Abstract: A multi-layer disk fan with blades operates quietly. The multi-layer disk fan with blades is formed by laminating a multiplicity of annular disks in a measured spaced relation, the arrangement having such a feature that a multiplicity of blades are interposed between the annular disks and the ends of the respective blades. The blades are further positioned a circumferentially measured spaced apart distance inward of the outer peripheral edges of the annular disks. Turbulent air flow caused by peeling-off at the tips of the blades through the effect of laminar flow by the disks is effectively prevented. Likewise, distortion in outlet speed at the outer peripheral edges of the annular disks is controlled, reducing noises from turbulent flow and interference and resulting in quiet operation.

Abstract: Rotatable circular plates are stacked apart to form thin air layers therebetween. Rotation of the circular plates moves air over an air treatment material: catalyst or adsorbent. In one embodiment, the air treatment material is affixed to the surface of the circular plates. In another embodiment, the circular plates are formed from the air treatment material. The increased velocity of air relative to the circular plates causes separation of laminar flow, promotes boundary-layer turbulence near the plate surfaces, and promotes propagating stall in the air layers. These phenomena enhance the contact between the flowing air and the air treatment material.