PEF COOKING DEVICE AND METHOD FOR CONFIGURING SAME

Abstract

A household PEF cooking appliance includes a container for food to be cooked, opposing outer PEF electrodes disposed in the container, and a partition variably disposed in the container between the outer PEF electrodes and oriented parallel to the outer PEF electrodes.

Claims

1-11. (canceled)

12. A household PEF cooking appliance, comprising: a container for food to be cooked; opposing outer PEF electrodes disposed in the container; and a partition variably disposed in the container between the outer PEF electrodes and oriented parallel to the outer PEF electrodes.

13. The household PEF cooking appliance of claim 12, wherein the outer PEF electrodes are immovably disposed in the container.

14. The household PEF cooking appliance of claim 12, wherein the partition includes a first strainer disposed in front of a first one of the outer PEF electrodes and a second strainer disposed in front of a second one of the outer PEF electrodes, at least one of the first and second strainers being spaced from an associated one of the first and second outer PEF electrodes at a distance which is variably settable.

15. The household PEF cooking appliance of claim 14, wherein the distance is settable manually or in a motorized manner.

16. The household PEF cooking appliance of claim 12, wherein the partition is a perforated plate, a wire mesh or a grid.

17. The household PEF cooking appliance of claim 12, further comprising a guide disposed parallel to the outer PEF electrodes in the container, said guide designed for insertion of the partition.

18. The household PEF cooking appliance of claim 17, wherein the partition is an electrically conductive partition which is inserted into the guide.

19. The household PEF cooking appliance of claim 18, wherein the electrically conductive partition is designed largely impervious or embodied as a strainer.

20. The household PEF cooking appliance of claim 17, wherein the guide is designed to electrically contact the partition inserted therein and selectively connectable to a PEF signal generator.

21. A method for configuring a household PEF cooking appliance which comprises a container for food to be cooked, opposing outer PEF electrodes disposed in the container, and strainers disposed in the container between the outer PEF electrodes and oriented parallel to the PEF electrodes, said method comprising increasing a distance of at least one of the strainers from an associated one of the outer PEF electrodes before or after the food to be cooked is placed in the container.

22. The method of claim 21, wherein the distance is settable manually or in a motorized manner.

23. A method for configuring a household PEF cooking appliance which comprises a container for food to be cooked, opposing outer PEF electrodes disposed in the container, and a partition disposed in the container between the outer PEF electrodes and oriented parallel to the PEF electrodes, said method comprising: inserting the partition into a guide disposed parallel to the outer PEF electrodes to delimit the container into useful subvolumes; and placing the food into one of the useful subvolumes of the container.

24. The method of claim 23, further comprising designing the partition as an electrically conductive partition for insertion into the guide.

25. The method of claim 23, further comprising designing the electrically conductive partition largely impervious or as a strainer.

26. The method of claim 23, further comprising: designing the guide to electrically contact the partition inserted therein; and selectively connecting the guide to a PEF signal generator.

Description

[0058] The properties, features and advantages of the invention, and the manner in which these are achieved, are clearer and easier to understand in the context of the following schematic description of an exemplary embodiment, which is explained in greater detail with reference to the drawings, in which:

[0059] FIG. 1 shows a simplified diagram of a PEF cooking appliance according to a first exemplary embodiment, with displaceable strainers installed in a container for food to be cooked, in a sectional side view;

[0060] FIG. 2 shows a strainer according to a first variant, in a side view;

[0061] FIG. 3 shows a section from the strainer according to the first variant, in a front view;

[0062] FIG. 4 shows a strainer according to a second variant, in a side view;

[0063] FIG. 5 shows the strainer according to the second variant, in a front view;

[0064] FIG. 6 shows a simplified diagram of a container for food to be cooked without partitions, in a sectional side view;

[0065] FIG. 7 shows a simplified diagram of a container for food to be cooked without partitions, filled with food to be cooked of a first type, in a sectional side view;

[0066] FIG. 8 shows a simplified diagram of a container for food to be cooked without partitions, filled with a food to be cooked in a first geometric arrangement, in a sectional side view;

[0067] FIG. 9 shows a simplified diagram of a container for food to be cooked, filled with a food to be cooked in the second geometric arrangement with a partition, in a sectional side view; and

[0068] FIG. 10 shows a simplified diagram of a PEF cooking appliance according to a second exemplary embodiment, with a plurality of partitions inserted into a container for food to be cooked, in a sectional side view.

[0069] FIG. 1 shows a simplified diagram of a PEF cooking appliance 1 in a sectional side view. The PEF cooking appliance 1 has a container for food to be cooked 2 with e.g. a rectangular periphery 3. A first outer PEF electrode 4a or a second outer PEF electrode 4b are immovably disposed at two opposing periphery sections (a left-hand side wall and a right-hand side wall here). The PEF electrodes 4a and 4b are designed in the form of plates and are oriented vertically. PEF signals PS can be applied to the PEF electrodes 4a, 4b by means of a PEF signal generator 5 in a manner which is known in principle. The PEF signal generator 5 can be activated by means of a control facility 18. The container for food to be cooked 2 is filled with water W and a food to be cooked G (in the form of a hotdog here).

[0070] The container for food to be cooked 2 additionally has a first partition in the form of a first strainer 6a which is disposed in front of the first PEF electrode 4a, and a second partition in the form of a second strainer 6b which is disposed in front of the second PEF electrode 4b. The strainers 6a and 6b are designed to be electrically non-conductive and are disposed parallel to the associated outer PEF electrodes 4a and 4b respectively. The strainers 6a, 6b are variably disposed, such that their distance a from the associated outer PEF electrode 4a or 4b can be variably set, e.g. manually or in a motorized manner, as indicated by the dual-headed arrows. The two distances a can be identical or different in this case.

[0071] This embodiment variant is based on the idea that during the preparation of food to be cooked G in PEF cooking appliances 1, the food to be cooked G is immersed in water W (having higher or lower salt content) between the outer PEF electrodes 4a and 4b respectively. Upon application of the PEF signals PS, current is introduced into the water W via these PEF electrodes 4a, 4b and conducted through the food to be cooked G. In practical use, two problems are presented here: if a user (e.g. in a moment of inattention) forgets an item of cutlery such as a spoon, a fork, a skewer or any other part made from highly electrically conductive material in the container for food to be cooked 2, this can result in a short circuit between the two PEF electrodes 4a and 4b respectively. The short circuit depends on the random position of this foreign body. It may therefore be that this foreign body is not initially detected when checking for a short circuit. This means that the short circuit might only occur during the preparation. Since very high voltages and therefore very high currents can typically occur, it must be anticipated that this short circuit could result in considerable noise emission, water W spurting out of the container for food to be cooked 2, and/or that the short circuit might not be detected quickly enough and therefore results in damage to the PEF signal generator 5. Problems related to usage can also occur: during the preparation of the food to be cooked G, particularly sausage such as e.g. veal sausage, in the container for food to be cooked 2, it may be that the food to be cooked G touches a contact plate at one end and touches one of the PEF electrodes 4a, 4b at the other end. If the conductivity of the water W does not correspond to the conductivity of the food to be cooked G (the conductivity of the food to be cooked G is usually much higher than the conductivity of the water W), the food to be cooked G represents a kind of short circuit between the PEF electrodes 4a, 4b. A similar effect can occur if a plurality of pieces of food to be cooked, e.g. hotdogs, are compressed between the PEF electrodes 4a, 4b. In this case likewise, the pieces of food to be cooked represent a considerably lower resistance between the PEF electrodes 4a, 4b than the water W. Common to all of these “food to be cooked resistances” is that they are practically impossible to assess in respect of the level of their electrical resistance value. This is because the bearing pressure between the food to be cooked G and one or both of the PEF electrodes 4a, 4b can change over time. It has been shown that small and locally very pronounced maxima in the energy transmission can occur at the points of contact. This locally pronounced greater energy transmission can adversely affect the quality of the food to be cooked G due to its point-specific heating. When preparing a food to be cooked G, this benefits most when separated from the PEF electrodes 4a, 4b during a PEF cooking process, particularly advantageously midway between the PEF electrodes 4a, 4b. By covering both contact plates 4a, 4b with the strainers 6a, 6b, it is now possible—as illustrated—to effect an enforced separation of the food to be cooked G from the PEF electrodes 4a, 4b, in particular at least approximately midway between the PEF electrodes 4a, 4b.

[0072] FIG. 2 shows a side view of a strainer 6a, 6b according to a first variant 6a-1 and 6b-1 respectively. FIG. 3 shows the strainer 6a-1, 6b-1 in a front view. The strainer 6a-1, 6b-1 is embodied as a planar perforated plate, as shown in cross section in FIG. 2, having a planar metallic sheet 7 into which holes 8, e.g. round holes, are introduced in a regular pattern 8. Such strainers 6a-1, 6b-1 are particularly easy to manufacture.

[0073] FIG. 3 shows a side view of a strainer 6a, 6b according to a second variant 6a-2 and 6b-2 respectively. FIG. 4 shows a section of the strainer 6a-2, 6b-2 in a front view. The strainer 6a-2, 6b-2 in this case is embodied as a wire mesh or grid 9 which likewise has holes 10 in a regular pattern. Such strainers 6a-2, 6b-2 advantageously have holes 10 as a particularly high proportion of the area, e.g. more than 50% of the total area, in particular more than 70%.

[0074] The strainers 6a-2, 6b-2 can have a planar shape in cross section like the strainers 6a-1, 6b-1. In order to provide greater mechanical stability, it can however be advantageous for the strainers 6a-2, 6b-2 to have a basic shape that is even but be three-dimensionally shaped in cross section, which can also be referred to as a raised hole pattern. This is illustrated in FIG. 5 by an exemplary zigzag type of shape.

[0075] Alternatively, the strainers 6a-2, 6b-2 can be made from a plate, in particular a sheet, and optionally deformed in the case of e.g. a non-planar shape.

[0076] The strainers 6a-1, 6b-1, 6a-2, 6b-2 are advantageously embodied in such a way that the cross section produced by the holes 8 in the water W and available for the conductivity of current is as large as possible while good stability of the strainers 6a-1, 6b-1, 6a-2, 6b-2 is nonetheless ensured.

[0077] The distance a of the strainers 6a-1, 6b-1, 6a-2, 6b-2 is advantageously changed before or after the food to be cooked G is placed into container for food to be cooked 2, but before a PEF cooking process is started. It can however also be adapted during a PEF cooking process.

[0078] In a sectional side view, FIG. 6 shows a simplified diagram of a container for food to be cooked 11 which is designed in a similar manner to the container for food to be cooked 2 but does not have any strainers 6a-1, 6b-1, 6a-2, 6b-2 and instead has three vertically oriented guides 12 for the insertion of a respective partition 13 (see FIG. 9) that is arranged parallel to the outer PEF electrodes 4a, 4b. The container for food to be cooked 11 can be used in the PEF cooking appliance 1, e.g. instead of the container for food to be cooked 2.

[0079] The guides 12 are incorporated in the electrically non-conductive side walls of the container for food to be cooked 11 which separate the side walls having the PEF electrodes 4a, 4b from each other. The guides 12 can be provided e.g. as pairs of opposing guide grooves. In the present figure, the only guide grooves drawn in are those disposed on a side wall 14 that is drawn in at the back. The parallel side wall at the front is not drawn in. The partitions 13 can be slotted into the guides 12 from above, e.g. by a user. By way of example here, the guides 12 and the PEF electrodes 4a, 4b are disposed parallel to each other and are equidistantly spaced.

[0080] When the container for food to be cooked 11 is filled solely with water W or the electrical conductivity of the food to be cooked G corresponds to the electrical conductivity of the water W, an at least approximately homogeneous current density is established in the container for food to be cooked 11 over the entire useful volume between the PEF electrodes 4a, 4b.

[0081] In daily use, it can occur that various types of food to be cooked G or foods must be prepared simultaneously. The following problem can occur in this case:

[0082] It is assumed that food to be cooked G located in the container for food to be cooked 11 have very different conductivities, e.g. as shown here by way of example with reference to hotdog pieces WS and small vegetables, e.g. potato cubes KW. The hotdog pieces WS have a comparatively high salt content and therefore have a comparatively high electrical conductivity. By contrast, potato cubes KW are usually more likely to have a low salt content and therefore a comparatively low electrical conductivity. The potato cubes KW have a tendency to sink to the bottom in the water W and stay there. Due to their fat content, the hotdog pieces WS have a tendency to drift upwards in the water W and remain buoyant there. If these two foods WS, KW are located in the water W of the container for food to be cooked 11 at the same time, they separate accordingly. This behavior is disadvantageous for the PEF cooking process because the batch of hotdog pieces WS, due to their higher conductivity, condenses or “attracts” the current density in the container for food to be cooked 11 and the current density in the potato cubes KW is thereby reduced. Otherwise expressed, the batch of potato cubes KW reduces or “discourages” the current density there due to its lower conductivity, and therefore the current density in the hotdog pieces WS increases. This means that the energy transmission into the hotdog pieces WS is increased and into the potato cubes K is reduced. The hotdog pieces WS are consequently heated and cooked more quickly than the potato cubes KW. This lack of uniformity is inherent in the food and cannot in principle be influenced in the implementation shown. This in turn noticeably impairs the cooking result and means that items of food to be cooked G having very different electrical conductivities (the hotdog pieces WS and the potato cubes KW in the example) often cannot be heated or cooked at the same time together in a container for food to be cooked 11. This applies in particular if the food to be cooked G which only receives a reduced energy input requires a particularly high energy input because it must be not only heated but also properly cooked during the course of preparation. This relates to the potato cubes KW in the example here, because the starch must gelatinize in the potato cubes KW in order to allow optimal processing in the digestive system.

[0083] A similar problem can occur if a food to be cooked G with an extended geometry is disadvantageously oriented in the container for food to be cooked 11:

[0084] An exemplary “favorable” distribution of whole hotdogs GW is illustrated in FIG. 7 with reference to the container for food to be cooked 11 without partitions 13. The current distribution is influenced by the presence of the hotdogs GW, but no problems are anticipated here owing to the more or less uniform distribution (parallel to each other) of the hotdogs GW.

[0085] However, the current distribution can already be disadvantageously influenced to a noticeable extent if as shown in FIG. 8 a single whole hotdog GW lies transversely. This produces regions in which the local current density and the local electrical field strength as indicated by broken-line arrows drop off significantly as indicated by the dotted-line ovals. Therefore the energy input into the hotdogs GW located in these regions also drops off locally. This problem is then aggravated if different types of food to be cooked G which physically separate are placed in the water W.

[0086] FIG. 9 shows a sectional side view of the container for food to be cooked 11 which is filled with a food to be cooked G in the form of whole hotdogs GW, with a partition 13 that is inserted in the central guide by way of example. By means of the partition 13, the useful volume NV of the container for food to be cooked 11 available to accommodate food to be cooked G is divided into two useful subvolumes NV1, NV2 on both sides of the partition 13. This has the advantage that in particular larger items of food to be cooked G such as long hotdogs GW can be forced into a more uniform distribution because there is no longer space for freedom of orientation.

[0087] The partition 13 drawn in here is an electrically conductive largely impervious partition, for example,. a metal sheet or metal plate with few or no holes. It is disposed parallel to and between the outer PEF electrodes 4a, 4b and on both sides has an electrically conductive surface with the same basic shape as the respective opposing PEF electrodes 4a and 4b respectively, being mirror-symmetrical in particular.

[0088] This partition 13 has the advantage of stabilizing or homogenizing the field distribution, as indicated by the broken-line arrows, even in the case of smaller items of food to be cooked G. This is because the partition 13, due to its comparatively very high electrical conductivity, represents an equipotential area for the electrical field in the container for food to be cooked 11 or defines the position of this equipotential area in the container for food to be cooked 11. High electrical currents flow within the partition 13 in this case, and have an equalizing effect. In the present example, the electrical field is therefore homogenized on at least that side of the partition 13 which faces away from the “unfavorably” positioned hotdog GW, i.e. in the useful subvolume NV2 in which the “unfavorably” positioned hotdog GW is not present.

[0089] The division of the useful volume NV into the two useful subvolumes NV1, NV2 by means of the partition 13 corresponds to a series circuit of the two useful subvolumes NV1, NV2. This is of no importance to the PEF pulse generator 5, resulting in the further advantage that the operation of the PEF pulse generator 5 does not have to be adapted to the presence of the partition 13 as such.

[0090] It is however also possible to insert electrically conductive or non-conductive strainers 6a into the guides 12, optionally in combination with partitions 13.

[0091] FIG. 10 shows a PEF cooking appliance 15 which is fitted with the container for food to be cooked 11. The PEF cooking appliance 15 differs from the PEF cooking appliance 1 in that (a) the guides 16 are designed as guides which can electrically contact the partitions 13 and (b) the signal outputs 5a and 5b of the PEF signal generator 5 can be variably interconnected to the PEF electrodes 4a, 4b and the guides 16 via a switching matrix 17. The guides 16 are therefore so designed as to electrically contact the partitions 13 that are inserted, such that PEF signals PS can be applied thereto. The switching matrix 17 can also be a component of the PEF signal generator 5.

[0092] The switching matrix 17 can be activated e.g. by means of the control facility 18. It can have corresponding switches, in particular electronic switches such as IGBTs etc. This means that the partitions 13 can be used selectively as simple partitions or as inner PEF electrodes.

[0093] Partitions 13, specifically partitions 13a, 13b and 13c, are now slotted into all three guides 16 in the container for food to be cooked 11. This has the advantage that larger foods can be forced even more effectively into a position that is favorable for PEF cooking in the four useful subvolumes NV1, NV2, NV3 and NV4, which are then comparatively small. In addition, it is then advantageously also possible to process (cook, heat, etc.) more than two different types of food to be cooked separately. The individual useful subvolumes NV1, NV2, NV3 and NV4 can then have different impedances if they contain different types of food to be cooked G. This applies even if they have identical dimensions.

[0094] For example , the switching matrix 17 can be configured or activated by the control facility 18 in such a way that: [0095] 1) In a first switching arrangement, a first signal output 5a of the PEF signal generator 5 is connected to e.g. the first outer PEF electrode 4a and a second signal output 5b of the PEF signal generator 5 is connected to the second outer PEF electrode 4b. The partitions 13a to 13c are then used like the partition 13 in FIG. 9 as simple partitions (and not as PEF electrodes) which represent an equipotential area and divide the useful volume NV of the container for food to be cooked 11 into four useful subvolumes NV1, NV2, NV3 and NV4. In the case of a container for food to be cooked 11 that is filled with water W, this corresponds to a series circuit of the useful subvolumes NV1 to NV4. This has the advantage that field distortions in the container for food to be cooked 11 can be reduced particularly effectively. [0096] 2) In a second switching arrangement, the PEF electrodes 4a, 4b and the partitions 13a to 13c are connected alternately to the first signal output 5a and the second signal output 5b. This corresponds to a parallel circuit of the useful subvolumes NV1 to NV4. This can be realized by connecting the first PEF electrode 4a, the central partition 13b and the second PEF electrode 4b to the first signal output 5a while the two outer partitions 13a and 13c are connected to the second signal output 5b, or vice versa. [0097] 3) In a third switching arrangement, the first PEF electrode 4a is connected to the central partition 13b while both PEF electrodes 4a, 4b are connected to the second signal output 5b, or vice versa. The partitions 13b and 13c are not connected to the signal generator 5. This results in a series circuit of the combined useful subvolumes NV1 and NV2, and NV3 and NV4 respectively, wherein the two series circuits are then interconnected in parallel. [0098] 4) In a fourth switching arrangement, the first PEF electrode 4a is connected to the left-hand partition 13a while both PEF electrodes 4a, 4b are connected to the second signal output 5b, or vice versa. The partitions 13b and 13c are not connected to the signal generator 5. This results in a series circuit of the combined useful subvolumes NV2, NV3 and NV4, which are interconnected in parallel with the useful volume NV1.

[0099] However, many other switching arrangements are fundamentally possible. This has the advantage that the total impedance that must be supplied with energy by the PEF signal generator 5 can be adapted to a value which is particularly suitable for the PEF signal generator 5.

[0100] In a development, the contacting of the outer PEF electrodes 4a, 4b and the partitions 12b and 12c to the PEF signal generator 5 can be changed during a cooking process, e.g. as a function of a measured total impedance.

[0101] The present invention is obviously not restricted to the exemplary embodiment shown here.

[0102] This means that the exemplary embodiments described above can also be combined with each other where possible. This also comprises, therefore, for example, a PEF cooking appliance which has at least one displaceable strainer and at least one guide for the insertion of at least one partition.

[0103] “A/an” or “one” can generally be understood to signify one or more, particularly in the context of “at least one” or “one or more” etc., provided this is not explicitly excluded as in e.g. the expression “precisely one”, etc.

[0104] A numerical value can include both the specified number and a normal tolerance range, provided this is not explicitly excluded.

LIST OF REFERENCE CHARACTERS

[0105] 1 PEF cooking appliance [0106] 2 Container for food to be cooked [0107] 3 Periphery of the container for food to be cooked [0108] 4a First outer PEF electrode [0109] 4b Second outer PEF electrode [0110] 5 PEF signal generator [0111] 5a First signal output of the PEF signal generator [0112] 5b Second signal output of the PEF signal generator [0113] 6a First strainer [0114] 6b Second strainer [0115] 6a-1 Strainer [0116] 6a-2 Strainer [0117] 6b-1 Strainer [0118] 6b-2 Strainer [0119] 7 Sheet [0120] 8 Hole [0121] 9 Wire mesh/grid [0122] 10 Hole [0123] 11 Container for food to be cooked [0124] 12 Guide [0125] 12a Guide [0126] 12b Guide [0127] 12c Guide [0128] 13 Partition [0129] 13a-13c Partitions [0130] 14 Side wall [0131] 15 PEF cooking appliance [0132] 16 Guide [0133] 17 Switching matrix [0134] 18 Control facility [0135] a Distance [0136] G Food to be cooked [0137] GW Whole hotdog [0138] KW Potato cubes [0139] NV Useful volume [0140] NV1-NV4 Useful subvolume [0141] PS PEF signal [0142] W Water [0143] WS Hotdog piece