US4812334A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for sealing ceramic heat exchangers
Assignee: Ceramtec GmbH
•
Filing: 1987-11-19
•
Granted: 1989-03-14
•
Expires: 2007-11-19
Abstract
Abstract Ceramic heat exchangers having narrow cross-sections are sealed by filling one side (which later will be the cold side) of the heat exchanger with a liquid synthetic resin and generating there a pressure higher than that on the other side (which later will be the hot side) of the heat exchanger, removing the excess resin and fully curing the synthetic resin. The process is suitable especially for ceramic heat exchangers of silicon nitride. In this case, a suspension of finely dispersed abrasive in a liquid phase can be pumped, before the treatment with the liquid synthetic resin, through that side of the heat exchanger which will later by the cold side, until the silicon nitride whiskers formed on reaction firing have been mechanically removed, and the heat exchanger can then be rinsed and dried.
Inventors
- 👤 Otmar Linsner
- 👤 Karl Berroth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:26
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/46; C04B41/49; C04B41/4905; C04B41/495; C04B41/4961; C04B41/80; C04B41/81; C04B41/82; C04B41/84; F; F28; F28F; F28F21/00; F28F21/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
52 words
A process for sealing a ceramic heat exchanger having narrow cross-sections, which comprises filling the cold side of the heat exchanger with a liquid synthetic resin and generating there a pressure higher than that on the hot side of the heat exchanger, removing the excess resin and fully curing the synthetic resin.
Claim 2
Dependent Claim
52 words
A process for sealing a ceramic heat exchanger having narrow cross-sections, which comprises filling the cold side of the heat exchanger with a liquid synthetic resin and generating there a pressure higher than that on the hot side of the heat exchanger, removing the excess resin and fully curing the synthetic resin.
Claim 3
Dependent Claim
16 words
The process as claimed in claim 1 wherein the ceramic heat exchanger consists of silicon nitride.
Claim 4
Dependent Claim
15 words
The process as claimed in claim 1 wherein the synthetic resin is a silicone resin.
Claim 5
Dependent Claim
15 words
The process as claimed in claim 3, wherein the silicone resin is a methylsiloxane resin.
Claim 6
Dependent Claim
14 words
The prccess as claimed in claim 3, wherein the silicone resin contains zinc dust.
Claim 7
Dependent Claim
14 words
The process as claimed in claim 1, wherein the synthetic resin is cured thermally.
Claim 8
Dependent Claim
52 words
The process as claimed in claim 2, which comprises pumping, before the treatment with the liquid synthetic resin, a suspension of finely dispersed abrasive in a liquid phase through the cold side, until the silicon nitride whiskers formed on reaction firing have been mechanically removed, and rinsing and drying the heat exchanger.
Claim 9
Dependent Claim
18 words
The process as claimed in claim 7, wherein the suspension also contains an agent for increasing the viscosity.
Claim 10
Dependent Claim
16 words
The process as claimed in claim 7, wherein the abrasive used is finely dispersed silicon carbide.
Claim 11
Dependent Claim
23 words
The process as claimed in claim 9, wherein the particles of the silicon carbide suspension have a size of at most 0.5 mm.
Claim 12
Dependent Claim
27 words
The process as claimed in claim 1, wherein, after the resin has been filled in, vacuum is applied to the the hot side of the heat exchanger.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |