Patent ID: 7585358
Filing Date: 2009-09-08
Classification: B01D

Abstract:
1. A recirculation filter comprising: a first layer defined between a first side and an opposing second side, the first layer configured to trap particles that are of a first size; a second layer having a first portion including a first side and a second side and a second portion including a first side and a second side, the second side of the first portion is adjacent to the first side of the first layer and the second side of the second portion is adjacent the second side of the first layer, the second layer configured to trap particles that are of a second size, wherein the second size of particles trapped by the second layer are greater than the first size of particles trapped by the first layer; and a third layer having a first portion including a first side and a second side and a second portion including a first side and a second side, the second side of the first portion of the third layer being adjacent the first side of the first portion of the second layer and the second side of the second portion of the third layer being adjacent the first side of the second portion of the second layer.