Guyson Corporation has designed and custom built a spacious automatic blast system for gritblast surface preparation of large aircraft engine components prior to thermal spray coating. The Model SP-12 also has an extra blast gun for hand-held operation at its interlocked manual touch-up station.
The SP-12 offers a work envelope with more than 200 cubic feet of space (6.1 cubic meters), with interior dimensions of 72 x 72 x 72 inches (1828 mm cube). A full depth access door with an abrasion resistant and replaceable gum rubber curtain is provided on both sides of the cabinet. Safety interlocks prevent operation of the blast machine when a door is opened.
Urethane rubber lines the cabinet’s 48-inch (1219 mm) diameter, 1,000 pound (450 kg) capacity powered turntable. The table can be rotated clockwise or counterclockwise, both in the automatic mode of operation and when jogged in the manual blasting mode. The speed of reversible table rotation is adjustable to enable processing of different components.
The blast cabinet is fabricated with forklift channels in its rigidly welded steel frame to facilitate relocation of the system. The cyclone media reclaimer and cartridge-type dust collector are similarly equipped for portability.
Three suction-blast guns are adjustably bracketed in position on a vertically traversing boom inside the blasting enclosure. This arrangement allows the nozzles to be pre-set at the correct angles and distances for coverage of many different components. The programmable motion of the blast guns is accurately controlled by a ball screw linear actuator with a stroke of 36 inches. Once the operator has set the start position, the number of traverse strokes, the duration of blast and airwash blow-off, table RPM and other blasting parameters, the surface preparation process can be repeated on a run of parts with a high degree of consistency.
To resist the effects of harsh abrasive grit blasting, the SP-12 system incorporates abrasion protection features such as cast urethane rubber ducting between the blast cabinet and the cyclone separator, bonded rubber lining of the blast chamber as well as the cyclone body, cone and inlet elbow, urethane media feed hoses and bronze blast guns with boron carbide lined nozzles. The view window at the manual blasting station is protected from frosting by a square-cut inner window gasketed in a quick-change frame.
Prospective users of automated surface preparation systems are encouraged to submit sample components for free laboratory testing and application engineering evaluation at the Guyson design and manufacturing center in northeastern New York State.