Patent ID: 7149272

Claim:
A filter for separating particles from cooling water in a nuclear plant of a light water type, wherein the filter has an inlet end and an outlet end and is arranged to permit through-flow of the cooling water in a main flow direction from the inlet end to the outlet end, wherein the filter includes a number of sheets, which extend in the flow direction from the inlet end to the outlet end, wherein said sheets are arranged beside each other and form passages for the cooling water through the filter front the inlet end to the outlet end, and wherein said sheets include a first portion, which extends from the inlet end, a second portion, which extends from the outlet end, and a third portion, which extends between the first portion and the second portion, wherein said sheets along the first portion have a wave-shape formed by a number of successive waves and extending in a transverse direction transversally to the flow direction, and wherein said sheets along the third portion have a wave-shape formed by a number of successive waves and extending in the flow direction, characterized in that each wave of said wave-shape of the first portion has a maximum amplitude, wherein the maximum amplitude decreases continuously in the flow direction towards the third portion, and that said maximum amplitude is zero at a transition to the third portion.