Heating pump for liquids, in particular for machines for dispensing beverages

Abstract

A heating pump for liquids comprises: a conduit (2) which has at least one curved section (21) comprising one or more turns concentric with a longitudinal axis (X), and a conductive portion made of electrically conductive material; a piston (3) provided with at least one ferromagnetic element, which is disposed concentrically with the curved section (21) relative to the longitudinal axis (31); a pumping chamber (4), in which the piston (3) is sealingly slidable, which has an inlet opening (41) connected to a source of liquid, and an outlet opening (42) connected to the conduit (2); a power supply unit (5) electrically connected to the conduit (2) and / or to the conductive portion and adapted to supply the conduit (2) and / or the conductive portion with a regulatable electric current; and a control board (6), connected to the power supply unit (5) and configured to control the electric current supplied to the conduit (2) and / or to the conductive portion.

Description

[0001] HEATING PUMP FOR LIQUIDS, IN PARTICULAR FOR MACHINES FOR DISPENSING BEVERAGES

[0002] DESCRIPTION

[0003] The present invention relates to a heating pumps for fluids.

[0004] The invention is particularly advantageous if used in machines for dispensing hot beverages, such as, for example, coffee machines and brewing machines, for both domestic and professional use and for battery- powered portable machines.

[0005] Various types of machines for dispensing hot beverages, such as coffee or infusions, are currently available on the market.

[0006] Most of the current machines comprise a boiler, a dispensing pump and brewing means for brewing the product to be emulsified (coffee, tea, barley, herbal teas, etc.). The boiler typically comprises an aluminium block, weighing around 1 Kg, capable of easily stabilising the temperature of the water at around 90-95 °C. The boiler is heated through current dissipation and, given the considerable mass of the aluminium block, with an energy expenditure that is far from negligible. Furthermore, heating of the aluminium block requires at least around 30 seconds.

[0007] The machines of the most recent generation are provided with a boiler that has a decidedly reduced mass compared to the previous ones. However, these machines require a more complex regulation system, capable of reacting around 100 times per second.

[0008] Furthermore, the current dispensing machines require the use of a pump. In the most widely used form, the pump essentially comprises a solenoid, in which the piston is associated with a ferromagnetic element and moves with alternating motion as a result of the power supply in alternating current to a coil concentric with the piston itself. The coil generates a magnetic field in the order of 200-300 ampere-turns. The weight of the pump is typically 0.5 Kg, of which half is given by the weight of the coil. The pump is therefore also a rather heavy and energy-intensive component.

[0009] The object of the present invention is to provide a heating pump with a weight and an energy consumption that are decidedly lower than those required by the boilers and the pumps currently used in machines for dispensing hot beverages.

[0010] The features and advantages of the present invention will become more apparent from the detailed description that follows of one embodiment of the invention in question, illustrated by way of non-limiting example in the appended figures, in which:

[0011] - Figure 1 shows a schematic view of a first embodiment of the heating pump according to the present invention;

[0012] - Figure 2 shows a schematic view in partial section of the heating pump of Figure 1 ;

[0013] - Figures 3a-3c show three different waveforms for a supply current supplied to a component of the heating pump;

[0014] - Figures 4 and 5 show, respectively, a second and a third embodiment of the heating pump according to the present invention.

[0015] The heating pump for liquids according to the present invention comprises a conduit (2), which has at least one curved section (21 ) concentric with a longitudinal axis (X). The curved section (21 ) is curved according to an annular or tubular shape, concentrically with the longitudinal axis (X). Preferably, the curved section (21 ) is curved according to a tubular spiral, concentric with the longitudinal axis (X). In other words, the curved section (21 ) has one or more turns (22) concentric with the longitudinal axis (X). The turns (22) present substantially delimit a space concentric with the longitudinal axis (X), typically surrounded by the magnetic circuit (53).

[0016] The conduit (2) comprises a conductive portion, made of electrically conductive material. By supplying an electric current to the conduit (2) and / or the conductive portion, it is possible to generate a tangent or overall direct magnetic field along the longitudinal axis (X); this is thanks to the presence of the curved section (21 ). In practice, the curved section (21 ) is capable of performing the same function as the coil of an electromagnetic actuator or solenoid. Furthermore, if traversed by an electric current, the conduit (2) is heated, so as also to heat the liquid inside it.

[0017] In the preferred but not exclusive embodiment illustrated in Figure 1 , the conduit (2) is made of electrically conductive material, i.e. it is the conduit (2) itself that defines the conductive portion.

[0018] In another possible embodiment, illustrated in Figure 5, the conductive portion comprises a conductor winding (23), wound in contact with the conduit (2). The conductor winding (23), in addition to producing a magnetic field when it is traversed by current, is also suitable for heating the conduit

[0019] (2). Preferably, the conduit (2) and the conductor winding (23) are in close thermal contact and are electrically insulated from one another. In the preferred but not exclusive embodiment illustrated, the conduit (2) and the conductor winding (23) are incorporated into a containment body (24) made of highly conductive thermal material.

[0020] The heating pump according to the present invention comprises a piston

[0021] (3), provided with at least one ferromagnetic element, which is disposed concentrically with the curved section (21 ) relative to the longitudinal axis (X). The piston (3) is therefore subjected to the action of the magnetic field produced by the curved section (21 ), translating along the longitudinal axis (X) as a function of the direction of the current supplied to the conduit (2). By supplying an alternating current to the conduit (2), it is possible to actuate the piston (3) sliding in alternate directions along the longitudinal axis (X), in order to obtain a pumping effect. As an alternative, the travel in one direction of the piston (3) is obtained by means of the magnetic field generated by the curved section (21 ), whereas the travel in the opposite direction is obtained through elastic means. The piston (3) is movable between two end stops.

[0022] The heating pump according to the present invention comprises a pumping chamber (4), in which the piston (3) is sealingly slidable. Preferably, an end or head portion (31 ) of the piston (3), provided with an outer gasket of known type, is housed and sealingly slidable in the pumping chamber (4). In a manner known in the sector, the head (31 ) of the piston contributes to delimiting the pumping chamber (4). The latter alters its volume by virtue of the displacement of the piston (3) between the end stops thereof. In a manner known in the sector, the pumping chamber (4) has an inlet opening (41 ), connected to a source of liquid, and a delivery opening (42), connected to the conduit (2). Each opening (41 ,42) is provided with a one-way control valve, respectively to allow only the entry or only the exit of the liquid from the pumping chamber (4). In the possible but not exclusive embodiment shown, the suction opening (41 ) is obtained through the piston (3) concentrically with the longitudinal axis (X). The suction valve is defined by a sphere (41 a) pushed into contact with the suction opening (41 ) by an elastic means, such as, for example, a spring. Similarly, the delivery valve is defined by a semi-spherical or spherical element (42a) pushed into contact with the delivery opening (42) by an elastic means, such as, for example, a spring.

[0023] A power supply unit (5) is electrically connected to the conduit (2) and / or to the conductive portion by means of the connections (50) and (51 ). The power supply unit (5) is adapted to supply the conduit (2) and / or the conductive portion with a regulatable electric current. As already emphasised, the supply of an electric current to the conduit (2) and / or the conductive portion generates a tangent or overall direct magnetic field along the longitudinal direction (X), thanks to the presence of the curved section (21 ). The heating pump according to the present invention further comprises a control board (6), connected to the power supply unit (5) and configured to control the electric current supplied to the conduit (2) and / or to the conductive portion.

[0024] The control board (6) can consist of a single electronic device, appropriately programmed to perform the functions described, or can comprise several, separate functional models (memory modules or operating modules), which can correspond to hardware entities and / or software routines that are part of the programmed device.

[0025] Alternatively, or in addition, such functions can be performed by a plurality of electronic devices over which the aforesaid functional modules can be distributed.

[0026] The control board (6) can moreover rely on one or more processors to execute the instructions contained in the memory modules.

[0027] Advantageously, the control board (6) is adapted to control the electric current supplied to the conduit (2) and / or to the conductive portion according to waveforms configured to obtain at least one of the following conditions: only heating of the conduit (2); heating of the conduit (2) and actuation of the piston (3) in alternate sliding along the longitudinal axis (X); only actuation of the piston (3) in alternate sliding along the longitudinal axis (X).

[0028] To this end, the control board (6) is adapted to supply the conduit (2) and / or the conductive portion with a direct current or an electric current with a frequency-modulatable or amplitude-modulatable waveform.

[0029] Examples of waveforms are shown in Figures 3a-3c, which illustrate diagrams with the time (t) on the x-axis and the current (c) on the y-axis.

[0030] In the first case, illustrated schematically in Figure 3a, the direct current produces the maximum heating of the conduit (2), whereas the piston (3) is kept still at an end stop, either as a result of the magnetic field produced by the curved section (21 ) and / or the conductive portion, or through other means.

[0031] In the second case, illustrated schematically in Figures 3b, 3c, the current is supplied with a waveform having a specific frequency, with an intensity comprised between zero and a specific value. In particular, the electric current is pulse-driven. This allows the production of a pulsed magnetic field, capable of displacing the piston (3) in one direction along the longitudinal axis (X), in the intervals in which the current pulses occur. In the intervals in which the current is zero, the piston (3) is displaced in the opposite direction to the previous one, as a result of the push exerted by a mechanical means. In the intervals in which the pulse current occurs, there is also a heating of the conduit (2). As a whole, the waveform described above allows both production of heating of the conduit (2) and displacement of the piston (3). By regulating the duration and / or the frequency in time of the current pulses, it is possible to regulate heating of the conduit (2) and frequency in time of the travels performed by the piston (3), and therefore the flow rate processed by the piston (3). In other words, by regulating solely the electric current supplied to the conduit (2) and / or to the conductive portion, it is possible, using appropriate waveforms, to actuate the pump and / or the heater independently, as required.

[0032] In a possible embodiment of the heating pump, the waveform of the electric current is modulated with the PWM (pulse width modulation) technique, or an equivalent technique.

[0033] Preferably, but not necessarily, the waveform of the electric current has a frequency higher than or equal to 50Hz. This makes functioning independently of the supply voltage possible. For example, considering a rated voltage of 24V, it is possible to supply the conductive section (21 ) with a voltage comprised between 18V and 36V, maintaining the current constant and regulating the duty-cycle of the PWM.

[0034] The heating pump according to the present invention allows considerable advantages to be obtained compared to the devices currently available, both in terms of energy saving and in terms of weight and overall dimensions.

[0035] By way of example only, consider that, typically, a traditional coffee machine has a boiler with a heating capacity of 600-1000 W and a solenoid pump with power of 50-80W, both functioning typically at 230V in alternating current at 50 Hz. For machines functioning in direct current, the heating power is 500-800W, whereas the power of the pump is 60-100W, since the pump powered with pulsed direct current is typically less efficient than the one in alternating current. The boiler is made with 0.5 Kg of aluminium, or more to stabilise the water temperature.

[0036] The pump supplied at 230V typically has a coil formed of 220 turns, with a resistance of 260 Ohm. The peak current is:

[0037] 230V / 260 Ohm = 0.88 Ampere x 1 .41 = 1 .128 Apk.

[0038] If there are 220 turns, 1.128 Apk x 220 turns = 248.16 ampere-turns are used to actuate the piston.

[0039] In a possible embodiment, the heating pump according to the present invention, which uses the conduit (2) in place of the coil of a traditional solenoid pump, has an average power of around 600W. Considering use with a duty-cycle at 50%, i.e. a waveform with current pulses of a duration equal to the time intervals in which the current is not supplied, there is a peak power of 1200W. If a 24 V battery power supply is considered, the current that traverses the tube is 1200W / 24V = 50Apk. In order to obtain around 250 ampere-turns, necessary to generate a magnetic field of sufficient intensity to actuate the piston (3), five turns are therefore necessary. The enormous advantage of the invention is therefore clear, as it allows the traditional coil with 220 turns to be replaced with one with five turns, defined by the curved section (21 ) of the conduit (2) which, in addition, also performs the function of heating the liquid, eliminating the 1 Kg aluminium boiler. Furthermore, given that the same energy used to actuate the piston (3) is also used for heating, an energy saving equal to the consumption of a traditional 50-100W pump is obtained.

[0040] Another important advantage is given by the fact that, thanks to the rapid heating that is obtained through the conductive portion of the conduit (2), the device can remain in stand-by at zero consumption and only be actuated following an effective request for heating made by the user, for example upon requesting dispensing of a beverage.

[0041] Advantageously, but not necessarily, the heating pump according to the present invention can be provided with an auxiliary winding (7), connected to the power supply unit (5) and concentric with the piston (3). Such auxiliary winding is connected to the power supply unit (5) in series or in parallel relative to the conduit (2), and operated by means of an auxiliary current. The auxiliary winding (7) is substantially a coil of the traditional type, usable to actuate the piston (3) in the case in which it is not necessary to heat the liquid or, in general, in cases in which it is not intended to supply power to the conduit (2).

[0042] Advantageously, but not necessarily, the heating pump according to the present invention comprises at least one of the following control sensors, connected to the control board (6): a first temperature sensor (61 ) for measuring the temperature of the liquid exiting the conduit (2); a second temperature sensor (62) for measuring the temperature of the liquid entering the pumping chamber (4); a third temperature sensor (63) for measuring the ambient temperature; a flow meter (64) for measuring the flow entering the pumping chamber (4). The control board (6) is adapted to regulate the electric current supplied to the conduit (2) as a function of a signal received from at least one of said control sensors.

[0043] Preferably, but not necessarily, the heating pump according to the present invention is provided with all the control sensors listed here above. The control board (6) is provided with a predictive artificial intelligence algorithm, configured to regulate the electric current supplied to the conduit (2) as a function of a desired temperature of the liquid exiting the conduit (2) and as a function of the signals received from the aforesaid control sensors.

[0044] In particular, the control board (6), through the predictive artificial intelligence algorithm, is able to map various conditions surrounding heating of the water, so as to be able to obtain a precise outgoing temperature without the need to perform frequent and complex controls. Furthermore, this allows to use sensors of an inexpensive and not particularly sensitive type.

[0045] Preferably, but not necessarily, the heating pump according to the present invention comprises a water detector (65) to detect the presence of water in the pumping chamber (4) and to send a corresponding indicative signal to the control board (6). In a possible embodiment, the water detector (65) is integrated into the flow meter (64). Preferably, the flow meter (64) is configured to send to the control board (6) a signal indicative of the presence of water simultaneously with measurement of the flow rate. The water detector (65) is connected to the control board (6). If the water detector (65) does not detect the presence of water, the control board (6) is configured to activate initially a supply of electric current with waveform appropriate to pumping, such as, for example, the waveform illustrated in Figure 3c. Subsequently to the detection of water, the control board (6) regulates the current with a waveform appropriate to pumping and heating, such as, for example, the waveform illustrated in Figure 4b.

[0046] In a possible embodiment, illustrated schematically in Figure 4, the heating pump according to the present invention comprises a second conduit (2a) that has a curved section (21 a). The second conduit (2a) is substantially similar to the first conduit (2) and has substantially the same characteristics as the first conduit (2). Preferably, the curved section (21 a) of the second conduit (2a) has loops or turns interposed with those of the curved section (21 ) of the first conduit (2). The second conduit (2a) is positioned hydraulically in parallel relative to the first conduit (2). The second conduit (2a) is connected to the power supply unit (5) in series relative to the first conduit (2).

[0047] If the second conduit (2a) has the same length as the first conduit (2), the overall resistance of the two conduits (2, 2a), connected in series to the power supply unit (5), duplicates with respect to the case in which only one conduit is present. If two conduits of double length (for example, 10 turns each) are inserted, the resistance quadruples, whereas the flow rate remains substantially the same, given that the length doubles but the section of the flow also doubles. This solution allows the supply voltage to be increased. In the example cited here above, the maximum admissible voltage is 30V. Using a second conduit (2a), the maximum admissible voltage is 120V.

[0048] The embodiment illustrated in Figure 5, in which the conductive portion comprises a conductor winding (23), wound in contact with the outer surface of the conduit (2), is more advantageous for supply voltages even higher than the ones indicated here above.

[0049] As already emphasised, the heating pump according to the present invention has a particularly advantageous application in a machine for dispensing hot beverages, such as, for example, a coffee machine and / or brewing machine, for both domestic use and professional use.

[0050] The machine for dispensing hot beverages comprises a water source (8), which may be in the form of a tank or an attachment to a water supply network. The machine further comprises a brewing chamber (9), adapted to receive a compound for brewing. In a known way in the sector, the brewing chamber (9) is substantially configured to house, for example, a pod or a capsule, or a specific quantity of compound without a container. Furthermore, the brewing chamber (9) is provided with a dispensing opening for the brewed product.

[0051] A source of electric energy (54) is connected to the control board (6) and by means of connections (50) and (51 ) to the conductive portion of the conduit (2). In a known way in the sector, the source of electric energy can be in the form of a battery and / or in the form of a connection intended to be connected to an electricity supply network.

[0052] The machine comprises a heating pump according to the present invention, wherein the water source (8) is connected to the inlet opening (41 ) of the pumping chamber (4) and wherein the brewing chamber (9) is disposed along the conduit (2).

Claims

CLAIMS1 . A heating pump for liquids, characterised in that it comprises: at least one conduit (2), which has at least one curved section (21 ), concentric with a longitudinal axis (X), and comprises a conductive portion made of electrically conductive material; a piston (3), provided with at least one ferromagnetic element, which is disposed concentrically with the curved section (21 ) relative to the longitudinal axis (X); a pumping chamber (4), in which the piston (3) is sealingly slidable, and which has an inlet opening (41 ), connected to a source of liquid, and an outlet opening (42), connected to the conduit (2); a power supply unit (5), electrically connected to the conduit (2) and / or to the conductive portion and adapted to supply the conduit (2) and / or the conductive portion with a regulatable electric current; a control board (6), connected to the power supply unit (5) and configured to control the electric current supplied to the conduit (2) and / or to the conductive portion.

2. The heating pump according to claim 1 , wherein the control board (6) is adapted to control the electric current supplied to the conduit (2) and / or to the conductive portion according to waveforms configured to obtain at least one of the following conditions: only heating of the conduit (2); heating of the conduit (2) and actuation of the piston (3) in alternate sliding along the longitudinal axis (X); only actuation of the piston (3) in alternate sliding along the longitudinal axis (X).

3. The heating pump according to claim 1 , wherein the control board (6) is adapted to supply the conduit (2) and / or the conductive portion with a direct current or an electric current with a frequency-modulatable waveform.

4. The heating pump according to claim 1 , wherein the control board (6) is adapted to supply the conduit (2) and / or the conductive portion with anelectric current with a waveform regulated with the PWM technique, through regulation of the duty cycle.

5. The heating pump according to claim 3 or 4, wherein the waveform has a frequency greater or less than 50Hz.

6. The heating pump according to any one of the preceding claims, comprising an auxiliary winding (7), connected to the power supply unit (5) and concentric with the piston (3).

7. The heating pump according to any one of the preceding claims, comprising at least one of the following control sensors, connected to the control board (6): a first temperature sensor (61 ) for measuring the temperature of the liquid exiting the conduit (2); a second temperature sensor (62) for measuring the temperature of the liquid entering the pumping chamber (4); a third temperature sensor (63) for measuring the ambient temperature; a flow meter (64) for measuring the flow entering the pumping chamber (4); wherein the control board (6) is adapted to regulate the electric current supplied to the conduit (2) and / or to the conductive portion as a function of a signal received from at least one of said control sensors.

8. The heating pump according to claim 7, wherein the control board (6) is provided with a predictive artificial intelligence algorithm, configured to regulate the electric current supplied to the conduit (2) and / or to the conductive portion as a function of a desired temperature of the liquid exiting the conduit (2).

9. The heating pump according to any one of the preceding claims, wherein the conduit (2) is made of electrically conductive material, so as to define said conductive portion.

10. The heating pump according to any one of the preceding claims, wherein the conductive portion comprises a conductor winding (22), wound in thermal contact with the conduit (2).1 1 . A machine for dispensing hot beverages, comprising: a source of water(8); a brewing chamber (9), adapted to receive a compound for brewing and provided with a dispensing opening; a source of electricity; and a heating pump according to any one of the preceding claims, wherein the source of water (8) is connected to the inlet opening (41 ) of the pumping chamber (4) and wherein the brewing chamber (9) is disposed along the conduit (2).

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