Gas Mixing System

For many processes, very accurate compositions of gas are required, which means simply adding two or more gas streams together isn’t sufficient. Our homogeneous gas mixing system enables operators to create accurate and precise gas compositions of two or more gases. Our gas mixers allow a repeatable and reliable process that helps eliminate discrepancies. They also ensure that operators have access to the exact gas compositions their processes require at any time. Mixing your own gas increases process efficiency and reduces the cost of having to purchase premixed gas cylinders.

• create homogeneous gas mixtures from percentages down to ppm-ranges
• high accuracy and repeatability with a fast response
• flow ranges from 300 mln/min up to 10,000 mln/min
• pressure rating up to 100 bar
• available with 1/4″ or 6 mm connections

Gas Mixing System

Up to 12 gas cylinders can connect to an equal amount of mass flow controllers. With accurate control, the gas flows enter a gas mixing chamber where it becomes a homogeneous mixture. Then, it can flow directly to the instrumentation, such as a gas chromatograph.

The ISO 6145-7:2009 standard describes a procedure to prepare calibration gas mixtures using commercially available thermal mass flow controllers. Calculation of the accuracy of the final gas composition that leaves the gas mixing system occurs through special software. The software considers the uncertainties in the gas flows and the gas composition of the initial gas cylinders.

Compared to the purchase of gas cylinders with premixed gas mixtures, the preparation of gas mixtures on-site has some advantages. For example, the lifetime of premixed gas mixtures can be limited and expired gas can be costly. Additionally, the costs for these gas cylinders can be quite high. And you can’t always be sure that the concentration of the gas is still good or that the mixture is still homogeneous.

Therefore, it can be beneficial for users to prepare gas mixtures on their own with very low concentrations of specific compounds. As an operator, you no longer need to invest in cylinders of premixed gas mixtures. And it gives a lot of flexibility and freedom to calibrate an analyzer in your own time. Overall, our gas mixing systems provide great value through high accuracy and flexibility and through capabilities from its Modbus protocol.

How to Create Custom Gas Mixtures

There is more to creating gas mixtures than simply combining two gas streams into one. For instance, if you need to dilute 1 mln/min of dopant with 10 ln/min of dilution gas, you cannot expect to obtain a homogeneous mixture unless an appropriate mixing chamber is used. Luckily, our homogenous gas mixing systems offer precision in low flow gas mixing applications.

A user-friendly, preprogrammed touchscreen interface allows users to easily input the composition of the desired gas mixture. Gas then automatically flows from bottles and into a gas mixing chamber using gas flow meters and controllers. There, the gas mixes homogeneously, which is then ready for direct use in processes or it can undergo compression for later use. The process is both accurate and repeatable and users of nearly any experience level can operate the gas mixing system. With our system it’s simple to blend your own high purity, homogenous gas streams on site.

Common Uses of a In-House Gas Mixing System

• mixing reference gas for analyzers
• calibrating gas chromatographs
• food and beverage production such as the fermentation of beer

Homogenous Gas Mixing Flow Diagram