Specifications include, but are not limited to: 1. Design and select components for continuous submerged operation. 2. Watertight while continually submerged 66' (20 m) deep. 3. Mixers shall be capable of 9 to 1 speed turn down ratio locally field adjustable. 4. Mixers shall be designed for continuous duty in mixing mixed media with ah maximum temperature of 104 degrees F. 5. Fluid characteristics: a). Municipal wastewater mixed liquor. 1) Anoxic and aerobic cells: up to 4,000 mg/l organic solids b). Small quantities of petroleum products, fats, greases, and detergents. 6. Aerobic cell mixers a). Maintain all particles in suspension and completely mixed conditions within aeration basin cell being mixed. b). One mixer per cell. c). Cell characteristics: 1). Rectangular, vertical walls, concrete tank. 2) Water level varies up to 0.5' (150 mm). 3) Cell bottom covered with grid of aeration air diffusers set approximately 1’ (300 mm) above cell bottom. 4) Dimensions each cell: a. Zone 9: 85’ L x 25.5’ W x 15’ SWD. b. Zone 10: 87’ L x 25.5’ W x 15’ SWD c. Minimum velocity gradient in each cell: G = 75 sec-1. d. Minimum mean velocity within each cell: 1.0 ft/sec
