Methods of Belt Conveyor Dust Management Part 2

The easiest and most effective method to control dust is to minimize air velocity.

Minimizing Air Velocity

The easiest and most effective method to control dust is to minimize air velocity. Dust particles are heavier than air, and they will settle out if given still conditions and enough time. By reducing air velocity, particles have a chance to fall back into the material stream. Dust travels in the air stream, so it stands to reason that if air is controlled, dust can be managed.

Perhaps the earliest (and easiest) dust-control technology is simply to enclose the airborne dust (or the dust-generating location/operation) so the dust particles have the opportunity to settle before being carried outside the area. This is a method of minimizing air velocity, and thus preventing the pickup of fine particles from a body of material. As the enclosure volume increases, the velocity decreases, allowing the airborne particles to drop from the air.

An effectively designed transfer chute reduces the air velocity by minimizing air drawn into the transfer point, sealing the leaks that allow dust-bearing air to escape and allowing the dust time to settle out of the air. The traditional transfer-point enclosure is the most common method used to combat dust. The advantage of the traditional steel chutework is that it is rigid, permanent and can completely enclose the transfer point. Even a basic technique, such as the installation of dust curtains at the exit end of the chute, is one method to slow air movement.

An effective enclosure can theoretically be put on any transfer point. However, in some operations rigid, permanent, completely enclosed transfer points cannot be used, so the equipment cannot be enclosed. For example, many sand and gravel operations require equipment to me mobile, so a fixed transfer chute is undesirable. Other operations may need to visually monitor a transfer point, so a completely enclosed chute would not be suitable.

See Also: Methods of Belt Conveyor Dust Management Part 1 | Part 3 | Part 4