Exothermic Engineering entered into stoker-fired boiler testing, inspection, modification and operator training in 2004 participating in a 2-year long research project at the Southern Illinois University campus power plant.  The project was to remove a retired Laclede stoker grate and retrofit a proprietary Barlow trash-burning grate.  Our task was to work with Barlow to help redesign the Barlow trash grate as necessary to burn coal.

From that beginning we have since tested, inspected, evaluated, improved and conducted troubleshooting on numerous old stoker-fired boilers throughout the States, Central America and the Caribbean.  Perhaps one of the most interesting plants was a pair of old natural draft open traveling grates at the Illinois School for the Visually Impaired.  Our tasks were to conduct performance testing, condition evaluation, and then design preparations for a baghouse retrofit.  In this situation there was no fuel flow or air flow measurement.  We invented a crude fuel flow measurement using a piece of yellow caution tape and dimensions at the coal feed area.  We used a hotwire anemometer and air inlet area dimensions to determine air flow and cross-checked it with flue gas O₂, and caught bottom ash in buckets to determine ash split and LOI.  It all worked.

Stoker LOI reduction involves a review of coal grind, grate link condition, and operating practices.  Few stokers these days are actually firing a stoker grade coal grind because it is so expensive.  Exothermic Engineering can determine what can be practically done to reduce both bottom ash and flyash LOI.

We enjoy working with these old stokers, and there are not many stoker experts left these days.  Please remember to give us a call when your stoker-fired boiler needs help.