Construction of the Energy Recovery Centre in St Dennis, Cornwall is now being undertaken by Vinci Environment UK who via their French operation have awarded the contract to supply two waste grabbing cranes to Konecranes Group. The cranes will be designed, built and installed by KONECRANES UK Ltd -Industrial Crane Division.
The cranes will be manufactured at Konecranes Scottish base in East Kilbride. Each will be 12 tonne capacity with a 23.1m span. Operation of the cranes will be fully automated, each with an ‘orange peel’ grab handling 8 cubic metres of waste at a time and delivering it from the receiving it and into hoppers for feeding the boilers in the waste to energy process plant. The weight of the waste in each grab is measured accurately to an accuracy of 0.75%. This involves using a double trolley where load cells are positioned between the upper and lower trolley which is inbuilt to Konecranes technology.
Other features include: Floodlights; heavy duty I beam festoon systems on travel and traverse, remote monitoring of the cranes in operation, condition monitoring, measuring the pile size in the waste pit and KONECRANES DynA Invertor variable speed control on all motions; DynAPilot Anti-Sway system, which will automatically dampen sway, reduce stress in structures and mechanical components. This also allows the bunker walls to be avoided, even with a grab that could be swinging where by the swing is taken out of the operation and thus avoiding grab damage through pit wall collision as this is the biggest source of downtime if collisions occur.
Also featured is Konecranes DynAReg system where unused power is fed back into the electricity network, reducing operating costs and removing the need for external resistances that would normally be used to absorb this power. The system is generally termed as network braking and comes into effect when lowering and deceleration is in operation.
One of the cranes will also have an auxiliary hoist to facilitate clearing of any waste tangle that may occur in the feed hoppers, the auxiliary hoist is equipped with a small grab which can dig deep into the hoppers, the auxiliary hoist will also be able to take a rescue basket for retrieving personnel that may have accidentally fallen into the waste pit and the auxiliary hoist can also be used for general lifting duties, thus avoiding removing the main grabs from the main hoists.
The crane controls will be contained in a client provided E-Room which is air conditioned, maintaining a constant temperature and environment, ensuring long life in the components. There will be an operators chair in a client provided control room overlooking the waste pit where an operator may drive the crane in manual or semi automatic mode if required. The chair has all controls, touch screen to show crane cycle position, alarms, allows the operator to adjust the crane functions and of course the chair allows stopping and starting of the automation. The crane also have radio control for service and maintenance duties.
The cranes are to be delivered in April 2014.