Vapor generator utilizing stacked fluidized bed and a water-cooled heat recovery enclosure

A vapor generator in which a plurality of vertically aligned fluidized beds are disposed in a furnace section with one of the boundary walls of the furnace section having openings therein for permitting the discharge of effluent gases from the fluidized beds. A heat recovery enclosure is formed adjacent said furnace section and shares a common wall with the furnace section for receiving the effluent gases, and a convection enclosure is disposed adjacent the heat recovery enclosure and shares a common wall with the latter enclosure for receiving the effluent gases from the heat recovery enclosure. The boundary walls of the furnace section, the heat recovery enclosure and the convection enclosure are formed by a plurality of interconnected tubes through which fluid is passed in a predetermined sequence to transfer heat from the fluidized beds to the fluid.