The design data of 40 chemical recovery boilers were collated and eval
uated. Key sizing characteristics were compared with industry-establis
hed design limits. Most of these limits were confirmed by the data. Th
e thermal design of the boilers was analyzed and it was concluded that
furnace surface area was the dominant feature. In addition to the hea
t input, the black liquor chlorine and potassium composition has becom
e a major consideration in sizing a new recovery boiler.