IanVG
Mechanical
- Jan 21, 2022
- 74
The only other thread that I could find on this topic is here. I have a tank that is used to store water for pumped non-potable use. The tank's rough dimensions are 8ft in diameter and roughly 10ft in depth (cylindrical shape). Approximately 1ft from the bottom I have a outlet for the tank that is piped to a pump that sits below the bottom elevation of the tank. The tank outlet in the tank is connected to a flexible floating ball extractor. The floating ball extractor has a suction inlet with a mesh to prevent the intake of particulate under around 0.1mm in size (or so!). The purpose of the extractor is to only use water from the top ~2 to ~6" inches of water in the tank.
The problem I am having is that the suction line is too long for when the tank level is low (starting at around ~2.5ft), so air is able to get trapped inside the flexible pipe. In addition, when the flexible pipe is partially filled with water, the suction inlet of the suction line begins to 'float,' which means it allows air inside the flexible pipe as well. The air inside the pump is causing cavitation as the pump is not able to be primed with so much air.
My question is if there is any official design guidelines or calculations someone can point me to for the proper sizing of the length for the flexible pipe for a floating ball extractor. I am less worried about the diameter of the individual components, as that is a only a pressure drop calculation, which affects NSPHa at the pump, and I am comfortable figuring out those numbers. The devices seem to be relatively common, but a couple quick google and Eng-Tips searches were not fruitful. Any tips to the right direction?
P.S. - I am also open to suggestions of better engineered floating extraction system that are less likely to trap air inside them.
The problem I am having is that the suction line is too long for when the tank level is low (starting at around ~2.5ft), so air is able to get trapped inside the flexible pipe. In addition, when the flexible pipe is partially filled with water, the suction inlet of the suction line begins to 'float,' which means it allows air inside the flexible pipe as well. The air inside the pump is causing cavitation as the pump is not able to be primed with so much air.
My question is if there is any official design guidelines or calculations someone can point me to for the proper sizing of the length for the flexible pipe for a floating ball extractor. I am less worried about the diameter of the individual components, as that is a only a pressure drop calculation, which affects NSPHa at the pump, and I am comfortable figuring out those numbers. The devices seem to be relatively common, but a couple quick google and Eng-Tips searches were not fruitful. Any tips to the right direction?
P.S. - I am also open to suggestions of better engineered floating extraction system that are less likely to trap air inside them.
