HUBER Heat Exchanger RoWin Modular design for use with all types of wastewater

The HUBER Heat Exchanger RoWin consists of a welded stainless steel construction in which horizontal pipe modules are arranged in parallel. The pipe modules are made of stainless steel to achieve maximum heat transfer efficiency. The pre-screened wastewater flows through the heat exchanger and, via the compactly arranged pipes, gives off its thermal energy to the cooling water. The energy for the heat pump is supplied through the heated cooling medium.

Due to the specific chemical-biological properties of wastewater a biofilm is developed over time on the heat transfer surfaces that significantly impairs heat transfer. Preventive cleaning of the heat transfer surfaces with an innovative, fully automatic cleaning mechanism therefore is applied to ensure the maximum heat transfer capacity is permanently maintained.

Sediments and solids settling on the tank floor are removed by a screw conveyor and returned to the sewer along with the cooled wastewater. Due to the enclosed tank design and return of solids thermal energy is the only emission from wastewater. The HUBER Heat Exchanger RoWin is available, as required, with an outer insulation for particularly exposed sites. Installed above ground, the system offers the benefits of easy maintenance and operation.

Due to its modular design the HUBER Heat Exchanger RoWin can be tailored to suit specific site requirements. In combination with a heat pump up to several hundred kilowatts of thermal output can be generated, depending on the unit size.

With the optimal combination of both systems municipalities or industrial enterprises can cover up to 80 % of the heat required from wastewater as energy source.

The HUBER Heat Exchanger RoWin C can be used for installation in the outlet of the wastewater treatment plant or in buffer tanks. Installed directly in the wastewater flow, the heat exchanger modules are optimally surrounded by the flow.

Due to the biological processes taking place, the temperature of effluents from sewage treatment plants is on average by 1 K higher than the inlet temperature. Furthermore, higher amounts of thermal energy can be extracted from WWTP effluents than with heat recovery plants installed in sewer systems.

The biological processes in the sewage treatment plant are not impaired and the introduction of the cool WWTP effluent outlet is beneficial for the flowing water biology. In addition, temperature and oxygen conditions in the waters are significantly improved.

If installed in the channel, no additional pumps are required as the wastewater flow normally runs off by gravity. This avoids costs and significantly improves the economic efficiency of such plants. Especially with regard to the energetic rehabilitation of wastewater treatment plants, the HUBER Heat Exchanger RoWin can make a decisive contribution.

Due to its compact design and installation in a channel or tank, no additional installation space is required and the available space utilised at an optimum. But biofilm growing on the heat exchanger surfaces cannot completely be ruled out with the use of the WWTP effluent. Integrated cleaning of the heat transfer surfaces therefore is of great importance to continuously maintain the maximum heat transfer capacity.

Several HUBER Heat Exchanger RoWin C units can be installed in parallel or in series for perfect adjustment to specific site conditions and customer requirements. Combined with load-bearing covers the units can also be installed under parking areas for example.