Gas Mixer GAMI

An MFC gas mixer controls each gas with its own digital mass flow controller (MFC) and combines the gas streams in the set ratio. In the GAMI each gas stream is controlled digitally and separately, in pressure or flow control and with mixing ratios from ppm to per cent. The controllers achieve a typical MFC accuracy of ± 0.3 % of full scale plus ± 0.5 % of reading – which is why the correct design and sizing of each controller is decisive for the quality of the mixture.

A mechanical gas mixer can set a mixture, but without analysis it cannot prove that the mixture stays correct. The digital GAMI actively controls every gas stream, monitors inlet and outlet pressure, raises alarms by SMS, email or relay contact and records all values. You change recipes on the touchscreen or remotely – also for mixtures of three or more gases and ppm doping.

As many as you need. The number of gas inlets is configured for your process, and each gas gets its own flow controller. One example from our production: a mixer with five gas inlets and nine flow controllers in total.

As standard, 0 – 5,000 ln/min total flow at 0.2 – 10 barg inlet and 0 – 9 barg outlet pressure, gas temperature 0 – 50 °C. For very wide control ranges we use several graded flow controllers per gas – in one project this gave a turndown of up to 1:60,000, from 1 mln/min to 60 ln/min. We design higher flow rates and pressures on the same modular platform.

Yes, with the right design. For aggressive or corrosive gases and higher pressures we use capillary mass flow controllers whose sensor sits behind a stainless steel wall. We plan hydrogen and fuel gas systems on a project basis; if the process needs a safety-related shutdown, we combine the mixer with the SIL Gas Control SGC (SIL 1 to SIL 3 to IEC 61511) – as SGC Mix in a shared housing or as SGC Sense with integrated analysis.

Yes. OPC UA and FTP are available as direct interfaces; in projects we have also implemented Modbus TCP, EtherCAT, PROFIBUS and PROFINET, among others. External start/stop signals, e.g. 24 V DC, can be integrated, and alarms are available as relay contacts in addition to SMS and email. LTE, LAN and USB are built in as standard.

Yes. The GAMI produces every recipe from ppm to per cent on site from the individual gases you already buy – for example shielding gas for welding, ppm doping such as oxygen in argon, or test and specialty gases in the lab. This saves cylinder logistics, waiting times and cylinder changes for every new mixture.

With fluctuating consumption, yes – unless the volume of the ring mains replaces it. As a rule of thumb for the initial design, the total buffer volume should be about one third to one half of the mixer output per minute. We recommend controlling directly to a target flow only when consumption is steady. Steady-Mix continuously adjusts the mixing output to your actual consumption – it is included in newly built devices, and existing systems receive it as an update with Connect Plus or Connect Enterprise.

Yes, with optional integrated gas analysis: CO₂ and O₂ in ppm and per cent, H₂ and He from 0 to 100 %, residual moisture and NO in the ppm range; further gases on request. The integrated data logger records all parameters; quality reports for audits are available in the Gasyco Dashboard. Where a GAMI is already in use, integrated analysis is more economical and more compact than a separate gas analyser.

In most cases, yes. A mass flow controller can be replaced with one with a larger flow range, and additional gas lines or integrated analysis can be retrofitted – the deciding factor is the space in the housing. The modification is carried out by our technicians or trained distribution partners, and we configure the control system via the remote connection.