Down-flow granular bed filter with automatically controlled splash plate.

摘要

A down-flow granular medium bed filter (10) is provided with at least one splash plate (20) for dissipating the force of influent liquid, the plate being mounted so as to be rotatable by lifting means (24,26) from a position parallel to the surface of the filter bed (14) to a position perpendicular to the bed surface when the liquid above the bed (14) rises to a selected first level (28). The splash plate (20) is maintained in the perpendicular position for the remainder of the filtration cycle, the backwash cycle and any chemical cleaning cycle, allowing unobstructed operation of the filter bed. The splash plate is returned to the original position parallel to the bed (14) at the start of another filtration cycle. <IMAGE>