| 摘要 |
The regenerator vessel (2) of a fluidised bed catalytic cracking plant operates with a lower dense phase of coke-contaminated catalyst undergoing regeneration and an upper dilute phase of such catalyst. Three arcuate main air distributors (16(a), 16(b) and 16(c)) are located in the dense phase of the fluidised bed. These distributors are provided with air for the purposes of fluidising the catalyst and supporting combustion of the carbon. Air is supplied to the distributors (16(a), 16(b) and 16(c)) via primary air supply conduits (36(a), 36(b) and 36(c)). Pure oxygen is also supplied to the conduits (36(a), 36(b) and 36(c)) via conduits (50(a), 50(b) and 50(c)). Valves (52(a), 52(b) and 52(c)) are operable independently to control the oxygen flow rate such that uniform combustion conditions are obtained throughout the dense phase and thus problems caused by any non-uniform distribution of the air are ameliorated. |
