The friction compensator — Visualizing refractory expansion

An increasing number of damages observed on calciner steel shells are a direct result of a volume increase of the refractory lining. Over years of operation, mineralogical alkali effects are mainly the cause. The thermal expansion of the refractory lining is a physical process and can be calculated and foreseen with the refractory engineering. However, volume increase due to mineralogical phenomena of refractory materials needs special attention. In order to compensate for expansion of the lining, various expansion joints are positioned in the refractory lining. These expansion joints have to be controlled, cleaned and, if necessary, filled with new expansion joint material. When neglected, expansion joints will be closed and will not fulfil their task anymore. As a result, structural damages of the calciner vessels and cyclones can be observed in several clinker burning lines worldwide. With a friction compensator, the plant operator now has a tool to determine and measure the expansion of the refractory lining, especially in calciners, without the need to interrupt production. An inspection of the expansion joints from inside the vessel is not necessary and the planning of repair measures will become easier.