| 摘要 |
<p>A cavity is formed on one side of the element; and sound waves are created in the cavity to eject material clogging the holes in the element. The pref. element is a flat box, one side of which is formed by a perforated plate through which gas, air, is blown, e.g. through sand, which eventually clogs the holes in the plate. Pref. the flat box is upside down and is covered by a plate (a) sealed on the box by self-lubricating plastic rail. A pulsator driven by compressed air is connected to plate (a) to generate infrasonic waves which drive the sand out of the holes in the bottom surface of the box. Esp. used for the continuous removal of sand blocking the outlet holes of air boxes forming a conveyor for cooling hot sand in the knock-out of a large foundry.</p> |
