Fluidized bed water pipe boiler divided type

A fluidized bed water tube boiler comprising a fluidized bed combustion section including a fluidized bed formed from a continuous water tube wall, a free-board section for burning volatile components produced in said fluidized bed combustion section, and a convective heat transfer section including a steam drum and a water drum connected to the downstream side of said freeboard section through water tubes for recovering heat from combustion exhaust gas;

• said boiler being characterized in that two collective headers comprising a freeboard section lower header and a fluidized bed combustion section upper header are provided so as to surround said water tube wall near the boundary between said fluidized bed combustion section and said freeboard section, said fluidized bed combustion section and said freeboard section being separable between said two headers, said fluidized bed combustion section is formed as a module which is constituted such that said fluidized bed combustion section upper header and a fluidized bed combustion section lower header provided so as to surround a lower portion of said fluidized bed are communicated with each other by a group of water tubes to form said wall of said fluidized bed combustion section, said freeboard section is formed as a module which is constituted such that said freeboard section lower header and a freeboard section upper header provided in an upper portion of said freeboard section are communicated with each other by a group of water tubes to form a wall of said freeboard section, and said freeboard section is separable from said convective heat transfer section, whereby said boiler is divided into three modules of said fluidized bed combustion section, said freeboard section and said convective heat transfer section.

A fluidized bed water tube boiler comprising three divided modules including a fluidized bed combustion section module comprised of a main fluidizing chamber forming a main fluidized bed to burn solid substances and a heat recovery chamber forming a heat recovery bed to recover heat from said main fluidized bed, a freeboard section module for burning volatile components produced in said main fluidized bed, and a convective heat transfer section module for recovering heat from combustion gas;

• said boiler being characterized in that said fluidized bed combustion section module is constituted by an upper header, a lower header and a water tube wall interconnecting both said headers, each header having the square form, and those water tubes of said water tube wall which are positioned in the left and right sides as viewed from the front of said boiler are constituted by groups of water tubes alternately protruding inwardly to greater and lesser extents respectively, said former group of water tubes being protected at their lower surfaces by a refractory material to define said main fluidizing chamber and said heat recovery chamber and also serving as a deflector adapted to change a fluidizing direction of a heat medium in said main fluidized bed, and said latter group of water tubes serving as heat recovery chamber in-bed heat transfer tubes of natural circulation type to recover heat from said heat recovery bed.