Liquefied gas dosing

"You know what you pump - in real-time."

Many chemical reactions that are conducted at high pressures require the supply of precise amounts of organic solvents, for example for extraction purposes. To replace traditional organic solvents, greener and more effective alternatives such as liquefied gases are considered.

Difficulties in handling these liquid/gas substances and lack of dosing precision have been typical obstacles for utilising liquefied gases in technical applications. However, when combining Bronkhorst mass flow controllers with WADose high pressure pumps, a simple yet complete solution is created to accurately dose liquefied gases at high pressures. 
A liquefied gas is a gas at atmospheric pressure and room temperature, which is turned into a liquid by cooling or compression. 
 
Check out the Bronkhorst solution

 

 

Process solution

The process solution for dosing liquefied gases consists of a WADose High Pressure Lite pump with an attached heat exchanger, combined with a Bronkhorst Coriolis mass flow controller and an EL-PRESS pressure meter. The function of the heat exchanger is to cool the pump head to below freezing temperature, in order to stimulate liquid forming and to prevent cavitation and outgassing. This to avoid pressure fluctuations and an unsteady liquid flow when dosing the chemical compounds. Flowbus is used as a standard communication protocol between the pump and the mass flow controller.

The combination of the WADose piston pump and the Coriolis mass flow controller allows for an accurate dosing of the liquefied gases. Stand-alone piston pumps are not hermetically tight and exhibit wear over time. Therefore, their setpoint may deviate from the real amount of chemical compound dosed, which is especially at stake when dosing low flows in the range of ml/min. In the current combination, the dosed quantity is accurately measured in-situ using the Coriolis mass flow controller, and this device controls the pump by adjusting the flow. This self-monitoring control circuit works continuously, making sure that the solution doses what it should do, so that ‘you know what you pump’ in real-time. Prior to using this solution, the supply of liquefied gases typically occurred uncontrolled, thus lacking necessary precision.