12-08-2013, 03:05 PM
A PRESENTATION ON BLASTING
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ABRASIVE BLASTING
DEFINITION
Abrasive blasting involves using a stream of abrasive material, propelled at high speed by compressed air, water, steam, centrifugal wheels or paddles against a surface, to clean, abrade, etch or otherwise change the original appearance or condition of the surface.
DESCRIPTION OF PROCESS OF ABRASIVE BLASTING
Abrasive blasting systems typically include three essential components: an abrasive container (i. e.,
blasting pot); a propelling device; and a blasting nozzle or nozzles. The exact equipment used depends to a
large extent on the specific application and type(s) of abrasive.
Three basic methods can be used to project the abrasive towards the surface being cleaned.
DESCRIPTION OF PROCESS OF ABRASIVE BLASTING
advantage of low silica content, but have been documented to release other contaminants, including
hazardous air pollutants (HAP), into the air.
Metallic abrasives include cast iron shot, cast iron grit, and steel shot. Cast iron shot is hard and
brittle and is produced by spraying molten cast iron into a water bath. Cast iron grit is produced by crushing
oversized and irregular particles formed during the manufacture of cast iron shot. Steel shot is produced.
DESCRIPTION OF PROCESS OF ABRASIVE BLASTING
Synthetic abrasives, such as silicon carbide and aluminum oxide, are becoming popular substitutes
for sand. These abrasives are more durable and create less dust than sand. These materials typically are
reclaimed and reused.
Other abrasives include mineral abrasives (such as garnet, olivine, and staurolite), cut plastic, glass
beads, crushed glass, and nutshells. As with metallic and synthetic abrasives, these other abrasives are
TYPES OF EQUIPMENTS IN ABRASIVE BLASTING
Suction Abrasive Blast Equipment: Uses the venturi principle to draw abrasive from a non-pressurized hopper to the blast gun where it is combined with the compressed air stream and propelled against the work surface.
Pressure Abrasive Blast Equipment: In a pressure blast machine the air pressure in the vessel and in the “pusher” line is the same. Pressure abrasive blast equipment has a single hose running to the blast nozzle.