Machine for processing liquid or semi-liquid food product and method for processing liquid or semi-liquid food product

Abstract

To thermally process liquid or semi-liquid food products, in particular by heating, in a more energy efficient manner, so as to reduce the environmental load of a process.SOLUTION: Provided is a machine for processing liquid or semi-liquid food products. The machine includes: a processing container for processing the liquid or semi-liquid food products, the processing container including walls and an outlet; a stirrer made at least partly from a ferromagnetic material and disposed inside the processing container, the stirrer rotating about a mixing axis to mix dispensed products; and an actuator connected to the stirrer to set the stirrer in rotation about the mixing axis. The machine also includes an induction element including one or more wound conductors for generating a magnetic field when an electric current flows through the one or more wound conductors, the induction element being disposed outside the processing container so that the magnetic field generated passes through at least part of the walls of the processing container to reach the stirrer and causes heating by magnetic induction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a machine for (especially thermally) treating liquid or semi-liquid food products and to a method for thermally treating a base food mixture in said machine.

[0002] In particular, the present invention relates to devices such as pasteurizers, cookers, or multi-function / combined machines that can perform both pasteurization and creaming in the same vessel. [Background technology]

[0003] Prior art machines comprise a product receiving element in which the mixture to be processed is placed and rotated by an agitator.

[0004] These machines are also equipped with a thermodynamic system integrated into the machine, making it possible to heat treat the products that are fed into them.

[0005] Generally speaking, a thermodynamic system comprises a closed circuit (with various thermodynamic elements) in which a heat exchange fluid circulates to exchange heat with a container to heat the container and enable the product to be thermally treated.

[0006] Unfortunately, prior art machines with thermodynamic systems are not particularly efficient in that they require large amounts of energy to generate the heat necessary to thermally process the product.

[0007] Furthermore, these thermodynamic systems are not easily adjustable, making the machines less flexible for different types of products that require specific processing according to a predetermined heating curve.

[0008] There is therefore a need to thermally process liquid or semi-liquid food products in a more energy-efficient manner, particularly by heating, in order to reduce the environmental impact of the process. Summary of the Invention

[0009] The object of the present invention is to meet at least the above-mentioned needs by providing a machine for processing liquid or semi-liquid food products, and a method for processing food products in said machine, which is capable of thermally processing food products in a particularly efficient manner. [Brief explanation of the drawings]

[0010] In relation to the above objects, the technical features of the present invention are clearly set forth in the following claims, and its advantages will be apparent from the following detailed description, taken in conjunction with the accompanying drawings, which show illustrative, and therefore non-limiting, embodiments of the present invention. [Figure 1] 1 shows a perspective view of a machine for processing liquid or semi-liquid food products according to the present disclosure; [Figure 2] 2 shows a schematic diagram of a first embodiment of an operating circuit applicable to the machine of FIG. 1; [Figure 3] 2 shows a schematic diagram of a second embodiment of an operating circuit applicable to the machine of FIG. 1; [Figure 4] 4 shows a schematic representation of part of the operating circuit of FIG. 2 or 3; DETAILED DESCRIPTION OF THE INVENTION

[0011] With reference to the accompanying drawings, the numeral 1 indicates a machine for producing and dispensing liquid or semi-liquid food products according to the present invention.

[0012] The machine 1 makes it possible to produce various kinds of liquid or semi-liquid products, for example bread and confectionery products, creams, soups, etc.

[0013] The machine 1 comprises a container 2 with walls 2A, 2B and an outlet 3 for the thermal treatment of liquid or semi-liquid food products.

[0014] The machine 1 may for example be a pasteurizer, a cooker or a multi-function / combined machine capable of performing both pasteurization and creaming in the same vessel 2.

[0015] Advantageously, heat treatment promotes the preservation and safety of the treated food by reducing oxidation of the final product.

[0016] The machine 1 is provided with a dispenser 14 for supplying the treated product.

[0017] The dispenser 14 is connected to the outlet 3 and comprises a closure element (not shown) that is movable to open and close the outlet 3 when product needs to be dispensed.

[0018] After undergoing the necessary thermal process in the container 2 , the product passes through the outlet 3 and can be dispensed via the dispenser 24 .

[0019] Preferably, the final product is then collected in a tub 14 as shown in FIG.

[0020] In the embodiment shown in Figure 1, machine 1 comprises a second container 28 in communication with container 2 (containers 2 and 28 are shown with dashed arrows as they are hidden from view inside the machine).

[0021] For example, the container 2 may be a cookware and the second container 28 may be a creaming cylinder.

[0022] The container 2 and the second container 28 are preferably, but not necessarily, oriented in the same direction to ensure compactness of the machine 1 .

[0023] However, it should be noted that the container 2 may have a primary deployment direction that is horizontal or vertical, as shown in FIGS.

[0024] If both container 2 and second container 28 are present, the machine may include a dispenser 26 configured to pour the contents of container 2 into a hopper 27 leading to second container 28 .

[0025] Dispenser 24 and dispenser 26 are provided with respective closure elements (to start or stop dispensing) that are independent of each other.

[0026] The machine 1 comprises an agitator 4 made at least partly from ferromagnetic material, which is placed inside the vessel 2 and rotates about a mixing axis A for mixing the products being fed.

[0027] The machine 1 comprises an actuator 5 connected to the agitator 4 for rotating the agitator 4 about a mixing axis A.

[0028] Preferably, the actuator 5 is an electric motor.

[0029] The agitator 4 comprises a first part 4A made from a first ferromagnetic material.

[0030] Advantageously, ferromagnetic materials can be easily magnetized when subjected to a magnetic field.

[0031] In one embodiment, the first portion 4A is at least partially made from ferritic steel.

[0032] In one embodiment, the first portion 4A has an austenitic steel coating (which can increase the hygiene of the agitator 4, improving its durability and ease of cleaning).

[0033] The agitator 4 comprises a second part 4B made from a different material (eg a different metal) than the first ferromagnetic material.

[0034] The machine 1 is characterized in that it comprises an inductive element 6 .

[0035] The inductive element 6 comprises one or more winding conductors 7 for generating a magnetic field M when a current flows through them.

[0036] The induction element 6 is arranged outside the treatment vessel 2 so that the generated magnetic field M passes through at least a portion of the walls 2A, 2B of the treatment vessel 2 to reach the stirrer 4 and heat the stirrer 4 by magnetic induction.

[0037] Advantageously, heating by magnetic induction makes it possible to generate thermal processes of shorter duration compared to other heating methods, while at the same time ensuring greater precision in the provision of heat power (based on the product being treated).

[0038] Advantageously, magnetic induction heating reduces heating transients, allowing the product being processed to be brought to a predetermined temperature more quickly.

[0039] In other words, this allows the heating of the machine 1 to be turned on and off very quickly.

[0040] Advantageously, heating by magnetic induction makes it possible to ensure a high power density in a particularly compact and reduced-sized system compared to conventional heating systems with an evaporator and a circuit through which a heat exchange fluid flows.

[0041] 3, the mixing axis A is vertical and the wall 2A defines a bottom 2A' of the container 2. The inductive element 6 is arranged outside the bottom 2A' of the container 2.

[0042] In the embodiment shown in Figure 2, the mixing axis A is horizontal and the wall 2A defines the rear part 2A'' of the vessel 2. The guide element 6 is arranged outside the rear part 2A'' of the treatment vessel 2 and opposite the outlet 3.

[0043] The inductive element 6 can be a simple single winding coil or a solenoid coil.

[0044] In one embodiment, the inductive element 6 is embodied in the form of a plate wrapped with a conductor 7 .

[0045] In one embodiment, the inductive element 6 comprises a ferrite core.

[0046] In this embodiment, the conductor 7 is wound around a ferrite core.

[0047] In one embodiment, the conductor 7 is wound to form one or more coils.

[0048] The conductor 7 is an electrical cable made from a material with low electrical resistivity, such as copper or steel.

[0049] The conductor 7 allows energy to be transferred through the wall of the vessel 2 to reach the stirrer 4 via an (alternating) electromagnetic field M.

[0050] When a conductive component, for example a ferromagnetic material (in this case the part 4A of the stirrer 4), is placed in the magnetic field M, it absorbs energy in the form of an induced current.

[0051] The induced currents, also called eddy currents, generate heat at the surface of the ferromagnetic part 4A due to the electrical resistance of the material (thereby resulting in the so-called Joule effect).

[0052] In other words, the current flows through the conductor 7 and generates an electromagnetic field M capable of generating induced currents in the agitator 4, which are converted into heat by the Joule effect.

[0053] Heating occurs in the ferromagnetic part 4A of the stirrer 4.

[0054] Advantageously, machines using magnetic induction heating are guaranteed to be particularly safe, as the electromagnetic field only affects the ferromagnetic parts of the stirrer and remains limited to its surface.

[0055] Furthermore, machines using magnetic induction heating are very effective and efficient in that they have particularly high heat transfer performance during heating.

[0056] Advantageously, the walls of the container 2 (e.g. walls 2A, 2B) remain cool and unaffected by the heating process, thus avoiding the risk of localized scorching of the food in the container. Indeed, it should be taken into account that the heating element, i.e. the agitator 4, continues to rotate during heating. This prevents the product from sticking to it, thereby reducing or mitigating the risk of localized scorching of the food.

[0057] The part 4A of the stirrer 4, which is heated by magnetic induction due to the magnetic field M, is immersed in the product to be heat-treated and thus causes the product to be heated.

[0058] Advantageously, heat is generated directly inside the container 2, with no heat loss to the surrounding external space.

[0059] Advantageously, heating by induction is a particularly efficient and rapid method for reaching the required heat intensity.

[0060] Advantageously, making the thermal process more efficient and faster leads to energy savings, which allows for reduced consumption.

[0061] Furthermore, heating by induction is particularly precise and makes it possible to obtain the required temperature profile.

[0062] The machine 1 comprises a control unit 10 .

[0063] The control unit 10 is configured to control and drive the actuator 5 .

[0064] Advantageously, the control unit 10 allows the heat treatment process to be automated.

[0065] Advantageously, automating the process facilitates repeatability of the thermal process cycle.

[0066] The control unit 10 is configured to simultaneously activate the inductive element 6 and the actuator 5 to rotate the agitator 4 while it is being heated.

[0067] Advantageously, by heating and simultaneously moving the agitator 4, it is possible to heat treat the product uniformly without the risk of overheating parts of the vessel 2 and burning the final product in contact with the heated parts, thus compromising the overall quality.

[0068] The machine 1 comprises a power conditioning unit 11 .

[0069] The power conditioning unit 11 is driven by the control unit 10 .

[0070] Unit 11 functions as a variable frequency voltage generator, which converts the fixed voltage of the mains power line into an AC voltage of the required frequency.

[0071] A power conditioning unit 11 is connected to the inductive element 6 in order to supply power to the conductor 7 in particular.

[0072] The power conditioning unit 11 is arranged to supply power to the conductor 7 at a constant effective voltage.

[0073] The power conditioning unit 11 includes an inverter 11A.

[0074] The inverter 11A is suitably configured to adjust the frequency of the voltage supplied to the conductor 7 in response to commands received from the control unit 10 .

[0075] The inverter 11A therefore makes it possible to vary the power transfer by adjusting the frequency of the supply voltage (which makes it possible to vary the current flowing through the conductor 7 of the inductive element 6).

[0076] The power conditioning unit 11 includes an AC-DC voltage conversion module 11B.

[0077] The conversion module 11B is connected to the main power line by a connector 13 .

[0078] The module 11B is connected to the input of the inverter 11A and supplies a DC voltage to the inverter 11A.

[0079] The conditioning unit 11 is configured to deliver power to the conductors 7 according to a number of different power levels.

[0080] Advantageously, adjusting the power according to different levels increases the precision and flexibility of the machine and ensures that the product is processed at an optimum temperature.

[0081] Advantageously, ensuring an optimum temperature is a particularly important aspect, especially for processes used in the production of bread and confectionery products.

[0082] In one embodiment, the power conditioning unit 11 can provide power between 5 and 30 levels, preferably between 10 and 20 levels.

[0083] According to one aspect, at least one of the power levels includes transmitting power in a pulsed mode.

[0084] In other words, at low power levels the system operates intermittently, powering on and off.

[0085] Advantageously, the pulsed mode further contributes to improving the energy efficiency of the machine.

[0086] In one embodiment, power levels numbering from 3 to 5 constitute levels in pulse mode.

[0087] According to one aspect, at least one of the power levels includes a booster mode.

[0088] Preferably, the booster mode operates at the most recent power level.

[0089] Booster mode is an operating mode that allows the inductive element 6 to absorb its rated maximum power (preferably between 2 kW and 9 kW) for a predetermined time interval.

[0090] In one embodiment, the machine 1 comprises a user interface 12 connected to the control unit 10 .

[0091] The user interface 12 is configured to allow selection of one of the power levels.

[0092] Therefore, the user interface 12 is provided with controls (physical or touch buttons or selectors) to allow the power level to be selected.

[0093] In one embodiment, the machine 1 comprises a first temperature sensor 32 located inside the vessel 2 and in communication with the control unit 10 .

[0094] Advantageously, having a sensor 32 in the vessel 2 makes it possible to measure the temperature of the product being processed.

[0095] In one embodiment, the machine 1 comprises a second temperature sensor 34 located on the agitator 4 and in communication with the control unit 10 .

[0096] Advantageously, having a sensor 34 on the agitator 4 makes it possible to measure the temperature of the agitator and therefore to sense the state of the induction element 6 and thereby to obtain a measure of the intensity of the induction heating that is occurring.

[0097] Advantageously, having both sensors 32 and 34 allows for overall control of the ongoing thermal process, making it possible to obtain measurements of the power transfer between the inductive element 6 and the agitator 4 and to obtain the required temperature profile for the product being processed.

[0098] In the embodiment shown for example in Figure 2 or 3, the machine 1 comprises a cooling system 15 comprising a closed circuit 16 arranged to circulate a heat exchange fluid.

[0099] The cooling system 15 is optional and its presence makes it possible to cool the food product during processing in the container 2.

[0100] Advantageously, it is possible to alternate between cycles in which the product is heated (by induction) and cycles in which the product is cooled (by activating the cooling system).

[0101] Preferably, the cooling system 15 comprises an evaporator 17 , a compressor 18 , a condenser 19 and a throttling element 20 .

[0102] The cooling system 15 , and in particular the compressor 18 , is activated and controlled by the control unit 10 .

[0103] The evaporator 17 associated with the vessel 2 preferably includes a coil to facilitate heat exchange between the heat exchange fluid and the vessel 2 .

[0104] The throttling element 20 is defined by at least one constricted portion of the circuit 16 or at least one valve configured to create a head loss in the heat exchange fluid, thereby reducing its pressure.

[0105] Condenser 19 is preferably an air-cooled condenser.

[0106] The heat exchange fluid flows through the compressor 18, the evaporator 17, the throttling element 20 and the condenser 19 in that order.

[0107] The present disclosure is also directed to a method for processing liquid or semi-liquid food products, comprising the step of providing a machine 1 according to at least one of the aforementioned features.

[0108] The method comprises at least Passing an alternating current through the conductor 7; generating a magnetic field M passing through the wall of the container 2; and heating the stirrer (4) with an electric current generated by the magnetic field (M) so as to heat the liquid or semi-liquid food by the stirrer (4).

[0109] Advantageously, magnetic induction heating provides optimal control of the temperature at which the process is carried out.

[0110] Advantageously, temperature control and uniform heating improve the quality of the final product.

[0111] The method includes the steps of heating the agitator 4 and simultaneously driving the agitator 4 .

[0112] Advantageously, heating the product and running the agitator simultaneously allows the product to be heat treated uniformly without the risk of overheating part of the vessel and burning the final product in contact with the heated part, thus compromising its overall quality.

[0113] In one embodiment, generating a magnetic field that flows through the wall of the container 2 comprises generating a pulsed magnetic field.

[0114] Advantageously, the pulsed mode further contributes to improving the energy efficiency of the machine.

[0115] Advantageously, making the process more efficient and reducing power consumption can reduce the environmental impact associated therewith.

Claims

1. A machine (1) for processing liquid or semi-liquid food products, comprising: a processing vessel (2) for processing liquid or semi-liquid food products, the processing vessel (2) having walls (2A, 2B) and an outlet (3); an agitator (4) made at least in part from a ferromagnetic material and arranged inside the treatment vessel (2), the agitator (4) rotating about a mixing axis (A) for mixing the food product being fed; an actuator (5) connected to the agitator (4) to rotate the agitator (4) around the mixing shaft (A); The machine (1) comprises an inductive element (6) comprising one or more winding conductors (7) for generating a magnetic field (M) when a current flows through the one or more winding conductors (7), The induction element (6) is arranged outside the treatment vessel (2) so that the generated magnetic field (M) passes through at least a part of the walls (2A, 2B) of the treatment vessel (2) to reach the agitator (4) and cause heating by magnetic induction.

2. 2. The machine (1) according to claim 1, wherein the mixing axis (A) is vertical and the induction element (6) is arranged outside the bottom (2A') of the treatment vessel (2).

3. 2. The machine (1) according to claim 1, wherein the mixing shaft (A) is horizontal and the induction element (6) is arranged outside the rear part (2A'') of the treatment vessel (2), opposite the outlet (3).

4. 4. The machine (1) according to any one of claims 1 to 3, wherein the agitator (4) comprises a first part (4A) made from a first ferromagnetic material and a second part (4B) made from a different material.

5. 5. The machine (1) according to claim 4, wherein the first part (4A) of the agitator (4) is made at least partly from ferritic steel.

6. 5. The machine (1) according to claim 4, wherein the first part (4A) of the agitator (4) has an austenitic steel coating.

7. Machine (1) according to any one of claims 1 to 3, wherein the inductive element (6) is made in the form of a plate.

8. 4. The machine (1) according to any one of claims 1 to 3, comprising a control unit (10) and a power conditioning unit (11) driven by the control unit (10) and connected to the inductive element (6) to supply power to the conductor (7).

9. 9. The machine (1) according to claim 8, wherein the power conditioning unit (11) comprises an inverter (11A) configured to adjust the frequency of the voltage on the conductor (7) in response to commands received from the control unit (10).

10. 10. The machine (1) according to claim 9, wherein the power conditioning unit (11) comprises an AC-DC voltage conversion module (11B) connected to the input of the inverter (11A) to supply a DC voltage to the inverter (11A).

11. 9. The machine (1) according to claim 8, wherein the power conditioning unit (11) is configured to supply power to the conductors (7) at a constant effective voltage.

12. 9. The machine (1) according to claim 8, wherein the power conditioning unit (11) is configured to supply power to the conductors (7) according to a plurality of different power levels, at least one of the plurality of power levels comprising transmitting power in a pulsed mode.

13. The machine (1) of claim 12, wherein at least one of the plurality of power levels includes a booster mode.

14. 13. The machine (1) according to claim 12, comprising a user interface (12) connected to the control unit (10) and configured to enable selection of one of the plurality of power levels.

15. 4. The machine (1) according to any one of claims 1 to 3, comprising a cooling system (15) having a closed circuit (16) configured so that a heat exchange fluid flows through a compressor (18), an evaporator (17) associated with the treatment vessel (2), a throttling element (20) and a condenser (19) in this order.

16. 4. A method for processing liquid or semi-liquid food products, comprising the steps of providing a machine according to any one of claims 1 to 3, further comprising: Passing an alternating current through the conductor (7); generating a magnetic field (M) passing through the wall (2) of the treatment vessel (2); and heating said stirrer (4) with an electric current generated by said magnetic field (M) to heat said liquid or semi-liquid food product by said stirrer (4).

17. 17. The method according to claim 16, comprising the step of driving the agitator (4) simultaneously with the step of heating the agitator (4).

18. 17. The method of claim 16, wherein generating a magnetic field (M) flowing through the walls (2A, 2B) of the treatment vessel (2) comprises generating a pulsed magnetic field.

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