Novel coalescer design with bed of waste polymer fibers for liquid aerosol separation

Abstract

This paper presents the development and optimization of a novel self-cleaning coalescer with drainage section, for liquid aerosol treatment. Four different waste polymer fibers were investigated as filter bed material for the novel coalescer: polyurethane (PU), polyethylene terephthalate of different origin (PET1 and PET2) and polypropylene (PP). Metal working fluid (MWF) mist from 6% of MWF emulsion was applied as liquid aerosol. Different bed thickness with and without preloading methods were tested to find an optimal separation efficiency for acceptable pressure drop. The applied air velocity through the coalescer was varied from 1 m/s to 5 m/s. Experimental results show that all investigated polymer materials could be successfully used as filter bed in the newly developed coalescer. The total separation efficiency is over 96% (between 96.73 and 99.98%) for almost all investigated conditions, except at the air velocity of 1 m/s, for PU and PP filter bed when it is 88.55% and 91.14%, respectively. Maximal separation efficiency for fraction 1 (0.2–0.3 µm) and 2 (0.3–1 µm) is 81.36% and 99.71%, respectively. The coalescer realizes maximal pressure drop of 4.75 kPa at 5 m/s air velocity in wet-steady state. The findings indicate that the novel coalescer could be easily optimized depending on inlet air quality and permissible level of PM1 in the outlet air.