| 摘要 |
<p>The apparatus comprises an abrasive hopper (1) pressurised by compressed air to deposit abrasive into a compressed air stream from a source thereof; and a pneumatic motor (21) driven from said source and driving two pumps (23, 41), namely, a pump (23) pumping water (acting as a damping fluid) from a tank (25), into the compressed air stream via an atomisation nozzle and a pump (41) for pumping a liquid additive from a tank (43) into the water. Preferably, the motor (21) is a fixed displacement variable speed device operated at a constant pressure, and the additive pump (41), a variable displacement device operated by the exhaust from the motor (21).</p> |
