Repeated, rapid speed cycling over a period of years imposes fluctuating stresses on the impeller blades of centrifugal fans. This can cause catastrophic failure and total destruction of the fan impeller and casing,
which is not designed to withstand such loading, shutting down production until the fan is replaced, as happened recently at Oakland Glass.
Oakland Glass, based in Dewsbury, is one of the UK’s leading independent glass processors and produces a range of energy saving and toughened sheet glass. It produces over 10,000 m2 of Oaktough® toughened glass per week, much of which is used in-house to produce sealed glazing units such as are used in conservatories. Because of its internal stress characteristics, toughened glass shatters into small fragments and cannot be reworked after tempering so sheets are cut to size before processing. Read PDF