14 – PNEUMATIC CONVEYING

This chapter presents the basic principles of pneumatic conveying and equations are presented along with a new pressure loss equation with examples. The greatest problem arises from the fact that different mass flow ratios, solid flow rate divided by the gas flow rate, imply different flow types in pneumatic conveying. At relatively high gas velocity, solids are conveyed in an apparently uniform suspension in a so-called lean or dilute-phase flow. Dilute-phase conveying systems are commonly used in long-distance pneumatic conveying systems. These systems operate effectively and reliably, even under rather dilute conditions. The new pressure loss equation presented here is based on determining two parameters: the velocity difference between gas and conveyed material and the falling velocity of the material. The advantage of this method is that no additional pressure loss coefficient is needed. This method can be applied to cases where solids are conveyed in an apparently uniform suspension in a so-called lean or dilute-phase flow.