OXIDATION OF GRAPHITE WITH OXYGEN BETWEEN 1000$sup 0$C AND 2000$sup 0$C. Project DRAGON.
The rates of oxidation of carbon and graphites have been measured in the temperature range 1000 deg C to 2000 deg C at pressures of 0.06 atmospheres to 1 atmosphere with gas velocities varying from 100 cm/sec to 10,000 cm/sec. Cold gas was directed on to the side of an electrically heated carbon rod; its temperature was measured by a disappearing filament pyrometer. By timing the retreat of the surface of the rod opposite the jet orifice, the rate of reaction was calculated. At atmospheric pressure and high temperatures the combustion rate of the most reactive material, thr porous carbon, was found to be mass transfer controlled and the mass transfer rates were correlated against gas velocity, the carbon temperature, the oxygen partial pressure and the total gas pressure. When a less reactive reactor graphite was oxidised at lower total gas pressure the rate was only partly controlled by mass transfer in the gas phase and by using the previously mentioned correlations the influence of mass transfer on the combustion rate was estimated. The least reactive material, pyrographite, seemed to be free from mass transfer control, so the combustion rate was in the chemical regime. Both the reactor graphite and pyrographite reaction rates reached a maximum at about 1700 deg C and then decreased at higher temperatures. This effect has been found before by Strickland-Constable with a maximum rate at 1200 deg C. The oxygen pressure used in this work was about 0.2 atmospheres. Explanations of the rather unusual kinetic behaviour of graphite have been proposed. (auth)
- Research Organization:
- Atomic Energy Establishment, Winfrith (England)
- NSA Number:
- NSA-24-038802
- OSTI ID:
- 4120563
- Report Number(s):
- DP-Report-108; CONF-620305-4; CONF-620407-3
- Resource Relation:
- Conference: Carbon Transfer Discussion Meeting, Winfrith, Dorchester, Dorset, England, 28-30 March 1962; Meeting of the Royal Institute of Engineers Nuclear Energy Section, The Hague, Netherlands, 6 Apr 1962.; Other Information: UNCL. Orig. Receipt Date: 31-DEC-70; Related Information: OECD High Temperature Reactor Project Dragon Report. Now open access.
- Country of Publication:
- United Kingdom
- Language:
- English
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