APPROXIMATE CALCULATION OF PRESSURE DROP IN BENDS BUILT IN PNEUMATIC CONVEYING PIPES IN THE CASE OF HIGH DENSITY CONVEYING

In this paper a computing method is described for the approximate determination of pressure drop in bends of different plain built into pneumatic pipes in the case of high density conveying. Particles moving in the bend decelerate because of the force acting on them. The conveying gas flow accelerates the decelerated particles in the connecting straight pipe section following the bend to a limit velocity belonging to the straight section if it is long enough. Pressure drop in the bend is approximately equal to the pressure drop necessary for accelerating the material again. Maximum velocity change occurs in a bend of vertical plane starting from vertical position, therefore this bend has the greatest pressure drop, too