World's largest vortex control unit for Glasgow
24 Mar 2010
London – Arc Energy Resources, a supplier of fabrication services and a principal fabricator to Hydro International, has supplied the world’s largest vortex flow control unit as part of a contract to produce five Hydro-Brake flow control units for the £53m White Cart Water flood prevention scheme for Glasgow City Council.
The scheme covers the White Cart Water and its tributaries and involves the formation of three flood storage reservoirs upstream of the city, which are capable of temporarily holding back the millions of gallons of floodwater generated by extreme rainfall.
The five conical shaped flow control units allow water to flow through the reservoir dams normally up to a pre-determined height, after which the increasing velocity causes a vortex to form. The air pressure within the vortex ’throttles’ the flow of water, slowing it down and allowing the reservoir to fill up. Water is then released to flow through the city in a controlled manner.
Each of the five units differs slightly in design, the largest (also the largest in the world) being six metres in diameter and eight metres long with an outlet size of 1.8 metres. The two largest Hydro-Brake units were also too large to be transported by road and too heavy to lift by helicopter, so with input from Arc Energy, each was designed in sections to create a ’former’.
When installed, the 12mm thick stainless steel formers will be encased in 600mm thick reinforced concrete to provide the structural strength required to withstand a through-flow of water estimated at 8,800 tonnes per second.
The project is said to be the first time the technique has been used to install vortex flow controls. In total, 60 tonnes of stainless steel were used in the manufacture the five flow control units.
