Filtration system chosen for coal power station

Edited by the Engineeringtalk editorial team Mar 26, 2007

Eclipse Magnetic's Filtramag has been selected as the preferred filtration system for the lubrication oil of the heavy-duty gearboxes fitted to the Drax coal pulverising mills.

Drax coal fired power station, near Selby North Yorkshire, is the cleanest and most efficient coal-fired power station in the UK.

The output capacity of the site's six turbo-generators is an impressive 4000MW, and it can currently provide enough power to meet 7% of the UK's electricity needs.

Each turbo-generator is supplied with superheated steam from a dedicated boiler, which burns pulverised fuel supplied by 10 grinding mills.

Following exhaustive trials, and despite facing stiff opposition from other manufacturers, Eclipse Magnetic's Filtramag has been selected as the preferred filtration system for the lubrication oil of the heavy-duty gearboxes fitted to the Drax coal pulverising mills.

To ensure that maintenance down time is minimised, an Eclipse Magnetic Filtramag filtration system is fitted along with a circulation pump, a motorised cooling fan and a thermostatic temperature control, onto an interchangeable transportable platform, containing quick release couplings.

The filtration element can easily be exchanged for a cleaned unit.

Where maintenance is required the platform can simply be uncoupled from any given pulverising mill and quickly exchanged with a replacement platform.

As part of a rolling programme, less efficient filters still used on many of the company's pulverising mills will be replaced by Filtramag units, as each mill is taken out of commission for major maintenance work.

Andrew Wilkinson, the Drax Engineer who oversaw the successful project explained.

"Efficient filtration has been proven to considerably extend the working life of each pulverising mill's heavy-duty gearbox".

"Previous company trials of magnetic filtration systems, conducted in the 1980s, had proved to be inconclusive, but the considerable progress made in the field by Eclipse Magnetics convinced us that Filtramag's outstanding filtration capability, maintenance-friendly characteristics and short investment pay-back period exactly matched our needs".

Drax makes every effort to balance its commitment to the country's energy needs with minimising environmental impacts on land, air and water.

The company's generating units are fitted with flue gas desulphurisation (FGD) equipment, removing 90% of the sulphur dioxide (SO2) from emissions, and work is underway to reduce still further emissions of oxides of nitrogen (NOX).

At the same time, by-products of the coal combustion and FGD processes are recycled for further use within the construction industry.

In line with the company's commitment to minimise environmental impact, the new Eclipse units will help improve recovery of contaminated debris entrained in the lubrication system, allowing better management of toxic waste.

Eclipse Magnetics has also developed a wide range of high-intensity, super-efficient filtration products that are designed for use across many industrial sectors.

A number of companies are specifying the fitting of Eclipse Magnetics' high-intensity filter systems to applications including machine tools and food processing plants.

Boasting sub-micron filtration capability, the design of the new Eclipse products enables the efficient removal of ferrous and paramagnetic particles from fluids such as cutting oils, re-circulating coolants and quenching oils.

Each of the Eclipse filtration systems incorporates rare earth magnetic material to ensure extremely high magnetic flux fields.

Whilst passing through these extremely strong magnetic fields, the design of the Eclipse Magnetic's filter chambers alters the characteristics of the fluid's flow, maximising both the surface area and time available for the magnets to attract and retain all suspended ferrous particles.

The many benefits currently being enjoyed by users of the Eclipse Magnetics high-intensity filter system include - no running costs, no maintenance cost, an end to the downtime normally associated with the changing of filter media, no fluid loss due to changing sodden cartridges, no back-pressure - even when the magnetic cores are totally saturated with fluid, and extended machine tool, cutting tool and coolant/oil life.