DIFFUSER SYSTEM FOR ABRASIVE BLASTER
A shutdown system for a media blast system includes a normally closed diverter path which remains closed to air flow during operation of the blast system. During shutdown, the air flow to the metering valve is shut off, shutting off the system. At the same time, the diverter path is opened, relieving pressure in the supply line by permitting pressurized air and abrasive in the supply line to back flow through the diverter from which it is exhausted, almost instantaneously shutting off flow through the nozzle. A diffuser system is included for receiving and exhausting residual abrasive media and for reducing the noise level of the exhausted air.
1 . A diverter/diffuser system for a media blasting system of the type having an air operated media metering valve for releasing a mixture of pressurized air and media through a downstream nozzle, the diverter/diffuser system comprising:
a. A diverter pressure line connected to the metering valve and the diverter/diffuser system;
b. A diverter switch for opening and closing air and abrasive flow to the diverter/diffuser system, wherein the switch is normally in the closed position during operation and is opened during shutdown mode;
c. A diffuser for receiving the air and abrasive flowing through the diverter system and expanding and exhausting it from the system.
2 . The diverter/diffuser system of claim 1 , wherein the diffuser includes a flow restrictor for reducing the noise level of the exhausted air.
3 . The diverter/diffuser system of claim 1 , wherein the diffuser includes a sound deadening material in the diffuser.
4 . The diverter/diffuser system of claim 1 , wherein the diffuser includes:
a. A lower intake chamber for receiving air and abrasive flow from the diverter;
b. An upper expansion chamber;
c. A restrictor plate between the lower intake chamber and the upper expansion chamber;
d. The upper expansion chamber further including an exhaust port for releasing air and abrasive from the system.
5 . The diverter/diffuser system of claim 2 , further including a baffle plate between the expansion chamber and the exhaust port.
6 . The diverter/diffuser system of claim 2 , wherein the flow restrictor is a baffle plate in the path of the air and abrasive flowing through the diverter.
7 . A diffuser for use in connection with a blast system for diffusing exhausted air and abrasive during shutdown, the diffuser comprising:
a. A lower intake chamber for receiving air and abrasive flow from the diverter;
b. An upper expansion chamber;
c. A restrictor plate between the lower intake chamber and the upper expansion chamber;
d. The upper expansion chamber further including an exhaust port for releasing air and abrasive from the system.
8 . The diffuser of claim 6 , further including a sound deadening material in the expansion chamber.
9 . The diffuser of claim 8 , wherein the sound deadening material is a sheet material covering the walls of the expansion chamber.
10 . The diffuser of claim 6 , including a baffle system in the expansion chamber between the restrictor plate and the exhaust port.
11 . The diffuser of claim 6 , wherein the diffuser includes a deflection element for redirecting the air and abrasive received from the diverter and any residual abrasive media flowing through the back through the diverter.
12 . The diffuser of claim 11 , wherein the deflection element is removable and replaceable.
13 . The diffuser of claim 12 , wherein the diffuser includes a flow restrictor for reducing the noise level of the exhausted air, and wherein the deflection element is upstream of the flow restrictor.