Flow regulators
Effectively prevent flooding and waterlogging
Due to the frequent occurrence of torrential rains, the proper control of stormwater discharge into the rainwater drainage network and watercourses is becoming particularly important
Failure to implement appropriate solutions may result in the risk of localised flooding, backwater, contamination of receiving bodies with pollutants from sewage and rainwater. To reduce the occurrence of such risks, Ecol-Unicon offers vortex flow controllers. Regulators are an alternative to complex gate and valve systems requiring manual or automatic operation. Working with the reservoirs, they reduce peak flows by ensuring that the runoff wave is equalised. The use of regulators also allows new sub-basins to be connected to existing municipal sewers without the risk of overloading them.
Benefits of use
Protecting infrastructure – controlling the water supply to reservoirs and sewers protects the network from overloading.
Preventing flooding – it delays the flow of water during heavy rainfall, reducing the risk of flooding.
Reduced pollution of the receiving body – slow flow allows for more effective treatment of water discharged into rivers.
Easy to operate – regulators do not require frequent cleaning, which simplifies maintenance.
Low failure rate – the equipment operates according to physical phenomena, which ensures reliable operation for years.
No clogging – regulators freely pass fine solids, eliminating the problem of blockages.
The cheaper alternative – regulators are a simpler and more cost-effective solution than complex flow throttling devices.
No need for power – regulators do not require electricity to operate.
Increased efficiency of storage reservoirs – the use of vortex regulators allows the capacity of the reservoirs to be reduced by 20–30% and speeds up their draining.
Widely applicable – regulators work well in rainwater pre-treatment, storage reservoirs and new drainage basins connected to existing sewer systems.
Application
- Retention tanks
- Sewage wells
- Stormwater sewer network
Types of flow regulators
Based on the installation method of the flow regulators, the following types can be identified:
| Regulator type | Variant | Designation | Installation |
|---|---|---|---|
| Conical | Conical vortex | ERSW-R | Drain pipe |
| Conical | Conical vortex | ERSW-S | Mounting plate on chamber wall |
| Conical | Conical vortex | ERSW-D | Mounting plate on chamber wall, rod * |
| Vertical | Vertical | ERC-D | Mounting plate on chamber wall, rod * |
| Vertical | Vertical | ERC-S | Mounting plate on chamber wall |
*) Rod – a connector allowing the regulator to be suspended from ground level on a mounting plate fixed to the chamber wall
Conical vortex regulators
Vertical regulators
Selection of the flow regulators
The regulators, selected individually according to the nature of the basin, are used in stormwater drainage, general drainage and on small watercourses. By utilising the retention capacity of sewer networks, they prevent flooding of urbanised areas and protect pre-treatment facilities (e.g. municipal sewage treatment plants) from hydraulic overloads.
The following parameters are required for selection of the device:
- Q – nominal regulator discharge rate [l/s],
- hmax – maximum impoundage upstream of the regulator [m],
- DN – outlet pipe diameter [mm],
- size of the chamber containing the regulator – length and width or diameter, height of chamber [m]
Operating method
The throttling effect in the regulators is achieved by increasing the flow resistance. One way to achieve this effect is to convert the kinetic energy of the inflow stream into vortex motion energy. The intensity of throttling depends on the amount of pressure of the liquid entering the unit. Initially, when inflow is low, the liquid flows freely. As the water inflow increases, a vortex motion develops inside the regulator and the flow is throttled.
In vortex regulators, the increasing pressure of the fluid column causes the air to be trapped in the upper part of the vortex chamber. The air becomes a source of additional resistance and the potential energy of the liquid is converted into vortex energy. This creates a throttling effect. This effect corresponds to the use of a reducer with a cross-section several times smaller than that of the regulator.
Under normal conditions, the discharge coefficient µ for an orifice of a certain bore size is constant, whereas for regulators this value varies, depending on the nature of the flow through the regulator (µ’ for free flow and µ” for vortex flow).
The regulator starts working at µ = µ’. When the water upstream of the regulator reaches the impoundage at which a vortex flow develops in the unit, the value of the flow coefficient µ changes to the characteristic value µ’. Further, the flow follows a rising or falling curve, depending on the evolution of the water level upstream of the regulator (Fig. 2).
In the final phase of draining, when the air trapped in the regulator finds an outlet, and the flow increases. A rapid return to the basic characteristic (µ= µ’) occurs – at this point, the so-called self-cleaning of the regulator takes place. This process occurs every cycle of the regulator, ensuring trouble-free operation. The maximum flow (Qmax) is reached twice and the average flow through the regulator (Qmean) corresponds to 80–90% of the maximum flow.
Conical and cylindrical regulators ensure that the required flow is achieved at two operating points, enabling the design of a by-pass system for the equipment and optimisation of the storage reservoir capacity.