Milk frothing with pressurized gas

1. A milk frothing device comprising:

a milk reservoir;

a supply of pressurized gas;

a mixing area for mixing milk from the milk reservoir and gas;

an injection gas conduit in fluid communication with the mixing area for injecting gas into milk in the mixing area;

a milk conduit that is tubular and extends from an interior of the milk reservoir to an exterior of the milk reservoir, the mixing area located inside the milk conduit;

a pressurized gas supply arrangement for driving milk from the milk reservoir to the mixing area,

the pressurized gas supply arrangement has a propelling gas conduit that extends into the interior of the milk reservoir and is configured to deliver pressurized propelling gas therein to pressurize the reservoir and propel pressurized milk from the reservoir to the mixing area; and

an in-line heater so constructed and arranged as to heat in-line only the pressurized milk propelled to the mixing area, with the remaining milk in the milk reservoir being unheated by the in-line heater.

2. The device of claim 1 , wherein the injection gas conduit is in fluid communication with the pressurised gas supply arrangement for injecting pressurised gas into milk in the mixing area.

3. The device of claim 1 , which comprises a frothing arrangement having at least one component selected from the group consisting of: a static mixer; a dynamic mixer; and a venturi-arrangement.

4. The device of claim 1 , wherein the pressurised gas supply arrangement comprises a pump for pressurizing the gas.

5. The device of claim 1 , wherein the pressurised gas supply arrangement comprises a pressurized gas tank.

6. The device of claim 1 , wherein the pressurised gas supply arrangement is associated with a regulator for regulating a flow or pressure in at least one gas conduit selected from the group consisting of the injection gas conduit and the propelling gas conduit.

7. The device of claim 6 , wherein the regulator comprises a regulation valve on the injection gas conduit.

8. The device of claim 1 , which has a non-frothing milk preparation mode in which no pressurised gas is injected into the milk circulating in the mixing area by the pressurized propelling gas.

9. The device of claim 1 , which comprises an active part that is mechanically disconnectably connected to an inert part.

10. The device of claim 1 , which comprises an exhaust system for immediate release of pressurized propelling gas from the milk reservoir.

11. The device of claim 1 , which has a standalone operative configuration for frothing milk and has a connection to an external power source or has internal power source.

12. The device of claim 1 , which has an accessory operative configuration.

13. The device of claim 1 , wherein the propelling gas conduit and the injection gas conduit are in fluid communication such that the gas provided by the propelling gas conduit and the gas provided by the injection gas conduit originate from the same pressurized gas supply.

14. The device of claim 4 , wherein the pump is configured to draw gas at atmospheric pressure.

15. The device of claim 7 , wherein the regulation valve is a manually or automatically controlled valve.

16. The device of claim 8 , wherein the non-frothing milk preparation mode is a heated non-froth milk preparation mode.

17. The device of claim 10 , wherein the release of pressurized propelling gas occurs at an end of frothing.

18. The device of claim 12 , wherein the accessory operative configuration is an operative configuration in fluid connection with a milk reservoir or a machine for preparing a beverage.