Abstract: Sludge to be dewatered is deposited on drainage slabs which slope toward a trough to which water draining from the deposited sludge is permitted to flow. Supported at the open top of the trough is a perforate member, and the trough is initially filled with a support water immersing the perforate member, the support water allowing sludge to flow over the perforate member, but minimizing the tendency of such sludge to settle through the perforate member. In the practice of the process disclosed, the support water is permitted to drain from its trough at approximately the rate new water drains to the trough from the deposited sludge.

Abstract: An industrial screen of the type having generally parallel wires looped about transverse support rods has chromium plated to at least the surfaces of the wire elements which contact one another in use. In the preferred embodiment hard chrome plating of entire wire elements is utilized.