Continuous flow at various material flow rates through a pneumatic transport system of a wide variety of granular and hygroscopic materials over a wide range of moistures, sizes and weights is achieved by gravity feed through a dispensing hopper having a portion of the side wall surface shaped as an irregular hyperbola. Thus, shipboard mounted or other portable transport system may be used to load or unload ship holds with grain, cement, seed, sand, sugar and other such materials at high flow rates through input and output hoses conveying materials from one location to another. The same system may be used at lower material flow rates achieved by lower density of materials in the pneumatic stream, thereby to sandblast and paint the ship hulls for example. Special flow rates may be chosen to adapt to given material characteristics or transport needs. Separation of input and output air transport paths is achieved by a centripetal air flow chamber filling the dispensing hopper with a store of the materials from which they continuously flow into a pneumatic conveyor tubing at controllable rates.