Method for the filtration of a suspension or emulsion

摘要

A suspension or emulsion is filtered by causing the same to flow upwards through a zone of filter medium of particle size forming a filter bed while the filter medium concurrently flows in a downward direction through the filter bed zone. Dirty filter medium at the bottom of the filter bed zone is transported to a wash device located above the filter bed zone and is washed as the dirty medium passes downward along a washpath in the wash device in counter current flow to wash liquid which passes upward though the wash device, whereafter the washed medium is returned to the top of the filter bed zone. A zone of filtrated liquid phase is maintained above the filter bed, and a portion of said filtrated liquid phase is supplied to the wash device as the wash liquid.