Without the reflux , no rectification would occur in the rectifying section , and the concentration of the overhead product would be no greater than that of the vapor rising from the feed plate 假如沒(méi)有回流,精餾段就無(wú)精餾作用,塔頂產(chǎn)品的濃度就不可能高于來(lái)自加料板的上升蒸汽的濃度。