| 摘要 |
PROBLEM TO BE SOLVED: To extend the run length of a delayed coker to increase the integrated throughput of oil. SOLUTION: A delayed coker 1 comprises a heat exchanger 20 to preheat stock oil by heat exchange, a heating furnace 10 to heat the preheated stock oil, and a plurality of coke drums 16 and 18 to produce decomposed hydrocarbon and coke from the heated stock oil and introduce the decomposed hydrocarbon into a fractionating column 14. In a method for operating the heating furnace 10 of the delayed coker 1, one cycle is defined as the period after the introduction of the heated stock oil is switched to the first coke drum 16 until it is switched to the second coke drum 18. The one cycle comprises in order a first step of making the throughput of the stock oil lower than the average throughput in one cycle, a second step of making the throughput of the stock oil higher than the average throughput and not higher than 120% of the average throughput, and a third step of making the throughput of the stock oil lower than the average throughput. The first step, the second step, and the third step occupy 10-40%, 20-80%, and 10-40%, respectively, of the time required for one cycle. COPYRIGHT: (C)2008,JPO&INPIT
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