Hot water or steam boiler

A boiler for steam or hot water comprising

• a furnace section defined substantially in its entirety by top, bottom and sidewalls formed of closely arranged horizontally and vertically extending liquid or steam tubes respectively;
• a plurality of vertically extending and horizontally spaced liquid or steam tubes positioned within said furnace section to form a partition wall dividing same into first and second chambers, said partition wall extending transversely to the flow of combustion gases;
• said horizontally and vertically extending tubes by the aforesaid arrangement being exposed to combustion radiation and flue gases within said furnace section;
• a convection section positioned laterally of said furnace section including at least one chamber for liquid or steam;
• convecting means for operatively connecting said furnace and convection sections to permit the flow of liquid or steam between said tubes and said chamber of the convection section;
• means for conducting flue gases from said furnace chamber to said convection section;
• and
• a plurality of flue gas tubes within said convection section arranged therewithin to conduct flue gases from said furnace chambers in a substantially U-shaped path through the liquid or steam chamber for heat exchange with the liquid or steam therewithin.