Demag Cranes has installed an automatic materials handling system at a wood fired cogeneration power station in Hamburg, Germany. The biomass cogeneration facility burns woodchip by-products from local forestry and landscaping activities, generating heat and electricity, whilst reducing the depletion of fossil fuel resources.

The Hamburg power station processes 32,000t of woodchip annually, generating over 13,000MWh of electricity per year and some 60,000MWh of heat, which warms 8,000 households in the district.

To meet the specific materials handling requirements of the Hamburg operation, Demag Cranes installed a 16.4m span, 11t SWL, automatic double girder overhead travelling crane, mounted with a specially developed 8m3 multi-jaw grab. The process crane features frequency regulated speeds in three directions for optimum travel and lifting characteristics. Controlled by warehouse management software, the system is designed for high volume handling. Long travel speeds of up to 50m/min, cross travel of up to 40m/min and hoisting rates of up to 50m/min facilitate the movement of 140m3 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 300m3 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 900m3 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.

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.