Abstract: A heat recuperator comprises a monolithic refractory block containing a first array of waste gas passages and a second array of combustion air passage segments oriented perpendicular to the waste gas passages. At least one turnaround manifold interconnects successive combustion air passage segments into multiple-pass passages. Preferably waste gas passages are tapered from a larger area entry aperture to a smaller area exit aperture. Successive combustion air segments are preferably tapered in opposite directions in the refractory block so that they can be interconnected to form a multiple pass passage with a substantially continuous taper from a smaller area initial entry aperture to a larger area exit aperture. The monolithic refractory block containing integral passages can be formed in a single casting or ramming operation.

Abstract: A heat recuperator comprises a monolithic refractory block containing a first array of waste gas passages and a second array of combustion air passage segments oriented perpendicular to the waste gas passages. At least one turnaround manifold interconnects successive combustion air passage segments into multiple-pass passages. Preferably waste gas passages are tapered from a larger area entry aperture to a smaller area exit aperture. Successive combustion air segments are preferably tapered in opposite directions in the refractory block so that they can be interconnected to form a multiple pass passage with a substantially continuous taper from a smaller area initial entry aperture to a larger area exit aperture. The monolithic refractory block containing integral passages can be formed in a single casting or ramming operation.