Electric heating device

Abstract

To provide an electrically powered heating device that enables more uniform heating. [Solution] An electric heating device 1 is provided, comprising a cylindrical container 2 configured to accommodate a conductive object to be heated, with at least the inside being electrically insulating, and a pair of electrodes 3 housed inside the cylindrical container 2 at both ends of the cylindrical container 2 and supplying current to the object to be heated, wherein the electrodes 3 include a flat plate portion having a flat plate shape and a peripheral portion erected vertically along the periphery of the flat plate portion, and current is supplied to the object not to be heated, at least via the peripheral portion.

Description

Technical Field

[0001] The present invention relates to an electrically heated device. In particular, the present invention relates to an electrically heated device for heating food.

Background Art

[0002] An electrically heated device is a device that directly passes an electric current through a heated object having conductivity and performs heating by the generated Joule heat. As disclosed in Patent Document 1, as an electrode for supplying an electric current to a heated object, a flat electrode provided with the heated object sandwiched therebetween is known. Electrically heated devices are roughly classified into those that accommodate a heated object in a cylindrical container and heat it in a substantially stationary state, and those that heat while flowing the inside of the cylindrical container. In order to make the current density between electrodes substantially uniform for uniform heating, when heating a heated object in a substantially stationary state by accommodating it in a cylindrical container, it is common to arrange flat electrodes in parallel at both ends of the heated object.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Due to heat radiation from the cylindrical container that houses the heated object, the temperature of the outer surface of the heated object is lower than that of the center. Also, since the electrical resistance value of an electrolyte such as salt water decreases as the temperature rises, when the heated object contains moisture such as food and electrolytes such as salt, current tends to flow more easily to the center of the heated object where the temperature is relatively high and the electrical resistance value is relatively low, and the temperature of the outer surface relatively decreases further. Thus, a situation where the temperature at the center easily rises and the temperature of the outer surface is difficult to rise occurs cyclically, and it has sometimes been difficult to achieve uniform heating. As a result, the desired quality may not be obtained.

[0005] This invention has been made in view of these circumstances, and aims to provide an electrically heated device that enables more uniform heating. [Means for solving the problem]

[0006] According to the present invention, a cylindrical container is configured to accommodate a conductive object to be heated, with at least the inside being electrically insulating, and a pair of electrodes are housed inside the cylindrical container at both ends of the cylindrical container and supply current to the object to be heated, wherein each electrode includes a flat plate portion having a flat plate shape and a peripheral portion erected vertically along the periphery of the flat plate portion, and at least via the peripheral portion, covered An electrically powered heating device is provided, which supplies electric current to the object being heated. [Effects of the Invention]

[0007] In the electrically heated device according to the present invention, a pair of electrodes for supplying current to the object to be heated is provided, each electrode including a flat plate portion having a flat plate shape and a peripheral portion erected vertically along the periphery of the flat plate portion. Near the outer surface of the object to be heated, a current is easily formed flowing from the peripheral portion of one electrode to the peripheral portion of the other electrode, thereby suppressing the concentration of current towards the center of the object to be heated. This enables more uniform heating. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of an electrically heated device. [Figure 2] This is a bottom view of the electrically heated device. [Figure 3] This is a cross-sectional view of an electrically heated device. [Figure 4] This is a perspective view of the electrode. [Figure 5] This is a perspective view of the electrode. [Figure 6] This is a cross-sectional view of the electrode. [Figure 7] This is a magnified view of the claws and protrusions. [Figure 8] This is a cross-sectional view of the locking mechanism. [Figure 9]This diagram schematically shows the flow of electric current when an object is heated. [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. The various modifications described below can be implemented in any combination.

[0010] In this embodiment, the electrically heated device 1 is arranged vertically so that its longitudinal direction and vertical direction coincide. However, the orientation of the device is not limited to this, and it may be arranged horizontally so that its longitudinal direction and horizontal direction coincide. The electrically heated device 1 may be mounted on a base (not shown).

[0011] The electrically charged heating device 1 of this embodiment can be applied to heating a conductive object F, and is particularly suitable for heating an object F whose electrical resistance decreases as its temperature rises. Specific examples of an object F whose electrical resistance decreases as its temperature rises include foods containing water and electrolytes such as salt. The electrically charged heating device 1 may be used, for example, for heating foods mainly composed of plant protein or animal protein for bonding or shaping purposes. To achieve substantially uniform heating, it is preferable that the object F has substantially uniform conductivity throughout, and that its components are uniformly dispersed by thoroughly kneading or other means.

[0012] As shown in Figures 1 to 3, the electrically heated device 1 of this embodiment comprises a cylindrical container 2, a pair of electrodes 3, a pair of terminals 35, a pair of insulating plates 37, a pair of lids 4, a pair of locking mechanisms 5, and a temperature sensor 7.

[0013] The cylindrical container 2 is a cylindrical body configured to accommodate the object to be heated F. When heating the object to be heated F, it is preferable that the space surrounded by the cylindrical container 2 and the pair of electrodes 3 is substantially filled with the object to be heated F without any gaps. The cylindrical container 2 in this embodiment has a cylindrical shape, but it may have other shapes such as a rectangular prism shape. The cylindrical container 2 is configured so that the inside is electrically insulating. This prevents current from being induced in the cylindrical container 2 and prevents electric shock when a user touches the cylindrical container 2. More specifically, the cylindrical container 2 in this embodiment includes an electrically insulating inner cylinder 21 and an outer cylinder 23 that covers the outer surface of the inner cylinder 21. The inner cylinder 21 and the outer cylinder 23 may be configured as a single unit. Also, since the inner cylinder 21 is in direct contact with the object to be heated F, it is preferable that it be made of a material with high corrosion resistance. The inner cylinder 21 is made of, for example, resin. The outer cylinder 23 is made of, for example, stainless steel. A gripping member 27 may be provided on the outer cylinder 23 of the cylindrical container 2 to serve as a handle for the electrically heated device 1.

[0014] The electrodes 3 are housed inside the cylindrical container 2 at both ends of the cylindrical container 2. When heating the object to be heated F, the electrodes 3 supply an electric current to the object to be heated F, generating Joule heat. The electrodes 3 are preferably made of a material with high conductivity and high corrosion resistance, such as titanium. As shown in Figures 4 to 6, the electrodes 3 include a flat plate portion 31 having a flat plate shape and a peripheral portion 33 that stands vertically along the periphery of the flat plate portion 31. The pair of flat plate portions 31 are arranged parallel to both ends of the object to be heated F. When the cylindrical container 2 has a cylindrical shape, the flat plate portion 31 has a disc shape. It is preferable that both the flat plate portion 31 and the peripheral portion 33 are configured to be in contact with the object to be heated F, but the heating thing Since the peripheral portion 33 is the main contributor to supplying current to F, some shrinkage occurs in the heated object F as it heats up, affecting the flat plate portion 31 and the heated object. thingEven if a minute gap occurs between them and F, it is considered that there is no problem with heating. That is, the electrode 3 supplies current to the object to be heated F through at least the peripheral portion 33. In the pair of electrodes 3, the line segment connecting the peripheral portions 33 to each other is relatively smaller in size than the line segment connecting the flat plate portions 31 to each other in the shortest distance. As a result, a current along the line segment connecting the peripheral portions 33 to each other in the shortest distance is likely to be formed. In other words, a current passing near the outer surface of the object to be heated F is likely to be formed, and substantially uniform heating becomes possible. Since the electrode 3 has a relatively simple shape, substantially uniform heating can be realized at a relatively low cost.

[0015] In order to enjoy the above-described effect by the peripheral portion 33, a certain size is required for the length L of the peripheral portion 33. On the other hand, if the length L of the peripheral portion 33 is too large, the current is attracted too much near the outer surface of the object to be heated F, and it becomes difficult for the current to flow to other locations. Also, since most of the current flows from the peripheral portion 33 of one electrode 3 to the peripheral portion 33 of the other electrode 3, there is a risk that the heating of the object to be heated F accommodated inside the electrode 3 becomes insufficient. Therefore, it is preferable that the length L of the peripheral portion 33 is appropriately selected according to the longitudinal size LF of the object to be heated F, in other words, the distance between the pair of flat plate portions 31. For example, the length L of the peripheral portion 33 may be about 5% or more and about 15% or less with respect to the longitudinal size LF of the object to be heated F. Note that the object to be heated F may undergo a volume change due to heating, but the length L of the peripheral portion 33 may be determined based on the longitudinal size LF of the object to be heated F before heating.

[0016] The thickness t of the peripheral portion 33 may be a size that can obtain the necessary strength. Also, if the thickness t of the peripheral portion 33 is too large, the current is dispersed, and it becomes difficult to obtain the effect of current attraction by the peripheral portion 33. Therefore, it is preferable that the thickness t of the peripheral portion 33 is appropriately selected according to the outer diameter of the electrode 3, that is, the size of the outer diameter φ of the flat plate portion 31. For example, the thickness t of the peripheral portion 33 may be about 2% or more and about 5% or less with respect to the size of the outer diameter φ of the flat plate portion 31.

[0017] The electrode 3 is electrically connected to a power supply (not shown) via a terminal 35. In order to prevent the electrode 3 from being electrically eroded and the components of the object to be heated F from being separated, the power supply is preferably an alternating current power supply, and more preferably a power supply capable of generating high-frequency alternating current. The terminal hole 311, which is the mounting hole of the terminal 35, is formed, for example, at substantially the center of the flat plate portion 31.

[0018] As will be described later, in this embodiment, the temperature sensor 7 is attached only to the lower side of the energization heating device 1. At this time, the temperature sensor insertion hole 313, which is the insertion hole of the temperature sensor 7, may be formed only in the lower electrode 3.

[0019] A groove 315 is formed on the outer surface of the electrode 3 and is configured to be able to attach a seal member 317. The seal member 317 is, for example, an O-ring, and prevents water droplets and steam generated from the object to be heated F from leaking out within the cylindrical container 2. In order to prevent a decrease in the strength of the peripheral edge portion 33, the groove 315 is preferably formed on the outer surface of the flat plate portion 31.

[0020] In the energization heating device 1 of this embodiment, both ends of the cylindrical container 2 are closed by a pair of lids 4, respectively, and are configured to heat the object to be heated F in a substantially stationary state. In order to prevent the user from getting an electric shock when touching the lid 4, the lid 4 is preferably electrically insulated. In this embodiment, the lid 4 is made of a conductive material such as stainless steel, but an insulating plate 37 having electrical insulation is provided between the lid 4 and the electrode 3 to electrically insulate the lid 4. The insulating plate 37 is, for example, a plate-like member made of resin.

[0021] A drain hole 43, which is a through hole for discharging water droplets and steam generated from the object to be heated F in the cylindrical container 2 to the outside, may be formed in the lid 4. In this embodiment, six drain holes 43 are formed at equal intervals along the circumferential direction. By providing the drain hole 43, it is possible to prevent the electrode 3 and the lid 4 from being energized through water droplets. Since the energization heating device 1 of this embodiment is arranged vertically, water droplets are likely to leak from the bottom due to gravity. Therefore, the drain hole 43 may be provided only in the lower lid 4.

[0022] The lid 4 and insulating plate 37 are formed with through holes for inserting the terminals 35 and for inserting the temperature sensor 7. However, in this embodiment, since the temperature sensor 7 is mounted only on the lower side of the energized heating device 1, the upper lid 4 and insulating plate 37 do not need to have through holes for inserting the temperature sensor 7.

[0023] The lid 4 is fixed in an openable and closable manner by a projection 231 formed on the outer cylinder 23 of the cylindrical container 2, a claw 41 formed on the lid 4, and a locking mechanism 5. In this embodiment, both of the pair of lids 4 are configured to be openable and closable relative to the cylindrical container 2, but only one of them may be configured to be openable and closable.

[0024] The projections 231 and claws 41 prevent the lid 4 from falling off. Furthermore, even if vapor pressure is generated inside the cylindrical container 2 and strong pressure is applied to the lid 4, the projections 231 and claws 41 prevent the lid 4 from flying off. The cylindrical container 2, more specifically the outer cylinder 23, has a plurality of projections 231 formed at intervals along the circumferential direction at both ends and extending radially outward. In this embodiment, the outer cylinder 23 has flange portions at both ends, but the projections 231 protrude further from the flange portions. The lid 4 has a plurality of claws 41 that are erected at intervals along its periphery, have a hook-like shape that is bent towards the center of the lid 4, and are configured to face the projections 231.

[0025] The locking mechanism 5 prevents the lid 4 from rotating. As shown in Figure 8, the locking mechanism 5 includes a tube 51, a piston 52, a rod 53, a biasing member 54, a handle 55, and a locking block 6. The locking block 6 is attached to the cylindrical container 2 and has a locking hole 61 that engages with the piston 52. The tube 51 is a housing with a lumen and is fixed to the lid 4 via a bracket 56. The piston 52 is inserted into the tube 51 so as to be able to move back and forth. The rotation of the lid 4 is prevented when the front end of the piston 52 is inserted into the locking hole 61 of the locking block 6. The rod 53 is inserted into the tube 51 so as to be able to move back and forth. The front end of the rod 53 is connected to the rear end of the piston 52. Inside the tube 51, a biasing member 54 is attached around the rod 53, and the biasing member 54 biases the piston 52 toward the locking hole 61. The biasing member 54 is, for example, a compression coil spring. The handle 55 is a grip provided at the rear end of the rod 53.

[0026] The lid 4 may have some play in the vertical direction relative to the cylindrical container 2, i.e., in the axial direction of the cylindrical container 2. As shown in Figure 7, the projection 231 and the claw 41 are configured to face each other with a gap between them when the end of the cylindrical container 2 is closed by the lid 4. As shown in Figure 8, the locking hole 61 has an elongated shape that is sufficiently larger vertically than the diameter of the piston 52. In other words, the locking hole 61 is a hole that is larger than the diameter of the piston 52 in a direction parallel to the axial direction of the cylindrical container 2. With this configuration, when heating generates a vapor pressure inside the cylindrical container 2 that exceeds atmospheric pressure, the lid 4 is pressed by the vapor pressure, the gap between the projection 231 and the claw 41 becomes smaller or disappears, and the position of the piston 52 rises towards the lid 4. This makes it possible to visually determine whether the inside of the cylindrical container 2 is under high pressure.

[0027] When closing the lid 4, first place the lid 4 over the cylindrical container 2, ensuring that the claws 41 do not collide with the projections 231. Then, grasp the handle 55 and rotate the lid 4 while pulling the piston 52 to move the piston 52 to the position of the locking hole 61, then release your hand to engage the piston 52 with the locking hole 61. At this point, the projections 231 and claws 41 are facing each other. In this way, the piston 52 and the locking hole 61 prevent the lid 4 from rotating, and the projections 231 and claws 41 prevent the lid 4 from falling off.

[0028] To open the lid 4, simply reverse the procedure. However, since the inside of the cylindrical container 2 may be under high pressure immediately after heating is complete, it is preferable to open the lid 4 after the heated object F has cooled sufficiently, for example, to below 100°C. When deciding whether or not to open the lid 4, one may check the temperature measured by the temperature sensor 7 or the like, but as mentioned above, it is also possible to determine this by visually checking the size of the gap between the projection 231 and the claw 41 and the position of the piston 52.

[0029] The temperature sensor 7 is configured to measure the temperature of the object F to be heated. The temperature sensor 7 is, for example, a thermocouple. More specifically, the temperature sensor 7 may be an ungrounded sheathed thermocouple. In this embodiment, it is attached to the lower electrode 3, but the mounting position and number of temperature sensors 7 are not limited thereto. For example, it may be attached to the upper electrode 3, or it may be attached to the side of the cylindrical container 2. When attaching the temperature sensor 7 to the electrode 3, it is preferable that the electrode 3 and the temperature sensor 7 are electrically insulated to prevent current from being induced in the temperature sensor 7. For example, an electrical insulator may be provided between the electrode 3 and the temperature sensor 7. The energized heating device 1 may be controlled based on the temperature measured by the temperature sensor 7. For example, the voltage applied to the electrode 3 may be feedback controlled based on the temperature measured by the temperature sensor 7.

[0030] Figure 9 schematically shows the current flow during heating of the object F, with currents C1 and C2 shown as dotted lines as part of the current. With the above configuration, current C1 is easily generated along the outer surface, preventing a temperature drop near the outer surface of the object F. Furthermore, the ratio of current C1 along the outer surface to current C2 passing through the center of the object F can be adjusted by the shape of the electrode 3, particularly the length L of the peripheral portion 33. In this way, by making the overall current density of the object F approximately uniform, more uniform heating becomes possible.

[0031] The present invention is not limited to the configuration of the embodiments described above, and various modifications or applications are possible without departing from the technical concept of the present invention. [Explanation of Symbols]

[0032] 1 Electrical heating device 2. Cylindrical container 231 Protrusion 3 electrodes 31 Flat plate part 315 Groove 317 Sealing member 33 Peripheral area 37 Insulating board 4 Lid 41 Nails 43 Drain holes 5. Locking mechanism 51 Tubes 52 pistons 53 Rods 54. Biasing member 6. Locking block 61 Locking hole 7. Temperature sensor F Heated object LF: Length of the object to be heated φ Outer diameter of the flat plate section L Peripheral length t Peripheral thickness

Claims

1. A cylindrical container configured to contain an electrically insulating and conductive object to be heated, The cylindrical container comprises a pair of electrodes, each housed inside the cylindrical container at both ends, which supply an electric current to the object to be heated. The electrode is A flat plate portion having a flat plate shape, The flat plate portion includes a peripheral portion that is erected vertically along the periphery of the flat plate portion, An electrically charged heating device, wherein current is supplied to the object to be heated, at least via the peripheral portion.

2. The electrically heated device according to claim 1, wherein the object to be heated is a food product containing water and electrolytes.

3. The electrically heated device according to claim 1, wherein the length of the peripheral portion is 5% or more and 15% or less of the length of the object to be heated in the longitudinal direction.

4. The flat plate portion has a disc shape, The electrically heated device according to claim 1, wherein the thickness of the peripheral portion is 2% or more and 5% or less of the outer diameter of the flat plate portion.

5. The energized heating device according to claim 1, wherein a groove is formed on the outer surface of the electrode, configured to allow the attachment of a sealing member.

6. The electrically heated device according to claim 1, further comprising a pair of lids that close off both ends of the cylindrical container.

7. The electrically heated device according to claim 6, wherein at least one of the lids has a drain hole which is a through-hole for discharging water droplets or steam generated in the cylindrical container.

8. The electrically conductive heating device according to claim 6, further comprising an insulating plate having electrical insulating properties, provided between the lid and the electrode.

9. The cylindrical container has a cylindrical shape and has projections at both ends that are spaced apart along the circumferential direction and extend radially outward. The lid has claws that are erected at intervals along the periphery of the lid, have a hook-like shape that is bent toward the center of the lid, and are configured to face the projection. The electrically heated device according to claim 6, further comprising a locking mechanism for preventing the rotation of the lid.

10. The locking mechanism is A tube fixed to the lid, A piston inserted through the aforementioned tube, A locking block attached to the cylindrical container and having a locking hole that engages with the piston, A rod inserted into the aforementioned tube and connected to the aforementioned piston, The energized heating device according to claim 9, further comprising a biasing member that biases the piston in the direction of the locking hole.

11. The aforementioned projection and the aforementioned claw are configured to be able to face each other with a gap between them. The electrically heated device according to claim 10, wherein the locking hole is larger than the diameter of the piston in a direction parallel to the axial direction of the cylindrical container.

12. The electrically heated device according to claim 1, further comprising a temperature sensor configured to measure the temperature of the object to be heated.

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