| 摘要 |
<p>A filter arrangement is provided. The filter arrangement generally includes an air filter (12) having an upstream surface (28) with a prefilter (4) positioned thereon. The prefilter preferably includes at least two layers of depth media (34, 35). In preferred systems, the prefilter includes two layers of depth media secured to one another by stitching (37, 40). In certain preferred arrangements disclosed, the prefilter includes an upstream layer of fibrous depth media (34) and a downstream layer of foam depth media (35), with two layers stitched to one another along peripheral edges. The invention also concerns provision of prefilters, and also air filter arrangements which include housings having air filters with prefilters according to the present invention operably positioned therein. Methods of construction and use are also provided.</p> |
