Effect of Paddle Design on Flocculation

Preliminary investigations demonstrate that paddle design may be a major contributing factor to the flocculation process. Laboratory tests using a solution of water with aluminum sulfate and sodium carbonate indicate that floc formation is affected by the following paddle parameters: (1) Surface roughness, (2) surface perforations, (3) paddle curvature, (4) surface area, and (5) paddle shape. A condition maintained throughout the entire test was a constant input of power through the paddles to the solution. The results indicate that especially surface perforations and certain degrees of surface roughness can significantly enhance the floc formation. It thus appears definite that the flocculation process may be more efficient with respect to the power input as a result of simple variations in the paddle design.