The BHSL Toploader is a fuel handling unit comprising a wheeled carriage mounted on elevated tracks which in turn form part of the side walls of the fuel bay. The carriage movement and precise position are monitored by inbuilt sensors. Initially and following offloading of new fuel, the carriage travels to its maximum limit; atthis point the scraper blade is lowered down to the floor or until the lower level sensor registers fuel.
The fuel handling Programmable Logic Controller (PLC) records the fuel ‘found at’ location and then drives the carriage back towards the discharge end. The fuel scraper blade starts to rise to maintain a fixed tension or drag between the blade and the fuel. This tension control ensures that the blade, whilst dragging fuel, does not dig in to the fuel but maintains a steady scrape along the surface.
The carriage continues to scrape fuel towards the discharge edge and collection conveyor. Sensors above the collection conveyor monitor whether fuel is already on the belt, if so the carriage remains stationary. If the conveyor is empty then the carriage moves forward, pulling fuel with the blade and into the conveyor. Forward movement ceases if the belt fuel sensors register fuel; if the sensors continue to call for fuel after the discharge then the fuel handling system returns the ‘fuel found’ location and repeats the extraction and scrape process.
A fuel demand signal is triggered by level sensors in the fuel buffer hopper. Remote Operators can also view the storage area through a camera, and manually operate the Toploader or Conveyor should the need arise.