Where is Abrasive Blasting work undertaken?
Abrasive Blasting can be performed in open sites for example on buildings, bridges, tanks, dock yards etc or it can be performed within enclosed environments such as blasting chambers, cabinets, or dedicated blast rooms.
When dealing with high risk products abrasive blasting is undertaken in dedicated blasting rooms with a pneumatic recovery system connected via ducting to a fixed dust collection unit. A pneumatic recovery system uses duct work and a vacuum system to recover garnet which is then transported by dilute phase pneumatic conveying through thick-walled piping. Cyclonic action is used to separate the used garnet from the air stream, down the hopper, and back into the blast pots to be reused. There are no filters in the recovery system, so exhausted air is fed back into the dust collector to be filtered
What determines the ventilation and dust control required for Abrasive Blasting?
Sizing the dust collector is critical. After establishing the correct airflow, air velocity, pressure resistance and air-to-cloth ratios the air blast room is attached to the appropriate size dust collection system and can then filter all dust and fume particulates from the room to ensure a safe working environment.
The blasting material and process used will also dictate the type of ventilation and air flow required to capture the airborne dust and fume along with the environment where blasting work is taking place. Extracted air can be ducted to a dust collector located outside a blast booth or drawn directly into a mobile dust collector by incorporating a hood.
For blasting operations where the process is contained, keeping the enclosure volume under a negative pressure with sufficient capture velocities on all open areas can be an effective method to control the contaminant.