Nitrox-mixtures production machine and related operating method

Nitrox-mixtures production machine (1) comprising:

• a molecular separator (2), which is structured so as to receive at inlet an airflow and to provide at outlet an intermediate Nitrox mixture with high oxygen percentage;
• a low-pressure compressor (3), which is adapted to supply an airflow at inlet of the molecular separator (2);
• a control valve (26) which is located upstream of the low-pressure compressor (3) and is adapted to regulate the flowrate of the airflow at inlet of the same low-pressure compressor (3);
• a mixing manifold (4), which communicates with the molecular separator (2) so as to receive said intermediate Nitrox mixture, and is structured so as to mix the intermediate Nitrox mixture with fresh air coming from the outside, in order to provide at outlet a final Nitrox mixture with predefined composition;
• and at least one oxygen sensor (5) that outputs a signal indicative of the percentage of oxygen present in said final Nitrox mixture;
• said Nitrox-mixtures production machine (1) being characterized by additionally comprising:
• at least one pressure sensor (7) that outputs a signal indicative of the pressure of the air in the molecular separator (2);
• an electronically-controlled driving device (28, 29, 34) which is adapted to move/shift, on command, the movable shutter of said control valve (26) so as to vary the flow rate of the airflow sucked by the low-pressure compressor (3);
• and an electronic control unit (25), which is connected to said at least one oxygen sensor (5) and to said at least one pressure sensor (7), and is configured so as to command said electronically-controlled driving device (28, 29, 34) as a function of the signals coming from said at least one oxygen sensor (5) and from said at least one pressure sensor (7).