SECONDARY COMBUSTION FURNACE

PROBLEM TO BE SOLVED: To reduce the quantity of a solid matter contained in an emitted secondary combustion exhaust gas as much as possible in a secondary combustion furnace for effecting secondary combustion of exhaust gas from a primary combustion furnace. SOLUTION: A first chamber 21 having a primary combustion gas introduction part 22 and a gas emission part 23 for a primary combustion exhaust gas provided below and above and a secondary chamber 26 having a gas introduction part 27 for introducing the exhaust gas provided at a position to a gas emission part 23 side and a combustion exhaust gas emission part 28 for emitting the gas to a flue provided at a position to a primary combustion gas introduction part 22 side are provided and the primary combustion gas introduction part 2 and a secondary air supply part 24 are arranged so as to make the primary combustion exhaust gas to whirlingly flow in along an inner wall of the first chamber 21, and the gas introduction part 27 is arranged so as to make the exhaust gas from the first chamber 21 to whirlingly flow in along an inner wall, and a solid matter collection part 29 for collecting solid matters separated from a gas passing through the chambers 21, 26 is provided below the first chamber 21 and the second chamber 26.