Mixing device, coffee machine provided with mixing device and use of mixing device

A mixing device for aerating and frothing a product that comprises a fluid component and at least one further component, comprising:

• a rotor having a rotational axis and a surface of revolution defined by the rotor upon rotation around its rotational axis, the surface of revolution extending from a first axial end to a second axial end, and the first axial end being located upstream with respect to the second axial end;
• a motor for rotating the rotor about the rotational axis;
• and
• a product exit conduit located downstream of the rotor and configured for dispensing the aerated and frothed product of the fluid and at least one further component,
• the rotor comprising a downstream part and an upstream part,
• the downstream part comprises a rotational body having a first end surface facing upstream, a second end surface facing downstream and a downstream rotational surface facing in a radial outward direction,
• the upstream part comprises an upstream rotational surface facing in a radial outward direction, the upstream rotational surface being provided with ribs, the ribs having radial edges facing in a radial outward direction, chambers being defined between adjacent ribs, the first end face and the upstream rotational surface, and
• the surface of revolution is defined by the downstream rotational surface and the radial edges of the ribs, wherein an angle of taper of the downstream rotational surface is different from, an angle of taper of the part of the surface of revolution determined by the radial edges of the ribs.

A mixing device for aerating and frothing a product that comprises a fluid component and at least one further component, comprising:

• a rotor having a rotational axis and a surface of revolution defined by the rotor upon rotation around its rotational axis, the surface of revolution extending from a first axial end to a second axial end, and the first axial end being located upstream with respect to the second axial end;
• a motor for rotating the rotor about the rotational axis;
• and
• a product exit conduit located downstream of the rotor and configured for dispensing the aerated and frothed product of the fluid and at least one further component,
• the rotor comprising a downstream part and an upstream part,
• the downstream part comprises a rotational body having a first end surface facing upstream, a second end surface facing downstream and a downstream rotational surface facing in a radial outward direction,
• the upstream part comprises an upstream rotational surface facing in a radial outward direction, the upstream rotational surface being provided with ribs, the ribs having radial edges facing in a radial outward direction, chambers being defined between adjacent ribs, the first end face and the upstream rotational surface, and
• the surface of revolution is defined by the downstream rotational surface and the radial edges of the ribs, wherein an axial length of the upstream part and an axial length of the downstream part are about the same.