PCT Pub. Date Jan. 5, 1995A process for drying water-containing materials in a closed-circuit system using a vertical drying tower having inlets located at a lower portion of the tower, the inlets circulating superheated steam in countercurrent to the water-containing materials descending through the vertical drying tower thereby drying the water-containing materials, the improvement being: (a) providing an auxiliary fluid having a temperature below that of the superheated steam entering into the vertical drying tower; (b) providing a double jacket having a permeable inner wall wherein the double jacket surrounds the lower portion of the vertical drying tower below the inlets; and (c) introducing the auxiliary fluid through the permeable inner wall of the double jacket and into the vertical drying tower in a tangential or radial direction relative to the permeable inner wall.