The article presents the results of experimental studies of the hydraulic and mass transfer characteristics of 1-m high roll polymeric mesh packing having a specific surface area of 240 m2/m3, equivalent diameter of 0.015 m, and free specific volume of 0.95, with a film countercurrent flow regime in the column with a spray density of 5.0‒25.0 m3/(m2 h) and air velocity of 0.5‒2.5 m/s. The air pressure difference, volumetric mass transfer coefficient, and air humidification efficiency with water are determined. Generalized empirical formulas for calculating these characteristics are derived. The roll polymeric mesh packing is compared with regular fill packs made of corrugated metal tape and corrugated vertical metal plates with a rough surface in terms of specific pressure difference and mass transfer efficiency. The possibility of using these fill packs in mechanical-draft mini cooling towers is considered. An algorithm for calculating the mini cooling tower efficiency and cooled water temperature after its having been in contact with air is presented. Graphic dependences of the hydraulic and heat-and-mass transfer characteristics on the operating parameters are given. Special attention is paid to an analysis of liquid distribution over the packing surface and liquid film formation, which is a key factor for intense mass transfer. A reasonable ratio between the air velocity and spray density under different operation conditions is determined. The study results can be used in design and modernization of water cooling systems, including those at industrial enterprises, in which it is necessary to maintain highly efficient heat transfer and use the most compact equipment.
Lapteva et al. (Thu,) studied this question.