| 摘要 |
A control system is disclosed for modifying the flow of hydrogen recycle gas to a reaction apparatus which includes the admixture of a hydrocarbon charge stock with a recycle hydrogen-hydrocarbon stream and passage of the same to a hydrocarbon reaction zone to convert the hydrocarbons to a product effluent stream that is cooled to form a separated, via a separation zone, liquid product stream (withdrawn from the process) and a vaporous hydrogen-hydrocarbon stream, which is divided into the hydrogen-hydrocarbon recycle stream and a hydrogen-hydrocarbon vent stream. The recycle stream is returned to admixture with the hydrocarbon charge stock by a compressor while the vent stream conduit, in connection with the recycle conduit, has a controllable flow restriction device. The control system senses the hydrogen concentration in the reaction zone effluent stream and compares that value with a predetermined selected concentration to develop a signal that is transmitted to the flow restriction device in the vent conduit. In this manner, the amount of hydrocarbon-hydrogen in the recycle stream is controlled by increasing or decreasing the amount of vent gas discharged from the process and thereby the amount of hydrogen-hydrocarbon gas substracted from the recycle gas stream.
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