Rueckstausieb und Verfahren zu seiner Herstellung

摘要

A backpressure grid plate is provided for a pressure filtration system of the type comprising a housing with an inlet and outlet for conducting fluid to be treated, a filter disposed in the housing between said inlet and outlet, and a backpressure grid means arranged between the filter and the inlet. The backpressure grid means comprises a plate containing minute openings which are equal in size and distributed unevenly over the surface area of the plate in such manner that the surface distribution density of the openings is lowest within an inner impact area of the plate which receives inflowing fluid to be filtered and is highest within a proximity area of the plate located immediately adjacent to and surrounding the impact area. The surface distribution density of the openings within an outer area surrounding the proximity area is lower than that of the proximity area and higher than that of the impact area.