Device for mixing water and diesel oil, apparatus and process for producing a water/diesel oil micro-emulsion

A process for preparing a water/diesel oil micro-emulsion, comprising:

• feeding a predetermined amount of a diesel oil into a mixing tank;
• feeding a predetermined amount of an emulsifying composition into the mixing tank;
• feeding a predetermined amount of water into the mixing tank;
• recirculating the batch in the mixing tank comprising said diesel oil, said emulsifying composition and said water through a recirculation conduit including a mixing device;
• and
• discharging the fuel micro-emulsion batch,
• wherein the mixing device comprises:
• at least one duct for flow of a liquid mixture, said duct extending along a main direction and including an inlet opening for receiving the liquid mixture and an outlet nozzle;
• a cone-shaped septum extending across the duct, and dividing the duct into an upstream portion and a downstream portion, the cone-shaped septum comprising a conical wall that is coaxial with respect to the main direction and tapering inwards towards the outlet nozzle;
• a first plurality of holes extending through the conical wall of the cone-shaped septum, for the flow of the liquid mixture from the upstream portion of the duct to the downstream portion of the duct;
• a plurality of lamellae extending across the duct in a labyrinth section of the downstream portion of the duct, said plurality of lamellae dividing the duct into a plurality of chambers;
• and
• a second plurality of holes extending through the lamellae between the plurality of chambers, wherein said second plurality of holes and said plurality of chambers delimit a labyrinth passageway for the flow of the liquid mixture through the duct towards the outlet nozzle.