In a coal dryer system, flexible joints are used on inlets and outlets of the recycle gas fans. These joints are primarily to isolate vibration to the structure and some minor thermal expansion. In this case study, the coal dryer system runs at 160 degCo, at approx. 10kPa, with the fans conveying a hot inert gas with entrained coal dust.

If the coal dust settles or builds up in the expansion joint liner and bolster seal, this will spontaneously combust when the inert coal dryer gets turned off and the dryer returns to normal ambient conditions, i.e. normal 21% O2 air. Hence it is of utmost importance that the internal design does not allow coal dust to build-up in them. The client has had smouldering coal dust and joint failures of fabric joints in the past, so bolster seals and liners will have to be suitable or to have a suitable alternate design.

HMA-POGC & Dekomte came in and offered our bespoke innovative solutions for this application. We have now incorporated a bolster to be directly out and up to the underside of the flow plate in the 10 style expansion joints (see below picture of a standard 10 style expansion joints).


The cuff, which is sewn, is clamped and retained in the fabric fixing flange. These will resist smouldering ash from degrading and entering into the expansion joint cavity. Such design is confident to offer the plant a long life reliable solution.


About Dekomte – The Expansion Joints Solutions Experts


“Knowledge is power”, founded by Günther de Temple in 1978, DEKOMTE realizes this idea through the cultivation, collection use and advancement of knowledge as the drivers of its business. Whether through technological advances in expansion joint technology or knowledge of our customers’ precise needs, for more than thirty years DEKOMTE has used this knowledge to constantly working to innovate its products, in terms of their technical quality, performance, value for money and their sustainability, delivering the best products and services to the power generation market.

Since 2009, HMA-POGC has been the official representative of Dekomte for the Australasia markets. CLICK HERE for more information on how we can help you.