Device for frothing a liquid
A device for frothing a liquid includes a tube-shaped housing with an inner surface having a curved periphery. At least one inlet is arranged in a lateral area of the housing for letting in the liquid and a frothing gas, and may have a tangential orientation with respect to the curved periphery of the inner surface of the housing. End faces of the housing are open and function as outlets of the device, where a longitudinal axis of the housing may extend in a horizontal direction. Rings may be provided inside the housing for keeping a rotating flow inside the housing during a period of time which is sufficiently long for a frothing process to take place in an effective manner.
1. A device for frothing a liquid by interaction with a gas, comprising a tube-shaped housing, wherein an inner surface of the housing has a curved periphery, wherein end faces of the housing are open for letting out two streams of frothed liquid, wherein at least one inlet is arranged in a lateral area of the housing for letting in the liquid and the gas for rotation the housing and frothing the liquid during operation of the device, wherein a ring arranged inside the housing for locally decreasing an inner diameter of the housing, an outer periphery of the ring being in contact with the inner surface of the housing, wherein the ring is a non-continuous ring including an interruption at one position, and wherein at least one end of the ring present at a position of the interruption is chamfered as a ramp to the ring in a direction of the rotation.
2. The device according to claim 1 , wherein a longitudinal axis of the housing extends in a horizontal direction.
3. The device according to claim 1 , wherein the at least one inlet is connected to the housing in a tangential orientation with respect to the curved periphery of the inner surface of the housing.
4. The device according to claim 1 , wherein the housing has a shape of a hollow, right circular cylinder.
5. The device according to claim 1 , wherein flaps are arranged at the open end faces of the housing for guiding frothed liquid away from the device during operation of the device.
6. The device according to claim 1 , being part of a beverage device for making a beverage, wherein the inlet is connected to a reservoir for containing a liquid, through a suction chamber of the beverage device which is arranged for receiving the liquid and which is open to a gas to be used for frothing the liquid.
7. The device according to claim 6 , wherein the inlet is connected to a steam generator of the beverage device, through the suction chamber.
8. A beverage device for making a beverage, comprising a device for frothing according to claim 1 , and a system for supplying liquid to be frothed and a frothing gas to the device, wherein the device for frothing is connected to the system through the at least one inlet.
9. The beverage device according to claim 8 , further comprising a steam generator, wherein the device is connected to the steam generator through the at least one inlet.
10. A coffee maker, comprising a unit for making coffee and a unit for making frothed milk, wherein the unit for making frothed milk comprises a device according to claim 1 , and a system for supplying milk to be frothed and air to the device, and wherein the device is connected to the system through the at least one inlet.
11. The device according to claim 1 , wherein the ring is oriented according to a turn of a helix.
12. The device according to claim 1 , comprising a single inlet and two rings, wherein the inlet is located at a position which is a central position as seen in a longitudinal direction of the housing, and wherein the two rings are located at positions which are positions at opposite sides of the inlet, at a same distance with respect to the single inlet.