Filter device, contains filters with parts containing small passages aligned with parts containing large passages

摘要

At least two of the filters (3) are oriented relative to the flow direction (8) so that the first part of one filter containing small passages (4) is aligned with the second part of the next filter containing large passages (5). A filter device (1) comprises two or more filters with at least two parts containing passages, the first part containing passages which are smaller than those in the second part. At least two of the filters are oriented relative to the flow direction so that the first part of one filter is essentially aligned with the second part of the next filter. An Independent claim is also included for a filter comprising a mesh containing holes with different sizes in one of the two directions in the mesh plane.