Articles & Case Studies

Hidrostal's pumps keep the runways clear at Heathrow Airport

Posted: Tuesday 18th April 2017

Hidrostal Ltd, the UK division of the Swiss pump manufacturer, has facilitated Heathrow Airport with the pumping technology required to maintain the smooth operation of its Terminal 5 runway. The fifth terminal at Heathrow opened its gates for passenger use this month nine years ago, after eight years of planning, six years of building and at a cost of £4.2 Billion.

Laing O'Rourke, the main contractor for the scheme, contacted Hidrostal back in 2001 to ask for their assistance in providing a suitable pumping solution at Heathrow. Hidrostal are renowned in their field for designing and delivering innovative solutions for challenging applications.

The vast majority of the huge 640 acre site consists of buildings, runways and hard standing. It is vitally important therefore that storm and surface water run-off is transferred quickly and efficiently away from these areas to ensure the smooth running of the airport.

The design specification required the pumps to be installed in a ten metre diameter shaft, seventeen metres deep with a three metre diameter inlet providing storm water from T5 to the pumps. The design flow of the system required a duty of 430 litres per second. In addition the pumping station was required to be self-cleansing due to the depth of the wet well and entry restrictions. An added complication arose as the pumps were required to discharge to a local lagoon via an oil water separator. This is due to the amount of contaminants within the storm water, such as aviation fuel, oils and aircraft anti-freeze.

The pumps were required at the initial stage of construction to help with storm water alleviation during the project.

The Hidrostal solution was to install three I10K-M01 79kW pumps into individual Prerostal basins, attached on the base of the wet well and installed on guide rails for easy installation and maintenance. The Prerostal swirl basin is a design that is constructed with a partial weir in front of a prefabricated Prerotation basin which directs the flow into the basins integral entrance channel. This tangential entrance channel causes the flow entering the basin to rotate in the same direction as the pump, thus creating a self-cleansing swirl that directs solids into the pump suction.

In addition to the self-cleaning properties of the Prerostal basin, the Hidrostal screw centrifugal impeller is ideally suited to pumping oily water. The low shear, gentle handling characteristics of the impeller ensure that there is virtually no emulsification of the oil droplets. This, combined with the flow matching and skimming effects of the Prerostal system, ensures that the separator operates at maximum efficiency.

In the thirteen years that the pumps have been operational at Heathrow Airport two of the pumps have been removed for servicing on only one occasion. The third continues to run as designed with no interruption in operation, despite continuous groundwater infiltration of 50 litres per second into the chamber.

The benefits of the system include:

Trouble free pumping over a period of 13 years with very minimal maintenance.

Reduction in airside movements during maintenance operations.

Self-cleaning station design with no requirement to remove silt and sludge build-up.

The use of the unique Hidrostal screw impeller ensures that the separator system works at peak efficiency.

Ian Jolly, System Specialist at Water Services comments that "The Hidrostal pumps have served Heathrow airport extremely well since their installation. They are reliable, efficient and have represented very good value."




Read the magazine online

December 2018

About the magazine »
Magazine archive »


Advertisements

Information for advertisers »

Pulsar New Banner
British Water Prominent Fluid Controls Verder Water Aid Pulsar Button June 13 buttonwood marketing Harvey Communications Huber wateractive
ATI UK