PLANT FOR BURNING WASTE

A plant (1) for burning waste comprises a rotary furnace (2), an after-burning chamber (3) connected to the furnace (2), a primary incineration part (4) comprising the furnace (2) and a first part (5) of the after-burning chamber (3) for initial incineration of the waste in an oxygen deficient environment at a lower temperature interval in the furnace (2) and in the first part (5) of the after-burning chamber (3) for producing combustible fumes therein, a secondary incineration part (6) comprising a second part (7) of the after-burning chamber (3) and a contracted passage (8) between the first and second parts (5, 7) of the after-burning chamber (3) for subjecting the fumes to an increase in velocity between the first part (5) and the second part (7) of the after-burning chamber (3). The passage (8) comprises an inlet (9) for forced injection of combustion air into the contracted passage (8) for conclusive combustion of the combustible fumes at a higher temperature interval in the passage (8) and in the second part (7) of the after-burning chamber (3). The contracted passage (8) comprises a narrowing part (10) followed downstream by a widening part (11) having a cross sectional area larger than the cross sectional area of the narrowing part (10) immediately upstream of the widening part (11).