Heating cooker

Abstract

To provide a heating cooker having a hot water tank with a relatively large volume, which has a short warm-up time until a desired temperature is reached and promotes convection in the hot water tank.SOLUTION: A heating cooker according to the present invention heats a liquid in a liquid vat that stores liquid for heating food by using a bottom heating source of an electromagnetic induction heating type arranged on the bottom surface of the liquid vat and a side heating source of the electromagnetic induction heating type that is arranged around the entire circumference of the outer surface of the vat. In particular, a non-magnetic member for blocking induction heating by the side heating source is interposed between the outer surface of the liquid vat and the side heating source so as to cover a part of the outer surface of the liquid vat, which creates a difference in the amount of heat generated on the side wall of the liquid vat. As a result, heated and unheated portions are formed on the side of the liquid vat, thereby promoting convection within the liquid vat.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an improvement to a commercial cooking device (e.g., a noodle boiler) used to heat food ingredients such as noodles and frozen foods such as fries served in restaurants, and in particular to a cooking device that uses electromagnetic induction as a heat source. [Background technology]

[0002] To make noodles taste good, it is important to use a lot of water so that the noodles can be loosened. For this reason, relatively large pots are used to boil noodles. In particular, the bathtubs (sometimes called boiling kettles or boiling pots, but hereafter referred to as "bathtubs") used for commercial purposes at restaurants and other establishments tend to be deep and often have a very large capacity to store water.

[0003] Naturally, the larger the water bath, the longer it takes to raise the water temperature in the bath to the desired high temperature. Also, to loosen the noodles, i.e., to prevent them from sticking together, it is necessary to generate convection in the water bath. The idea of ​​cooking by promoting convection is not limited to boiled noodles, but is also widely used in rice cookers, and it is recognized that it is also necessary for fryers that use the liquid in the water bath as cooking oil to cook fries and other foods (for example, see Patent Documents 1 and 2 below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-147015 A [Patent Document 2] JP 2002-102071 A Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, to promote convection in a bathtub, the heating source is divided into strong and weak heating parts and placed around the bathtub. For example, instead of using a large burner to strongly heat the bottom of the bathtub, a weak heating source with a small amount of heat, such as an electric heater, is placed away from the strong heating source so that strong and weak heating occur simultaneously when the bathtub is heated. Convection is a phenomenon in which liquids or gases become lighter when heated and move upwards, while cold parts move downwards, so that the top and bottom move in an alternating direction. Therefore, strong and weak heating sources with different amounts of heat are placed in different locations to facilitate heat circulation.

[0006] However, when using a large hot water tank, if a partial low heating method is used in which only a portion of the heat source is turned on low, it takes a long time to heat the water or hot water in the tank to the desired high temperature. Therefore, the use of a partial low heating method in large hot water tanks used for commercial purposes is not welcomed by kitchen staff.

[0007] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a cooking device having a hot water bath with a relatively large volume, which has a short warm-up time until the desired temperature is reached and which promotes convection within the hot water bath. [Means for solving the problem]

[0008] In order to solve the above problems, the heating cooker of the present invention is characterized in that it comprises a liquid vat for storing liquid for heating food, a bottom heating source of an electromagnetic induction heating type arranged on the bottom surface of the liquid vat, a side heating source of an electromagnetic induction heating type arranged around the entire circumference of the outer surface of the liquid vat, and a non-magnetic member interposed between the outer surface of the liquid vat and the side heating source to block induction heating by the side heating source, the non-magnetic member covering a portion of the outer surface of the liquid vat and arranged in multiple stages according to the depth of the liquid vat.

[0009] In the cooking device according to the present invention, the non-magnetic member is composed of the plurality of divided non-magnetic members, the side heating source is formed by winding a coil wire around a bobbin-type coil holder having a hollow inside, and the liquid tank is fitted into the hollow of the coil holder. In the cooking device according to the present invention, the non-magnetic member is interposed between the coil holder and the coil wire, and the non-magnetic member is an aluminum plate. Effect of the Invention

[0010] The cooking device according to the present invention uses an electromagnetic induction heating source to strongly heat the bottom and sides all at once, so the time it takes to heat the liquid in the liquid vat to the desired temperature is short. In addition, a non-magnetic member is interposed between the heating source installed on the outer wall of the liquid vat and the liquid vat, so the amount of heat generated differs on the side wall of the liquid vat. As a result, heated and unheated areas are formed on the side of the liquid vat, promoting convection within the liquid vat. [Brief description of the drawings]

[0011] [Figure 1] 1 is an overall configuration diagram showing an outline of a heating cooker according to an embodiment of the present invention; [Diagram 2] 13 is a diagram showing that a non-magnetic member is arranged around the outer wall of the cooking device. FIG. [Diagram 3] FIG. 13 is a diagram showing an example of a non-magnetic member having an upper and lower two-tier structure. [Figure 4] 3 is a diagram showing an example in which the non-magnetic members shown in FIG. 2 are arranged with different sizes. [Diagram 5] 4 shows an example in which the non-magnetic members shown in FIG. 3 are arranged with different sizes. [Figure 6] 4 is a diagram showing another example in which the non-magnetic members shown in FIG. 3 are arranged with different sizes. [Figure 7] FIG. 13 is a diagram showing an example of a configuration using a bobbin-type coil holder. [Figure 8] FIG. 13 is a diagram showing another example of a configuration using a bobbin-type coil holder. BEST MODE FOR CARRYING OUT THEINVENTION

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted with the same reference numerals as much as possible, and duplicated description will be omitted. In the following description, the upper side in FIG. 1 is expressed as the upper side in the height direction when the electromagnetic cooker 1 is placed on a work table or the like, and the lower side in FIG. 1 is expressed as the lower side in the height direction. In this embodiment, a noodle boiler is taken as an example of a cooking device, but the cooking device is not necessarily limited to a noodle boiler, and can be applied to other cooking devices such as a fryer.

[0013] FIG. 1 is a schematic cross-sectional view showing one embodiment of a noodle boiler 100. The noodle boiler 100 mainly includes a hot water tank 1 for containing liquid (such as water or hot water), an electromagnetic induction coil 2 arranged on the bottom of the hot water tank 1, electromagnetic induction coils 3 (3a and 3b) arranged around the hot water tank 1, a bottom inverter device 4 connected to the electromagnetic induction coil 2, and side inverter devices 5a and 5b connected to the electromagnetic induction coils 3a and 3b. In this embodiment, a dedicated inverter device is connected to each of the electromagnetic induction coils on the bottom and side, but one inverter device may control both the electromagnetic induction coils on the bottom and side, or one side inverter device may be used (hereinafter, the side inverter devices 5a and 5b are collectively referred to as the side inverter device 5). The bottom (or side) of the hot water tank 1 has an outlet 6 for discharging the liquid in the hot water tank 1 to the outside, which is connected to an outlet pipe 7.

[0014] The hot water tank 1 of this embodiment is made of conductive stainless steel and has an inclined surface where the horizontal cross-sectional area decreases toward the bottom of the tank. Note that the present invention can also be applied to cylindrical tanks in which the horizontal cross-sectional areas of the upper and lower parts are approximately equal, and to hot water tanks of other shapes.

[0015] When a current is passed through the electromagnetic induction coils 2 and 3, magnetic lines of force are generated, and when these magnetic lines of force pass through the stainless steel (conductive) bath 1, eddy currents are generated, which are converted into Joule heat by the electrical resistance of the bath 1, thereby inductively heating the bath 1. The bottom electromagnetic induction coil 2 heats the water or hot water in the bath from the bottom of the bath all at once, while the side electromagnetic induction coil 3 heats it from the side. The electromagnetic induction coil 3, which is arranged to surround the outer wall of the bath 1, is formed by wrapping a series of electric wires around the outer wall of the bath 1 multiple times. The electromagnetic induction coil wires 2, 3 are made by twisting together a number of copper wires coated with enamel varnish so that a coating layer can be formed, and then further applying a heat-resistant coating, but a work coil may also be used.

[0016] The noodle boiler 100 of this embodiment strongly heats the bottom and sides all at once using the electromagnetic induction coils 2 and 3, and therefore can avoid the long warm-up time required to reach the desired temperature that was an issue with the conventional partial weak heating method (wherein part of the heat source is heated weakly). Furthermore, a distinctive feature of the electromagnetic induction coil 3 for the sides in this embodiment is that it is configured with aluminum plate 8a and / or aluminum plate 8b interposed between the electromagnetic induction coil 3 and the hot water tank 1. In other words, the electromagnetic induction coil 3 is wound around the outer wall many times to cover the aluminum plate 8a and / or aluminum plate 8b, forming a coil.

[0017] FIG. 2 shows an example where an aluminum plate 8a is attached to the outer wall of the hot water tank 1. A single aluminum plate 8a with a size of about half the circumference of the coil is installed between the electromagnetic induction coil 3a and the hot water tank 1. However, the aluminum plate 8a does not necessarily have to be about half the circumference of the hot water tank 1. Since the degree of convection varies depending on the material properties of the hot water tank 1 and the ingredients put into the hot water tank 1, the size of the aluminum plate 8a is adjusted according to the ease with which the convection state occurs (in the case of ingredients that are easy to break apart and do not require large convection phenomena, for example, it is sufficient that about 1 / 4 of the circumference of the coil is covered with the aluminum plate 8a). Note that, although FIG. 2 shows the size of the aluminum plate 8a to be symmetrical with respect to the center of the hot water tank 1, it may be asymmetric in length. Therefore, since the aluminum plate 8a is attached to part of the periphery along the outer wall of the hot water bath 1, the outer wall of the hot water bath 1 is divided into areas where the aluminum plate 8a is present and areas where it is not.

[0018] In the case of electromagnetic induction heating, sufficient heat is not generated for non-magnetic materials with low resistivity such as aluminum. As a result, if an aluminum plate 8a is placed opposite the coil wire 3a wound around the outer wall of the bath 1, the magnetic field flows to the surface of the aluminum plate, but the aluminum plate itself does not generate heat because of its low electrical resistance. On the other hand, the magnetic field is shielded from the bath wall opposite the aluminum plate. In other words, the magnetic field lines of the side electromagnetic induction coil 3a do not reach the aluminum plate and the portion of the outer wall of the bath corresponding to that position, so it is heated only slightly (or not at all) compared to when the aluminum plate 8a is not present. Therefore, the amount of heat generated in the side wall of the bath 1 differs depending on whether the aluminum plate 8a is present or not, and the side of the bath 1 is formed into heated and unheated areas.

[0019] In this way, since there are multiple aluminum plates 8a between the side electromagnetic induction coil 3a along the outer wall of the hot water tank 1, part of the side of the hot water tank 1 remains at a low temperature. However, since the side electromagnetic induction coil 3 is controlled to strong heating by the side inverter device 5 (for example, the side inverter device 5a), it does not become like the conventional partial weak heating method, except when the ratio of the effective area of ​​the aluminum plate 8a to the outer circumference of the side is extremely large. The side heating is performed at a strong heating level just like the bottom heating. Also, in the present invention, the presence or absence of a physical object called a non-magnetic material promotes convection. Therefore, there is no structural or control complexity in the side inverter device, such as multiple side inverter devices adjusting the frequency to create a difference in the amount of heat generated in the side electromagnetic induction coil 3.

[0020] In this embodiment, an aluminum plate is used because it is assumed that a general frequency (about 20 to 30 kHz) is used in electromagnetic induction heating (IH), but it does not necessarily have to be an aluminum plate. When an intermediate frequency electromagnetic field of about 90 kHz is used, for example, or aluminum may not be sufficient as a heat suppression material depending on the material of the bath 1, other non-magnetic materials may be used as appropriate. In addition, the wall surface of the bath 1 at the outlet direction of the discharge pipe 7 discharges the liquid in the bath toward the wall surface facing the wall surface where the aluminum plate 8a is mainly present, but the direction of the discharge pipe 7 may be set so that the liquid is discharged from the wall surface where the aluminum plate 8a is present.

[0021] The effect of the present invention is most noticeable when using a large bathtub that takes time to heat up when heating the liquid inside, but even if a bathtub with a large horizontal cross-sectional area and depth is used, the desired temperature is reached in one go because strong heating is applied from the bottom and sides. In the case of a large bathtub 1, convection in the entire bathtub 1 can be promoted by arranging aluminum plates of a large size (length) according to the surrounding area.

[0022] In addition, cooking may be performed using a deep hot water bath 1 with a small amount of water or hot water. If the aluminum plate 8a is located on the upper side of the hot water bath 1 and the water or hot water does not reach the position of the aluminum plate 8a, the expected convection hardly occurs. Therefore, examples of the position and arrangement of the aluminum plate are shown in Figures 3, 5, and 6.

[0023] Figures 3, 5, and 6 show examples in which the electromagnetic induction coil 3 for the side is configured with an upper coil 3a and a lower coil 3b in two tiers, one above the other. If the electromagnetic induction coils 3a and 3b for the side are divided into two tiers, when the amount of liquid in the bath tub 1 is small, current is passed only through the lower coil 3b to generate heat, and when the amount of liquid exceeds the position (height) of the lower coil 3b, current is passed through both the upper coil 3a and the lower coil 3b. This allows switching to limit the heating range according to the amount of liquid in the bath tub 1, thereby saving power. The aluminum plates may be arranged in three or more tiers rather than being limited to two tiers depending on the depth of the bath tub 1.

[0024] In accordance with the multi-stage electromagnetic induction coil 3, the aluminum plates 8 are arranged with an upper aluminum plate 8a and a lower aluminum plate 8b. In the case of Fig. 3, a similar aluminum plate 8b is further arranged below the aluminum plate 8a shown in Fig. 2. Although the aluminum plates 8a and 8b in Fig. 3 are present at positions shifted vertically, the aluminum plate 8b may be arranged at a different outside (for example, on the opposing wall) from the outer wall on which the aluminum plate 8a is present by shifting its position.

[0025] Figures 5 and 6 show an example in which multiple small rectangular aluminum plates are arranged, unlike the aluminum plates 8a and 8b in Figures 2 and 3. Figure 5 shows an example in which the aluminum plates 8a and 8b provided around the outer wall of the hot water tank 1 are arranged so that they are uniformly aligned in the vertical direction, and Figure 6 shows an example in which the aluminum plates 8a and 8b are arranged in a staggered pattern. Note that the number of aluminum plates and the spacing between adjacent aluminum plates are not limited to those shown in Figures 5 and 6. There may be one or two aluminum plates on each of the four sides of the outer wall of the hot water tank 1, or some of the aluminum plates may be aligned vertically as in Figure 5 and the remaining aluminum plates may be arranged in a staggered pattern as in Figure 6. Moreover, Fig. 4 shows an example in which small rectangular aluminum plates, as shown in Fig. 5 and Fig. 6, are used instead of the aluminum plates shown in Fig. 2. The size (number) and arrangement of these aluminum plates are determined based on which part of the hot water bath 1 should generate the least amount of heat, in accordance with the heating requirements required in relation to the food ingredients, and the direction and strength of the convection currents in the hot water bath 1 are controlled.

[0026] As described above, in the case of this embodiment, even if the noodle boiler 100 has a large volume, the water or hot water in the tank can reach a desired temperature quickly because the bottom of the tank 1 is strongly heated all at once using the bottom electromagnetic induction coil 2, and the side of the tank is also strongly heated using the side electromagnetic induction coils 3 (3a, 3b). Also, because aluminum plate 8a and / or aluminum plate 8b are interposed between the side electromagnetic induction coils 3 (3a, 3b) on the side of the tank, a difference occurs in the amount of heat generated on the side walls of the tank 1, which promotes convection.

[0027] Second Embodiment In the noodle boiling device 100 of the embodiment described above, the side electromagnetic induction coil 3 is formed by winding a coil wire directly around the hot water tank 1 so as to cover an aluminum plate arranged on a portion of the outer wall of the hot water tank 1. With this configuration, the hot water tank 1 and the side electromagnetic induction coil 3, which is the heat source, are integrated, and replacement or repair of the coil wire requires the tank to be removed from the housing before the work can be performed, which is time-consuming. The larger the noodle boiling device 100, the more noticeable this becomes.

[0028] Therefore, in the cooking appliance 200 of the second embodiment, the hot water bath 1 may be inserted into a hollow bobbin-type coil holder 9 manufactured to match the shape of the side surface of the hot water bath 1, so that the hot water bath 1 and the electromagnetic induction coil 3 for the side surface are not integrated together, as shown in Fig. 7. In this embodiment, the cavity of the coil holder 9 is a through hole, but it may also be a bottomed cavity.

[0029] As shown in Figure 7(a), the coil holder 9 has a hollow bobbin shape. Figure 7(b) shows the state in which the electromagnetic induction coil 3 is wound around the coil holder 9. At this time, aluminum plates 8a and 8b are placed on the coil holder 9, and the coil wire is wound so as to cover these aluminum plates 8a and 8b. Therefore, the coil wire is wound indirectly around the outer surface of the tumble bath 1 via the coil holder 9, forming an electromagnetic induction coil for the side surface.

[0030] Flanges 10 are provided on each of the upper and lower edges of the coil holder 9 to prevent the wound coil wire from coming off the coil holder and to facilitate attachment and detachment to the tumbler 1. As shown in Figure 7(c), highly permeable ferrite (ceramics whose main component is iron oxide) 11 is attached to the outside of the electromagnetic induction coil 3 to confine the magnetic force.

[0031] Although magnetic fields pass through ferrite itself, as it is a sintered alloy (powdered), the generated electric current does not flow through it, and it has the characteristic of not generating heat like iron. Structurally, one side of the magnetic field generated by the electromagnetic induction coil 3 enters the magnetic bath side, and the other side becomes the side that should not be heated, such as the outer wall. By placing ferrite between the electromagnetic induction coil 3 side and the exterior of the bath 1, the magnetic field can be induced into the ferrite, making it difficult for the magnetic field to enter the outer wall. As a result, even if the equipment is magnetic, it does not heat up easily. Ferrite can also stabilize the flow of magnetic lines, which has the effect of preventing uneven heating of the bath.

[0032] FIG. 8 shows a bobbin-type coil holder 9 when using the small rectangular aluminum plate shown in FIGS. Although not shown, in Figs. 7 and 8, a heat insulating material (such as a heat insulating fiber member) may be used between the coil holder 9 and the hot water tank 1 for the purpose of keeping the temperature constant. In addition, the technical effect of the present invention will not change even if the aluminum plates 8a, 8b are placed directly on the outer wall surface of the tumble bath 1 and then the tumble bath 1 is inserted into the coil holder 9, rather than interposing the aluminum plates 8a, 8b between the coil holder 9 and the coil wire. Furthermore, the cavity in the coil holder 9 is not limited to a through hole, but may be a bottomed cavity.

[0033] In the case of the cooking appliance 100 of the first embodiment or the cooking appliance 200 of the second embodiment, even if a hot water bath with a relatively large volume is used, strong heating is performed from both the bottom and the side of the hot water bath 1, so the temperature rise time can be shortened. Furthermore, the aluminum plate 8a and / or aluminum plate 8b interposed between the electromagnetic induction coil 3 for the side prevents the magnetic field lines from the electromagnetic induction coil from reaching the hot water bath and generating eddy currents due to their material properties. Therefore, the side surface corresponding to the location where the aluminum plate 8a and / or aluminum plate 8b are present does not generate sufficient heat, so a difference occurs in the amount of heat generated on the side wall of the hot water bath 1, and as a result, convection can be promoted. [Explanation of symbols]

[0034] 1 Hot water tank (liquid tank) 2. Electromagnetic induction coil for the bottom 3. Electromagnetic induction coil for sides 3a Upper coil 3b Lower coil 4 Bottom inverter unit 5 Side inverter device 6 Outlet 7 Discharge pipe 8 Aluminum Plate 8a Aluminum plate 8b Aluminum plate 9 Coil holder 10 Flange 11 Ferrite 100 Noodle boiler 200 Noodle boiler

Claims

1. a liquid tank for storing a liquid for heating food; a bottom heating source of an electromagnetic induction heating type disposed on a bottom surface of the liquid tank; a side heating source of an electromagnetic induction heating type arranged around the entire outer periphery of the liquid tank; a non-magnetic member interposed between an outer surface of the liquid vat and the side heating source to block induction heating by the side heating source, the non-magnetic member covering a portion of the outer surface of the liquid vat and arranged in multiple stages according to the depth of the liquid vat; A heating cooker comprising:

2. The cooking device according to claim 1 , wherein the non-magnetic member is composed of the plurality of divided non-magnetic members.

3. 2. The cooking device according to claim 1, wherein the side heating source is formed by winding a coil wire around a bobbin-type coil holder having a hollow inside, and the liquid tank is fitted into the hollow of the coil holder.

4. The cooking device according to claim 3 , wherein the non-magnetic member is interposed between the coil holder and the coil wire.

5. The cooking device according to any one of claims 1 to 4, wherein the non-magnetic member is an aluminum plate.

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