Rain spillway basins are being filled about 50 times a year. After each filling, deposited sludge must be removed as soon as possible in order to avoid rotting. The initial expectation of a possible construction of self-cleaning rainwater basins could not be realized.
Quite the contrary, massive sludge sediments in a rain spillway basin indicate an effective working. Thus, the deposited sludge in the rainwater basin for certain is not released into open water.
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A very effective way to automatically clean the basin is the forceful flushing with tipping buckets after the basin’s draining because of a low risk of dirt escaping to lower rainwater overflow chambers as rain has already stopped. Tipping buckets have the advantage of requiring less flush water and almost no energy. Discharge height is the only decisive factor. |
Water flow from the tipping bucket in the basin has been simulated as a two-dimensional model. The transient simulation was executed with a „free surface model“ taking both fluid phases (water and ambient air) into consideration.
