8.3.1.1 Minimum conveying air velocity
For fine powdered materials such as cement, barytes, fly ash and bentonite, that have good air retention properties, the relationship will generally be similar to that of material type A. With this group of materials a minimum conveying air velocity of about 10–12 m/s is usually sufficient to convey the material in dilute phase suspension flow.These materials are generally capable of being conveyed in dense phase, at low values of velocity, and at very high values of solids loading ratio if the pressure gradient is sufficiently high (see Figure 1.1). When conveyed at increasing solids loading ratios, these