Decanter centrifuge systems qualify for grant of 40% in new scheme

DECANTER centrifuges and fluidised bed combustion are among the new manure handling methods which farmers will have to become familiar when the Nitrates Directive is implemented next February.

The revised Farm Waste Management Scheme includes a new 40% grant-rate for decanter centrifuge systems, and a new scheme will also support demonstration of new technologies such as fluidised bed combustion.

Centrifuges are a common technology, being a basic feature in washing machines, for example.

A washing machine in the spin cycle acts as a centrifuge, when the drum spins at high speed, and the water is forced from the clothing and out of the holes in the drum by centrifugal forces. The same principle can be used to separate out the water and solids in farm slurry.

Decanter centrifuges are used on pig farms which process slurry through biogas plants.

Fluidised bed furnaces are used on farms which produce energy from biomass in fine particle or liquid from.

A boiling bed of pre-heated sand (at temperatures of 500 to 900°C) provides the combustion medium, into which the biomass fuel is either dropped (if it is dense enough to sink into the boiling sand) or injected if particulate or fluid.

These systems do not need grates, but require methods of preheating the air or sand, and may require water cooled injection systems for less bulky biomass feedstocks and liquids.