Low to medium pressure high temperature all-ceramic air to air indirect heat exchangers with novel ball joints and assemblies

An all-ceramic, air-to-air, indirect heat exchanger which comprises in combination:

• (A) an all-ceramic ball joint for use in an all-ceramic, air to air, indirect heat exchanger, said ball joint comprising a spherical body having an outer surface and an inner surface and having a near side and a tube side, said near side having a truncated face to form a flat surface on said near side;
• said spherical body having a first opening through it from the near side through the tube side;
• said tube side having a truncated face to form a flat surface on said tube side;
• said tube side having a second opening in alignment with and larger than the first opening to form a shoulder within said second opening to accommodate a ceramic tube therein;
• said outer surface of said spherical body being covered with a smooth, refractory ceramified, frit glaze;
• (B) an assembly comprising
• (i) a tile which forms part of a tube sheet, said tile having at least one round opening through it and having a plug side and a tube side and an inside surface, said opening having a discontinuous annular ring on the interior surface and near the front end thereof;
• (ii) a closure ring having a length essentially one-half of the width of the tile and has a top surface, a bottom surface, a near end and a distal end wherein the top surface is bonded to the bottom surface of the tile near the back end of the tile such that the distal end of the closure ring is essentially vertically aligned with the tube side of the tile, said closure ring having an arcuate notch in the near end and at the bottom thereof, said arcuate notch being covered with a coating of a smooth, refractory ceramified frit glaze and mating with the spherical body outer surface;
• (iii) a plug, said plug having a top surface, a bottom surface, a near end, a distal end and a horizontal midpoint, there being a discontinuous channel in said top surface to accommodate the discontinuous annular ring of the tile;
• said plug having an second arcuate notch in the near end and at the bottom thereof, said second arcuate notch being covered with a smooth, refractory ceramified frit glaze and mating with the spherical body outer surface, said plug having a curved face at its distal end which begins at the bottom surface and near the horizontal midpoint and ends at the near end near the top surface;
• said closure ring and said plug providing a channelled opening between them at their near ends;
• (iv) at least one friable, crushable, alignment ring, said alignment ring located in said channelled opening, said tile, closure ring and plug being ceramic bodies, and further in combination with,
• (C) multiple ceramic heat exchanger tubes being fitted with an assembly on each end.