Pressure filter with changing particulate medium - having upwards flow of liq. with medium being extracted from turbulent zone and returned

摘要

Filter is vessel with two perforated screens, one near the base one near the top. Lip. to be filtered is injected above the lower screen tangentially so as to form a vortex in which particulate medium is entrained and from which it can be removed. The medium is then cleaned in a separate column and is reinjected into the filter vessel below the upper screen. Liq blows up through the bed and screen and filtrate leaves from the top. The filter can be drained from a valve in the base. The bed slowly moves down the vessel.