| 摘要 |
There is disclosed apparatus for blasting with abrasive particles comprising a blast pot (10) which is continuously pressurised, a chamber (12) above the blast pot (10) and communicating therewith by means of a first drop valve (13), a second drop valve (14) in the top of said chamber (12) for establishing a communication between said chamber (12) and an unpressurised supply (15) of abrasive particles and timer means (21) for alternately pressurising and depressurising said chamber (12), the arrangement being such that when said chamber (12) is depressurised, the first (13) and second (14) drop valves are closed and open respectively to allow abrasive particles from said supply (15) into said chamber (12) and when the chamber is pressurised, the first (13) and second (14) drop valves are open and closed respectively to allow abrasive particles from the chamber (12) into the blast pot (10). |
