The reflux ratio controller is a device that regulates the proportion of reflux to product flow via solenoid valves or time-delay relays. It can be installed either inside or outside the distillation column. Its core function is to adjust the ratio of reflux to product flow within the distillation column (adjustable from 0 to 99%), supporting both batch and continuous operations. It is suitable for conventional distillation as well as specialized distillation scenarios such as extraction and azeotropic distillation.