Patent ID: 7393206

Claim:
A heat exchange furnace comprising: a combustion furnace unit adapted to burn fuel such that combustion gases are generated therein; a thermal insulating device including a surrounding wall disposed around said combustion furnace unit so as to define an annular heat exchange space therebetween, said surrounding wall being formed with an air inlet unit and an air outlet unit that are communicated with the heat exchange space and the ambient surroundings, and a plurality of upright buffer plates disposed between said surrounding wall and said combustion furnace unit for dividing said heat exchange space into a plurality of air chambers communicated with each other; a lower gas-guiding member connected fixedly to a lower end of said surrounding wall for sealing a lower end of said heat exchange space, said lower gas-guiding member being formed with a plurality of lower gas transfer chambers; an upper gas-guiding member connected fixedly to an upper end of said surrounding wall for sealing an upper end of said heat exchange space, said upper gas-guiding member having a gas entrance chamber communicated with said combustion furnace unit, a gas exit chamber, a plurality of upper gas transfer chambers disposed between said gas entrance chamber and said gas exit chamber, and a gas outlet communicated with said gas exit chamber and the ambient surroundings; and a conduit assembly having at least one conduit unit including a plurality of conduit sets disposed within said heat exchange space and around said combustion furnace unit, any two adjacent ones of said conduit sets being communicated with each other by a respective one of said lower gas transfer chambers in said lower gas-guiding member and said gas entrance chamber, said gas exit chamber, and said upper gas transfer chambers in said upper gas-guiding member in such a manner that said upper and lower gas-guiding members as well as said conduit unit constitute cooperatively a serpentine gas flow path disposed within said heat exchange space.