Air slide is one of the efficient and economical method of conveying bulk powder material. A little low-pressure air, an aeration bed and small inclined product over long distance is all that is required. Air slides are used extensively in conveying homogenous dry powder in many industries.
- Fluidised bed conveying: With fluid-bed conveying, the pneumatic gravity conveying, bulk material is subjected to the air flow at a velocity greater than the air velocity at the fluidising point. The bulk material is fluidised in this manner. If this takes place in a trough, inclined by a few degrees, then the flow of the bulk material down the trough is like that of a fluid.
- The trough gradients are necessary for a bulk material movement and the associated product flow rates are material dependent. Flow troughs operate very economically, especially with fine grained and heavy powders. Fans suffice for air production resulting into low energy requirements.