Hoppers located near waterways face certain challenges. Regulations often require that no dust or materials from the hopper loading operation enter the water. Areas near waterways often have increased wind conditions that complicate controlling the dust. DSI combines Dry Fog System technology with DustTamer Wind Screen Systems as shown in the photo. The DustTamer fabric screen is installed on the perimeter of the hopper typically on three sides. The DustTamer fabric serves several purposes:
- Due to the fabrics engineered porosity, ambient wind is directed away from the hopper pocket by allowing some air bleed-through that equalizes the pressure on both sides of the screen. The equalization of pressure outside to inside the hopper prevents the wind from rushing into the hopper and instead passes by the hopper seeking out lower pressure zones. If a solid material with no porosity is used in-place of the porous screen, the wind will hit the solid wall and seek out the low pressure zone inside the hopper, forcing the dust out of the pocket.
- This same pressure equalization effect allows for the Dry Fog to stay in the pocket along with the airborne dust for a long enough period of time for the micron size fog droplets to attach to like size airborne dust particles. The agglomerated particles increased mass will make the slightly wetted particles to fall back into the hopper without wetting the material inside the hopper.
- The fabric will also help capture larger wetted particles that due to there mass and velocity try to escape the containment area.
- If the loading of the hopper is from a large and sudden dump (grab bucket or E-Crane) the screen helps contain the fog that is generated at the hopper prior to the dump. This Pre-fog provides a large reservoir of fog droplets in a high concentration that scrubs the air when the dump occurs and air displacement projects dust particles into the air.