Flow regulators – effectively prevent flooding and waterlogging
Due to the frequent occurrence of driving rain, proper regulation of the discharge of water from the rainwater drainage network and other watercourses becomes particularly important. Failure to use appropriate solutions may result in the risk of flooding, sewer flooding, backflow, contamination of sewage and rainwater receivers, etc. To prevent similar risks, Ecol-Unicon offers flow regulators made of HDPE.
Regulators effectively replace complex gate and valve systems that require manual or automatic operation. Working in conjunction with retention tanks, they ensure that the run-off wave is balanced and limit peak flows, thereby mitigating hydraulic surges. The use of regulators also allows new catchments to be connected to existing municipal sewers without the risk of overloading them.
TABLE OF CONTENTS
- Types of Ecol-Unicon flow regulators
- Benefits of using flow regulators
- Operating principle
- Application of flow regulators
- Selection of flow regulators
Ecol-Unicon FLOW REGULATOR TYPES
Based on the way flow regulators are installed, we distinguish between types:
* rod – connector fitted on a mounting plate attached to the chamber wall that allows the regulator to be suspended from ground level
FLOW REGULATOR – BENEFITS
- simple and compact design for trouble-free operation
- self-cleaning of the regulator reduces maintenance and service operations to a minimum
- no components or moving parts, reducing the risk of failure
- no need to supply and connect electrical power, reducing running costs
- HDPE material design – non-corrosive
- an alternative and less expensive solution to complex throttling devices, e.g. automatically controlled components
OPERATING PRINCIPLE OF CONICAL AND VERTICAL REGULATORS:
The throttling effect in the regulators is achieved by increasing flow resistance. One way to achieve this effect is to force a vortex flow or to cross two fluid streams. The intensity of throttling depends on the pressure of the fluid entering the device. Initially, when the inflow is low, throttling does not occur and the fluid flows freely. As the inflow of the fluid increases, the free flow throttles spontaneously.
In the conical and vertical regulator, the increasing pressure of the fluid column causes the air to close at the top of the vortex chamber. The air becomes a source of additional resistance and the potential energy of the fluid is converted into vortex energy. This creates a choking effect. This effect corresponds to the use of a venturi 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 changes with the pressure of the incoming fluid, from an initial value µ’ to a value µ”.
The regulator starts operation at µ= µ’. In the initial stage of the vortex flow, the coefficient µ changes to the characteristic value µ’. Further on, the flow takes place according to an ascending – throttling characteristic. As pressure decreases, the flow decreases according to the descending characteristic (Fig.1). When the air trapped in the regulator finds an outlet, the flow increases. There is a rapid return to the basic characteristic (µ= µ’) – at this point the so-called self-cleaning of the regulator occurs. This process takes place in every cycle of the regulator, which ensures trouble-free operation. The maximum flow (Qmax) is reached twice and the average flow through the regulator (Qsr) corresponds to 80-90% of the maximum flow.
Conical vortex regulators ensure that the required flow is achieved at two operating points, enabling the construction of a by-pass system for the equipment and optimisation of the retention tank capacity.
USE OF FLOW REGULATORS
- Retention tanks
- Sewer manholes
- Stormwater drainage network
SELECTION OF FLOW REGULATOR
The regulators, which are individually selected according to the nature of the catchment area, are used in rainwater and combined sewer systems and on small watercourses. By utilising the retention capacity of sewer networks, they prevent flooding of urbanised areas and protect water treatment facilities (e.g. municipal sewage treatment plants) from hydraulic overloads.
Parameters required to select the device:
- Q – nominal regulator discharge rate [l/s],
- hmax – maximum damming upstream of the regulator [m],
- DN – drain pipe diameter [mm].
- size of the chamber in which the controller will be installed – length and width or diameter, height of the chamber [m].
