| 摘要 |
<p>A diffuser which includes a cylinder open at one end and closed at the opposite end, the open end of the cylinder being securable to air supply; the wall of the diffuser being formed with a plurality of holes therethrough, each hole having a larger diameter on the exterior of the wall of the diffuser than on the interior of the wall of the diffuser, the longitudinal axis of each hole being inclined at an acute angle to both the radius and the longitudinal axis of the diffuser, and the orientation of each hole with respect to the longitudinal axis of the diffuser being such that when the diffuser is rotated about it longitudinal axis in use, the leading edge of each hole is at a higher elevation than the trailing edge of each hole.</p> |
