'Periodica Polytechnica Budapest University of Technology and Economics'
Abstract
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