Vacuum line and method for controlling a vacuum line to reduce explosion potential via injection of diluent gas to lower flammable gas concentration

A vacuum line comprising:

• a pumping device including at least one rough pumping device configured to be able to discharge pumped gases at atmospheric pressure;
• a gas treatment device comprising:
• a treatment chamber configured to treat, at atmospheric pressure, the gases pumped by the rough pumping device,
• a discharge pipe connecting a discharge of the rough pumping device to an inlet of the treatment chamber,
• at least one auxiliary pumping device configured to lower the pressure in the discharge pipe, and
• a diluent gas injection device configured to inject a diluent gas into a stream of the pumped gases, downstream of an intake of the rough pumping device;
• a pressure sensor configured to measure the pressure prevailing in the discharge pipe;
• and
• a control unit configured to control the auxiliary pumping device and the diluent gas injection device according to a first operating mode in which the pressure prevailing in the discharge pipe is maintained at less than or equal to 20,000 Pa or according to a second operating mode in which the pressure prevailing in the discharge pipe is greater than 20,000 Pa, the control unit being configured to control the injection of the diluent gas by the diluent gas injection device in the second operating mode.