Hopper Design for Floc Blanket
Given the calculated amount of sludge the tank will create, a continuous sludge drainage system was created. This was done to decrease the size of the hopper in the tank. It was desired to keep the hopper small so that there would be minimal disturbance in the tank. φ floc is the specific volume of the floc, it was found to be 0.016. Most of the sludge produced is assumed to be made of alum. The alum concentration is approximately 10 mg/L. This alum concentration is used in the φ floc determination. The rate of sludge build-up is the sedimentation tank flow rate times φ floc.
Unable to find DVI conversion log file.When calculated, the sludge volume accumulated over two days was determined to be 1.105 x 10^3 L. We created this hopper with a conical funnel with flex-hose connected at the bottom. This small funnel will continuously drain sludge out of the tank and into the outlet panel. The hose will be 2m long and 1.27cm (1/2") in diameter. The diameter was determined using the manifold equation used in the design of the effluent launder design. If no sludge consolidation occurs, then the flow rate for the sludge drain must equal φ floc~Q ~tank, or approximately 380 mL/min.