| Autor: |
N.Y. Kirov, I.McC. Stewart |
| Rok vydání: |
1975 |
| Předmět: |
|
| Zdroj: |
Symposium (International) on Combustion. 15:1401-1411 |
| ISSN: |
0082-0784 |
| DOI: |
10.1016/s0082-0784(75)80399-7 |
| Popis: |
The paper develops the concept that in fixed bed gas producers continuously blown steam added to control clinker formation is effective predominatly because of the increased heat capacity, whereas when steam and oxidant are admitted alternately endothermic reduction takes place in the highest temperature zone and is effective in clinker control with much less steam. Analyses of published operating data on air-blow and oxygen continuous producers and cyclic water-gas sets are consonant with this view. Experimental data from a small (0.2 m) refractory lined producer with both air-steam and oxygen-steam operation showed that to control clinker about 50% more steam was required with continuous than with pulsed operation. Cycle times of one half to one minute were used. Centerline gas analysis indicated that pulsed operation gave substantially better steam-decomposition and thermal efficiency. Extensive data is summarized for operations with a larger (0.7 m diameter) water jacketted producer with bulk gas sampling. The same ability for clinker control is shown; pulsed operation at 2 mols steam/mol oxygen is at least equivalent to continuous operation at 3 mols/mol. Gasification performance is seen to be marginally better with pulsing. No difficulty was experienced in holding the hot zone to the bottom of the fuel bed. A good approximation to the relative amounts of steam required is obtainable by calculation of an overall heat balance from entry of the gasification medium to the point where 90% of the oxygen has been consumed in terms of an arbitrarily fixed temperature at that point. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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