Demag cranes help feed biomass power station

Demag Cranes has installed an automatic materials handling system at a wood-fired cogeneration power station at Hamburg, Germany.

The facility has been developed under the auspices of Schuler Consulting Engineers, to meet the increased demand for sustainable energy solutions.

The biomass cogeneration facility burns 32,000 tonnes of woodchip annually.

To meet the specific materials handling requirements of the Hamburg operation, Demag Cranes installed a 16.4 m span, 11 t SWL, automatic double girder overhead travelling crane, mounted with a specially developed 8 cu m multi jaw grab.

The process crane features frequency regulated speeds, in three directions for optimum travel and lifting characteristics.

WMS control
Controlled by warehouse management software, the system is designed for high volume handling. Long travel speeds of up to 50 m/min, cross travel of up to 40 m/min and hoisting rates of up to 50 m/min facilitate the movement of 140 cu m of woodchip per hour.

A load sway damping system provides smooth lifting and movement, avoiding the possibility of damage caused by collision of the grab and the pit walls.

Raw biomass is delivered to the plant by trucks and deposited in a 300 cu m tipping pit, where it is automatically monitored for moisture content and fuel grade.

Once the vehicle has cleared the tipping area, the crane system moves the woodchip to three pre-determined zones, within the 900 cu m intermediate bunker, according to fuel grade.

The system is programmed to maintain a fixed fill level within the silo, which feeds the furnace.

When fixed sensors indicate that the minimum fill level is reached, the crane system automatically transports biomass material from the storage bunker to replenish the silo.

In addition to the movement of biomass, the crane also handles the blending of woodchip to ensure optimum combustability.

Blending ratio
Should the system detect that raw material is too moist, or of insufficient fuel grade, the warehouse management software determines the required blending ratio.

The crane then picks up biomass from the various zones of the buffer store, to achieve the required blend ratio for efficient heat generation.

The Demag automatic crane system offers a number of advantages over alternative materials handling systems, such as wheel loaders.

Increased productivity, lower noise emissions, less manpower and reduced operating costs are amongst the benefits.