TPi January 2013

products & developments Storm water treatment with integrated oil separation

Rainwater must frequently be treated before it can be discharged or infiltrate into the soil so that no pollutants reach water bodies or groundwater. Fränkische Rohrwerke’s SediPipe line offers an effective alternative to space- consuming storm water sedimentation tanks. The SediPipe XL-Plus system, which is installed under trafficked areas, features two flow separators that remove both particles and light liquids from the storm water flowing through the system. Due to its high treatment performance, the SediPipe modular system is also a suitable choice for larger connected areas of several hectares. With project- specific planning and flexible design options, treatment performance and pipe diameters can be tailored to the specific situation. Accidents and spills in conjunction with leaking light liquids, such as oil or diesel fuel, or where these mix with quench water, can never be entirely excluded on trafficked areas. SediPipe XL-Plus provides for spills: a flow separator in the upper pipe cross section separates entrained light liquids even in case of high flow rates. “SediPipe XL-Plus

SediPipe connection

The retention of light liquids has been tested by the TÜV Rheinland LGA Products GmbH. The discharge values match those of a class I oil separator according to DIN EN 858-1 (residual oil level ≤ 5.0mg/l, which corresponds to an oil retention of at least 99.9%). The lower flow separator collects the fine particles that, due to their large surfaces, bind the largest amount of pollutants and heavy metals. The stretched and tubular sedimentation chamber is a clear advantage: flow rectification significantly reduces the time and distance until a particle settles and prevents vortex generation and short-circuiting. Additionally, the flow separator prevents the particles from being remobilised and therefore the sediment from being discharged from the lower pipe cross section during heavy rainfall. The SediPipe XL series consists of four system sizes: 600/6, 600/12, 600/18 and 600/24. The systems can easily be combined into large-scale systems – a 24m-pipe treats storm water of an area of up to 4ha. Cleaning of SediPipe is usually performed during regular sewer flushing. The open valve flap and the slope of the sedimentation pipe cause the mud to slide to the low point in the start shaft where it can be vacuumed. The system is then cleaned and can be operated again immediately. Fränkische Rohrwerke Gebr Kirchner GmbH & Co KG – Germany info.drain@fraenkische.de www.fraenkische-drain.de

guarantees the utmost spill prevention for water bodies also during heavy rainfall or inflowing quench water,” said Michael Schütz, head of product management at Fränkische Drainage. “Thanks to the upper flow separator, the systems even reach the performance of a coalescence separator.” If a water-oil mix enters the SediPipe XL-Plus system after an accident, the running water separates the oil into many small drops. The fine drops rise very slowly in the system and are collected in the upper pipe area, where there is little water movement. The flow separator acts similar to a coalescence separator: its lattice structure collects smallest oil drops and merges them to form larger

drops which can be separated more easily and rise to the pipe crown. The drops are collected in the target shaft to form a firm oil layer upstream of the immersion pipe that cannot be flushed out, even in case of subsequent heavy rains.

SediPipe XL-Plus sedimentation system with two flow separators

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Tube Products International January 2013

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