Sugar solution
15 Jan 2000
To an outsider, it is hard to believe that the production of sugar from beet would have an aggressive effect on mechanical seals in a process plant.
Sugar production involves diffusion, filtration, and crystallisation of a sugar solution which, in the early part of the production process, contains damaging sugar crystals and grit. The combination of grit and slow shaft speed was costly to British Sugar at its Bury St Edmunds plant, not only in maintenance to repack conventional gland seals, but also in energy costs and lost product.
John Crane's answer to the problem was to fit one of its Series A seals to the drive end of the 15 18 inch mingler shaft. Because the stationery and rotary faces are split, maintenance can be carried out in situ, without dismantling the equipment. A standby inflatable seal can be fitted on the product side of the seal so the seal itself can be worked on without affecting its integrity.
At the non-drive end, a type 37FSB split seal was outside mounted. This seal can be fitted to worn shafts without modifying original equipment.
