Heat exchanger for high-temperature applications

A heat exchanger comprising:

• a) a corrugated strip, the strip being folded back and forth upon itself to define a stack having a plurality of folds, the stack having two ends,
• b) a plurality of pieces of corrugated material, the pieces being inserted within said plurality of folds, wherein the pieces have corrugations which are non-parallel to corrugations of the strip,
• c) a plurality of duct attachments affixed to the stack, and
• d) a high-temperature sealant disposed on an outside surface of the stack, wherein the sealant is disposed at least at the ends of the stack,
• wherein the sealant has a coefficient of thermal expansion which approximates a coefficient of thermal expansion of materials forming the stack, and wherein the sealant includes metal particles.

A heat exchanger comprising:

• a) a corrugated strip, the strip being folded back and forth upon itself to define a stack having a plurality of folds, the stack having first and second sides and two ends,
• b) a plurality of pieces of corrugated material, the pieces being inserted within said plurality of folds, wherein the pieces have corrugations which are generally perpendicular to corrugations of the strip,
• c) a plurality of duct attachments, each duct attachment comprising means for holding the stack together, and for providing fluid access to an interior region of the stack, wherein there are at least two duct attachments on the first side of the stack, and wherein there are at least two duct attachments on the second side of the stack, and
• d) a high-temperature sealant disposed on an outside surface of the stack, wherein the sealant is disposed in locations not spanned by said duct attachments,
• wherein the sealant has a coefficient of thermal expansion which approximates a coefficient of thermal expansion of materials forming the stack, and wherein the sealant includes metal particles.

A heat exchanger comprising:

• a) a strip of material that has been folded back and forth upon itself to define a stack, the material having corrugations which define channels for fluid flow, the stack having first and second sides for receiving first and second fluid streams,
• b) means for directing fluid flow within the stack such that said first and second fluid streams flow within the stack without commingling and in sufficient proximity to allow heat transfer between the streams, and
• c) means for sealing the stack such that fluid cannot flow to or from a region outside the stack except through said directing means,
• wherein the sealing means comprises a moldable material that has been allowed to harden so as to seal the stack,
• wherein the moldable material has a coefficient of thermal expansion which approximates a coefficient of thermal expansion of the stack, and wherein the sealant includes metal particles.

A method of making a heat exchanger, comprising:

• a) folding a corrugated strip back and forth upon itself to define a plurality of folds,
• b) inserting cut pieces of corrugated material within the folds of the corrugated strip, the folded strip and the cut pieces together defining a stack,
• c) affixing a plurality of duct attachments to the stack, and
• d) applying a sealant to portions of the stack which are not covered by the duct attachments,
• further comprising selecting a coefficient of thermal expansion of the sealant so as to approximate a coefficient of thermal expansion of the stack,
• wherein the selecting step includes mixing the sealant with metal particles so as to produce a mixture having a desired coefficient of thermal expansion.