FILTERING METHOD AND APPARATUS

摘要

The present invention relates to a filtering method, in which the suspension to be filtered is passed into contact with the filtering surface of the filter element, whereby due to the pressure difference prevailing across the filtering surface the filtrate flows through the filtering surface and separated solids substantially remain in the sus- pension. According to the invention the suspen- sion to be filtered is passed to flow downwards along the filtering surface, whereby the filtering through the filtration surface takes place from the falling film and the separated solids are dis- charged with the falling film without forming a harmful solids layer on the filtering surface. An even liquid film falling on the filtering surface is generated by recirculating suspension from the bottom of the filter to the upper part of the filter element. The invention also relates to an ap- paratus for realizing the method, which may be applied especially for clarifying green liquor.