Patent US4140738A successfully refreshed from Google Patents.
US4140738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of block fuel elements for high temperature reactors
Assignee: Hobeg Hochtemperaturreaktor Brennelement GmbH
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Filing: 1977-03-07
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Granted: 1979-02-20
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Expires: 1997-03-07
Abstract
Abstract There is provided a process for the production of block fuel elements for gas cooled high temperature reactors by multiple step molding of a granulated graphite material comprising a mixture of natural graphite powder, synthetic graphite powder and binder resin together with coated fissile and fertile fuel particles using a lubricant and a hydrocarbon, alcohol, phenol, amine, aldehyde, ketone or ether as an air displacing agent whereby the outer form and the cooling gas channels are produced by molding and the molding temperature in the last molding step is above the softening point of the binder resin and wherein the binder resin is so chosen that it has a softening point at least 15° C above the melting point of the lubricant used and the block is ejected from the die in the temperature interval between the melting point of the lubricant and the softening point of the binder resin.
Inventors
- 👤 Milan Hrovat
- 👤 Lothar Rachor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:45
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/42; G21C3/58; G21C3/62; G21C3/64; C; C04; C04B; C04B35/00; C04B35/515; C04B35/52; C04B35/528; C04B35/532; G21C21/00; G21C21/02; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
168 words
In a process for the production of a block fuel element for a gas cooled high temperature reactor by multiple step molding of a granulated graphite material comprising a mixture of natural graphite powder, synthetic graphite powder and binder resin together with coated fissile and fertile fuel particles using a lubricant and an air displacing agent and wherein the outer form and the cooling gas channels are produced by molding and wherein the molding temperature in the last molding step is above the softening point of the binder resin, the improvement comprising employing a binder resin that has a softening point at least 15° C. above the melting point of the lubricant used, after the last molding step cooling the block fuel element to a temperature below the softening point of the binder resin and above the melting point of the lubricant and ejecting the block from the die in the temperature interval between the melting point of the lubricant and the softening point of the binder resin.
Claim 2
Dependent Claim
168 words
In a process for the production of a block fuel element for a gas cooled high temperature reactor by multiple step molding of a granulated graphite material comprising a mixture of natural graphite powder, synthetic graphite powder and binder resin together with coated fissile and fertile fuel particles using a lubricant and an air displacing agent and wherein the outer form and the cooling gas channels are produced by molding and wherein the molding temperature in the last molding step is above the softening point of the binder resin, the improvement comprising employing a binder resin that has a softening point at least 15° C. above the melting point of the lubricant used, after the last molding step cooling the block fuel element to a temperature below the softening point of the binder resin and above the melting point of the lubricant and ejecting the block from the die in the temperature interval between the melting point of the lubricant and the softening point of the binder resin.
Claim 3
Dependent Claim
47 words
The process of claim 1 wherein the air displacing agent is an organic compound having a very low vapor pressure at room temperature and a vapor pressure of about 760 Torr at the molding temperature, said organic compound being liquifiable under moderate pressure at the molding temperature.
Claim 4
Dependent Claim
20 words
The process of claim 2 wherein the air displacing agent is a hydrocarbon, alcohol, phenol, amine, aldehyde, ketone or ether.
Claim 5
Dependent Claim
22 words
The process according to claim 3 wherein the air displacing agent has a vapor pressure less than 10 Torr at room temperature.
Claim 6
Dependent Claim
19 words
The process of claim 4 wherein the air displacing agent has a boiling point of 131° to 212° C.
Claim 7
Dependent Claim
15 words
The process of claim 5 wherein the molding temperature is from 135° to 200° C.
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein the binder is a phenol-formaldehyde novolak.
Claim 9
Dependent Claim
11 words
The process of claim 7 wherein the lubricant is stearic acid.
Claim 10
Dependent Claim
12 words
The process of claim 8 wherein the air displacing agent is octanol.
Claim 11
Dependent Claim
25 words
The process of claim 1 wherein the binder resin has a softening point of 25° to 40° C. above the melting point of the lubricant.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-02-19 | 1982-08-21 | 1983-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-19 | 1986-08-21 | 1987-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-19 | 1990-08-21 | 1991-02-20 | $7700.00 | Window Closed / Lapsed |