TPT March 2011

T echnology U pdate

Coil and weld half pipe jackets simultaneously

The half pipe is formed from slit coil stock in a continuous progression. Various shapes and material gauges can be used. Coil pitch can be varied as the half pipe is applied to the tank shell. The one pass system can be designed to handle various tank diameters and lengths. Carell Corporation – USA Fax: +1 251 937 0957

CARELL is the exclusive North American distributor and support/service provider for a new half pipe jacket manufacturing technology that is claimed to save production time and manpower to uniformly form and apply high quality half pipe jackets to thermally conditioned tank shells. At the Fabtech 2010 show in Atlanta, Carell displayed a stainless steel tank shell with low profile half pipe jackets. This jacket was automatically formed and welded to the shell in this new high tech production cell.

Email: sales@carellcorp.com Website: www.carellcorp.com

Carell’s stainless steel tank

High-performance sedimentation systems

THE efficiency of wastewater treatment systems to clean wastewater has improved continuously over the last few decades. Stormwater discharge is the main source of pollution of waters today. Legal framework requirements demand the rethinking of the subject of stormwater. The EU Water Framework Directive demands ‘good conditions’ for all European water bodies, and the new German Federal Water Act (Wasserhaushaltsgesetz- WHG), adopted in March 2010, bans new combined sewer systems. It demands stormwater infiltration or discharge without pollution with wastewater for all of Germany. Many cases require cleaning of the stormwater runoff to avoid pollutants being transported into water bodies and ground water. With the Sedi-pipe programme, Fränkische Rohrwerke, a leader in the field of stormwater management, has created an efficient solution for this. Sedimentation is observedwhen particles of solid material slowly sink to the ground in a jar of water. All this requires is gravity and enough time. Stormwater sedimentation tanks have used this principle for a long time. Stormwater is diverted through large concrete tanks, the flow velocity is slowed down and dirt particles sink to the ground. For the sediment on the ground not to be stirred up and discharged in case of heavy rainfall, these tanks must be at least 2m deep. This makes significant tank volumes necessary. Sedi-pipe accomplishes this more effectively: sedimentation takes place in a horizontal pipe with a built-in flow separator.

This special lattice creates a zone with little water movement, from which the sediment is not discharged during heavy rainfall. This achieves the same cleaning performance as a stormwater sedimentation tank, but with a much smaller volume. The fineandultra-fineparticles contained in the stormwater bind the largest amount of pollutants due to their large surface. The aim is to retain these particles in particular, and it takes a long time for these particles to sink. The long form of the sedimentation pipe is an advantage here, because it reduces the time and distance until a particle settles, and therefore very fine particles settle. The flow separator prevents the parts from being remobilised and therefore from being discharged during heavy rainfall. Sedi-pipe therefore retains large amounts of fine particles and consequently large amounts of the pollutants. The performance capacity has been tested and confirmed by independent institutes. Existing Sedi-pipe systems are intended for use in upstream infiltration systems, especially in interaction with Rigofill retention/infiltration units. With Sedi-pipe XL, Fränkische has increased the number of possible applications of the Sedi-pipe, allowing high cleaning performance when large areas are connected before infiltration or discharge into receiving waters. Through project- specific design, cleaning performance and pipe diameter can be designed to suit individual requirements. Extra large storage volumes for light liquids (spill

prevention) and mud are also possible. The shallow installation depth compared to regular stormwater sedimentation tanks facilitates building under high ground water conditions. The Sedi-pipe XL series consists of four system sizes: 600/6, 600/12, 600/18 and 600/24. The systems can be combined into large-scale systems to replace standard stormwater sedimentation tanks. Building specifications are usually very clear: the system should be space-saving and below ground, installation should be easy and fast, and in case of possibly high levels of ground water also achievable with low installation depths. Furthermore, the requirements of water regulations must be met. “Sedi-pipe systems meet all of the above requirements,” commented Michael Schütz, head of product management. The system maintains a constant water level, which keeps the sediment muddy. Maintenance of the system is usually performed during regular sewer flushing and only requires vacuuming of the contents. The slope of the sedimentation pipe causes the mud to slide to the low point of the system in the start shaft. If required, cleaning can be supplemented by using high-pressure jetting. Sedi-pipe XL shafts are accessible for maintenance and inspection if necessary, and have a diameter of 1,000mm. Fränkische Rohrwerke – Germany Fax: +49 9525 88 412 Email: info.drain@fraenkische.de Website: www.fraenkische-drain.de

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M arch 2011

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