11 November 2019

In this post, we explain what back pressure technology can mean for vacuum distillation applications.

Frequent challenges in distillation processes

Distillation is often used in chemical laboratories and industry in processes and applications that aim to separate substances from one another using the difference in boiling point. Is is particularly useful when extracting or separating complex molecules in substances that are sensitive to temperature.

Distillation is a common technique. However, when substances have relatively high boiling points, raising the temperature is no longer efficient. By reducing the pressure, boiling will occur already at a lower temperature. For this reason, vacuum distillation is often used for separation of high boiling point compounds and solvents. Vacuum distillation is also useful to apply in distillation of temperature sensitive products like hormones or air-sensitive compounds.

During distillation, temperature fluctuations may occur, which may affect the rate of evaporation. Especially in processes where precision is key, this can be problematic. On the other hand, the pressure from the pump can fluctuate, leading to similar complications. It is therefore of key importance that vacuum regulators for distillation applications are accurate. Accurate vacuum control is necessary to precisely distill the necessary substance. Regulators that have this ability usually lack the robustness to withstand corrosive compounds or increased temperatures.

One solution for both problems

Equilibar back pressure regulators in the EVR Series solve both these problems with one apparatus: This regulator can meticulously keep a reduced pressure at its setpoint, despite possible fluctuations in the flow or supply pressure. When using closed-loop control, bandwidths as low as 0.1% can be achieved. This is possible because the EVR back pressure regulator only has one moving part, the diaphragm. The moving diaphragm is chemically resistant, can respond with practically no delay and causes no static friction. In addition to that, the multiple orifice technology enables stable control with two-phase flow.


schematic of vacuum distillation processing using Equilibar EVR Series back pressure regulator





Available materials

EVR bodies are available in a range of materials, from metallics like SS316L, Hastelloy C276 and Monel to polymeric materials like PTFE, PEEK, PVC and more.