OPTIMIZING DRY POLYMER

A number of factors go into effectively optimizing dry polymer. The thorough understanding of each of these factors is one reason VeloDyne systems are so effective in optimizing the performance of such a wide range of polymers.

EFFECTIVE POLYMER PARTICLE WETTING

Optimizing dry polymer performance starts with effectively wetting each individual polymer particle. The most efficient way to achieve this is by separating the particles just prior to wetting, so each individual particle is exposed to wetting. Methods such as simply metering dry polymer into a wetting bowl require longer wetting times, which can result in shear damage caused by the mixing impeller.

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PROPER SOLUTION CONCENTRATIONS

Proper solution depends on the type of polymer you use. Cationic polymers are typically prepared at solution concentrations between 0.25% to 0.5%. Anionic polymers are typically prepared between 0.1% and 0.25% solution. The solution can then be further diluted after the solution metering pumps through a secondary dilution system.

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PROPER MIXING

When polymer is first wetted, the molecule is not susceptible to damaging shear induced by a tank

mixing impeller. However, during the hydration process the polymer elongates and becomes susceptible to shear, which can degrade the polymer’s effectiveness. Too low

of mixing energy, or insufficient mix times will prevent the polymer from fully uncoiling. Too much mixing energy or mixing for too long will damage the polymer. Inducing higher initial impeller speeds that are then decreased

as the polymer becomes more activated delivers a better performing polymer solution.

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SUFFICIENT POLYMER AGING

The amount of aging time required to reach optimal performance depends on a number of factors including the type of polymer water temperature. It’s not uncommon for systems to be designed with insufficient aging time. For optimum system flexibility, performance and with proper preparation as described above, it’s recommended that cationic polymer systems provide 45 to 60 minutes of aging, and anionic polymer systems can deliver up to 120 minutes of aging.

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