FLUIDIZED BED COMBUSTION METHOD FOR BURNING WASTES

A fluidized bed combustion method for burning wastes using a fluidized bed furnace without being affected by fluctuation of the quantity and quality of wastes fed into the furnace, if any, thereby preventing CO gas, etc. from discharging out of the furnace, is provided. This furnace comprises a number of air-diffusing tubes (5) for feeding a primary air to the fluidized bed (3), arranged parallel with each other at the bottom of the fluidized bed (3), and a free space part formed above the fluidized bed (3) for burning unburnt matters with a secondary air, said air-diffusing tube (5) having a number of nozzles provided along the axis of the tube and a primary air control means including an open-close damper (7) for controlling the quantity of air to be fed. And the method is carried out by feeding said primary air into the fluidized bed (3) through said air-diffusing tubes (5) one after another according to a predetermined open-close pattern by means of said primary air control means so that the ratio of the air quantity Uo to the minimum fluidizing air quantity Umf (Uo/Umf) is in the range of 1.4 to 4 when said damper is opened and in the range of 0.5 to 2 when said damper is closed, and at intervals of 1 to 10 seconds, preferably 2 to 10 seconds, and 10 to 100 seconds, respectively.