Mixing device for frothing beverages and method of using same

1. A mixing device comprising:

a whipper housing comprising a beverage inlet, a beverage outlet, and a front wall, the front wall comprises bumps elevated from a surface of the front wall, an upper surface of each bump is flat, edges of the upper surface are sharp, and the upper surface of each bump is parallel to the surface of the front wall;

a rotor;

a back wall, the whipper housing and the back wall forming a whipper chamber in which is lodged the rotor, the rotor comprising a radial back surface facing the back wall and a radial front surface opposed to the radial back surface, the radial front surface facing the front wall of the whipper housing; and

a drive shaft configured to drive the rotor, the drive shaft supported by the back wall.

2. The mixing device according to claim 1 , wherein the beverage outlet is positioned at the lowest position of the front wall of the whipper housing.

3. The mixing device according to claim 1 , wherein the bumps are regularly positioned on the front wall around a rotor central axis except in the beverage outlet.

4. The mixing device according to claim 1 , wherein all the bumps have the same shape and size.

5. The mixing device according to claim 1 , wherein each bump extends along a whole radial length of the front wall.

6. The mixing device according to claim 1 , wherein for each bump, a width is greater than a height.

7. The mixing device according to claim 1 , wherein the bumps comprise a quadrilaterally-faced hexahedra solid shape.

8. The mixing device according to claim 1 , wherein a sum of surfaces of all the bumps is between 20 and 75% of the surface of the front wall of the whipper housing.

9. The mixing device according to claim 1 , wherein the front wall comprises 3 to 11 bumps.

10. The mixing device according to claim 1 , wherein the bumps are elevated between 0.5 and 2 mm above the surface of the front wall.

11. The mixing device according to claim 1 , comprising a dissolution chamber attached to the beverage inlet of the whipper housing.

12. The mixing device according to claim 1 , wherein the rotor is a disc comprising four grooves radially extending on the radial front surface, the grooves being equally distanced one from the other.

13. The mixing device according to claim 1 , wherein the beverage outlet is positioned at the lowest point of the front wall of the whipper housing, the front wall of the whipper housing comprises seven bumps equally positioned on the surface of the front wall around the beverage outlet,

the seven bumps comprise the same cuboid shape,

the seven bumps are elevated between 0.8 and 1.3 mm above the surface of the front wall,

a sum of surfaces of the bumps represents 30 to 40% of the surface of the front wall, and

the rotor is a disc comprising four grooves radially extending on the radial front surface, the grooves being equally distanced one from the other.

14. The mixing device according to claim 1 , wherein the front wall of the whipper housing comprises a truncated cone shape tapering from a diameter of about 38 mm to about 26 mm, and the rotor has a diameter of about 25 mm.

15. A beverage dispenser comprising a mixing device comprising:

a whipper housing comprising a beverage inlet, a beverage outlet, and a front wall comprising bumps elevated from a surface of the front wall, an upper surface of each bump is flat, edges of the upper surface are sharp, and the upper surface of each bump is parallel to the surface of the front wall;

a rotor;

a back wall, the whipper housing and the back wall forming a whipper chamber in which is lodged the rotor, the rotor comprising a radial back surface facing the back wall and a radial front surface opposed to the radial back surface, the radial front surface facing the front wall of the whipper housing; and

a drive shaft configured to drive the rotor, the drive shaft being supported by the back wall.

16. A method for preparing a frothy beverage, the method comprising:

introducing a beverage ingredient and a diluent into a mixing device comprising

a whipper housing comprising a beverage inlet, a beverage outlet, and a front wall comprising bumps elevated from a surface of the front wall, an upper surface of each bump is flat, edges of the upper surface are sharp, the upper surface of each bump is parallel to the surface of the front wall,

a rotor,

a back wall, the whipper housing and the back wall forming a whipper chamber in which is lodged the rotor, the rotor comprising a radial back surface facing the back wall of the whipper housing and a radial front surface opposed to the radial back surface, the radial front surface facing the front wall of the whipper housing, and

a drive shaft configured to drive the rotor, the drive shaft being supported by the back wall; and

rotating the rotor.

17. The method according to claim 16 , wherein the beverage ingredient is a milk powder or a cocoa powder.

18. The method according to claim 16 , wherein the rotor is rotated at a speed of at least 10000 rpm.

19. A method for preparing a frothed cocoa beverage or a frothed milk beverage comprising:

introducing a cocoa or froth milk beverage ingredient into a mixing device comprising

a whipper housing comprising a beverage inlet, a beverage outlet, and a front wall comprising bumps elevated from a surface of the front wall, an upper surface of each bump is flat, edges of the upper surface are sharp, the upper surface of each bump is parallel to the surface of the front wall,

a rotor,

a back wall, the whipper housing and the back wall forming a whipper chamber in which is lodged the rotor, the rotor comprising a radial back surface facing the back wall of the whipper housing and a radial front surface opposed to the radial back surface, the radial front surface facing the front wall of the whipper housing, and

a drive shaft configured to drive the rotor, the drive shaft being supported by the back wall; and

rotating the rotor to prepare the frothed cocoa or milk beverage.