Civil Engineering Reference
In-Depth Information
Fig. 23-17.
Belt press installation at Cedar Park, Texas, water-treatment plant (Courtesy of
Ashbrook-Simon-Hartley)
In the fixed-volume recessed plate filter press, liquid sludge is pumped by high-
pressure pumps into a volume between two filter plates. On the face of each individual
plate a filter cloth is mounted. As a result of the high pressure that the sludge is under,
a substantial portion of the water in the feed sludge passes through the filter cloth and
drains from the press. Sludge solids and the remaining water eventually fill the void
volume between the filter cloths, so that continued pumping of solids to the press is
no longer productive. At this point, pumping is stopped, and the press is opened to
release the dewatered sludge cake prior to initiation of a new ''pressing cycle.''
In the fixed-volume recessed plate press, a cloth filter medium is used on both sides
of the filtering volume. As shown in Figure 23-20, sludge is pumped into the volume
between the cloth sides, and water is expelled through the medium. Sludge pumping
