British Sugar gets back in gear
9 Apr 2010
King’s Lynn, UK – When a worm gear drive crown wheel failed due to overload on a crucial conveyor belt at British Sugar’s Wissington plant in King’s Lynn, which produces bioethanol, amongst other sugar products.
The conveyor fed limestone and coke into a kiln to help purify the sugar at the plant, which processed over 3 million tonnes of beet this year alone. In the run-up to the plant’s busiest time of year, two men and a shovel loader were hired to manually load the feeder for 24 hours per day, but this could only be a temporary measure due to cost.
British Sugar approached Siemens Industry’s mechanical handling division, which had supplied the original Flender Cavex 280 worm gear unit in 1997. Any delivery delay could have affected the start of British Sugar’s next ’campaign’ period and would also have meant no time for running in and appropriate checks.
British Sugar had already looked at a refurbished competitor’s unit, but it had a lower rating than the Flender one and the company’s engineers were not confident that it would be suitable.
The Siemens service team suggested a more energy-efficient, bevel helical Flender FZG gearbox, size B3HH08. Where the existing 280 Cavex worm gear unit had a rating of 12,500Nm at 1,000rpm, the new Flender bevel helical unit was rated at 27,000Nm, a considerably higher torque rating.
The bevel helical unit also had the same hollow shaft diameter as the Cavex worm gear unit, so the customer could use the existing headshaft. This unit could be supplied direct from the Siemens Bradford factory, and that it would provide improved efficiency. The old unit was between 74% and 85% efficient; the new one offered 95% efficiency, an improvement of at least 10%.
The new unit was selected and supplied within eight days of British Sugar’s enquiry, against which drawings were submitted with the quotation to ensure suitability for the customer that the existing hydraulic motor would also fit.
