| 摘要 |
PURPOSE:To prevent the lowering in filtering accuracy and to easily perform the removal of a cake, by protecting a filter element by providing a perforated member covering the outer periphery of the filter element. CONSTITUTION:In filtering, a filtering aid is mixed with a liquid containing a suspended substance to form a precoat layer between a filter element 15 and a perforated member 19 such as a net member. The suspended substance is adhered to the outer periphery of the perforated member 19 through the precoat layer and a liquid passes through the gaps of the filter element 15 to be discharged to the outside from through-holes while receives filtering. A cake is laminated and formed to the outer periphery of the perforated member 19 with the advance of filtering but, in the removal of the cake, because the fluid injected from a cylindrical core body through the through-holes at the time of backwashing to generate foam when passes through the perforated member 19, the removal of the cake is performed by said foam and, when the cake is scraped off by a knife, said cake is scraped off from the perforated member 19 from the outer peripheral side thereof.
|
