MFC mixing systems
Systems for corrosive gases
The gas mixing systems in the TOX series are suitable for use in harsh industrial production environments where the process requires a high-precision gas mixture of at least one corrosive and at least one inert gas.
The gas-carrying components of these systems are located in a gas safety cabinet whose atmosphere is controlled by an ambient air monitoring system. If the permissible gas concentration is exceeded, a visual and audible alarm is signalled and the cabinet atmosphere is extracted.
If necessary, the internal cabinet temperature can be regulated and the gas line heated.
The gas mixing systems in the TOX series have the following functions:
Flow control
In the flow-controlled versions, the desired flow rate for the carrier gas and the desired percentage of admixture gases are set at the user interface. This data is processed by the PLC and converted into a high-precision mixed gas by the thermal mass flow controllers. With this design, the downstream process is supplied with an absolutely constant quantity of mixed gas and a constant concentration of mixed gas.
Pressure control
In the pressure-regulated versions, the desired mixed gas outlet pressure and the desired percentage of admixing gases are set at the user interface. This data is processed by the PLC and converted into a high-precision, pressure-controlled mixed gas by the thermal mass flow controllers. In this version, a variable quantity of mixed gas is fed to the downstream process at a constant pressure and concentration.
Additional options are available for both versions:
Automatic emergency gassing
With this option, the generation of the mixed gas is maintained (then with reduced mixing accuracy) if the power supply fails. The operator does not need to intervene.
Automatic cylinder switching device
With this option, the gas cabinet is prepared to hold two gas cylinders. The connections for the gas are located in the gas cabinet. If one gas cylinder is depressurised, the system switches over to the reserve cylinder and an alarm is triggered.
Standard services
1. mains connection either 24 V DC or 230 V AC.
2. cylinder holder and connection for the admixing gas in the gas cabinet.
3. all system parts in contact with the medium are oil and grease-free and made of special materials suitable for the medium used.
4. leakage test of the system with helium.
Application examples
1. Zentrale Gasversorgung
2. Leichtmetall-Schmelzprozesse
3. Metall-Bearbeitungsprozesse
4. Oberflächenveredelungen
5. Schutzbegasungen mit Mischgas