| 摘要 |
A filtration system utilizing a plurality coaxial, vertically disposed, filter elements for clarifying a liquid passed therethrough. Upon the accumulation of a predetermined amount of materials on or in the filter cake, the filter chamber is sealed and the contents drained creating a pressure differential across the filter elements to maintain the integrity of the filter cake on the filter septum. After the contents of the filter chamber have been drained the chamber is positively pressurized to remove any filtrate remaining in the filter cake and to dry the filter cake on the filter septum prior to removal. The expended filter cake and accumulants are removed from the filter septum and conveyed from the filter chamber by a discharge system. The filter chamber is filled with liquid and the filter septum mechanically scrubbed to remove any residual materials therefrom. A quantity of precoat or filter aid material is added to the liquid in the filter chamber and the filter aid bearing liquid circulated through the filter elements and the filtration system in a closed loop to form a precoat filter cake on the filter septum. The flow rate of the circulation is sufficient to maintain the integrity of the filter cake so formed until such time as the filter cake removes a sufficient amount of accumulants from the influent to create a predetermined pressure differential thereacross which will maintain the integrity of the filter cake on the filter septum at the influent flow rate.
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