Since material type A is capable of being conveyed in dense phase, conveying at a solids loading ratio of about 80 is possible with a pressure drop of 3 bar over 200 m,which agrees reasonably with Figure 1.1. With a minimum conveying air velocity of about 4 m/s, from Figure 8.1, a minimum air flow rate of about 0.08 kg/s is required.A minimum conveying air velocity of about 15 m/s is required for the type B material and so a minimum air mass flow rate of over 0.3 kg/s has to be employed. Despite the high value of conveying line pressure drop the maximum value of solids loading ratio that can be achieved with material type B is only about eight.