The present invention broadly comprises a multiport filter having at least three intake ports and at least two layers—a first layer for containing particles 3 microns or greater and a second layer that contains particles 3 microns or less in size. In alternate embodiments, the filter includes a third...http://www.google.es/patents/US7597731?utm_source=gb-gplus-sharePatente US7597731 - Operating room smoke evacuator with integrated vacuum motor and filter
Operating room smoke evacuator with integrated vacuum motor and filter
