Claims
- 1. A heat recuperator comprising a cross flow ceramic core within a housing, the core comprising ribbed layers for the flow therethrough of combustion air to be heated, the core also comprising other ribbed layers for the flow therethrough of hot exhaust gas, the combustion air ribbed layers being stacked alternatively with the hot gas ribbed layers, the air flow through the combustion air ribbed layers being orthogonal to the gas flow through the hot gas ribbed layers, the air flow through the combustion air ribbed layers being triple pass, the passes being separated from each other by divider ribs, each pass having supporting ribs therein providing channels for the air flow, the construction of the divider ribs being such as to reduce the number of said supporting ribs required for support of all the layers in the core, the divider ribs being thicker than the ribs in the hot gas ribbed layers, the divider ribs being sealed to prevent air in one pass from leaking to an adjoining pass, and metal inserts in the housing that face with the divider ribs so as to cause the air flow to be triple pass.
- 2. The heat recuperator of claim 1 wherein the divider ribs are thicker than the supporting ribs.
- 3. The heat recuperator of claim 1 wherein there are two divider ribs on each combustion air ribbed layer.
- 4. The heat recuperator of claim 1 wherein the part of each metal insert facing the divider ribs is a leg having about the same width as the divider ribs.
- 5. The heat recuperator of claim 1 wherein the first pass of the triple pass is wider than the other two passes and has two supporting ribs therein, there being only one supporting rib in each of the other two passes.
Parent Case Info
This application is a continuation of application Ser. No. 705,256, filed 2/25/85 now abandoned which is a division of Ser. No. 536,030, filed 9/26/83 now pending.
This invention concerns ceramic cross-flow heat recuperators. Such recuperator comprise a ceramic heat-exchanger core within a suitable housing and are shown in U.S. Pat. Nos. 3,948,317, 4,083,400, 4,130,160, 4,262,740, 4,279,297, 4,300,627 and 4,362,209. In such cores, a gas to be heated flows through ribbed layers in the core, and a hot gas flows orthogonally thereto through similar ribbed layers alternated therewith. The flow is actually through channels between ribs. This invention is particularly concerned with a triple pass core, that is to say, a core where one of the gases is thrice passed through the core, in the manner shown in UK patent appliction 2,110,361A, corresponding to U.S. application Ser. No. 325,415, filed Nov. 27, 1981.
We have found that a problem can occur in prior art cores, such as those shown in U.S. Pat. Nos. 4,083,400, 4,130,160, 4,300,627, 4,362,209 and 4,379,109, when used in triple pass recuperators. In such cores, the edges may comprise a solid wide rib, as in FIG. 7 of U.S. Pat. No. 4,362,209 or a plurality of closely spaced ribs, as in FIG. 6 of U.S. Pat No. 4,362,209 or FIG. 3 of U.S. Pat. No. 4,300,627, but the supporting ribs between edges are quite thin and are usually uniformly spaced, so that all the channels are usually about the same width. The problem is that the ribs are too thin to ensure a reliable seal to adjoining layers throughout the life of the core, the seal usually being made by a ceramic cement. In a single pass core, such a reliable seal is not usually necessary, since no harm results from the leak of a gas from one channel over the top of a rib where the seal has failed to the adjoining parallel channel. However, in a triple pass core, if such a leak occurs at a divider rib, that is to say, a rib which separates opposite flows, the efficiency can be substantially reduced. This invention solves the problem by providing greater seal area, for example, by making the divider ribs, which separate opposite flows, thicker. Such thicker ribs provide greater area for sealing the rib to the layer thereabove.
US Referenced Citations (3)
| Number |
Name |
Date |
Kind |
|
4130160 |
Dziedzic |
Dec 1978 |
|
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4362209 |
Cleveland |
Dec 1982 |
|
|
4466482 |
Dorazio et al. |
Aug 1984 |
|
Divisions (1)
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Number |
Date |
Country |
| Parent |
536030 |
Sep 1983 |
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Continuations (1)
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Number |
Date |
Country |
| Parent |
705256 |
Feb 1985 |
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Patent Grant
4679623
