Abstract: A system for preparing a beverage comprises a beverage maker (15) and a cartridge (10) that is removably arranged in the beverage maker (15). The cartridge (10) comprises a beverage making unit (1) having a duct system (30) for conveying flows of steam and flows of liquid. The duct system (30) comprises two combinations of ducts (31, 32; 41, 42), wherein the arrangement of the ducts (31, 32; 41, 42) of each combination is adapted to enabling a flow of steam to perform a pumping action on a flow of liquid. The beverage maker (15) comprises a steam generator (16) having two steam sockets (17, 18), wherein each of the steam sockets (17, 18) is in communication with another combination of ducts (31, 32; 41, 42) of the duct system (30). As each of the combinations of ducts (31, 32; 41, 42) is associated with a different steam inlet (36, 46), and the steam inlets (36, 46) may be located at different positions on the cartridge (10), it is achieved that the duct system (30) may be of a relatively simple design.

Abstract: A disposable cartridge (10), which is suitable for use in a process of preparing a beverage, comprises a pump unit (1). A duct system (30) of the pump unit (1) has a first duct (31) and a second duct (32) which merges into the first duct (31), wherein an angle (?) between the ducts (31, 32) is considerably smaller than 90°. In a process of preparing a beverage, a first fluid is supplied by an inlet portion of the first duct (31), and a flow of a second fluid is supplied by the second duct (32). At the position where the ducts (31, 32) meet; a transfer of momentum from the flow of the second fluid to the first fluid takes place, so that an underpressure is obtained, as a result of which the first fluid is put in motion. Furthermore, a joint flow of the first fluid and the second fluid is obtained in an outlet portion of the first duct (31).