Experimental study on demisting and water recovery of the cooling tower by strengthening the flow fields and condensing in a novel device

Abstract

In order to minimize the water loss in wet cooling tower, it was designed a novel water recovery device which consisted of a gas-liquid separation unit (GLSU) and a condensing unit (CU) in this paper. After being cooled by the condensing unit, water vapor was condensed into liquid droplets and mixed with the original water droplets. Then the liquid droplets were recovered by GLSU, which was composed of a cyclone separator (CS) and a fibrous coalescer (FC). The condensing unit was spiral coil pipes. The bottom coil inserted in the cyclone separator could strengthen the flow fields and avoid the back-mixing and re-entrainment phenomenon. A superhydrophobic coating of glass microfibers surface was prepared by dipping the fibrous coalescer into the mixtures of polydimethylsiloxane (PDMS) and silicon dioxide (SiO2) nanoparticles. The results showed that when the temperature of cool water was 10 °C, the maximum water recovery efficiency could reach 87%. While without the cool water, the maximum efficiency was only 35%. After setting the bottom coil, the efficiency was 5% higher than without the coil pipes. With superhydrophobic modification of the fibrous coalescer, the efficiency was 6% higher than that without modification.