An experimental study on a horizontal energy-saving pneumatic conveying system with soft fins

Abstract

In order to reduce power consumption and conveying velocity, a new pneumatic conveying system where soft fins are mounted in a horizontal plane through the pipe axis in the front of inlet is proposed in this paper. The experimental study focuses on the effect of the different fin's lengths on the horizontal pneumatic conveying system in terms of frequency characteristics of fin's oscillation, pressure drop, conveying velocity, particle flow pattern, power consumption and additional pressure drop. The test pipeline consisted of a horizontal smooth acrylic tube with an inside diameter of 80mm and a length of about 5m. The polyethylene spherical particles of density 978kg/m3 and 952kg/m3 with diameters of 2.3mm and 3.3mm are used as conveying materials. The mean air velocity is varied from 10 to 17m/s, and the solid mass flow rate is from 0.20 to 0.45kg/s. Comparing with the conventional pneumatic conveying, the pressure drop, minimum and critical velocities, power consumption and additional pressure drop can be reduced by using soft fins in lower air velocity range. The efficiency of fin is quite evident with increasing the length of fin. The maximum reduction rates of the minimum velocity and power consumption by using soft fins are about 14.8% and 25.5%, respectively. By analyzing the frequency characteristics of fin's oscillation, Strouhal number of more efficient fins is about St=0.65 in the range of low air velocity.