JP4603932B2 - Heating device - Google Patents

Description

  The present invention relates to a heating apparatus that heats a food or drink having fluidity as an object to be heated while continuously conveying it.

  To heat foods and drinks with low viscosity such as juice and soup, and fluid foods and drinks such as pasty foods with high viscosity such as honey, jam and miso For example, as described in Patent Documents 1 and 2, a joule heating device has been developed that energizes food and drink itself and heats the food and drink with Joule heat.

As described in the above publication, the joule heating device that heats electricity while continuously flowing food and drink has a tubular member that continuously guides food and drink, that is, a heating pipe, and the food and drink are contained in the heating pipe. A current is caused to flow from the electrode provided in a pair to the heating pipe to the food and drink. A single heating pipe is usually provided with a plurality of electrodes, and the heating device includes a type constituted by a single heating pipe and a plurality of heating units for heating food and drink to a predetermined sterilization temperature in a plurality of stages. Some types are composed of pipes.
Japanese Patent No. 2821087 Japanese Patent No. 2840014

  When the food or drink is joule-heated, even if a constant voltage is supplied between the electrodes, the current value differs depending on the conductivity of the food or drink, that is, the electrical resistance. For this reason, the voltage to be applied to the electrode based on the final heating temperature of the food and drink is obtained in advance by experiments, and a reference applied voltage is applied to the electrode during energization heating. When heating food or drink, a reference applied voltage is set for each type of food or drink.

  In a heating device that energizes and heats while transporting food and drink having fluidity, the temperature of the heated food and drink is detected by a temperature sensor, and power is supplied to the electrodes based on the deviation between the detected temperature and the set temperature. The power supplied from the unit is feedback controlled. Such a control method is the same for both a heating device consisting of a single pipe and a heating device consisting of a plurality of pipes. When the temperature of the heated food and drink is detected, the power is feedback controlled. Since the electric power is controlled based on the temperature after the heating is finished, there is a possibility that the final heating temperature may vary due to a delay in the time until the electric power is controlled. In order to be able to heat to the sterilization temperature, it is necessary to allow a sufficient heating temperature.

  Food and drink are continuously supplied from the hopper to the heating device by a pump. When the remaining amount of food and drink in the hopper decreases, the same kind of food and drink is newly put into the hopper. In the hopper, for example, when strawberry jam is sterilized by heating, the strawberry is crushed with a kneader together with a seasoning and the like to be put into a fluid food material, and the food material is put into one hopper. Since the input amount is batch-processed, the conductivity may be different for each input amount. Therefore, if the electrical conductivity is different between the food material that has been newly added to the hopper and the food material that has already been input, if the current is heated while being continuously conveyed, the change in the electrical conductivity will also occur. There may be variations in the final heating temperature.

  An object of the present invention is to enable energization heating to a desired temperature with high accuracy while transporting fluid food and drink.

The heating device of the present invention is a heating device that heats food and drink having fluidity by Joule heat while continuously transporting food and drinks as heated objects in the flow channel, and is formed of an insulating material and forms the flow channel. An upstream and downstream energization heating unit each having a tubular member and an electrode provided in a pair with the tubular member, and an upstream power supply for supplying electric power to the electrode provided in the upstream energization heating unit A unit, a downstream power supply unit that supplies power to the electrode provided in the downstream energization heating unit, and a first temperature that detects the temperature of the object to be heated flowing into the upstream energization heating unit A temperature sensor, a second temperature sensor for detecting the temperature of the heated object flowing out from the upstream energization heating unit , and a heating end temperature of the heated object flowing out of the downstream energization heating unit The third temperature Sa and, from the downstream side of the power supply unit to the electrode provided on the electrical heating unit of the downstream side based on the upstream side deviation between the detection value of the first and the second temperature sensor and the detection value of the temperature sensor When the supplied power is feedforward controlled and the upstream deviation is less than or equal to a predetermined value, the downstream energization heating unit is controlled based on the downstream deviation between the target heating temperature and the temperature detected by the third temperature sensor. Control means for performing feedback control on power provided from the downstream power supply unit to the provided electrode in preference to feedforward control .

  The heating apparatus according to the present invention is characterized in that the upstream power supply unit supplies power of a constant voltage to the electrodes provided in the upstream heating unit.

  In the heating device of the present invention, the upstream and downstream energization heating sections are each formed by a heating unit having a plurality of ring-shaped electrodes and a plurality of insulating cylindrical bodies disposed between the electrodes. It is characterized by doing.

  In the heating device of the present invention, the downstream energization heating unit is formed by a plurality of heating units each having a tubular member made of an insulating material and forming the flow path and electrodes provided in pairs with the tubular member. The maximum voltage supplied to the electrode in the most downstream heating unit among these heating units constituting the downstream heating unit is the maximum voltage supplied to the electrode in the upstream heating unit. It is characterized by lower than.

  According to the present invention, the heating device has an upstream energization heating unit and a downstream energization heating unit, and the downstream energization heating unit based on the temperature rise value in the upstream energization heating unit, that is, the upstream deviation. Since the electric power supplied to the electrodes of the first and second electrodes is controlled, the downstream energization heating unit is feedforward-controlled based on the upstream deviation, and the food or drink that is heated by the heating device Can be heated to the heating target temperature with high accuracy, and can be rapidly set to the heating target temperature particularly at the time of start-up.

  According to the present invention, in addition to feedforward control, feedback control is performed on the power supplied to the electrode of the downstream heating unit based on the downstream deviation between the final heating temperature flowing out of the heating device and the target heating temperature. Therefore, the object to be heated can be set to the target heating temperature with high accuracy.

  According to the present invention, it is possible to perform energization heating according to the temperature state of the object to be heated by switching between feedback control and feedforward control according to the state.

  When a constant voltage is applied to the electrode in the upstream energization heating section, the temperature rise value in the upstream energization heating section corresponds to the conductivity or resistance value of the heated object, that is, the electrical property, and the heated object is Depending on the condition, it can be energized and heated. Therefore, for example, in the case of heating food or drink continuously supplied from within the hopper, when heating the same kind of food or drink newly introduced into the hopper after the heating of the food or drink introduced into the hopper is completed. Furthermore, the variation in the heating temperature can be suppressed in advance by detecting the change in the electrical properties of the new food or drink based on the upstream side deviation and feed-forward controlling the power to the downstream energization heating unit.

  The downstream heating unit is composed of a plurality of heating units, and the maximum value of the power value supplied to the electrode of the most downstream heating unit in the downstream heating unit is determined in the upstream heating unit. When the electric power value supplied to the electrode is smaller than the maximum value, the energization amount in the most downstream heating unit that heats the object to be heated that is approaching the final heating temperature can be controlled with higher accuracy.

  FIG. 1 is a schematic diagram showing the overall configuration of a food and beverage production system equipped with the heating device of the present invention. This production system heats food and beverage having fluidity such as strawberry jam as a heated object. A hopper 11 that is used to produce food and drink and that contains food and drink prepared in a fluidized state in advance and accommodates a predetermined amount of food and drink, and a heated object that is continuously supplied from the hopper 11 are preheated. It has a preheating device 12 and a joule heating device 13 that heats an object to be heated continuously supplied from the preheating device 12 to a predetermined sterilization temperature. The object to be heated heated to the predetermined sterilization heating temperature by the joule heating device 13 is continuously supplied to the cooling device 14 and cooled, then supplied to the recovery tank 15 and stored therein, and the recovery tank 15 To a filling machine (not shown) for filling a packaging bag or the like.

  The preheating device 12 has a plurality of preheating pipes 22 formed in a flow path therein and connected in series by a connecting pipe 21 and connected to the hopper 11 by a pipe 17a provided with a pump 16a. The object to be heated in the hopper 11 is conveyed to the flow path in each preheating pipe 22 at a constant flow rate by the pump 16a. An outer pipe 23 is attached outside each preheating pipe 22, and a heating chamber 24 to which a heating medium is supplied is formed between the preheating pipe 22 and the outer pipe 23, and hot water is generated in each heating chamber 24. Hot water heated by the machine 25 is supplied as a heating medium via the pipe 26. The object to be heated that flows continuously in the preheating pipe 22 is indirectly heated by the preheating pipe 22 that is heated by the heating medium. For example, when strawberry jam is used as the object to be heated, the heating temperature is about 40 to 60 ° C. Until preheated.

  The Joule heating device 13 connected to the preheating device 12 by a pipe 17b has four heating units 28 from the first stage to the fourth stage, in which a flow path is formed and connected to each other in series by a connection pipe 27. The object to be heated that has been preheated to a predetermined temperature by the preheating device 12 is heated to the sterilization temperature by the Joule heating device 13. For example, when using strawberry jam as a food or drink to be heated, it is heated to a temperature of about 85 to 98 ° C. The joule heating device 13 shown in FIG. 1 has four heating units 28, and an object to be heated that has passed through the final heating unit 28 is held at a final heating end temperature for a predetermined time in a hold tube 29 as a heat insulator. Later, it is conveyed to the cooling device 14 by the pipe 17c. The joule heating device 13 is not composed of four heating units 28 as shown in the figure, but is composed of any number of heating units 28 according to the type of food or drink to be heated, the transport flow rate, and the like. Can do.

The cooling device 14 has a plurality of cooling pipes 32 in which flow paths are formed and connected to each other in series by connecting pipes 31. The cooling device 14 is connected to the joule heating device 13 by a pipe 17 c and is heated after the heating is finished. Objects are conveyed to the flow paths in the respective cooling pipes 32. An outer pipe 33 is attached to the outside of each cooling pipe 32, and a cooling chamber 34 to which a cooling medium is supplied is formed between the cooling pipe 32 and the outer pipe 33, and each cooling chamber 34 has a chilled water generator. Cooling water generated by 35, that is, a chiller, is supplied as a cooling medium through a pipe 36. The object to be heated that continuously flows in the cooling pipe 32 is indirectly cooled by the cooling pipe 32 that is cooled by the cooling medium, and is conveyed to the recovery tank 15 via the pipe 17d. A pump 16b is attached to the connection pipe 31 in order to adjust the pressure of the food and drink flowing through the cooling device 14. A discharge pipe 37 connected to the recovery tank 15 is provided with a pump 16c for supplying an object to be heated to the filling machine.

  In the case shown in FIG. 1, the joule heating device 13 includes a preheating device 12 and a cooling device 14, and is incorporated in a manufacturing system for producing food by sterilizing and heating food and drink. However, when the preheating device 12 is not used, the joule heating device 13 is directly connected to the hopper 11 by piping, and when the cooling device 14 is not used, it is directly connected to the recovery tank 15 by piping. Become. In addition, the food and drink after being heated by the Joule heating device 13 and cooled by the cooling device 14 may be directly carried out toward the filling machine or the like without being collected in the collection tank 15.

  FIG. 2 is an enlarged cross-sectional view showing one of the four heating units 28 constituting the joule heating device 13, and the heating unit 28 is a heating pipe having a circular cross section in which a channel 41 for guiding an object to be heated is formed. A member 42 is provided. The tubular member 42 is composed of a plurality of ring-shaped electrodes 43 and a plurality of cylindrical bodies 44 disposed therebetween, and the heating unit 28 includes a tubular member 42 composed of the electrodes 43 and the cylindrical bodies 44. The tubular member 42 is provided with a pair of electrodes 43. Each electrode 43 is formed of a conductor such as titanium or stainless steel, and each cylindrical body 44 is formed of an insulator such as resin. Joint portions 45 and 46 on the inflow side and the outflow side are attached to both ends of the tubular member 42. A power supply unit 47 is connected to each electrode 43 via a cable, and a high frequency current is supplied from the power supply unit 47 so that the pair of electrodes 43 adjacent to each other in the flowing direction of the object to be heated have opposite polarities. Supplied. The number of electrodes 43 provided in each heating unit 28 shown in FIG. 1 is arbitrarily set according to the heating temperature and the like.

  FIG. 3 is a block diagram showing a control circuit for controlling energization to the electrodes of the joule heating device 13. In FIG. 3, the four heating units 28 shown in FIG. d, the most upstream heating unit 28a constitutes an upstream energization heating unit 48, and the three downstream heating units 28b to 28d constitute downstream energization heating units 49, respectively. is doing. The pipe 17b is provided with a first temperature sensor 51 for detecting the temperature of the object to be heated flowing into the heating unit 28a as the upstream side heating unit 48, and connected to the connecting pipe 27 connected to the outlet of the heating unit 28a. Is provided with a second temperature sensor 52 for detecting the temperature of the object to be heated flowing out of the heating unit 28a. Further, the connecting pipe 27 connected to the outlet of the heating unit 28d at the final stage is a third temperature that detects the heating end temperature of the heated object that is heated in all the heating units 28a to 28d and flows out of the heating unit 28d. A sensor 53 is provided. If the first temperature sensor 51 detects the temperature before the object to be heated is heated by the heating unit 28a, the first temperature sensor 51 is attached to the inlet side end of the heating unit 28a. Also good. If the temperature of the object to be heated after being heated by the heating unit 28a is detected, the second temperature sensor 52 may be attached to the outlet side end of the heating unit 28a. The temperature sensor 53 may be attached to the outlet side end of the heating unit 28d.

  A power supply unit 47a serving as an upstream power supply unit is connected to the electrode 43 provided in the heating unit 28a serving as the upstream current heating section 48. From the power supply unit 47a, the direction in which the object to be heated flows is connected. Electric power is supplied to the electrodes 43 adjacent to each other so that the voltage between the electrodes is constant. On the other hand, a power supply unit 47b as a downstream power supply unit is connected to the electrodes 43 provided in the three heating units 28b to 28d as the downstream energization heating unit 49, and the power supply unit 47b is heated. The power supplied to the electrodes 43 that are adjacent to each other in the direction in which the object flows is controlled according to the temperature detected by the temperature sensors 51-53.

  In each of the power supply units 47a and 47b, the power supplied to the electrode 43 is controlled by a control signal from the control unit 54 as a control means. As described above, power is supplied from the power supply unit 47a to the electrode 43 so as to have a constant voltage, whereas the voltage is controlled in the power supply unit 47b based on the detection values of the temperature sensors 51 to 53. The For example, power of a constant voltage is supplied to the pair of electrodes 43 in the heating unit 28a so that the interelectrode voltage becomes 900V. On the other hand, the heating units 28b to 28d are supplied with electric power having an arbitrary voltage that sets the maximum value of the interelectrode voltage to 800 V, for example, or the heating units 28b to 28d have mutually different maximum voltage values. An arbitrary voltage is supplied. In the case where the maximum voltage values are different between the heating units 28b to 28d, the maximum value is set to 800 V for the heating unit 28a on the most upstream side, the maximum value is set to 700 V for the heating unit 28c, and the heating unit 28d The maximum value is set to 600 V, for example.

  As described above, the plurality of heating units 28b to 28d constituting the downstream energization heating unit 49 are configured such that the supplied electric power is different from each other and the electrode 43 of the downstream energization heating unit 49 has an arbitrary voltage. It can be. Assuming that the value for setting each maximum voltage value is an MV value and the MV value corresponding to the maximum voltage value is 1, the electrode 43 of the downstream heating unit 49 has a maximum voltage value, that is, a voltage value of 100%. The power of 800V, 700V, and 600V is supplied. When the MV value is 0.5, 400V, 350V, and 300V electric power, which is 50% of the maximum value of each, is supplied to the electrode 43.

  In this way, the downstream energization heating unit 49 is configured by a plurality of heating units 28b to 28d, and among these heating units 28b to 28d, the heating unit 28b on the most upstream side goes to the heating unit 28d on the most downstream side. When the voltage supplied to the electrode 43 is sequentially lowered to 800 V, 700 V, and 600 V, the voltage change amount with respect to the unit MV value in the downstream heating unit 28 d is made smaller than the voltage change amount in the upstream heating units 28 a and 28 b. Therefore, in the most downstream heating unit 28d that finally heats under a temperature state close to the heating target temperature, the heating temperature of the object to be heated can be controlled with high accuracy. Thereby, a to-be-heated material can be heated to heating target temperature with high precision.

  The control unit 54 is provided with a microprocessor CPU for calculating control signals, a ROM for storing control programs, arithmetic expressions and data, and a RAM for temporarily storing data. The signal corresponding to the inflow temperature T1 detected by the first temperature sensor 51, the signal corresponding to the outflow temperature T2 detected by the second temperature sensor 52, and the heating detected by the third temperature sensor 53 A signal corresponding to the end temperature T3 is sent. When the temperature deviation between the inflow temperature T1 and the outflow temperature T2, that is, the upstream side deviation ΔT1 (T2-T1) is calculated, power of a constant voltage is supplied to the electrode 43 in the upstream energization heating unit 48, and thus the upstream side deviation ΔT1. Is a value corresponding to the conductivity and resistance of the object to be heated. The control unit 54 feeds the power supply unit 47b forward-forward so as to control the power supplied to the electrodes 43 of the three heating units 28b to 28d as the downstream energization heating unit 49 based on the upstream deviation ΔT1. Control. In this way, a reference signal for power (product of current and voltage) control is sent from the control unit 54 to the upstream power supply unit 47a so that the voltage in the upstream heating unit 48 is constant. Yes. Further, a control signal is sent from the control unit 54 to the downstream power supply unit 47b so that the power supplied to the downstream energization heating unit 49 is controlled based on the upstream deviation ΔT1.

  The control unit 54 is connected to an operation panel 55 provided with an input key for setting a heating target temperature Ta for the object to be heated, and the heating end temperature T3 detected by the third temperature sensor 53 and the heating target. A temperature deviation from the temperature Ta, that is, a downstream deviation ΔT2 (absolute value of a temperature difference between Ta and T3) is calculated. The control unit 54 feedback-controls the power supply unit 47b so as to control the power supplied to the electrodes 43 of the three heating units 28b to 28d as the downstream energization heating unit 49 based on the downstream deviation ΔT2. To do.

  As described above, the power supplied to the electrodes 43 of the heating units 28b to 28d constituting the downstream energization heating unit 49 is feedforward controlled based on the upstream deviation ΔT1 by changing the MV value. In addition, since feedback control is performed based on the downstream deviation ΔT2, the object to be heated is heated to the heating target temperature Ta with higher accuracy than when only the feedback control is performed, both at the time of starting the heating device and at the steady state. can do. In particular, by performing feedforward control when the heating device 13 is started up, it is possible to quickly shift to a steady state.

  Therefore, for example, in the case of heating food or drink continuously supplied from within the hopper 11, after the heating of the food or drink put into the hopper 11 is finished, the same kind of food or drink is newly added to the hopper 11. When a new batch of food or drink is heated after charging, even if the electrical properties of the new food or drink are different from the electrical properties of the food and drink section that has been heat-treated before that, that is, the batch is different. Even if the conductivity changes from the previous batch, the change at the time of switching is detected on the basis of the upstream deviation ΔT1, and the feed-forward control of the power to the downstream energization heating unit makes it possible to control the heating temperature of the food and drink. Variations can be suppressed in advance.

  FIG. 4 is an algorithm showing an example of the energization control procedure in the heating device described above. In step S1, detection values from the first to third temperature sensors 51 to 53 are read, and based on the read detection values. An upstream deviation ΔT1 is calculated (step S2) and a downstream deviation ΔT2 is calculated (step S3). In step S4, it is determined whether or not the upstream deviation ΔT1 is larger than the set value A. If the upstream deviation ΔT1 is larger than the set value A, step S5 is executed, and the step S6 is performed based on the MV value calculated based on the upstream deviation ΔT1. Thus, power is controlled by feedforward control. On the other hand, when it is determined in step S4 that the upstream deviation ΔT1 is smaller than the set value A, step S7 is executed, and the power is controlled by feedback control in step S8 based on the MV value calculated based on the downstream deviation ΔT2. Is done.

  The setting value A for determining whether to perform feedback control or feedforward control may be a constant value, and a setting formula corresponding to the line characteristics of the heating device is stored in the memory, and the setting formula at the time of control The set value A may be obtained by calculating.

  5A is a longitudinal sectional view showing another specific example of the heating unit, and FIG. 5B is a transverse sectional view of FIG. 5A. The heating unit 28 includes a tubular member 61 having a square cross section in which a channel 41 for guiding an object to be heated is formed. The tubular member 61 is formed of an insulating material such as resin, and two plate-like electrodes 43 are attached to the inner surface of the tubular member 61 so as to face each other, and a power supply unit 47 is connected to each electrode 43 by a cable. Has been. At both ends of the tubular member 61, joint portions 45 and 46 on the inflow side and the outflow side are attached.

  FIG. 6 is a longitudinal sectional view showing still another specific example of the heating unit 28. The heating unit 28 includes a tubular member 71 having a circular cross section in which a channel 41 for guiding an object to be heated is formed. The tubular member 71 is formed of an insulating material such as a resin. Plate-like electrodes 43 are attached to both end faces of the tubular member 71 so as to face each other, and a power supply unit 47 is connected to each electrode 43 by a cable. At both ends of the tubular member 71, joint portions 45 and 46 on the inflow side and the outflow side are provided. In this type of heating unit 28, the tubular member 71 may have a square cross section.

  FIG. 7 is a longitudinal sectional view showing still another specific example of the heating unit 28. The heating unit 28 includes a tubular member 81 having a circular cross section in which a flow path 41 for guiding an object to be heated is formed, and both ends of the tubular member 81 are closed by end plate portions 82. The plate portion 82 is formed of an insulating material such as resin. A cylindrical electrode 43 a is fixed to the inner surface of the tubular member 81, and both ends of the rod-shaped electrode 43 b disposed at the center of the tubular member 81 are fixed by end plate portions 82. A power supply unit 47 is connected to both cylindrical and rod-shaped electrodes 43a, 43b by cables, and inflow and outflow side joint portions 45, 46 are provided at both ends of the tubular member 81.

  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, the Joule heating device 13 has a plurality of heating units 28, but the Joule heating device 13 is formed by one heating unit, and the upstream half region is used as the upstream heating unit 48, and the downstream side. A half region may be the downstream energization heating unit 49. Further, the downstream energization heating unit 49 may be formed by one heating unit 28, and the upstream energization heating unit 48 may be formed by a plurality of heating units 28. Further, as shown in FIG. 1, the joule heating device 13 of the present invention can be used alone without being used together with the indirect heating type preheating device 12, and the heating device of the present invention is also used as the preheating device 12. be able to.

It is the schematic which shows the whole food / beverage manufacturing system structure provided with the heating apparatus of this invention. It is an expanded sectional view which shows one of the four heating units which comprise a joule heating apparatus. It is a block diagram which shows the control circuit which controls electricity supply with respect to the electrode of a Joule heating apparatus. It is an algorithm which shows an example of the electricity supply control procedure in a heating apparatus. (A) is a longitudinal cross-sectional view which shows the other specific example of a heating unit, (B) is a cross-sectional view of (A). It is a longitudinal cross-sectional view which shows the other specific example of a heating unit. It is a longitudinal cross-sectional view which shows the other specific example of a heating unit.

Explanation of symbols

11 Hopper 12 Preheating device 13 Joule heating device 14 Cooling device 15 Recovery tanks 28, 28a to 28d Heating unit 42 Tubular member 43 Electrode 44 Cylindrical body 47a Power supply unit (upstream power supply unit)
47b Power supply unit (downstream power supply unit)
51 1st temperature sensor 52 2nd temperature sensor 53 3rd temperature sensor 54 Control unit (control means)

Claims (4)

A heating device that heats by Joule heat while continuously transporting food and drink having fluidity as a heated object in a flow path,
A tubular member made of an insulating material that forms the flow path, and an upstream and downstream energization heating unit each having an electrode provided in a pair with the tubular member;
An upstream power supply unit that supplies power to the electrode provided in the upstream energization heating unit;
A downstream power supply unit that supplies power to the electrodes provided in the downstream energization heating unit;
A first temperature sensor for detecting a temperature of the heated object flowing into the upstream energization heating unit;
A second temperature sensor for detecting the temperature of the object to be heated flowing out from the upstream heating section;
A third temperature sensor for detecting a heating end temperature of the object to be heated flowing out from the downstream heating unit;
Based on the upstream deviation between the detection value of the first temperature sensor and the detection value of the second temperature sensor, an electrode provided in the downstream energization heating unit is supplied from the downstream power supply unit. When electric power is feedforward controlled and the upstream side deviation is less than or equal to a predetermined value, the downstream side electric heating unit is provided based on the downstream side deviation between the heating target temperature and the detected temperature of the third temperature sensor. And a control unit that feedback-controls the power supplied from the downstream power supply unit to the electrode in preference to the feedforward control . 2. The heating apparatus according to claim 1 , wherein the upstream power supply unit supplies electric power having a constant voltage to the electrode provided in the upstream energization heating unit. 3. 3. The heating apparatus according to claim 1 , wherein the upstream and downstream energization heating units include a plurality of ring-shaped electrodes and a plurality of insulating cylindrical bodies disposed between the respective electrodes. A heating device characterized by being formed by each unit. The heating apparatus according to any one of claims 1 to 3 , wherein the downstream energization heating unit is provided in a pair with a tubular member made of an insulating material and forming the flow path, and the tubular member. The maximum voltage supplied to the electrode in the most downstream heating unit among these heating units, which are formed by a plurality of heating units each having an electrode and constitute the downstream energization heating unit, is more upstream than this. A heating apparatus characterized by being lower than a maximum voltage supplied to an electrode in a heating unit.

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