Fluidized bed furnace

A fluidized bed furnace for heating waste to extract a combustible gas from the waste, comprising:

• a furnace body having a bottom wall which supports fluidizable particles from therebelow so as to make up a fluidized bed for heating the waste, and a sidewall standing upwardly from the bottom wall, wherein the bottom wall has a discharge port provided at a position offset from a center position of the bottom wall in a specific direction to discharge non-combustible substances in the waste together with a part of the fluidizable particles, and an upper surface of the bottom wall is inclined to become lower toward the discharge port so as to cause the non-combustible substances to fall on the upper surface of the bottom wall toward the discharge port;
• a gas supply section for blowing a fluidizing gas from the bottom wall of the furnace body toward the fluidizable particles to fluidize the fluidizable particles;
• a plurality of temperature detection sections for detecting a temperature of the fluidized bed;
• a control section for controlling the gas supply section;
• and
• a waste supply section for supplying waste from a supply-side portion of the sidewall located on a side opposite to the discharge port across the center position of the bottom wall, to a region on the fluidized bed, the region being adjacent to the supply-side sidewall portion,
• wherein:
• the gas supply section includes a plurality of wind boxes each of which is provided on a lower side of the bottom wall to extend in a direction orthogonal to a direction from the supply-side sidewall portion toward the discharge port and adapted to blow the fluidizing gas from a given position in the orthogonal direction toward the fluidizable particles, and a feeding unit adapted to feed the fluidizing gas to each of the wind boxes in a manner capable of adjusting an air ratio of the fluidizing gas to be fed to each of the wind boxes, individually, wherein the plurality of wind boxes are arranged side-by-side in the direction from the supply-side sidewall portion toward the discharge port;
• the plurality of temperature detection sections are arranged at respective positions allowing detection of temperatures of an upper position and a lower position which are vertically spaced in a first region of the fluidized bed, the first region being vertically overlapping with a first one of the wind boxes closest to the supply-side sidewall portion, and allowing detection of temperatures of an upper position and a lower position which are vertically spaced in a second region of the fluidized bed, the second region being vertically overlapping with the discharge port or a second one of the wind boxes closest to the discharge port;
• and
• the control section is operable to adjust an air ratio of the fluidizing gas to be fed from the feeding unit to each of the wind boxes, individually, based on the temperatures detected by the temperature detection sections, so as to make the temperature of the fluidized bed be raised in a direction from the first region toward the second region.