Cooling tower fill compositions

#Cooling towers are utilized to remove heat from process water through evaporation and heat transfer. Fill utilized in such cooling towers should possess high heat resistance and, equally important, minimal water saturation capacity.

#It is well-known that asbestos fibers and synthetic rubber binders can be formed into felt sheet compositions that, when suitably shaped, can be utilized to make generally satisfactory cooling tower fill. Customarily, such sheets are impregnated with various materials to improve the sheets' rigidity, lifetime and wet strength, decrease the sheets' rate of water absorption and to provide sheet materials that lend themselves more readily to the formation of shaped cooling tower fill materials in corrugated and saddle forms. Suitable impregnating materials are resins such as melamine-formaldehyde resins and phenol resins and chlorinated rubber. The chlorinated rubber is particularly desirable to use for such purposes because, besides the advantageous properties set forth above, it also imparts an improved degree of fire resistance to the asbestos synthetic rubber binder sheets.

#It has been discovered, however, that asbestos-rubber binder sheets which normally take up water based resins such as melamine formaldehyde resins and phenol resins do not as readily take up the chlorinated natural rubber. Therefore, it would be desirable to improve the saturation capacity of the sheets for the chlorinated natural rubber.

#The following examples demonstrate the preparation of the composition of this invention. Carbopol 801 is a trade designation for an acrylic acid polymer having a molecular weight of about 250,000.

#______________________________________ Amount Ingredients (Parts by Weight) ______________________________________ asbestos fibers 28.8 g (100) Carbopol 801 0.144 g (0.5) carbon black coloring agent 0.425 g (1.5) antioxidant (Flectol H) 0.103 g (0.36) vinylidene chloride latex 3.17 g (11) (Dow 30175.00) ______________________________________

#To a mixing vessel containing about 1500 ml of water were added the total amounts of the refined asbestos fibers, the Carbopol, the coloring agent and the antioxidant. The contents of the mixing vessel were slurried for about 2 minutes to assure full dispersion of the ingredients at 1.9% consistency. The total amount of synthetic rubber latex was added with stirring for about 2 minutes until the latex precipitated, that is, the latex deposited on the fibers thus serving as a drainage aid and a binder in the resulting composition.