JP2013218983A - Heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating device for preventing sparks from an edge portion of a plate-like electrode.SOLUTION: A heating device 9a has: a heating unit 19 on which a first plate-like electrode 11 and a second plate-like electrode 12 opposed to each other across a heating space 13 are provided; and a power source unit for supplying power to the plate-like electrodes 11, 12 and generating Joule heat to a heated object between the two plate-like electrodes 11, 12. Outer peripheral edges 21a-21d of the first plate-like electrode 11, and outer peripheral edges 22a-22d of the second plate-like electrode 12 are displaced from each other.

Description

  The present invention relates to a heating device for heating food and drink with Joule heat using the food and drink as a heated object.

  In order to cook or sterilize a food or drink as a heated object, a heating device that heats the food or drink by Joule heat is used. In order to heat food and drink having fluidity such as juice, honey, jam, etc., as described in FIG. 5 of Patent Document 1, the tubular member in which the flow path is formed and the inner surface thereof are opposed to each other. A heating apparatus having two plate-like electrodes arranged in pairs has been developed, and electric power is supplied to each plate-like electrode from a power supply unit. The food and drink flowing between the plate electrodes are heated by Joule heat by the current flowing between the plate electrodes.

  A heating apparatus is developed as described in Patent Document 2, in which a high electric field is applied to a pair of plate-like electrodes to heat the object to be heated and to sterilize microorganisms such as bacteria contained in the object to be heated. Has been. This heating device is a high electric field type heating device in which a Coulomb force is applied to a microorganism cell by applying an electric field from the outside to the microorganism cell contained in the object to be heated. In this heating device, when the applied electric field is increased, the cell membrane of the microorganism is damaged by the Coulomb force, and the electroporation phenomenon occurs by utilizing the phenomenon that micropores are formed on the surface of the cell membrane, that is, the electroporation phenomenon occurs. When an object to be heated is heated by Joule heat while applying a high electric field to the microorganism to such an extent that it cannot be repaired, the cells of the microorganism are destroyed and the microorganism can be killed in a short time.

JP 2006-320402 A JP 2008-288095 A

  As described in Patent Documents 1 and 2 above, in a conventional heating apparatus that heats an object to be heated by Joule heat by passing an electric current through the pair of plate-like electrodes to the object to be heated. The two plate electrodes forming a pair have the same size, and the current-carrying areas are the same. Each plate electrode is supplied with electric power from the power supply unit, and the potential difference between both plate electrodes is the same as a whole including the central portion and the peripheral portion of the plate electrode.

  However, when the current when power was supplied to the plate electrode was measured, it was found that the current flowing between the outer peripheral edge portions of the plate electrode was higher than the current flowing through other parts. As described above, when the current between the outer peripheral edge portions of the plate electrode is higher than that of other portions, a spark may be generated at the edge portion of the plate electrode depending on the type of the object to be heated and the energization conditions. When a spark occurs, the heated object is locally overheated, the entire heated object is not uniformly heated, and in order to improve the heating quality, it is necessary to set energization conditions according to the type of the heated object. . In order to set the energization condition, it is necessary to perform a plurality of trials and errors according to the type of the object to be heated. It takes time to set the energization condition, and the setting operation cannot be easily performed.

  An object of the present invention is to provide a heating device that prevents the occurrence of sparks from the edge portion of a plate-like electrode.

  The heating device includes a heating unit provided with first and second plate-like electrodes arranged to face each other across a heating space, and supplies power to the plate-like electrodes to supply the two plate-like electrodes. And a power supply unit that generates Joule heat in a heated object between the outer peripheral edge of the first plate electrode and the outer peripheral edge of the second plate electrode. .

  If the outer peripheral edges of the two plate electrodes arranged with a heating space between each other are shifted, current flows from the outer peripheral edge of one plate electrode to the current-carrying surface of the other plate electrode. Thus, it is possible to prevent a spark from occurring between the outer peripheral edge portions of both plate-like electrodes. Thereby, it is prevented that a to-be-heated object becomes a local overheating state, the to-be-heated object is uniformly heated, and the heating quality of a to-be-heated object can be improved. Moreover, in order to prevent the occurrence of sparks, it is not necessary to set energization conditions according to the type of the object to be heated, and the setting operation of the heating device can be easily performed.

  When a voltage of 0.2 kV or more is applied per 1 mm distance between electrodes in the heating space, the cell membrane of the microorganism can be destroyed by the electric field effect and the object to be heated can be sterilized and heated. In such a high electric field type heating apparatus, a spacer made of an insulating material provided with a long hole for forming a heating space is arranged between two plate-like electrodes so that the distance between the plate-like electrodes is increased. And a high electric field can be applied to the object to be heated flowing in the heating space.

It is a longitudinal cross-sectional view which shows the heating apparatus which is one embodiment. It is the sectional view on the AA line in FIG. It is a perspective view which shows the longitudinal cross-section of the tubular member shown by FIG. It is a perspective view which shows the longitudinal cross-section of the tubular member which is a modification. It is a cross-sectional view of the tubular member shown in FIG. It is a longitudinal cross-sectional view which shows the heating apparatus which is other embodiment. It is the BB sectional view taken on the line of FIG. It is CC sectional view taken on the line of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The heating device 9a shown in FIGS. 1 to 3 includes a tubular member 10 having a substantially square cross section as shown in FIG. The tubular member 10 is made of an insulating material such as synthetic resin and has four wall portions 10a to 10d. The first plate electrode 11 and the second plate electrode 12 are mutually spaced across the heating space 13 on the inner surfaces of the two wall portions 10 a and 10 b facing each other among the inner surfaces of the tubular member 10. Opposed to each other. As shown in FIG. 1, an inflow side joint 14 is provided at one end of the tubular member 10, and an outflow side joint 15 is provided at the other end, and each joint 14, 15 is a fastening rod. 16 is fastened to the tubular member 10.

  As shown in FIG. 1, an inflow side pipe 17 is connected to the inflow side joint 14, and an outflow side pipe 18 is connected to the outflow side joint 15. A hopper (not shown) is connected to the inflow side pipe 17, and food and drink as a heated object accommodated in the hopper is supplied to the inflow port 14 a of the inflow side joint 14 by a pump. The article to be heated supplied to the inflow port 14 a flows through the heating space 13 and is discharged to the outflow port 15 a of the outflow side joint 15. The heated object conveyed to the outlet 15a is discharged to the outside through the outflow side pipe 18. Thus, the heating unit 19 is formed by the tubular member 10 provided with the two plate-like electrodes 11 and 12.

  As shown in FIG. 2, a power supply unit 20 is connected to the two plate electrodes 11, 12 forming a pair in the heating unit 19. The power supply unit 20 supplies power having a frequency of about 20 kHz. A current flows through the object to be heated by the power supplied from the power supply unit 20 to the plate electrodes 11 and 12 in a state where the object to be processed is supplied into the heating space 13, and the object to be heated is heated by Joule heat. Is done. As described above, a high-frequency current is supplied from the power supply unit 20 to both plate-like electrodes 11 and 12, and the low potential side of the power supply unit 20 is connected to the first plate-like electrode 11. The high potential side is connected to the second plate electrode 12.

  As shown in FIG. 1, when the length of the first plate electrode 11, that is, the dimension in the direction in which the object to be heated flows is L1, and the dimension in the same direction of the second plate electrode 12 is L2, The length L1 is longer than the length L2. As shown in FIG. 2, when the dimension in the width direction of the first plate electrode 11 is W1, and the dimension in the width direction of the second plate electrode 12 is W2, the width W1 is larger than the width W2. ing. Both end corners of the inner surface of the first plate electrode 11 are outer peripheral edges 21a and 21b on the end side as shown in FIGS. 1 and 3, and both side corners of the inner surface are shown in FIG. As shown, the outer peripheral edges 21c and 21d are formed on the side portions. Similarly, both end corners of the inner surface of the second plate electrode 12 are outer peripheral edges 22a and 22b on the end side as shown in FIG. 1, and both side corners of the inner surface are shown in FIG. As shown, the outer peripheral edges 22c and 22d on the side portions are formed. A flat surface surrounded by all the outer peripheral edges 21 a to 21 d in the first plate-like electrode 11 serves as a current-carrying surface 23, and similarly surrounded by all the outer peripheral edges 22 a to 22 d in the second plate-like electrode 12. The flat surface to be provided is a current-carrying surface 24. The energization surface 23 of the first plate electrode 11 has a larger area than the energization surface 24 of the plate electrode 12, and the outer peripheral edges 22 a to 22 d of the second plate electrode 12 The plate-like electrode 11 is shifted to the inner sides of the outer peripheral edges 21a to 21d. That is, the outer peripheral edges 22a to 22d of the second plate electrode 12 are opposed to the current-carrying surface 23 of the first plate electrode 11, and the outer peripheral edges of both the plate electrodes 11 and 12 are shifted from each other. .

  When the outer peripheral edges of both plate-like electrodes 11 and 12 are opposed to each other as in the prior art, when a potential difference is applied between the electrodes by supplying electric power to each of the plate-like electrodes 11 and 12, In this portion, more current may flow than portions between other flat surfaces, and sparks may occur between the peripheral edges. For this reason, when a to-be-heated material passes between the outer peripheral edges of both plate-shaped electrodes 11 and 12, it will be in an overheated state rather than passing through the site | part between electricity supply surfaces, and it will not be heated uniformly in the whole to-be-heated material. There was a thing.

  On the other hand, if the outer peripheral edges of both plate electrodes 11 and 12 are shifted from each other with respect to the current-carrying surface, the current flowing between the outer peripheral edges will be dispersed, and no occurrence of sparks is observed. The object to be heated did not generate overheating and could be heated to a uniform temperature as a whole. In particular, when the second plate electrode 12 is set to the high potential side and the outer peripheral edges 22a to 22d are shifted inward with respect to the outer peripheral edges 21a to 21d of the first plate electrode 11, the second plate on the high potential side. The current flowing from the outer peripheral edges 22a to 22d of the electrode 12 toward the first plate electrode 11 is dispersed on the current-carrying surface 23 of the first plate electrode, and no spark is generated.

  In the heating apparatus shown in FIGS. 1 to 3, the sizes of both plate-like electrodes 11 and 12 are different, and the second plate-like electrode 12 is smaller than the first plate-like electrode 11. . As shown in FIGS. 2 and 3, the energizing surface 23 of the first plate electrode 11 attached to the wall portion 10a of the tubular member 10 is flush with the exposed surface of the wall portion 10a. The current-carrying surface 24 of the second plate electrode 12 attached to the wall 10b is flush with the exposed surface of the wall 10b. Thus, as for both plate-shaped electrodes 11 and 12, the corner | angular part of the outer peripheral surface of plate-shaped electrode itself becomes an outer periphery edge.

  FIG. 4 is a perspective view showing a longitudinal section of a modified tubular member, and FIG. 5 is a transverse sectional view of the tubular member shown in FIG.

  Unlike the case described above, the two plate-like electrodes 11 and 12 attached to the tubular member 10 have the same size. As shown in FIG. 4 and FIG. 5, an insulating layer 25 is provided in a strip shape on the outer peripheral portion of the second plate electrode 12, and each boundary portion between the insulating layer 25 and the plate electrode 12 is provided. Outer peripheral edges 22a to 22d are formed. As described above, when the outer peripheral portion of the plate electrode 12 is covered with the insulating layer 25, the two plate electrodes 11, 12 have the same size, and the outer edges of both plate electrodes 11, 12 are mutually connected. Since it can be shifted, both plate-like electrodes 11 and 12 can be manufactured using one type of plate-like electrode.

  Although the heating device 9a shown in FIG. 1 has one heating unit 19, a plurality of heating units 19 are connected in series to form a single heating device, and the object to be heated in a plurality of stages. You may make it heat-process.

  6 to 8 show a high electric field type heating device 9b according to another embodiment. This heating device 9b has a first plate-like electrode 11 and a second plate-like electrode 12, and a spacer 32 made of an insulating material and having a long hole 31 is disposed between them. The heating unit 19 of the heating device 9b is formed by two plate electrodes 11 and 12 and a spacer 32. The heating space 13 is formed by the long hole 31 and both the plate-like electrodes 11 and 12, and the thickness dimension of the heating space 13, that is, the distance between the electrodes is D. Both plate electrodes 11 and 12 and the spacer 32 are fastened by a plurality of bolts 33. The bolt 33 and the plate electrodes 11 and 12 are insulated from each other so that the plate electrodes 11 and 12 are not electrically connected via the bolt 33.

  One plate-like electrode 11 is provided with an inlet 14a, and the other plate-like electrode 12 is provided with an outlet 15a. The inflow side piping 17 is connected to the inflow port 14a, and the outflow side piping 18 is connected to the outflow port 15a. A hopper (not shown) is connected to the inflow side pipe 17, and food and drink as a heated object accommodated in the hopper is supplied to the inflow port 14 a by a pump. The object to be heated supplied to the inflow port 14a flows through the heating space 13 formed by the long holes 31 and is discharged to the outflow port 15a. The heated object conveyed to the outlet 15a is discharged to the outside through the outflow side pipe 18. The flow rate of the object to be heated flowing in the heating space 13 is set so that the Reynolds number Re is 2300 or more. However, the Reynolds number Re is represented by Re = vd / ν. v is the average flow velocity of the heated object, d is the inner diameter of the tube member, and ν is the kinematic viscosity coefficient of the heated object.

  A power supply unit 20 is connected to both plate-like electrodes 11 and 12, and the plate-like electrodes 11 and 12 have a voltage of 0.2 kV or more per 1 mm distance between electrodes, that is, a voltage of 0.2 kV / mm or more. A high frequency of about 20 kHz is supplied. Thus, when a high voltage is applied between the electrodes, even if microorganisms such as cells are contained in the object to be heated, the microorganisms have micropores on the surface of the cell membrane due to the electroporation phenomenon, and the cells of the microorganisms are removed. It can be destroyed and microorganisms such as bacteria can be killed in a short time. Thus, the object to be heated is heat sterilized by Joule heat and electroporation.

  The outer peripheral edges 21a to 21d are formed by the contact portion between the first plate electrode 11 butted against one side surface of the spacer 32 and the inner peripheral surface of the elongated hole 31, and the flat surface surrounded by the outer peripheral edges 21a to 21d is formed. An energizing surface 23 is formed. The outer peripheral edges 22a to 22d are formed by the contact portion between the second plate electrode 12 butted against the other side surface of the spacer 32 and the inner peripheral surface of the elongated hole 31, and a flat surface surrounded by the outer peripheral edges 22a to 22d is formed. An energizing surface 24 is formed.

  The inner peripheral surface of the long hole 31 formed in the spacer 32 has a tapered shape, and the opening areas of both surfaces are different. As shown in FIG. 8, the opening on the plate electrode 11 side of the long hole 31 is L1 in the direction in which the object to be heated flows, and the length of the opening on the plate electrode 12 side is L2. Then, the length L1 is longer than the length L2. Furthermore, if the width dimension of the opening on the plate electrode 11 side of the long hole 31 is W1, and the width dimension of the opening on the plate electrode 12 side of the long hole 31 is W2, the width W1 is larger than the width W2. ing. Accordingly, the outer peripheral edges 21 a to 21 d formed by the contact portion between the first plate electrode 11 and the inner peripheral surface of the long hole 31 are in contact with the second plate electrode 12 and the inner peripheral surface of the long hole 31. The outer peripheral edges 22 a to 22 d formed by the portions are shifted to the outside, and the area of the energizing surface 23 is larger than the area of the energizing surface 24.

  As described above, a high voltage high frequency of 0.2 kV or more per 1 mm distance between the electrodes is supplied from the power supply unit 20 to both plate electrodes 11 and 12. A low potential side of the power supply unit 20 is connected to the electrode 11, and a high potential side is connected to the second plate electrode 12.

  In this way, when the outer peripheral edges of both plate-like electrodes 11 and 12 are shifted from each other with respect to the current-carrying surface, the current flowing between the outer peripheral edges is dispersed, and no occurrence of sparks is observed. The object to be heated did not generate overheating and could be heated to a uniform temperature as a whole. In particular, when the second plate electrode 12 is set to the high potential side and the outer peripheral edges 22a to 22d are shifted inward with respect to the outer peripheral edges 21a to 21d of the first plate electrode 11, the outer peripheral edges 22a to 22d are changed to the outer peripheral edges. The current flowing toward 21a to 21d was dispersed on the current-carrying surface 23 of the first plate electrode, and no spark was generated.

  In the high electric field type heating device 9b, it is necessary to reduce the distance between the electrodes in order to increase the potential difference per 1 mm between the electrodes without excessively increasing the voltage applied to both the plate electrodes 11 and 12. A spacer 32 is interposed between the two plate electrodes 11 and 12, and the heating space 13 is formed by the long hole 31 and both the plate electrodes 11 and 12. On the other hand, in the heating device 9a, the plate electrodes 11 and 12 are arranged on the inner surface of the rectangular tubular member 10 in order to enlarge the heating space 13. The heating space 13 may be formed by interposing a spacer 32 between the plate electrodes 11 and 12.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, you may make it provide the cooling device for cooling the plate-shaped electrodes 11 and 12 in each heating apparatus 9a and 9b. Further, the present invention is also applied to a heating apparatus in which two plate electrodes 11 and 12 are arranged in a container and batch processing is performed on the object to be heated without flowing the object to be heated in the heating space 13. Can do.

DESCRIPTION OF SYMBOLS 10 Tubular member 11 1st plate electrode 12 2nd plate electrode 13 Heating space 14a Inflow port 15a Outlet 17 Inflow side piping 18 Outflow side piping 19 Heating unit 20 Power supply unit 21a-21d of 1st plate-shaped electrode Peripheral edges 22a to 22d Peripheral edges 23 and 24 of the second plate electrode Current-carrying surface 25 Insulating layer 31 Long hole 32 Spacer

Claims (7)

A heating unit provided with first and second plate-like electrodes arranged to face each other across a heating space;
A power supply unit that supplies electric power to the plate electrode and generates Joule heat on an object to be heated between the two plate electrodes;
A heating apparatus, wherein an outer peripheral edge of the first plate electrode and an outer peripheral edge of the second plate electrode are shifted from each other.   2. The heating apparatus according to claim 1, wherein an inflow side joint that supplies an object to be heated into the heating space and an outflow side joint that discharges the object to be heated that has passed through the heating space to the outside are heated. A heating apparatus provided in a unit and heated while conveying an object to be heated into the heating space.   3. The heating device according to claim 1, wherein a spacer made of an insulating material is provided between the first plate-like electrode and the second plate-like electrode, and a long hole for forming the heating space is provided. And an outer peripheral edge of the first plate electrode formed by a contact portion between one opening surface of the elongated hole and the first plate electrode, the other opening surface of the elongated hole, and the second A heating apparatus characterized in that an outer peripheral edge of the second plate electrode formed by a contact portion with the plate electrode is shifted from each other.   3. The heating device according to claim 1, wherein an area of the first plate electrode is smaller than an area of the plate electrode, and an outer peripheral edge of the second plate electrode is the first plate electrode. A heating device, which is arranged inside the outer peripheral edge.   3. The heating device according to claim 1, wherein an insulating layer is provided on an outer peripheral portion of the second plate electrode, and the second plate is formed by a boundary portion between the insulating layer and the second plate electrode. A heating apparatus, wherein an outer peripheral edge of the plate electrode is disposed inside an outer peripheral edge of the first plate electrode.   4. The heating device according to claim 3, wherein a voltage of 0.2 kV or more is applied per 1 mm distance between the electrodes in the heating space through which an object to be heated formed between the first and second plate electrodes flows. A heating apparatus characterized by destroying a cell membrane of microorganisms by effect and sterilizing and heating an object to be heated. The heating apparatus according to any one of claims 3 to 6, wherein the first plate-like electrode is a high-potential side electrode, and the second plate-like electrode is a low-potential side electrode. A heating device.

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