Volume No. 5 Issue No.: 1 Page No.: 34-45 July-September 2010




Parag Dalal

School of Studies in Environment Management, Vikram University, Ujjain, (INDIA)


Received on : March 02, 2010




In the field of air pollution cleaning, the existing literature concluded that it was impractical using cyclones to achieve a particle cut size smaller than 10 μm. Particle cut size refers to the particle diameter at which the separation efficiency is more than 50%. Cyclone technology has been limited to the use for small volume air sampling and large particle separation in air cleaning. In this paper, particle separation theory for a uniflow aerodynamic deduster a cyclone type of dust separator is examined and a new particle cut-size equation is modeled and developed. Based on this equation, the particle separation efficiency can be improved substantially by choosing appropriate design parameters and air flow conditions. Important parameters for the design of such a deduster are identified closely. These parameters include the diameters and the length of the annular chamber, vane angle and the air flow conditions such as the tangential air velocity and turbulence intensity within the separation chamber. The particle cut-size is found less sensitive to the tangential air velocities (associated with increasing pressure) higher than 3 m/s and the separation chamber length longer than 0.5 m. i.e., increasing the tangential velocity and/or altering the chamber length, these both are not efficient to improve the particle separation efficiency. The annular gap, d, and the average annular radius, Ra, should be as small as practical size. The vane angle should be as large as the cut-off pressure and the air flow rate permits the flow of the particles easily. The turbulent intensity should be minimized. The cut-size equation and the sensitivity analysis were used to develop a prototype of a uniflow deduster with which particle cut-sizes as small as 3 μm have been achieved at a low pressure of 100 Pa (0.4 in. water). The description and performance evaluation of the deduster are presented in a separate paper.


Keywords : Particle separation, Air quality, Uniflow dedusters, Tangential velocity, PM10