SAND FILTRATION APPARATUS

摘要

An annular column of sand is suported by a central core and an outer tube both of which have sloping louvres. Water is pumped radially inwards through the outer louvres and filtered water is removed via the inner louvres. Sand from the bottom of the column is recirculated via the core and delivered to a separator at the top of the appts. Scrubbed sand is returned to the top of the column so that the coarse particles fall towards the outer edge of the column.