Under what circumstances would you use a pneumatic conveyor instead of alternative means of moving solids around?(a)[6 m (b)What are the four different types of powders as in the Geldart

classification and how does it help assess the suitability for pneumatic transfer?[10 marks] (c)What impact does the hardness of the solid have on the materials of construction and potential operating problems of a pneumatic conveyor and why is dense phase more robust? How would you detect any problems?[4 marks]