Blast room upgrade

The steam turbines at the power station are subject to stringent maintenance programmes as part of a statutory outages schedule that requires turbine rotors, spindles and casings to be regularly cleaned and inspected.  In the past the rotors, which include segments weighing up to 60 tonnes, were transported to the manufacturer’s premises on Teesside for this work.
 
The new blast-room measures 6m high x 7m wide x 12m long and has large double doors to allow items to be driven in on a trailer or lift truck. After cleaning to remove scale and other contaminants, each section is inspected and any remedial work is carried out before glass bead abrasive is used to produce a final surface finish.
 
The blast-room is constructed from double-skinned panels filled with 100mm thick acoustic insulation to reduce noise levels externally by up to 30dBA. A welded steel floor protects the concrete floor from damage, and the walls are protected by rubber curtains. The air ventilation and dust extraction system is rated at 14,000 cfm and provides a linear airflow the length of the room.  Large particles fall to the floor, while dust is collected on filter cartridges and then automatically deposited in bulk bags for collection by lift truck.  Air inlets and extraction points have been designed and positioned to ensure good visibility for operators.
 
Staff sweep used abrasive to the input end of a separator system where contaminants, fines and dust are removed.  Large contaminants are removed by a rotary screen, while finer materials are removed by an air wash system. Suitable clean abrasive falls into a storage hopper for use as required.  A magnetic separator has also been included to remove ferrous material. Clean abrasive is returned to a 10-tonne-capacity double-outlet storage hopper that feeds the blasting equipment, providing complete recycling of recovered abrasive.