On the down-comer from the cyclone on a fluidized bed boiler, there is an expansion joint to take the axial expansion of the duct.
The normal design is a standard fabric expansion joint, with upstands of the refractory lined duct. This system operates well for a short period of time, but due to high ash content in the duct, a seizing up of the joint cavity soon takes place. This blocking of the joint imposes large forces into the ducting causing cracking.
DEKOMTE have worked on an engineering solution which surpasses the lone function of the fabric component, and considers how to develop an envelope of space allowing movement of the duct. The introduction of sealing air as part of the internal refractory and flow plate design, ensures space for the axial compression of the joint.
DEKOMTE have in service many joints which are functioning for over 10 years with no maintenance.
Installation location of expansion joint
Design solution: expansion joint with aerodynamic ash barrier
Installed DEKOMTE Solution
DEKOMTE fabric expansion joint as a compensation element with aerodynamic ash barrier in a cyclone down pipe of a fluidized-bed boiler