GB1070494A - Improvements in or relating to continuous band filters - Google Patents

Abstract

An endless filter medium (e.g. cloth) (8), Fig. 1, (not shown) is supported by preferably two endless bands (1, 1\sv)(e.g. of rubber with reinforcing fabric embedded therein), travelling side by side and separated longitudinally by a narrow gap (5). A stationary suction box (12) extends beneath the upper run of the bands and under the gap. Each band has an upstanding rib (2) or (2\sv) along its outer edge only, and has transverse drainage fluites (4, 4\sv), Fig. 2 (not shown), communicating with the gap. The gap is maintained by spacers (6), Fig. 3 (not shown), at intervals, those at the ends of the suction box serving to prevent ingress of air thereto. In a modification, Figs. 4 to 6 (not shown), the bands abut instead of being separated by a gap, and each abutting edge is formed by a wall extending no higher than the tops of the ribs separating the flutes. Drainage perforations are provided near the abutting edges. In a further modification, not illustrated, the two bands are associated with a third band travelling between them and having no upstanding edge ribs. Two longitudinal gaps equivalent to gap (5) are thus provided and a suction box is disposed beneath each of them. A perforated rubber cloth may be inserted beneath the filter medium.