Filter fitted with a deblinding device

Claim 1

A filter comprising: a stack of several distinct filter elements each having external and internal radial circumferences assembled together to form an annular sleeve having a cylindrical inner circumference, wherein each of said filter elements includes a plurality of isolated radial segments which stack to form a plurality of isolated columnar filter sections, and wherein each of said filter elements further includes on its external and internal radial circumferences a plurality of communication orifices to provide communication through each of said filter sections between said external and internal circumferences; and a rotary shut-off valve fitted to rotate coaxially within said sleeve and against said cylindrical inner circumference of said sleeve such that, for given successive angular positions of said valve in said sleeve, said valve opposes corresponding successive, individual filter sections to block said sections against flow therethrough, while flow through the other filter sections is permitted, said valve further having a ported shut-off chamber cut therein to oppose and communicate only with opposing communication orifices in said cylindrical inner circumference of corresponding blocked filter sections when said valve is in said given angular positions, wherein the shape of said ported shut-off chamber and the arrangement of said communiction orifices opposing it are such that, for said given angular positions of said valve in relation to said stack of said filter elements, only one part of said filter elements within said corresponding blocked filter section are in communication with said ported shut-off chamber.