Wastewater System Cuts Maintenance 87.5%

Wastewater-pumping system solves chronic clogging problems at Heathrow Airport.

One of Heathrow’s aircraft wastewater vehicles, transporting sludge to the Central Area Sanitation unit.

By Mark Willson, Xylem Inc.

London’s Heathrow is one of Europe’s busiest airports, daily serving more than 200,000 passengers with an average of 1,200 flights arriving and departing. To service all of the systems that support those people and planes, Heathrow Airport Water Services Department manages an extensive network of 120 pumping stations. As can be expected, a system of this size doesn’t always operate smoothly.

Chronic clogging issues at one of the airport’s wastewater pumping stations were one problem area. To solve it, department personnel agreed to install and pilot the Flygt wastewater pumping system, manufactured by Xylem Inc., Rye Brook, NY.

As well as delivering consistently clog-free pumping, the Flygt Concertor, a wastewater-pumping system with integrated intelligence, dramatically reduced energy consumption by 53% at the pumping station.

The Challenge

The Central Area Sanitation unit adjacent to Terminal 1 is a receiving station for all aircraft toilet waste and was experiencing a very tough clogging challenge. The station manages wastewater directly from aircrafts.

The wastewater contains a high level of non-biological solids including various types of plastic material, wipes, disposable diapers, and clothing. This stringy material can be difficult to pump since it can easily get caught on the impeller and partially block the pump, leading to increased energy consumption and, in worst cases, full pump blockage.

This challenging wastewater application led to regular clogging and the sump not being kept properly clean.

“We would usually have to deal with two or three clogging issues during a three-month period,” said Ian Jolly, systems specialist for water, Heathrow Airport Water Services Department. “We also used to see a shelf of fat and material deposits build up on the walls of the sump, as well as floating debris. This presented a very tough challenge to our existing wastewater pumps which we frequently had to de-clog.”

Integrated clog-free technology

Heathrow Airport required a solution that would solve the operational costs and environmental problems caused by:

• high levels of floating debris on the surface of the wet well
• higher than normal percentages of rag/non-biological solids in the wastewater.

The Heathrow team trusted Xylem’s expertise in solving these particularly challenging problems and agreed to a trial of the Flygt Concertor. “We have used a number of Flygt technologies over the years and have found the Flygt team to be very willing to listen to our needs, always eager to find a solution,” Jolly said.

Flygt Concertor

As a world’s first, Flygt’s wastewater-pumping system combines built-in sump and pipe-cleaning functionalities in a single integrated solution. It is capable of tackling sump floating debris as well as pipe sedimentation. Furthermore, the pump-cleaning function, together with Adaptive N-hydraulics, effectively detects and solves clogging from large debris.

It is precisely the integration of intelligent functionality that makes Flygt Concertor a unique wastewater-pumping system. It provides unparalleled results and long-term positive benefits for many applications. 

Since the installation of Flygt Concertor at the Heathrow Central Area Sanitation Unit in November 2015, Concertor has provided absolute clog-free operation, as well as a remarkable improvement in the wet-well environment.

“Since installing Concertor we have had absolutely no clogging and the sump remains clean with no fat build-up,” Jolly said. “As well as peace of mind—which really is priceless—the cost savings are significant at approximately 87.5% of the annual costs in cleaning and servicing.”

The maintenance on the system is greatly reduced, according to Tomas Brannemo, senior vice president, President Transport, Xylem, Inc.

“Normally, you would have clogging issues, pipe blockages, and the sump itself would get floating grease,” he said. “The entire system would need to be cleaned with a vacuum truck. Concertor’s integrated intelligence has sump and pipe cleaning built inside. At regular intervals, this system automatically takes down the level, sucks up the debris, and flushes it out so that the sump is clean. It also goes through pipe cleaning cycles as well as automatically recognizing and unclogging itself if clogging should occur.”

Ian Jolly, System Specialist for Water Services at Heathrow Airport, pleased with Flygt Concertor’s trial results.

Energy reduced by more than 50%

The system aims to deliver proven reliability at the lowest total cost of ownership and to achieve this it also, among other benefits, drastically reduces energy consumption.

In the case of the once-troublesome Central Area Sanitation Unit pumping station, energy savings have increased to 53% which, again, is a result of sophisticated software and cutting-edge components. The Energy Minimizer function automatically ensures that all the pumps run at their most efficient duty points together with:

• IE4 high-efficiency motor
• self-cleaning Adaptive N-hydraulics
• constant power functionality.

Additionally, since there is no need for ventilation, cooling, or heating of cabinets, customers benefit from substantial energy savings throughout the system’s total life cycle.

“Concertor’s compact design allowed it to fit into the existing position within the pump station, without any extra investment required to enlarge the cabinet. From an aesthetic and practical consideration the reduced panel-requirement size will be of great benefit,” Jolly said. “It was simple to install and very user friendly. Actually, the trial pump was installed by one of the airport’s water services mechanical technicians, who was not experienced in the commissioning of wastewater-pumping systems and quickly gained confidence with the ease of installation and operation.” RP

Mark Willson is a field sales engineer for Xylem managing infrastructure accounts in the South East region of the UK, with responsibility for Xylem product sales into Thames Water and Heathrow Airport accounts. Willson has more than 15 years of experience in the water-treatment sector. Prior to joining Xylem, he worked in the water-treatment and petrochemical sectors, and with Ford Motor Co. as a project engineer. He holds a BEng degree in mechanical engineering and a teaching degree.