Process and a device to clean substrates

A system comprising

• a. an air-water jet device configured for cleaning a substrate comprising a first nozzle and a second nozzle,
• i. the first nozzle is in fluid communication with a feed water source;
• and
• ii. the second nozzle is connected to an air source;
• wherein both the first nozzle and the second nozzle are positioned relative to a central axis (NOR);
• wherein the first nozzle is at an angle (α) of between 1 and 60° relative to the central axis;
• wherein the second nozzle is at an angle (φ) of between 1 and 45° relative to the central axis;
• wherein the central axis is normal to a surface of the substrate;
• wherein a mouth of the second nozzle is positioned more forward along the central axis in the direction of flow than a mouth of the first nozzle, wherein the offset (OS) distance along the central axis between the mouth of the first nozzle and the mouth of the second nozzle is between 0.5 and 5 mm;
• wherein the first nozzle and the second nozzle are positioned so as to result in:
• (i) mixing of the air and the feed water at the mouth of the second nozzle when the device is in operation and
• (ii) water from the first nozzle forming a film around the second nozzle when the device is in operation;
• and
• wherein the second nozzle does not co-axially surround the first nozzle;
• and
• b. a detergent dosing device comprising a chamber,
• wherein the chamber comprises a detergent composition, and wherein the chamber is positioned between the feed water source and the first nozzle;
• wherein the detergent dosing device comprises an auto-shut-off device configured to close a water inlet and/or an outlet of the dosing device when the detergent composition is spent.