The placement of the dry fog nozzles is the most important aspect to achieving effective dust suppression and ensuring no wetting of material. The dry fog spray should be generated and contained in a well designed shrouding. For example, a conveyor chute which eliminates dissipation due to wind and also ensures treatment time necessary to suppress and control airborne dust.
The dry fog spray is generated above the dust problem area and not directly onto the material. As the airborne dust is generated within the conveyor transfer chute, the dry fog suppresses the dust through particle agglomeration ensuring the dust is controlled within the transfer chute itself.
The basic principles involved for location of the nozzles are as follows:
- Nozzle spray pattern should not directly impinge upon any surface or structure
- Nozzles should be mounted in order to maximise the ability to fill the shrouding
- The fog should avoid direct contact with the material being suppressed
- Nozzles must be protected or shielded to avoid damage from falling material
- Nozzles should be mounted to minimise exposure to a heavy-laden dust air stream. This will avoid erosion of the nozzle components
- Spray patten of nozzles should be generated so that all the fugitive dust emissions are forced to pass through the blanket of fog