Apparatus and method for heating food

Abstract

The device (1) for heating and optionally cooking a food product (14) comprises a forming tube (2), a filling slide (8) guided in the forming tube, a first cap (15) associated with the filling slide and a second cap (18), the two caps (15, 18) each having concave surfaces (16, 21) facing each other and defining a cavity (33) therebetween, the food product can be fed into the cavity (33) by the filling slide, the device (1) being configured for heating the food product by means of a heating device (27). The device (1) comprises an air valve (22) in the second cap. Furthermore, a corresponding method for heating the food product.

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for heating food, preferably to at least partially cook the food. Summary of the Invention

[0002] Devices for ohmic heating or cooking food by passing an electric current through electrically conductive food are already known, for example, from U.S. Pat. No. 3,167,000 or U.S. Pat. No. 4,642,847. WO 00 / 76330 A1 describes a system for the continuous production of food products. A method for treating food by ohmic heating arises from European Patent No. 3,032,956 B1. European Patent No. 2,895,014 B1 discloses a device for pasteurizing food masses by applying an electric current having a frequency in the range of 10 MHz to 50 MHz. In that device, convexly curved electrodes are used. As an alternative to ohmic heating, food may be heated by supplying energy by thermal conduction or electromagnetic radiation.

[0003] While conventional devices and methods have the advantage that food can be heated or cooked relatively evenly and homogeneously without localized excessive heating or burning, the performance of conventional devices and methods is also limited.

[0004] It is an object of the present invention to provide an apparatus and method for heating food that allows for higher productivity compared to conventional apparatus and methods.

[0005] This object is met by an apparatus having the features of claim 1 or by a method for heating foodstuffs having the features of claim 9. Advantageous further developments of the invention are set out in the dependent claims.

[0006] The device according to the invention and the method according to the invention are particularly suitable for heating, and possibly also for cooking, pasty foods, such as sausage meat or pasta. When sausage meat is used as food, pre-cooked or already fully cooked sausage products, for example hot dog sausages or so-called Vienna sausages, can be produced during processing by the device or method according to the invention.

[0007] The forming tube used in the apparatus does not necessarily have to have a circular cylindrical shape. The forming tube may have a circular internal cross section, but may also have other shapes, for example, oval, square, polygonal, etc. The forming tube must furthermore be sufficiently heat-resistant, i.e., made from a non-conductive or generally non-conductive material that must easily withstand temperatures of, for example, 80°C, preferably 100°C, or more preferably at least 120°C.

[0008] The formed tube must be mechanically strong enough to withstand relatively high internal pressures without deformation, which can be achieved by a suitable wall thickness, for example, of at least 0.5 cm, preferably at least 1 cm, more preferably at least 1.5 cm.

[0009] The forming tube may comprise a partially or entirely transparent material (e.g., a window). This has the advantage that the process of the food product, particularly the visual changes, can be recognized or monitored visually or with a vision system as the food product is heated. In addition to or as an alternative to a transparent material, the forming tube may at least partially comprise a ceramic material. From the viewpoint of the food product, it is advantageous if the material of the forming tube is wear-resistant and / or has a non-stick effect.

[0010] The filling slide is guided so that it can move within the forming tube. This filling slide is shaped so that, in theory, its outer cross section fits the inner cross section of the forming tube, but is slightly smaller. The filling slide may be hollow and thus be part of a line for feeding the food product into the cavity. In this form, the filling slide may be called a filling tube.

[0011] The device is provided with two caps, one associated with the filler slide and one opposite the filler slide, into which a food product can be received. Both caps have opposing concave surfaces that define a cavity therebetween for receiving the food product. By "concave" here, it is meant that at least a portion of the surface of each cap facing the cavity is concave, but the entire surface of the cap facing the cavity may also be concave. Such a concave surface has been found to be favorable for the subsequent shape of the finished food product and for the heat input to the food product.

[0012] According to the invention, the device comprises an air valve in the second cap. As will become clear from the following description, this measure has proven to be very advantageous in terms of the particularly high productivity of the device according to the invention. "Air valve" means that air can pass through the valve. "In the second cap" in the context of the invention means that the air valve can be located in, at or next to the second cap, but in each case on the side of the cavity located opposite the filling slide.

[0013] The cavity formed between the caps may be evacuated, preferably by means of an air valve, i.e. a negative pressure may be generated in the cavity compared to normal pressure. For this purpose, the device may comprise or be connected to a vacuum source or vacuum pump in order to be able to cause evacuation by means of the air valve.

[0014] The device may be configured to generate a negative pressure in the cavity of, for example, 500 mbar, preferably 200 mbar, or even 100 mbar or less.

[0015] Before the food product is introduced into the cavity via the fill slide, evacuation of the cavity is at least partially, but preferably completely, completed via the air valve. This provides the advantages of, first, allowing the food product to be filled into the cavity more quickly than if it were filled against the normal pressure prevailing in the cavity. Second, lower back pressure in the cavity reduces the energy requirements for filling. Third, the risk of undesirable air being mixed into the food product when it is filled is reduced.

[0016] The device may be configured to apply a voltage between the first and second caps, resulting in a current flowing through the food placed between the caps. To this end, the two caps are preferably configured as electrodes, and the device, such as a heating device, includes its own power source or a connection to an external power source. The device may also include a control device configured to apply a voltage between the two electrodes for a certain time or over a certain time interval. Needless to say, the food must be electrically conductive in order to be heatable when a current is applied to it.

[0017] Copper alloys have been found to be particularly effective as materials for the electrodes. At least the surface of the electrode facing the cavity may optionally be coated with a silver layer to improve electrical conductivity and to prevent corrosion, the silver coating preferably having a thickness of 5 to 20 micrometers.

[0018] As an alternative to, or in addition to, ohmic heating, the device may be configured to heat or possibly cook food using electromagnetic radiation. In this embodiment, for example, a microwave generator may be provided as the heating device of the device, and food placed in the cavity may be exposed to microwaves generated by the microwave generator.

[0019] Additionally or alternatively, the apparatus may be configured to heat the food product by thermal conduction. In this configuration, a heating device may be provided to initially heat the forming tube before the forming tube transfers heat to the food product placed in the cavity, for example, because the heating device comprises a heating cartridge embedded in the forming tube or a heating liquid bath containing the forming tube.

[0020] It is contemplated that compressed air may be supplied to the cavity formed between the caps via an air valve. To this end, the device may be equipped with or connectable to a compressed air source. The supply of compressed air to the cavity may assist and significantly simplify the removal or ejection of the finished processed food product on the other side of the air valve, or may be used to clean the forming tube.

[0021] An embodiment in which the cavity between the caps can be evacuated via an air valve and air can be supplied to this cavity under normal pressure for ventilation, or compressed air can be supplied, is particularly preferred. In this embodiment, the air valve therefore has a dual function. If either air under normal pressure or compressed air can be supplied, the air valve has a triple function. Ventilation can already provide the advantage of avoiding deformation of the food product when the filling slide is retracted.

[0022] From a design standpoint, it has been found advantageous to configure the air valve as a conical valve, which can withstand the required pressure, is small, and can therefore be installed at least partially in a molded pipe if desired. Furthermore, the conical valve allows for precise actuation and reliable closure.

[0023] The construction of the device is particularly simple if the air valve is constructed integrally with the second cap. This means that the valve seat (but not the valve body, which can of course be moved relative to it) is formed integrally with the second cap. In this way, the number of components of the device is reduced.

[0024] It has proven advantageous for the second cap to be arranged fixedly relative to the forming tube, in this way the second cap may be particularly firmly fixed and can act as a counter-bearing for the discharge pressure, in particular when the treated food is discharged.

[0025] In an alternative embodiment, the second cap is mounted for movement relative to the forming tube, allowing the second cap (which may optionally be configured as a second electrode) to be displaced relative to the forming tube to form an opening in the cavity through which the food product can be ejected after it has been heated.

[0026] The filling slide can preferably be moved completely out of the forming tube. This allows the processed food product to be discharged through the same opening that the filling slide can be inserted into the forming tube. The filling slide is conveniently guided or mounted in a position where it is moved completely out of the forming tube so as to ensure that it maintains or reassumes axial alignment with the forming tube, so that it can be relatively quickly and safely returned after the food product has been discharged so that it can be reintroduced into the forming tube.

[0027] In one advantageous embodiment, the fill slide is equipped with a fill valve that is shut off and only opens when food product is being filled into the cavity by the fill slide, the shutoff making it possible to ensure that a predetermined maximum volume of food product is always filled into the cavity.

[0028] It is conceivable that the fill slide may be configured as a hollow fill tube. Alternatively, the fill slide may have a generally U-shaped cross section with a fill groove on the outside of the fill slide. However, a hollow fill tube configuration has the advantage that it is easier to shut off.

[0029] The device may comprise a collet. The collet may be attached to, for example, the forming tube, and the filling slide may be temporarily attached or clamped inside the collet. For this purpose, the collet may comprise two clamping jaws that are movable relative to each other. This provides the advantage that the filling slide can be at least temporarily attached in a fixed manner to the forming tube while the food product is being heated. This prevents premature outward movement of the filling slide due to internal pressure of the food product and destruction of the food product during processing.

[0030] It is particularly preferred that the collet is configured to be electrically conductive. This allows, for example, if the food product is to be heated by ohmic heating, to supply current to a first cap configured as an electrode and provided on the filling slide. The collet may be used for localized transmission of electricity and heat (heating integrated into the clamping jaws) to the cap (electrode) of the filling slide. Positioning and holding of the filling slide may be performed or assisted by an actuatable external mechanical stop.

[0031] The apparatus may further include an ejector. The ejector may be configured in a rod shape. The ejector may be used to push the food product out of the forming tube after the food product has been heated and both the first cap and the second cap have been removed from the forming tube. The ejector may optionally include a flexible cleaning lip for mechanically cleaning the inner wall of the forming tube as the food product is ejected from the forming tube.

[0032] In the method according to the invention for heating, and possibly cooking or boiling, food, the food is filled into the cavity of the forming tube by means of a filling slide and then heated globally or at least locally. This method can be carried out by means of one of the device variants described above. According to the invention, the cavity is evacuated via an air valve before the food is filled into the cavity, i.e., a negative pressure is generated in the cavity compared to normal pressure. This makes it easier to fill the food and reduces the energy demands due to lower resistance, while at the same time preventing or at least significantly reducing the undesirable mixing of air into the food and the possible formation of steam bubbles.

[0033] The filling slide is preferably displaced within the forming tube while the cavity is being filled with food. This displacement is caused by the filling pressure of the food being filled into the cavity, i.e., a kind of recoil effect. To avoid the stick-slip phenomenon, the movement of the filling slide may be regulated by a throttle valve. The advantage of displacing the filling slide during cavity filling is that the cavity can be kept relatively small initially and thus can be evacuated quickly, which increases productivity.

[0034] It has been found to be advantageous to apply a relatively high filling pressure to the food product filled into the cavity, at least 10 bar, preferably even at least 15 bar, and more preferably in the range of 15 bar to 25 bar. These pressures allow the cavity to be filled quickly and the filling slide to be pushed out of the forming tube. In embodiments, this pushing is possible without the need for an active drive to displace the filling slide out of the forming tube.

[0035] Preferably, the filler slide can be moved completely out of the forming tube so that the food product can be released from the forming tube. In this way, the filler slide in a sense frees an opening through which the food product can be released after heating.

[0036] The ejection, or so to speak, of the food product from the forming tube can be achieved or at least assisted by supplying compressed air to the cavity. By avoiding mechanical components for ejection or ejection, the device is less complex and easier to clean.

[0037] It is particularly preferred that the compressed air used for ejection is supplied to the cavity via the air valve used for exhaust, which therefore has the dual function of not only exhausting but also assisting in the ejection of the food product from the cavity.

[0038] In one embodiment, a collet may be provided to at least temporarily secure the filler slide in position while the food product is heated. The collet may optionally be electrically conductive and thus may be used to supply electrical current to and through the food product to heat it by ohmic heating.

[0039] In one variant of the method, for example, a rod-shaped ejector is used to mechanically extrude the heated food product from the forming tube. In this case, it is advantageous for the two caps to be removed from the forming tube prior to the extrusion process. The ejector may optionally be equipped with a flexible cleaning lip for mechanically cleaning the inner wall of the forming tube as the food product is extruded.

[0040] As already mentioned in the introduction, the food product may for example be a pasty mass or a so-called forcemeat, such as dough or sausage meat.

[0041] The voltage used between the two electrodes in the device according to the invention and in the method according to the invention in the case of ohmic heating is preferably in the range of 150 V to 650 V. The amperage during the treatment of the food product may reach a value of, for example, 1 to 5 A, and the power during heating may be 0.5 to 2.5 kW, preferably 1 to 1.5 kW. A duration of, for example, 10 s to 45 s for the treatment of the food product by ohmic heating has proven to be suitable. The optimum value depends, for example, on the type of food product and, if applicable, on its concentration and / or moisture content.

[0042] In this respect, it should be noted that all features described in the context of an apparatus also apply to the method according to the invention and its variants, and conversely, features described in the context of a method may also apply to an apparatus.

[0043] Advantageous embodiments of the invention are explained in more detail below with reference to the drawings. [Brief explanation of the drawings]

[0044] [Figure 1] 1 is a schematic diagram showing the essential components of a first embodiment of a device according to the invention; FIG. [Figure 2] FIG. 2 shows the embodiment of FIG. 1 in a first state. [Figure 3] 2 shows the embodiment of FIG. 1 in a second state. [Figure 4] FIG. 2 shows the embodiment of FIG. 1 in a third state. [Figure 5] FIG. 2 shows the embodiment of FIG. 1 in a fourth state. [Figure 6] FIG. 2 shows the embodiment of FIG. 1 in a fifth state. [Figure 7] FIG. 2 shows the embodiment of FIG. 1 in a sixth state. [Figure 8] FIG. 2 shows the embodiment of FIG. 1 in a seventh state. [Figure 9] FIG. 2 shows a second embodiment of the device according to the invention in a first state. [Figure 10] 10 shows the embodiment of FIG. 9 in a second state. [Figure 11] 10 shows the embodiment of FIG. 9 in a third state. Identical or corresponding components are given the same reference numerals throughout the figures. The components and parameters of the apparatus described below together allow for the greatest productivity gains when operating the apparatus, but may represent independent inventions individually or in any subcombination. DETAILED DESCRIPTION OF THE INVENTION

[0045] FIG. 1 shows a simplified schematic diagram of the individual components of various embodiments of a device 1 for heating food according to the present invention. The device 1 comprises a forming tube 2. The forming tube may have a substantially cylindrical outer surface 3 and may be made of a non-conductive material, in particular a transparent material such as Plexiglas, entirely or at least partially. It is also conceivable that the forming tube 2 is made of ceramic. The forming tube 2 has an interior 4 defined by an inner wall 5. In this embodiment, the central section of the interior 4 is also cylindrical, although the interior 4 may have any other cross-sectional shape. In this embodiment, the interior 4 may have a diameter of, for example, 0.5 cm to 4 cm, although larger diameters are also conceivable. The interior 4 comprises a first opening 6 and a second opening 7 at each end of the interior.

[0046] The filling slide 8 is movable relative to the forming tube 2 and is brought to be at least partially inserted into the interior 4 of the forming tube 2. The outer contour of the filling slide 8 is configured to fit the cross-section of the interior 4 of the forming tube, but is preferably sized minimally smaller than the cross-section of the interior 4 in order to seal the interior 4 at the first opening 6, yet still be able to move relatively easily within the interior 4. Thus, in this embodiment, the outer contour 9 of the filling slide 8 may be circular.

[0047] In this embodiment, the filling slide 8 is configured as a filling tube, i.e., a line 10 that is internal to the filling slide and is closed at its distal end (left in FIG. 1 ) by a filling valve 11, configured in the present invention, for example, as a conical valve. The filling slide 8 communicates with a reservoir 13 that receives the food product 14 to be heated, for example via a flexible supply line 12, shown diagrammatically. The food product 14 may be in the form of a paste, for example dough or sausage meat. The food product 14 can be transported to the filling slide 8 via the supply line using a suitable transport device, such as a pump (not shown).

[0048] The filling slide 8 comprises a first cap 15 at the distal end (to the left in FIG. 1 ) of the filling slide. The cap 15 comprises a concave surface 16 facing towards the interior 4. The opening of the filling valve 11 is located approximately in the center of the concave surface 16.

[0049] The forming tube 2 comprises a step 17 in the region of the second opening 7. A second cap 18 having a cap body 19 can be inserted into the step 17. The cap body 19 comprises a flange 20 which can be inserted into the step 17. The second cap 18 comprises a concave surface 21 facing towards the interior 4 of the forming tube 2 or towards the concave surface 16 of the filling slide 8, respectively.

[0050] A valve element 23 forming the air valve 22 of the second cap 18 is movably mounted within the cap body 19. In this embodiment, the air valve 22 is configured as a conical valve, with the air valve opening located approximately in the center of the concave surface 21 of the second cap 18. An air line 24 connects the air valve 22 to a vacuum source 25, such as a vacuum pump.

[0051] A collet 26 is arranged in the forming tube 2 in the region of the first opening 6. The collet 26 comprises two clamping jaws 26a, 26b which are movable relative to one another between an open position and a clamping position. In the open position, the spacing between the clamping jaws 26a, 26b is large enough to allow the filling slide 8 to pass between the clamping jaws 26a, 26b.

[0052] As a further component, the apparatus 1 includes a heating device 27, which can be connected to a control device 28 of the apparatus 1. The heating device 27 is used to provide energy for heating the food product 14 placed in the forming tube 2. For this purpose, the heating device 27 can be configured in various ways. For example, the heating device can be a microwave generator that generates microwave radiation 29 and directs the microwave radiation toward the food product 14 placed in the forming tube 2. Alternatively, the heating device can be or include a liquid bath in which the forming tube 2 is embedded for heat absorption, and / or the heating device 27 can include an electrical resistance element that abuts the forming tube 2 or that can be embedded in the wall of the forming tube 2. In a further embodiment, the heating device 27 can have or include a power source and be configured to ohmically heat the food product placed in the forming tube 2, as described herein below. In this embodiment, the first cap 15 and the second cap 18 are configured as a first electrode and a second electrode, respectively, i.e., made of an electrically conductive material. The concave surfaces 16, 21 of the first and second electrodes 15, 18 may optionally be provided with a coating made, for example, of silver. In this embodiment, the collet 26 and the filling slide 8 are also preferably conductive or made of a conductive material, and a power line 30 extends from the heating device 27 to the second cap 18 or collet 26, respectively.

[0053] As a further component, the device disposes of a generally rod-shaped ejector 31. The ejector comprises a ring-shaped cleaning lip 32 formed from a flexible material. The cleaning lip 32 is sized to enable the ejector 31 to mechanically clean the inner wall 5 of the interior 4 of the forming tube 2 when it is pushed from right to left through the interior 4.

[0054] For clarity, some components of the device 1 are no longer shown in Figure 2. The device 1 is in a first state. The filling slide 8 is inserted as far as possible into the interior 4 of the forming tube 2. The collet 26 is placed in its open position. The second cap 18 is inserted into the step 17 in the second opening 7 of the forming tube 2. The first cap 15 and the second cap 18 are in contact with each other or spaced a minimum distance from each other. The concave surfaces 16, 21 of the two caps 15, 18 form a cavity 33 between the two caps 15, 18.

[0055] The air valve 22 is in its open position, with the valve element 23 retracted towards the left. A vacuum source 25 ensures, via air line 24, that the cavity 33 is evacuated through the air valve 22. The air pressure in the cavity 33 can be reduced to a value below 500 mbar, preferably below 200 mbar, or even below 100 mbar.

[0056] Figure 3 shows the device 1 in a second state. Starting from the first state shown in Figure 2, the valve element 23 of the air valve 22, which is configured as a conical valve, has been moved to the right into its valve seat, so that the air valve 22 is closed. This completes the evacuation of the cavity 33. This has the advantage that the subsequent filling of the cavity 33 with the food product 14 is countered by significantly less resistance, as well as reducing the risk that any air contained in the cavity 33 as it is filled will mix with the food product 14 and form undesirable bubbles therein that could potentially burst and destroy the food product when it is heated or cooked.

[0057] FIG. 4 shows the device 1 in a third state, i.e., at the start of filling the cavity 33 with food. In this state, the filling valve 11 is open. The (generally pasty) food 14 is delivered from the reservoir 13 via the supply line 12 to the filling slide 8. The food 14 is filled into the line 10 inside the filling slide 8 under very high pressure, for example, between 10 and 25 bar, and passes through the filling valve 11 into the cavity 33. The internal pressure of the food 14 in the cavity 33 acts as a driving force for the filling slide 8, moving it to the right-hand side. This is because the first cap 18 is attached more firmly to the forming tube 2 than the filling slide 8. This can be seen in FIG. 4, where a (small) space is already formed between the first cap 15 and the second cap 18. Naturally, the cavity 33 is no longer empty once filling with the food 14 begins; it can even (and generally will) be completely filled with the food 14. Whether the space between the two caps 15, 18 is wholly or partly filled, the term "cavity" 33 in the context of the present invention is used for reasons of consistency.

[0058] 5 shows the device 1 in a fourth state in which the cavity 33 has been completely filled with the food product 14. The entire space between the first cap 15 and the second cap 18 is filled with the food product 14.

[0059] The fill valve 11 of the fill slide 8 is shut off. The clamping jaws 26a, 26b of the collet 26 are in a closed position. In the closed position, the clamping jaws 26a, 26b of the collet 26 clamp the fill slide 8 between them, so that the fill slide is fixedly attached to the forming tube 2.

[0060] In this state, heating of the food product 14 can be performed. As explained above, the heating device 27 is used to supply heat to the portion of the food product 14 contained in the cavity 33. This can be done by thermal conduction through the forming tube 2, by supplying electromagnetic radiation, e.g., microwave radiation 29, or by ohmic heating, in which a voltage is applied via the collet 26 and the conductive filler slide 8 between the first cap 15 and the second cap 18 configured as electrodes. The current flows through the food product 14, which is also electrically conductive, and is converted into heat by the electrical resistance of the food product 14, which heats the food product 14 at least locally, and preferably globally and uniformly. By "heating" is meant that the temperature of the food product increases, e.g., by at least 5°C, thereby optionally cooking the food product 14. The voltage between the two caps 15, 18 configured as electrodes may be, e.g., 150V to 650V, and may be applied for, e.g., 5 to 45 seconds.

[0061] Figure 6 shows the apparatus in a fifth state. Starting from the state shown in Figure 5, the collet 26 has assumed its open position. The filler slide 8 has been moved towards the right-hand side and completely removed from the forming tube 2. The assembly including the second cap 18 has also been moved out of the step 17 and completely removed from the forming tube 2. The heated food product 14 is still positioned in the interior 4 of the forming tube 2. The shape of each end of the food product 14 is defined by or corresponds to the shape of the concave surfaces 16, 21 of the caps 15, 18, respectively.

[0062] 7 shows the apparatus 1 in a sixth state. Once the assembly including the fill slide 8 and second cap 18 has been removed from the forming tube 2, the forming tube 2 has been moved out of alignment 34 with the fill slide 8 and second cap 18. One option for doing this is to mount the forming tube 2 on a guide 35 and offset it along the guide relative to the fill slide 8. Another option is to place the forming tube 2 (or multiple such forming tubes 2) on a carrier 36, for example a rotating drum 36, and use the carrier 36 to move it out of alignment 34. Another option is to keep the forming tube 2 stationary while moving the assembly including the form slide 8 and second cap 18.

[0063] The interior 4 of the forming tube 2 is then aligned with the ejector 31. The ejector is inserted into the interior of the forming tube 2 through the first opening 6. As the ejector 31 is moved towards the left hand side, the cleaning lip 32 swipes along the inner wall 5 of the interior 4, thus cleaning the inner wall 5. The second opening 7 is free or open.

[0064] Figure 8 shows the device 1 in a seventh state. Starting from the state of Figure 7, the ejector 31 has been moved far enough through the interior 4 of the forming tube 2 that the cleaning lip 32 at the distal end of the ejector 31 leaves the second opening 7 of the forming tube 2. In this way, the heated (or cooked) food 14 is ejected or discharged from the forming tube 2. As a result, the device 1 or method, respectively, produces heated, pre-cooked or further cooked food, such as sausages, for example hot dog sausages, or (pre-)baked sticks from dough.

[0065] Following release of the food product 14, the device 1 returns again to the first state shown in Figure 2 and the cycle begins once again.

[0066] 9 shows a further embodiment of the device 1 according to the invention. As in the first embodiment, the cap body 19 including the second cap 18 is fixed relative to the forming tube 2. The cap body 19 may be rigidly attached to the forming tube 2 for this purpose.

[0067] As a further difference, air valve 22 may be connected via air line 24 to not only vacuum source 25 but also selectively to compressed air source 37. Instead of compressed air source 37, element 37 may simply be a connection to ambient air (normal pressure). Directional control valve 38 may be actuated by controller 28 to ensure that air valve 22 is always fluidly connected to only one of vacuum source 25 or compressed air source 37.

[0068] The filling and heating of the food product 14 is carried out similarly to the first embodiment, including the evacuation of the cavity 33 before the food product 14 is filled through the filling slide 8. Figure 9 shows the device 1 in a state where the heating of the food product 14 is completed and the filling slide 8 has been completely removed from the forming tube 2. Figure 10 shows the embodiment according to Figure 9 in a second state. Starting from the state shown in Figure 9, the air valve 22 is open and connected by the directional control valve 38 to a compressed air source 37 or ambient air under normal pressure. Thus, air or compressed air is directed into the cavity 33 by the air valve 22 of the second cap 18.

[0069] As shown in Figure 11, the compressed air ensures that the heated food 14 is expelled or discharged to the right-hand side from the forming tube 2. The second cap 18 or the cap body 19 of the second cap is fixedly connected to the forming tube 2 and therefore acts as a counter-bearing. At the same time, the compressed air can have a cleaning effect on the inner wall 5 of the interior 4.

[0070] Based on the illustrated and described embodiments, the device according to the invention and the method according to the invention can be modified in many ways. For example, in the second embodiment, it is considered that the compressed air source 37 and the directional control valve 38 may be omitted if ventilation of the cavity 33 by the air valve 22 at normal pressure is already sufficient to eject the food product 14 from the forming tube 2 as shown in FIG. 11. The air valve 22 may be formed integrally with the cap body 19, but this is not necessarily the case. For example, the air valve may be arranged on the wall of the forming tube 2, adjacent to the cap 18. At higher temperatures or longer treatment times, the product in the cavity 33 may be sterilized.

Claims

1. An apparatus (1) for heating food (14), comprising: a molded tube (2) made of a non-conductive material; a filling slide (8) guided so as to be movable within said forming tube (2); a first cap (15) associated with said filling slide (8); A second cap (18) and Equipped with the first cap and the second cap (15, 18) each have a concave surface (16, 21) facing each other and defining a cavity (33) therebetween; The food product (14) can be fed into the cavity (33) via the filling slide (8), the device (1) comprises a heating device (27) configured to heat the food product (14) placed in the cavity (33); In the apparatus (1), The second cap (18) is provided with an air valve (22); the cavity (33) formed between the caps (15, 18) can be evacuated via the air valve (22) by a vacuum source; Device (1).

2. 2. The device according to claim 1, characterized in that air under atmospheric pressure or compressed air can be supplied to the cavity (33) formed between the caps (15, 18) via the air valve (22).

3. 3. The device according to claim 1 or 2, characterized in that the air valve (22) is configured as a conical valve.

4. 3. The device according to claim 1 or 2, characterized in that the air valve (22) is formed integrally with the second cap (18).

5. 3. Device according to claim 1 or 2, characterized in that the second cap (18) is arranged stationary relative to the forming tube (2).

6. 3. Apparatus according to claim 1 or 2, characterized in that the filling slide (8) can be moved completely out of the forming tube (2).

7. 3. The device according to claim 1 or 2, characterized in that the first cap and the second cap (15, 18) are configured as electrodes, respectively, and the heating device (27) is configured to apply a voltage between the first cap and the second cap (15, 18).

8. A method for heating a food product (14), comprising filling the food product (14) into a cavity (33) defined by a first cap (15) and a second cap (18) each having a concave surface (16) facing each other via a filling slide (8) guided so as to be movable within a forming tube (2), and once the food product (14) has been filled into the cavity (33), the food product (14) disposed within the cavity (33) is at least locally heated by a heating device (27), characterized in that the cavity (33) is evacuated via an air valve (22) before the food product (14) is filled into the cavity (33).

9. 9. A method according to claim 8, characterized in that the filling slide (8) is moved within the forming tube (2) while the cavity (33) is filled with the food product (13).

10. 10. A method according to claim 8 or 9, characterized in that the filling pressure of the food product (14) filled into the cavity (33) is at least 10 bar.

11. 10. A method according to claim 8 or 9, characterized in that the filling slide (8) is moved completely out of the forming tube (2) for ejection of the food product (14) from the forming tube (2).

12. 10. The method according to claim 8 or 9, characterized in that the food product (14) is ejected from the forming tube (2) by supplying compressed air into the cavity (33) or with the aid of supplying compressed air into the cavity (33).

13. 10. The method according to claim 8 or 9, characterized in that the first cap and the second cap (15, 18) are configured as electrodes, respectively, and that a current is generated in the food product (14) by applying a voltage between the first cap and the second cap (15, 18).

14. 10. A method according to claim 8 or 9, characterized in that a collet (26) is provided to at least temporarily fix the filling slide (8) while the food product (14) is heated.

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