For larger WWTPs several heat exchangers are used. By adding further modules, the operator can react flexibly and quickly to an increasing demand for heat energy and increase the capacity of the plant. Depending on local conditions, the heat exchangers can be integrated into a concrete channel or as a tank version in the sewage treatment plant environment.
Heating with the Sewage Treatment Plant Effluent
Heating with the Sewage Treatment Plant Effluent
Treated wastewater as a regenerative energy source with high energy potential
The effluent of a sewage treatment plant represents a great potential for heat recovery and can make an important contribution especially to energy-efficient retrofitting of sewage treatment plants.
All the wastewater that has been fed to the treatment plant via the sewage system is discharged into the receiving watercourse via a central outlet after treatment, so that large quantities of water are always available here. In addition, due to biological processes taking place, the temperature of effluents from sewage treatment plants usually is on average by 1 K higher than the inlet temperature.
When heat is extracted from the effluent water of the treatment plant, it cools down accordingly. Since the discharge of cooler water has a favourable effect on the temperature and oxygen conditions in the receiving water, there is an advantage for flowing water biology.
HUBER Heat Exchanger RoWin C installed in a concrete tank. The flow streams through the heat exchanger by gravity
HUBER Heat Exchanger RoWin C tank version being lifted into the concrete tank
HUBER Heat Exchanger RoWin C installed in a channel.
The Process
Sewage treatment plant as a sustainable energy source
Energy suppliers are increasingly discovering the potential of a sewage treatment plant as a source of energy and as a way of generating sustainable energy.
Optimal installation increases economic efficiency
To extract heat from the treated wastewater, the installation of the HUBER Heat Exchanger RoWin is necessary. The HUBER Heat Exchanger RoWin C version is particularly suitable for use in the outlet of a wastewater treatment plant. There is no tank, the heat exchanger modules are placed directly in the effluent stream and are thus optimally exposed to the flow.
Installation of the heat exchanger in the channel or in a separate basin allows the use of the gravity flow from the sewage treatment plant. This means that no additional pumping energy is required. Innovative overflow weirs ensure optimal overflow even with varying effluent volumes.
Optimal installation minimises costs and significantly increases the economic efficiency of such a system. The possibility of connecting the compact heat exchangers in parallel or in series opens up options for ideal adaptation to basin and wastewater conditions. Combined with load-bearing covers, the units can also be installed under parking areas for example.
Fully automatic cleaning ensures long-term efficiency
Utilisation of the clarified effluent from sewage treatment plants does not completely exclude biofilm formation on the heat exchanger surfaces. Therefore, fully automated cleaning of the exchanger tubes integrated in the HUBER Heat Exchanger RoWin is a key point for permanent and maximum heat transfer efficiency.
