Abrasive blasting equipment and self-cleaning abrasive trap therefore

Claim 2

Abrasive blasting equipment as in claim 1 wherein said means for directing inlet air to said trap comprises a conduit connected between the downstream side of said inlet valve and the abrasive trap to admit inlet air under pressure to said trap whereby air travels backward through said trap from the time the inlet valve is opened until the pressures in the trap aNd the tank are equalized.

Claim 3

Abrasive blasting equipment as in claim 2 wherein said screen is cylindrical and exhaust air flows inwardly from the outside and inlet air flows outwardly from the inside.

Claim 4

Abrasive blasting equipment for use with a high pressure air source including a tank, a pressurizing path attached to said tank, an inlet valve in said pressurizing path for communication with said high pressure air source, an exhaust path attached to said tank, an exhaust valve in said exhaust path for communication with ambient pressure, an abrasive trap between said tank and said exhaust valve, a conduit attached to the downstream side of said inlet valve in communication with said abrasive trap, a pop-up valve for preventing reverse flow in said pressurizing path, and means for causing said inlet and exhaust valves to operate in mutually opposite open and closed conditions whereby when said exhaust valve is opened abrasive entrained in air flow through said exhaust path is collected in said trap and when said inlet valve is opened abrasive collected in said trap is entrained in air flow through said exhaust path and returned to said tank until said tank and trap pressures equalize.