| 摘要 |
<p>Filtration apparatus has parallel filtration chambers (A, B, C, D) each of which has a filter screen and a cake of particulate material accumulated thereon for enhanced filtration. In normal use three chambers are in filtering operation, filtering fluid between an inflow conduit (100) and an outflow conduit (106); whilst one chamber, D as shown, is off-line. When another chamber, for example A, needs to have its filter screen de-caked it is taken out of operation and chamber D is brought into operation. After de-caking it is necessary to prepare the filter screen of chamber A for subsequent filtration and this is achieved by switching a fan (114) on, so that fluid filtered through chamber A is drawn through a recirculation conduit (108) and back into the inflow conduit (100). It cannot leave the apparatus until it has undergone effective filtration in one of the other filtration chambers. After an interval the filter screen in chamber A will have an adequate cake and is ready to be brought on-line.</p> |
