Approach for measuring heat and material balances in recovery furnaces

Engineering studies of the kraft recovery furnace have been hampered in the past by the difficulty in measuring heat and material balances within the furnace. Instrumentation installed on a recovery furnace has been designed to permit closure of the heat balances to within plus or minus 10% around the entire furnace and around the individual furnace elements. This installation includes 128 waterwall heat-flux meters of a new design to measure wall heat absorption, plus gas-side and steam-side temperature and flow measuring equipment to permit the calculation of heat flows around each boiler element. Data taken with this instrumentation package demonstrate that heat balance closure approaching 98% has been obtained around the firebox under oil-fired conditions.