4 - Hydraulic resistance of impinging stream devices

Abstract

This chapter discusses the hydraulic resistance of the impinging stream contactor. The hydraulic resistance or the pressure drop of the device to be employed has a crucial influence on the total power consumption. The investigation of the hydraulic resistance of the impinging stream contactor reveals that the resistance of the gas continuous impinging stream device is not large and consequently, the power consumption is acceptable, provided the structure of the device is reasonably designed and the material impinging streams being applied for is properly selected, not too heavy and not too large. The hydraulic resistance of a gas-continuous impinging stream device can be considered to result from the following factors: the drag force due to friction between the gas flow passing through the accelerating tube and the wall of the tube; the friction force between the gas flow and the particles in dispersed phase; the impingement between the opposing streams and certain structural factors of the equipment involved, such as sudden contraction of flow passage and some other structural parts etc. The most important operating parameter for gas-continuous impinging streams is the velocity of the gas flow at the outlet of the accelerating tube, also called impinging velocity or u0.