As part of the addition of two new high efficiency units to the Tanjung Jati B coal-fired power plant in Central Java, Indonesia, Clyde Bergemann was entrusted with the delivery of the bottom ash handling systems. Mitsubishi Hitachi Power Systems, Ltd. (MHPS), supplier of the ultra-supercritical pressure boilers, opted for DRYCON, Clyde Bergemann’s class leading bottom ash solution. The scope the project also included the crusher station, transfer conveyor and system controls.
Clyde Bergemann’s solution consists of a fabric compensator and a transition hopper, isolating gates with jaw crusher function, the DRYCONTM steel plate conveyor, a crusher station and a transfer conveyor for each of the two units.
To absorb the axial and lateral expansion of the boiler, the heat-resistant fabric compensator is directly attached to the combustion chamber. Collection hoppers below catch the hot bottom ash. Each hopper leg is equipped with a grating and a hydraulic driven crusher combination at the outlet, shredding oversized particles to a tolerable size. The jaw crushers can also be used to seal off the boiler from the DRYCON. The bottom ash hoppers can serve as short-term storage for up to eight continuous hours of boiler operation.
The hoppers are followed by the DRYCON steel plate conveyor that automatically transports and cools the bottom ash utilising air only. DRYCON draws ambient air along the conveyor and in counter flow to the hot ash, effectively transferring heat back into the boiler.
A bifurcating (branched) chute feeding the ash into crushers is fitted below the DRYCON conveyor head. The crushers are built in redundancy – when one is operational, the other is in standby mode as a backup.
A subsequent conveyor transfers the cooled bottom ash to the silo. In contrast to competitive products, the DRYCON technology usually replaces the need for a second conveyor and is capable of transporting the material directly to the silo with an incline of up to 45°. In this case the silo was located offset the center line of DRYCON and therefore needed a further transfer conveyor to meet site requirements.
Delivery of the both systems is scheduled around the end of 2019.
“This order for us not only marks an important step with regards to the acceptance of the DRYCON technology in Asian markets”, states Dr. Christian Mueller, CEO and President of the Clyde Bergemann Power Group. “We are also proud and pleased to be awarded the contract by MHPS – our first joint dry bottom ash handling project.”