Method of making a monolithic refractory recuperator

Claim 1

A method for making a heat recuperator comprising the steps of: forming a monolithic block containing a first array of waste gas passages therethrough and a second array of combustion air passage segments therethrough, said combustion air passage segments being oriented in a direction substantially perpendicular to said waste gas passages, the average diameter of some combustion air passage segments being greater than that of other combustion air passage segments; forming at least one turnaround manifold containing at least one passage for interconnecting a pair of combustion air passage segments; and coupling said turnaround manifold to said monolithic block in such position as to interconnect a pair of combustion air passage segments having different average diameters, thereby forming at least one multiple-pass combustion air passage in which the average diameter of successive segments increases from one segment to the next.

Claim 2

A method for making a heat recuperator comprising the steps of: forming a monolithic block containing a first array of waste gas passages therethrough and a second array of combustion air passage segments therethrough, said combustion air passage segments being oriented in a direction substantially perpendicular to said waste gas passages, the average diameter of some combustion air passage segments being greater than that of other combustion air passage segments; forming at least one turnaround manifold containing at least one passage for interconnecting a pair of combustion air passage segments; and coupling said turnaround manifold to said monolithic block in such position as to interconnect a pair of combustion air passage segments having different average diameters, thereby forming at least one multiple-pass combustion air passage in which the average diameter of successive segments increases from one segment to the next.

Claim 9

A method for making a heat recuperator comprising the steps of: forming a monolithic block by casting a refractory ceramic material to form a first array of tapered waste gas passages and a second array of tapered combustion air passage segments, said combustion air passage segments being oriented in a direction substantially perpendicular to said waste gas passages, at least three groups of combustion air passage segments being formed in said monolithic block, a first group of combustion air passage segments having a first average diameter, a second group of combustion air passage segments having a second average diameter greater than said first average diameter, and a third group of combustion air passage segments having a third average diameter greater than said second average diameter; forming at least two turnaround manifold containing a plurality of passages for interconnecting pairs of combustion air passage segments, each such passage interconnecting only one pair of combustion air passage segments; and coupling one turnaround manifold to said monolithic lithic block in such position as to interconnect a plurality of combustion air passage segments of the first group with a plurality of combustion air passage segments of the second group; and coupling a second turnaround manifold to said monolithic block in such position as to interconnect a plurality of the combustion air passage segments of the third group to a plurality of the combustion air passage segments of the second group which are interconnected by the first manifold to combustion air passage segments of the first group, thereby forming a plurality of multi-pass combustion air passages in which the average diameter of successive segments progressively increases.

Claim 10

A method for making a heat recuperator comprising the steps of: forming a monolithic block by casting a refractory ceramic material to form a first array of tapered waste gas passages and a second array of tapered combustion air passage segments, said combustion air passage segments being oriented in a direction substantially perpendicular to said waste gas passages, at least three groups of combustion air passage segments being formed in said monolithic block, a first group of combustion air passage segments having a first average diameter, a second group of combustion air passage segments having a second average diameter greater than said first average diameter, and a third group of combustion air passage segments having a third average diameter greater than said second average diameter; forming at least two turnaround manifold containing a plurality of passages for interconnecting pairs of combustion air passage segments, each such passage interconnecting only one pair of combustion air passage segments; and coupling one turnaround manifold to said monolithic lithic block in such position as to interconnect a plurality of combustion air passage segments of the first group with a plurality of combustion air passage segments of the second group; and coupling a second turnaround manifold to said monolithic block in such position as to interconnect a plurality of the combustion air passage segments of the third group to a plurality of the combustion air passage segments of the second group which are interconnected by the first manifold to combustion air passage segments of the first group, thereby forming a plurality of multi-pass combustion air passages in which the average diameter of successive segments progressively increases.

Claim 11

A method for making a heat recuperator comprising the steps of: forming a monolithic block by casting a refractory ceramic material to form a first array of tapered waste gas passages and a second array of tapered combustion air passage segments, said combustion air passage segments being oriented in a direction substantially perpendicular to said waste gas passages; said waste gas passages being tapered from a larger area entry aperture to a smaller area exit aperture; said air combustion passage segments are tapered in opposite directions in the monolithic block; forming at least one turnaround manifold containing a plurality of passages for interconnecting pairs of combustion air passage segments, each such passage interconnecting only one pair of combustion air passage segments; and coupling said turnaround manifold to said monolithic block in such position as to interconnect a pair of combustion air passage segments, thereby forming at least one multiple-pass combustion air passage in which successive segments produce a multiple-pass combustion air passage with a substantially continuous overall taper from a smaller area entry aperture to a larger area exit aperture.

Claim 12

A method for making a heat recuperator comprising the steps of: forming a monolithic block by casting a refractory ceramic material to form a first array of tapered waste gas passages and a second array of tapered combustion air passage segments, said combustion air passage segments being oriented in a direction substantially perpendicular to said waste gas passages; said waste gas passages being tapered from a larger area entry aperture to a smaller area exit aperture; said air combustion passage segments are tapered in opposite directions in the monolithic block; forming at least one turnaround manifold containing a plurality of passages for interconnecting pairs of combustion air passage segments, each such passage interconnecting only one pair of combustion air passage segments; and coupling said turnaround manifold to said monolithic block in such position as to interconnect a pair of combustion air passage segments, thereby forming at least one multiple-pass combustion air passage in which successive segments produce a multiple-pass combustion air passage with a substantially continuous overall taper from a smaller area entry aperture to a larger area exit aperture.