摘要 |
A filter having filter openings, which openings vary in cross-section automatically in accordance with an inherent variable of the medium passing there through. The openings can vary in response to the heat of the medium passing through the openings. The openings can include a perforated plate screening the openings and having elements, which shift the plate relative to the openings. The elements can be springs and can include a shape memory alloy.
|