Elga Process Water's engineers assessed the water quality at Seabank Power and proposed an emergency response that would put an Aquamove MoDi trailer mounted water treatment unit on site
Seabank Power's 1140MW generating station in Avonmouth, Bristol, a joint venture between British Gas and Scottish Hydro-Electric, is one of the UK's biggest Combined Cycle Gas Turbine stations. Although CCGT heat recovery steam generators operate at lower pressures than conventional power station boilers, the feedwater quality is just as critical, particularly in respect of silica which can cause major plant failures. Consequently the make-up water demineralisation plant is vital to generation capacity, and plant downtime will reduce station output and lose revenue.

Demineralisation plants are susceptible to all sorts of problems - even a change in water supply can cause loss of quality - so Seabank Power's 'disaster prevention' philosophy required an emergency plan to cope with total failure of the 50m3/h demineralisation plant; a plan that was formulated with the help of engineers from Elga Process Water's Aquamove mobile plant team.

It was Seabank Power's Station Chemist, Tony Gilbert, who selected Aquamove as the company's emergency partner: 'We chose Aquamove because of the pre-planning service they offered'.

'Having a plan that Aquamove helped to draw up meant that their team would be familiar with the site prior to having to deal with an emergency and that really appealed to us'.

Elga Process Water's engineers assessed the water quality at Seabank Power and proposed an emergency response that would put an Aquamove MoDi trailer mounted water treatment unit on site within a matter of hours.

The MoDi trailer provides two streams of ion exchange which are capable of producing 50m3/h of high purity water with 0.1micro-S/cm conductivity and 20ppb silica.

The equipment is all installed in a standard 40' trailer which is insulated and supplied with heating and lighting so that, inside the container, the environment is just like most plant rooms.

The trailers are also kitted out with all necessary safety equipment.

Once exhausted, the complete trailer is returned to Elga Process Water's state of the art Regeneration Centre in Stoke, where 50 years of experience in the handling of ion exchange resins is brought to bear.

That means zero discharge on site, and no problems of handling or disposal of regenerant chemicals in the emergency plant, which allows Seabank staff to concentrate on operating the power station without having to worry about extra safety and waste issues.

The Aquamove team visited site and together with Seabank, identified that getting demineralised water from the MoDi trailer into the 8m tall storage tanks would involve hauling 100mm flexible pipes to high level.

As a result, a new fixed pipe with a ground level quick-release coupling to feed the demineralised water tank was installed.

At the same time they provided a valved water supply with quick release connection and a power point local to the MoDi parking bay.

In the event of a demineralisation plant failure, a call to Aquamove's 24 hour emergency line will have a MoDi trailer on the road within two hours and, thanks to the strategic connections, operational within an hour of arrival on site.

Its one thing to have a plan, but quite another to be certain that everyone knows about it.

So, once the modifications had been made, Seabank Power got together with the Aquamove team and carried out an exercise that simulated a demineralisation plant failure.

The exercise was videoed and is used as a training aid for the Power Station's operations staff.

Aquamove's fleet of mobile water purification plant, provides pure water any time and any where for a wide range of requirements from emergency pure water supplies, to rental for capacity management, maintenance shut downs or outage cover, with 24 hour, 7 days a week response.