DETERMINATION OF THE VOLUMETRIC COEFFICIENT OF MASS TRANSFER IN COOLING TOWERS WITH JET–FILM CONTACT DEVICES

A new construction of the cooling tower sprinkler block consisting of jet–fi lm contact devices has been developed. The proposed packings are capable of increasing the surface of contact of phases at a small number of wetting points, a minimum percent of droplet entrainment by a gas fl ow, and a low hydraulic resistance. Based on the method of transfer units, generalizing the results of experimental investigations of the process of water cooling in the developed cooling tower sprinkler block, an expression has been obtained for calculating the volumetric coeffi cient of mass transfer with account for the ratio between the mass fl ow rates of air and water, as well of the wetting density. It has been established that an increase in the mean-fl ow speed of air leads to an increase in the values of the volumetric coeffi cient of mass transfer because of the increase in the degree of gas fl ow turbulence. Comparison results of calculations of the volumetric coeffi cient of mass transfer for different cooling tower sprinkler blocks are given. It has been established that at small ratios of unit loads (G_m/L_m up to 0.5) a sprinkler made of lattice elements is most effi cient. It has been proven that on increase of the ratio of init loads (G_m/L_m > 0.5), the sprinkler block consisting of the proposed jet–fi lm contact devices has the highest cooling capability. The expression obtained for calculating the volumetric coeffi cient of mass transfer can be used in designing and modernization of industrial, cooling towers with jet–fi lm contact devices.
   
Author:  A. V. Dmitriev, O. S. Dmitrieva, and I. N. Madyshev
Keywords:  heat/mass transfer, cooling, jet–fi lm contact device, circulating water, cooling tower
Page:  113