A.进料与回流之比B.回流与进料之比C.充与塔顶采出之比D.回流与塔底采出之比
A.1.47h-1B.1.47hC.0.687h-1D.0.687h
A.关闭长明灯、燃料气炉前阀B.关闭烟道挡板C.测爆D.测氧