Reflux ratio adjustment
Thread Content
How should the reflux ratio be adjusted under high load? Is there any difference from low-load adjustment? Is it better to be bigger or smaller?
The product is of qualified quality, and it saves energy depending on the load level.
The minimum return flow rate required to meet the product separation requirements.
Generally, the greater the load, the greater the backflow; it is necessary to consider the analysis results from the top and bottom of the tower. Of course, the lower this value, the more energy-efficient it is
When the load is high, the operating pressure can be increased appropriately as long as it is within the design limits; the top temperature of the tower can be raised and the reflux ratio can be decreased, provided that this does not affect product quality. Increasing the reflux ratio can lead to a vicious cycle. If the top pressure and temperature cannot be adjusted, the only option is to reduce the load
If the product quality is satisfactory, the lower the reflux ratio, the less energy consumption.
Minimize the concentration inside the tower as much as possible, and reduce the reflux ratio
It is recommended to make adjustments within the framework specified by the process; a reference point should be established for such adjustments. For example, when the amount of reflux liquid remains constant, the volume of the rising gas should be adjusted； When the amount during the rising phase is constant, adjust the return fluid. It cannot be infinite; adjustments must be made within the range of design parameters.
When increasing the reflux ratio under high load, be careful of flooding. When the quality at the tower top is satisfactory, the pressure and temperature can be adjusted appropriately; it is not recommended to increase the reflux ratio significantly. . . Personal opinion
I have a tower with side extraction, along with a control sensor for side extraction. Today, the amount of material extracted via side extraction was higher than usual; the liquid level in the reflux pipe dropped (to full reflux), and the liquid level at the bottom of the tower decreased as well. Yet the temperature of the sensor remained lower than normal, which resulted in contamination of the material at the bottom of the tower! Is the reboiler too small, or are there other issues with the tower? Please provide an explanation and let me know how to make the adjustments