Recirculation
The furnace has been designed to ensure that the fuel conversion to heat energy is complete and with a minimum of undesirable emissions. The furnace is lined with refractory designed to withstand the operating temperatures.
The ‘seething’ mass of hot sand has excellent thermal properties. If manure is presented which is particularly wet, then this can be broken up and the ‘thermal shock’ can be spread within the sand very quickly. The combustion is reliable, even when the quality of the fuel is not.
There are limits to every process of course, and broiler manure must typically have a Moisture Content of less than 45% (it can be higher for short periods) to be reliably processed. Improved growing conditions on BHSL sites result in average moisture content lower that 45%.