Bartosz Kaźmierczak
Politechnika Wrocławska

A simulation of the functioning of a modern overfall with a cylindrical vortex regulator on a combined sewage system was conducted in this work. In a cylindrical vortex regulator, liquid flows into the device through a connector tangent to the cylinder generator. From this, the liquid receives a vortex motion, which is maintained throughout the entire chamber width all the way to an outlet hole on the cylinder head. In the motion, peripheral speed is increased when approaching the cylinder axis. Because of the centrifugal force in the vortex chamber, the pressure decreases towards its axis until it reaches an ambient pressure on the air core surface. The air core being generated has a crucial influence on the throttling efficiency of the device. The atomized liquid in the outflow creates a cone with the angle of flare γ. For the modelling of storm overflow activity a combined drainage area of F = 60 ha was suggested. The overfall was loaded with sewage and wastewater. A typical, triangular hydrograph of the wastewater inflow to the storm overflow was applied here. The given hydraulic model of storm overflow activity includes a series of characteristic, occurring in sequence phases of filling and emptying of the overfall chamber. The phases were distinguished with the description of boundary conditions in reference to the precisely determined range of variables during the fillings and flows. On the basis of the formulated hydraulic and mathematical models of the storm overflow activity, a computer programme for the numerical simulation of the functioning of the aforementioned overflows was developed. The simulation of a storm overflow functioning on a combined sewage system proved a high level of sewage-treatment plant protection from a hydraulic overload by the application of modern, unconventional storm overflows. Irrespective of the assigned load, sewage outflow stream towards the sewage-treatment plant is stabilized on a demanded level. Current methods of designing storm overflows do not take into account the frequency of storm discharges to the receiver, as well as they do not offer the possibility of their duration and volume determination and thus they do not allow for the assessment of pollution load that is drained off in discharges towards receivers. The simulations of storm overflows functioning allow for determination of these parameters for already designed overflow and for any assigned load. Therefore they constitute a valuable instrument supporting the process of designing this type of objects, as it has been proved in this work.

Słowa kluczowe
modelowanie matematyczne; cylindryczny regulator

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