I am working on a project to increase the CT time in an old steel tank with a wooden roof. Baffling has been ruled out because we could not find an acceptable way to support the baffling within the tank and not hit the wooden beams which support the roof. We have decided to install a manifold within the tank which would be located on the opposite side of the tank from the outlet. Computer modeling is already done. This manifold would distribute the water into a series of outlets facing straight up. My current design for the manifold has it entering the tank and going through three wide-angle turns to stay close to the edge of the tank. It is about 6” off the floor. At the last outlet, the pipe comes to a dead end. We would like to use PVC for this manifold to reduce the costs. One additional constraint is that the manway for this tank is 20” and the roof hatch is 24” by 36”.
Two problems:
1.) How do I confirm that the flow will be evenly distributed between the manifold outlets? I have already verified that the total headloss in the pipe (18”) is less than the headloss through each of the outlets (6”.)
2.) How do I control thrust on this pipe (approximately 4100 pounds on dead end)? Thrust is outward toward walls. I am not allowed to weld to the bottom of the tank. My first thought is to put big concrete blocks in with pipe supports on them, but I do not know of a manufacturer. Precast would be better for getting the tank operational as quickly as possible - but size limits on manway and hatch are a big problem. Obviously, anything we select needs to be NSF approved.
Two problems:
1.) How do I confirm that the flow will be evenly distributed between the manifold outlets? I have already verified that the total headloss in the pipe (18”) is less than the headloss through each of the outlets (6”.)
2.) How do I control thrust on this pipe (approximately 4100 pounds on dead end)? Thrust is outward toward walls. I am not allowed to weld to the bottom of the tank. My first thought is to put big concrete blocks in with pipe supports on them, but I do not know of a manufacturer. Precast would be better for getting the tank operational as quickly as possible - but size limits on manway and hatch are a big problem. Obviously, anything we select needs to be NSF approved.
