JP2015080455A - Continuous energization heating apparatus for fluidity food material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent abnormal variation of voltage and current between electrodes, collapse of an AC waveform, difficulty of control, and damage of a transformer of a power supply caused by affection of leak current from an annular electrode for energization heating, when food materials are energized and heated by applying AC voltage across adjacent annular electrodes for energization heating, in a continuous energization heating apparatus in which electrodes for grounding are disposed on the respective outsides of electrodes on both side ends, among plural annular electrodes for energization heating forming a pipe line for energization heating.SOLUTION: Two electrodes for voltage application positioned on both end sides of a pipe line for energization heating are connected to an output terminal on the reference potential side of an output transformer of an AC power supply, among three or more annular electrodes for voltage application.

Description

  The present invention relates to a food material having fluidity that can be continuously fluidized and transported in a pipe (in a pipeline), such as a liquid food material (including beverages), a solid-liquid mixed food material, or a gel food material. The present invention relates to a device for continuously energizing and heating while continuously flowing and transporting the inside of a pipe line for sterilization and cooking, and the like.

  Recently, a method for heating food materials for sterilization, cooking, etc. has been put to practical use by applying an energization heating (Joule heating) method in which a food material is directly energized and generates heat by the electrical resistance of the food material. . An apparatus for continuously heating a flowable food material in the pipeline by energization heating while continuously flowing the flowable food material in the pipeline has been proposed in, for example, Patent Document 1, Patent Document 2, and the like. It has become.

  A basic configuration of a conventional example of such a continuous energization heating apparatus will be described with reference to FIGS. In an actual food manufacturing plant, etc., a plurality of current heating units are connected in series to form a continuous current heating device, and the flowable food material that has passed through one current heating unit is sequentially transferred to the adjacent current heating unit. First, FIG. 8 shows one current heating unit 3 based on FIG. 2 of Patent Document 1.

In FIG. 8, the electric heating unit 3 as a whole forms a hollow pipe (electric heating pipe) 15 having a flow path 19 through which the flowable food material flows. The energization heating conduit 15 has a plurality (six in the illustrated example) of annular electrodes 5 _{1 to} 5 ₆ made of a conductive material such as titanium arranged at intervals, and each of the annular electrodes 5 _{1 to} 5. _The hollow cylindrical insulating tubes 7 _{1 to} 7 _{7 made of} an electrically insulating material such as a resin are disposed between the annular electrodes 5 ₁ and 5 ₆ on both ends and outside the annular electrodes 5 ₁ and 5 _6.
And the whole is coupled by coupling means (not shown). In the example of FIG. 8, the insulating tube bodies 7 ₁ and 7 ₇ on both ends also serve as the flange members 11A and 11B.

Each annular electrode 5 ₁ to 5 ₆ Further, as the potential difference between adjacent electrodes occurs, is connected to an AC power source 4. Here, as the AC power source 4, for example, a high frequency power source that generates an AC high frequency current with an effective voltage of about 50 to 3000 V at a frequency of about 1 to 30 kHz is used. Then, odd-numbered annular electrodes 5 ₁ , 5 ₃ , 5 ₅ counted from the left in FIG. 8 are electrically connected to one output terminal (first output terminal) 4a of the high-frequency AC power supply 4 via the wiring 6A. The even-numbered annular electrodes 5 ₂ , 5 ₄ , 5 ₆ counted from the left in FIG. 8 are electrically connected to the other output terminal 4b via the wiring 6B.

For example, if the fluid food material is supplied from the left side of FIG. 8 to the current heating conduit 15 in the current heating unit 3 and the fluid food material is flowed to the right side of FIG. sequentially moving while in contact with the inner surface of the annular electrode 5 ₁ to 5 ₆ arranged at intervals. At this time, a high frequency voltage is applied between the adjacent annular electrodes, that is, between each of the annular electrodes 5 ₁ , 5 ₃ , 5 ₅ and the annular electrodes 5 ₂ , 5 ₄ , 5 _6. Since a potential difference occurs alternately between the electrodes, a current flows through the fluid food material between the electrodes. As a result, the food material generates heat (joule heat) due to the electrical resistance of the fluid food material, and the temperature of the food material rises. That is, Joule heating is performed. As a result, the food material is sterilized or sterilized, and the food material is cooked (modified).

By the way, the current heating device uses the fact that the food material itself generates heat due to resistance heat generation (Joule heat generation) by passing an electric current through the food material, so that the food material itself has conductivity. It is assumed. for that reason. Leakage current also flows through the food material flowing in the pipes outside the annular electrodes 5 ₁ , 5 ₆ (on the pipe extension direction side) located at locations closest to both ends of the pipes. Such a leakage current may cause an electric shock accident of an operator or the like.

Therefore, in an actual energization heating unit, for example, as shown in FIG. 9, a grounding annular electrode 9 </ b> A similar to each of the annular electrodes 5 _{1 to} 5 ₆ is provided further outside the annular electrodes 5 ₁ and 5 ₆ on both ends. , 9B are disposed via insulating tube bodies 7 ₁ , 7 ₇ , and flange members 11A, 11B are further provided outside the grounding annular electrodes 9A, 9B (for example, (See FIG. 2 of Patent Document 2). In this case, the grounding annular electrodes 9A and 9B are connected to a ground potential member, for example, a grounding rod 33 inserted into the ground GN, through the grounding wires 6C and 6D. If the grounding annular electrodes 9A and 9B are provided in this way, the leakage current from the annular electrodes 5 ₁ and 5 ₆ to the outside flows to the ground GN, so that the grounding annular electrodes 9A and 9B are outside. It is possible to prevent leakage current from flowing out (to the pipe extension direction) and to prevent occurrence of a dangerous situation such as an electric shock of an operator or the like.

  In general, the flange members 11A and 11B are often made of a conductive metal. Therefore, in some cases, the ground members 6A and 6D are provided on the flange members 11A and 11B without providing the grounding annular electrodes 9A and 9B. The flange members 11A and 11B themselves are also provided with a function as an annular electrode for grounding by connecting them.

  FIG. 10 shows the overall configuration of the continuous energization heating apparatus 1 incorporating a plurality of, for example, three units of the energization heating unit 3 shown in FIG. In addition, although the code | symbol of 3A, 3B, 3C is attached | subjected to the three electric heating units, each electric heating unit 3A, 3B, 3C is respectively the same structure as the electric heating unit shown with the code | symbol 3 in FIG. belongs to.

  This continuous energization heating apparatus 1 includes, for example, three energization heating units 3A, 3B, and 3C in a frame body 5 that has a rectangular frame structure as a whole by combining square bars made of metal such as steel and aluminum. They are arranged vertically with a slight inclination with respect to the horizontal plane. And each electricity heating unit 3A, 3B, 3C is connected in series by the piping 8. FIG. In practice, the electric heating units 3A, 3B, 3C and the pipe 8 are fixed in the frame 5 by a support member (not shown) mainly made of steel, aluminum or the like. Then, the grounding annular electrodes 9A, 9B (or the flange member having the grounding annular electrode function) of the current heating units 3A, 3B, 3C are connected to the frame of the frame body 5 by ground wirings (upstream side ground wirings) 6C, 6D. In addition, another ground wiring (downstream ground wiring) 6E is connected to an appropriate portion of the frame body 5, and the downstream ground wiring 6E is grounded to a ground potential member, for example, the ground GN. Often connected to the rod 33.

As described above, if each of the energization heating units is provided with grounding annular electrodes on both ends of the energization heating pipe line 15 or the grounding annular electrode function is provided to the flange members on both ends, leakage occurs. It is possible to prevent the current from flowing to the outside of the grounding annular electrode or the flange member. However, when a large continuous energization heating device of a scale that is used for actual operation is configured, depending on the connection relationship with the high-frequency AC power supply, it flows in the applied voltage between the electrodes and the food material that seems to be affected by the leakage current. Problems such as abnormal fluctuations in the current value and the occurrence of an abnormal phenomenon in which the high-frequency waveform is disrupted, and excessive current flowing through the transformer of the power supply, causing damage to the transformer, Recognized that problems such as loss of controllability occur.
If abnormal fluctuations occur in the voltage applied between the electrodes or the current flowing through the food material, the food material cannot be heated to the required temperature, resulting in insufficient heating or sterilization. There is a possibility that the food material may be altered by excessively high temperature, or may be seized on the inner surface of the annular electrode. Moreover, the control for heating the food material to a required temperature may be difficult due to such abnormal fluctuations in voltage and current and collapse of the AC waveform.

JP 2006-320402 A JP 2001-169733 A

  The present invention has been made against the background of the above circumstances, and among the plurality of energization heating annular electrodes constituting one energization heating conduit as described above, two energization heating annular electrodes on both ends are provided. In the continuous energization heating device in which the grounding annular electrode is disposed outside each of the two, when the food material is energized and heated by applying an AC voltage between the adjacent energization heating annular electrodes, the two energization heating devices It is effective that the inter-electrode voltage and current fluctuate abnormally, the AC waveform collapses, control becomes difficult, and the power transformer is damaged due to the influence of the leakage current from the annular electrode to the outside. It is an object of the present invention to provide a continuous energization heating device that can be prevented.

As a result of repeated experiments and examinations by the present inventors in order to solve the above-described problems, in the energization heating unit or the continuous energization heating apparatus as shown in FIGS. It has been found that the occurrence of abnormal fluctuations in voltage and current due to current cannot be reliably suppressed.
That is, in the electric heating unit shown in FIG. 9, of the annular electrode 5 ₁ to 5 ₆ constituting the electric heating conduit 15, the annular electrode 5 ₁ located at one end of the conduit, the power 4 It is connected to one output terminal 4a, the annular electrode 5 ₆ located at the other end end of the conduit is connected to the other output terminal 4b of the power supply 4. Therefore, there is always a potential difference between the annular electrodes 5 ₁ , 5 ₆ located at both ends of the conduit.

Here, the leakage current from the annular electrode 5 ₁ at one end of the conduit to the outside, through the grounding ring electrodes 9A, ground line 6C, 6D (and 6E) as, escapes to the ground GN, tube leakage current from the annular electrode 5 ₆ on the other end side of the road to the outside from the ground ring electrodes 9B, is released into the ground GN through ground line 6D (and 6E).

However, as described above, if there is a potential difference between the annular electrodes 5 ₁ , 5 ₆ located on both ends of the pipe line, between the annular electrodes for grounding 9A, 9B outside these annular electrodes 5 ₁ , 5 ₆ , At a certain moment (especially at the peak of the high-frequency waveform), a large potential difference occurs due to the leakage current.

  Moreover, in an actual large-sized electric heating apparatus, the length of the electrical path from the grounding annular electrodes 9A and 9B to the ground GN having the ground potential often reaches several meters or more. On the other hand, the grounding annular electrode 9A on one end side of the pipe line and the grounding annular electrode 9B on the other end side are electrically connected by a ground wiring (for example, ground wiring 6C). The length of the electrical path connecting the grounding annular electrodes 9A and 9B is usually much shorter than the length of the electrical path from the grounding annular electrodes 9A and 9B to the ground GN. . In particular, as shown in FIG. 10, the grounding annular electrodes 9A and 9B on both ends of each energization heating unit are connected to the frame of a frame 5 made of steel, for example, by upstream ground wiring. When connecting to the ground GN by the ground wiring on the downstream side from this point, the electrical resistance of the steel frame of the frame body is much higher than the ground wiring with low electrical resistance such as copper, so the electrical resistance was considered The effective electrical path is very long.

  The large current difference between the grounding annular electrodes 9A and 9B as described above and the large difference in the effective length of the electrical path are combined, and the leakage current is caused by the grounding annular electrode 9A. , 9B hardly flows to the ground GN, and is short-cut by an electrical path (ground wiring 6C) connecting between the grounding annular electrodes 9A and 9B, so that one grounding annular electrode is connected to the other grounding annular electrode. It will flow in. Such a short-circuited leakage current flow is indicated by a solid arrow P1 in FIG. In addition, the flow of the leakage current that should flow to the original ground GN is indicated by a broken line arrow P2 in FIG. As a result of the shortcut flow of the leakage current between the grounding annular electrodes 9A and 9B, the current and voltage between the electrodes including the grounding annular electrode vary. Here, since the magnitude of the leakage current changes from moment to moment depending on the state of the flowable food material flowing in the pipeline, it is difficult to predict the voltage and current fluctuations caused by the leakage current as described above. Therefore, it must be said that it is an unexpected variation.

  In addition, as shown in FIG. 10, when a plurality of energization heating units 3A, 3B, 3C are connected in series and installed in one frame 5, an electrical path on the earth side between the respective energization heating units. As a result, the leakage current generated in one current-carrying unit flows into the grounding annular electrode of another current-carrying heating unit, and the abnormal fluctuations in voltage and current described above also occur on that unit side. There is.

Therefore, as a result of further studies by the present inventors in order to suppress the occurrence of the abnormal phenomenon due to the leakage current as described above, the present invention has been made.
That is, the above abnormal phenomenon is mainly caused by the potential difference between the annular electrodes on both ends of the conduit of the energizing heating unit, so that the annular electrodes on both ends of the conduit are always at the same potential. If configured, it is considered that the occurrence of the abnormal phenomenon can be suppressed, and as a result of actual experiments, it has been found that the occurrence of the abnormal phenomenon due to the leakage current can surely be suppressed, and the present invention has been made.

Specifically, the continuous energization heating device for the flowable food material of the basic aspect (first aspect) of the present invention is:
Three or more voltage application annular electrodes having at least an inner peripheral surface made of a conductive material and four or more insulating tubes having at least an inner peripheral surface made of an electrically insulating material are alternately arranged along a common axis. An electrode for applying voltage adjacent to each other by an AC power supply device while forming a current-carrying heating pipeline and continuously fluidly transferring a fluid food material in the lengthwise direction in the current-heating channel. In a continuous energization heating device for fluid food material that is heated by energizing the fluid food material in the pipeline continuously in the length direction of the pipeline by applying an alternating voltage between
An annular grounding functional member having at least an inner peripheral surface made of a conductive material on both sides in the pipe extension direction from the two voltage application electrodes located on both ends of the energization heating pipe via an insulating pipe. Disposed, and those grounding functional members are electrically grounded,
Further, in the AC power supply apparatus, the output terminal on the reference potential side and one or more output terminals on the alternating potential side whose potential is inverted to positive and negative with respect to the reference potential are drawn from the secondary winding of the output transformer. And
Among the voltage application annular electrodes, the two voltage application electrodes located on both ends of the current heating conduit are commonly connected to a reference potential side output terminal of the output transformer. To do.
Here, the grounding functional member means a conductive flange member in the case where a grounding annular electrode similar to the voltage application annular electrode or a conductive flange member is provided at both ends of the current heating conduit. doing.

Moreover, the continuous electric heating apparatus of the fluid food material of the second aspect of the present invention is the continuous electric heating apparatus of the first aspect,
The grounding functional member on one end side and the grounding functional member on the other end side of the energization heating conduit are electrically connected by a wiring connecting between them, and the ground wiring is drawn from at least one grounding functional member. And is electrically grounded.

Furthermore, the continuous energization heating device of the fluid food material according to the third aspect of the present invention is the continuous energization heating device according to the first or second aspect,
The energization heating pipe is divided into a plurality of zones in the length direction, and a voltage applied between the voltage application ring electrodes in one zone and a voltage application ring electrode in another zone. Each voltage application ring-shaped electrode is connected to an output transformer of the power supply device so that a voltage to be applied is different.

Moreover, the continuous electricity heating apparatus of the fluid food material according to the fourth aspect of the present invention comprises:
Three or more voltage application annular electrodes having at least an inner peripheral surface made of a conductive material and four or more insulating tubes having at least an inner peripheral surface made of an electrically insulating material are alternately arranged along a common axis. An AC power source is disposed between adjacent voltage application electrodes while forming a current-carrying heating conduit and continuously fluidly transferring the fluid food material in the length direction in the current-heating conduit. A plurality of energization heating units are provided that are heated by energizing the fluid food material in the pipeline continuously in the length direction of the pipeline by applying an alternating voltage by the apparatus,
An annular structure in which at least the inner peripheral surface is made of a conductive material on both sides in the pipe extension direction from the two voltage application electrodes located at both ends of the electric heating heating pipe in each of the electric heating units. The grounding functional members are arranged, and those grounding functional members are electrically grounded,
In the AC power supply device, an output terminal on the reference potential side and one or more output terminals on the alternating potential side in which the potential is inverted positively and negatively with respect to the reference potential are drawn from the secondary winding of the output transformer. ,
In addition, a plurality of current heating units are connected in series,
Moreover, there are two voltage application electrodes located on both ends of the current heating conduit in one current heating unit, and two voltage application electrodes located on both ends of the current heating conduit in the other current heating unit. The output transformer is commonly connected to an output terminal on the reference potential side.

Moreover, the continuous electric heating apparatus of the fluid food material of the fifth aspect of the present invention is the continuous electric heating apparatus of the fourth aspect,
The grounding functional member on one end side of the current heating conduit in each of the current heating units and the grounding functional member on the other end side are electrically connected by a wiring connecting between them, and at least one grounding functional member The ground wiring is drawn out from the ground and is electrically grounded.

Furthermore, the continuous energization heating device of the fluid food material according to the sixth aspect of the present invention is the continuous energization heating device according to the fourth or fifth aspect,
Each voltage application annular electrode is connected to the power source so that the voltage applied between the voltage application annular electrodes in one energization heating unit is different from the voltage applied between the voltage application annular electrodes in another energization heating unit. It is connected to the output transformer of the apparatus.

  According to the present invention, the grounding annular electrode is disposed on the outer side of each of the two energizing heating annular electrodes on both ends among the plurality of energizing heating annular electrodes constituting one energizing heating conduit. In the continuous energization heating apparatus for fluid food materials that is used, when an AC voltage is applied between adjacent annular electrodes for heating and heating to energize and heat the flowable food materials, the two annular electrodes for heating and heating are outward. Due to the effects of leakage current, especially the leakage current from the earth ring electrode, the inter-electrode voltage and the current flowing through the food material may fluctuate abnormally, the AC waveform may be disrupted, and the power transformer may be damaged. Or the controllability can be effectively prevented.

It is a side view which shows an example of the electricity heating unit used for the continuous electricity heating apparatus of this invention. FIG. 2 is a transverse plan view of the energization heating unit shown in FIG. 1. FIG. 3 is an enlarged cross-sectional plan view showing an enlarged main part of the energization heating unit shown in FIG. 2. It is a wave form diagram which shows typically an example of the alternating voltage waveform impressed between the electrodes for voltage application in an energization heating unit. It is a figure which shows the other example of the electricity heating unit used for the continuous electricity heating apparatus of this invention, and is a cross-sectional top view in the same position as FIG. It is a side view which shows an example of the whole structure of the continuous electricity heating apparatus comprised by incorporating the three electricity heating units shown by FIGS. 1-3. It is a schematic diagram which shows the electrical connection relationship of the continuous electricity heating apparatus shown by FIG. It is a schematic solution figure which shows an example of the electricity supply unit used for the conventional continuous electricity heating apparatus. It is a schematic diagram which shows the other example of the electricity supply unit used for the conventional continuous electricity heating apparatus. FIG. 10 is a schematic illustration showing an overall configuration of continuous energization heating configured by incorporating the three energization heating units shown in FIG. 9.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  1 to 3 show an example of an electric heating unit 3 used in the continuous electric heating apparatus according to the present invention.

1 to 3, the energization heating unit 3 basically includes a plurality (seven in this embodiment) of voltage application ring electrodes 5 _{1 to} 5 ₇ and a pair of ground ring electrodes (ground function). members) 9A, 9B and, among the voltage application annular electrode ₅ 1-5 _7, insulating tube ₇ 2 to between five mutual voltage applying annular electrode ₅ 2-5 ₆ except for both ends 7 ₇ , and insulating tube bodies 7 ₁ , 7 ₈ between the voltage application annular electrodes 5 ₁ , 5 ₇ and the grounding annular electrodes 9 A, 9 B on both ends, respectively. The unit energization heating unit 3 includes a pair of flange members 11A and 11B as constituent members for connecting and supporting the voltage application annular electrodes 5 _{1 to} 5 ₇ and the ground annular electrodes 9A and 9B, A plurality of (for example, two or four as a whole) connecting shaft rods 11 are provided.

Each of the voltage application annular electrodes 5 _{1 to} 5 ₇ is formed into a hollow ring shape with at least an inner peripheral surface made of a conductive material, and in this embodiment, each voltage application annular electrode 5 _{1 to} 5 _7. Is entirely made of a conductive metal material.
The grounding ring electrode 9A, 9B, like the voltage applying annular electrode 5 _{1-5 7,} which at least the inner circumferential surface is made into a hollow ring shape by a conductive material, in this embodiment, each The whole of the grounding annular electrodes 9A and 9B is made of a conductive metal material.

Voltage applying annular electrode 5 _{1-5 7} and the earth ring electrodes 9A, as the metal material used to 9B, aluminum, aluminum alloy, copper, may be used iron-based material such as copper alloy, or stainless steel However, Ti (titanium) or a Ti alloy is recommended as a metal material that has good corrosion resistance, oxidation resistance, and light weight and that does not adversely affect food materials.

On the other hand, each of the insulating tube bodies 7 _{1 to} 7 ₈ is made into a hollow short cylindrical shape by an electrically insulating material such as resin or ceramic, and is made of a hard resin such as PEI resin or PEEK resin. It has been.

The voltage-applying annular electrodes 5 _{1 to} 5 ₇ , the grounding annular electrodes 9A and 9B, and the insulating tube bodies 7 _{1 to} 7 ₈ are each provided with an insulating tube body between the electrodes, and the grounding annular electrodes are provided at both ends. The electrodes and insulating tube bodies are alternately arranged so as to be alternately arranged in series so as to be in close contact with each other, and a current-carrying heating conduit 15 is formed as a whole. That is, the insulating tube bodies 7 _{2 to} 7 ₇ are positioned between the voltage application ring electrodes 5 _{1 to} 5 ₇ , respectively, and the outsides of the voltage application ring electrodes 5 ₁ , 5 ₇ on both ends on both ends ( In the extending direction), the electrodes and the insulating tube bodies are alternately arranged so that the grounding annular electrodes 9A and 9B are positioned via the insulating tube bodies 7 ₁ and 7 ₈ , and are heated as a whole. A current-carrying heating conduit 15 that is continuous from one end side to the other end side and has a flow path 19 through which the fluid food material to be passed passes is formed. Incidentally, where the voltage application annular electrode 5 _{1-5 7,} FIG. 1, the left end of the voltage application ring electrode of FIG. 2 1st and voltage applying annular electrode 5 _1, and then counted to the right The Nth voltage application ring electrode is the Nth voltage application ring electrode _5N .

  Further, flange members 11A and 11B are disposed outside the arrangement structure of the electrodes and the insulating tube bodies (both ends of the energization heating conduit 15). These flange members 11A and 11B are made of a metal such as stainless steel, titanium, titanium alloy, or a hard resin, and have a shape in which a hollow cylindrical portion 11b is integrally protruded on one side of the hollow disk portion 11a. It is said that. And the hollow part inside the hollow disk part 11a of the flange members 11A and 11B and the hollow cylinder part 11b is connected to the food material flow path 19 in the above-mentioned conduit 15 for electric heating. The other disk surface of the hollow disk portion 11a of each flange member 11A, 11B is in contact with the side surface of each of the grounding annular electrodes 9A, 9B. Therefore, each electrode and insulating tube constituting the energization heating conduit 15 are sandwiched between the one flange member 11A and the other flange member 11B.

  And between the location near the outer periphery of the hollow disk portion 11a of the flange member 11A on one end side of the pipe line and the location near the outer periphery of the hollow disk portion 11b of the flange member 11B on the other end side of the pipe line is for electric heating. The electric heating unit 3 is assembled as a whole by being connected by a plurality of connecting shaft bars 13 (for example, four; only two are shown in FIGS. 1 and 2) parallel to the pipe line 15. That is, each connecting shaft rod 13 is formed with a threaded portion at the tip, and penetrates the hollow disk portion 11a of one flange member 11A and the hollow disk portion 11b of the other flange member 11B, Mutual contact surfaces (side surfaces) of each member (each insulating tube and each annular electrode) from one flange member 11A to the other flange member 11B by tightening between the hollow disk portions 11a and 11b with a nut 13a Are in close contact. In practice, as shown in FIG. 3, it is usual to seal each member by interposing a flat annular gasket 14 between the members.

  Support members 21 </ b> A and 21 </ b> B for fixing and holding the electric heating unit 3 at a predetermined position in the frame 5 to be described later are attached to appropriate portions of the electric heating unit 3. In the present embodiment, the support members 21A and 21B are formed in a ring shape or a rectangular shape having a central hollow portion, and are configured so that the connecting shaft rod 13 penetrates the peripheral portion thereof.

The voltage application annular electrodes 5 _{1 to} 5 ₇ in the energization heating unit 3 are connected to the power supply device 23 via voltage application wires 27 and 29. The power supply device 23 basically includes a high-frequency power source 231 that generates a high-frequency current of about 1 to 30 kHz using commercial AC from the outside, and an output transformer (transformer) that boosts the output to about 50 to 3000 V and outputs it. ) 232 and a control circuit 233 for controlling output current (power), waveform, output timing, and the like.

  In the output transformer (transformer) 232, the output terminal 23A on the reference potential side is drawn from an appropriate tap position (generally, the end of the secondary winding) in the secondary side (high voltage side) winding 232A. A plurality (three in the illustrated example) of alternating potential side output terminals (first to third output terminals) 23B to 23D are drawn from other different tap positions. The secondary winding 232A is assumed to float from the ground potential. An AC voltage of about 200 to 800 V, for example, having a high frequency of about 1 to 30 kHz appears between the output terminal 23A on the reference potential side and the first to third output terminals 23B to 23D on the alternating potential side. Yes.

Specifically, for example, V ₁ = 200 V between the first output terminal 23B on the alternating potential side and the output terminal 23A on the reference potential side, and the second output terminal 23C on the alternating potential side and the output on the reference potential side The secondary side (high voltage) has a potential difference of V ₂ = 600 V between the terminal 23A and V ₃ = 800 V between the third output terminal 23D on the alternating potential side and the output terminal 23A on the reference potential side. Side) The tap position of the winding 232A is determined.

Then, from the selected output terminal (second output terminal 23C in the illustrated example) and the reference potential side terminal 23A among the first to third output terminals 23B to 23D on the alternating potential side and the reference potential side terminal 23A. AC so that the (high-frequency) current is supplied to the voltage application annular electrode ₅ 1-5 ₇ via the wiring 27 and 29.

  The high-frequency waveform output from the power supply device 23 is not particularly limited, and may be appropriately selected from a sine wave, a pulsed rectangular wave, a triangular wave, a sawtooth wave, and the like.

Here, among the voltage application annular electrodes 5 _{1 to} 5 ₇ , _every other electrode including the electrodes 5 ₁ and 5 ₇ on both ends is connected to the output terminal 23 A on the reference potential side in the power supply device 23. . That is, the odd-numbered voltage application annular electrodes 5 ₁ , 5 ₃ , 5 ₅ , 5 _{7 as} counted from the food material supply side are connected to the output terminal 23 A on the reference potential side via the first voltage application wiring 27. Has been. On the other hand, the electrodes 5 ₁ , 5 ₃ , 5 ₅ , 5 ₇ , that is, the even-numbered annular electrodes for voltage application 5 ₂ , 5 ₄ , 5 ₆ counted from the food material supply side, For example, the second output terminal 23 </ b> C on the alternating potential side is connected via the voltage application wiring 29.

  On the other hand, the grounding annular electrodes 9A and 9B in the energization heating unit 3 are connected to a ground potential portion, for example, a grounding rod 33 inserted into the ground GN via grounding wirings 31 and 32.

  Next, a situation where the fluid food material is heated by the energization heating unit 3 configured as described above will be described. Here, it is assumed that the fluid food material is supplied from the left side in FIGS. 1 to 3, that is, from the flange member 11 </ b> A side.

  The fluid food material fed from a pressure pump (not shown) passes through an appropriate inlet-side supply pipe 35, reaches the hollow cylinder portion 11b of one flange member 11A, and enters the flow path 19 of the electric heating and heating pipe line 15 Are continuously pumped and discharged from the hollow cylindrical portion 11b of the other flange member 11B toward the appropriate outlet supply pipe 37.

In the flow path 19 of the electric heating conduit 15, fluid food material is continuously in contact with the inner surface of the voltage application annular electrode 5 _{1-5 7.} Between the adjacent voltage application ring electrodes, that is, between the odd number voltage application ring electrodes 5 ₁ , 5 ₃ , 5 ₅ , 5 ₇ and the even number voltage application ring electrodes 5 ₂ , 5 ₄ , 5 ₆ . A high-frequency voltage is applied between them, whereby a high-frequency current flows in the food material between adjacent annular electrodes for voltage application, heat is generated by the electrical resistance of the food material, and Joule heating proceeds.

For example, since the voltage applying annular electrode 5 ₁ is connected to the output terminal 23A of the reference potential side, and the reference potential and V _0, the voltage applying annular electrode 5 ₂ next to the second output of the alternating voltage side if the potential of the _{V 2} have been connected to the terminal 23C, as shown in FIG. 4, between the electrodes ₅ 1, _{5 2,} alternately _[V 0 + _{V 2), (V} 0 -V ₂ ] is given.

Here, the voltage applying annular electrode 5 ₁ at one end of the electric heating conduit 15 (food material supply side), it more between the outer grounding ring electrode 9A, mainly food material itself electrically conductive Therefore, a leakage current flows. This leakage current is released to the ground GN through the grounding wires 31 and 32. Similarly, the voltage applying annular electrode 5 ₇ on the other end side of the electric heating conduit 15 (food material discharge side), it more even between the outer grounding ring electrode 9B, leakage current flows. This leakage current is released to the ground GN through the ground wiring 32. As described above, since the leakage current flows from the voltage application ring electrodes 5 ₁ and 5 ₇ through the ground ring electrodes 9A and 9B to the ground GN by the ground wiring, there is a considerable electric resistance. The potentials of the grounding annular electrodes 9A and 9B do not become the ground potential (0V) of the ground GN, but become the potential corresponding to the electrical resistance distribution from the grounding annular electrodes 9A and 9B to the ground GN.

Meanwhile, one end voltage applying annular electrode 5 ₇ of the voltage applied annular electrode 5 ₁ and the other end of the (food material supply side) (food material discharge side) are both connected to a reference potential side of the terminal 23A because there, at any time, the potential of the voltage application annular electrode 5 ₇ of the voltage applied annular electrode 5 ₁ and the other end side (food material discharge side) of one end side (food material supply side) is _equal. Therefore, one end side of the voltage applying annular electrode 5 ₁ (food material supply side) and the potential difference between the grounding ring electrode 9A of the adjacent, voltage application annular electrode 5 on the other end side (food material discharge side) ₇ and the potential difference between the adjacent grounding annular electrode 9B are substantially equal at any timing. This means that at any timing, the potential difference between the grounding annular electrode 9A on one end side and the grounding annular electrode 9B on the other end side is substantially zero.

  In the present embodiment, the grounding annular electrode 9A on one end side and the grounding annular electrode 9B on the other end side are electrically connected by the grounding wiring 31, but the grounding annular electrodes 9A and 9B are connected to each other. Since the potentials are substantially always equal, it is possible to prevent a leakage current from flowing from the ground annular electrode on one end side to the ground annular electrode on the other end side from the outside. Here, since the grounding annular electrode constitutes a part of a conduit for the food material to flow and heat and heat the food material, if a leakage current flows into the grounding annular electrode from the outside, Although the current flowing through the material varies, the leakage current from the outside is avoided as described above. As a result, the current flowing through the food material can be kept constant without being varied.

  Also, in terms of voltage, if there is a leakage current (alternating current) flowing from the grounding annular electrode at one end to the grounding annular electrode at the other end, the potential of the grounding annular electrode at the other end is at a certain timing, Although it becomes abnormally high or conversely low, the potential between the electrodes also fluctuates accordingly. However, in the configuration of this example, there is no inflow of leakage current from the outside to the grounding annular electrode. Therefore, such potential fluctuation is also avoided.

  All or most of the leakage current from each grounding annular electrode 9A, 9B is released to the ground GN via the grounding wirings 31, 32.

With the above-described operation, it is possible to reliably prevent an abnormal phenomenon from occurring due to leakage current flowing from the outside to the grounding annular electrode on the other end side from the grounding annular electrode on the other end side.
That is, it is certain that the current flowing through the food material in the flow path 19 of the energization heating pipe 15 fluctuates abnormally, and that the voltage between the electrodes constituting the energization heating pipe 15 fluctuates abnormally. To be avoided. For this reason, for example, it is possible to effectively prevent the food material in the pipeline from being heated excessively, causing the food material to be altered, or scorching the food material to the inner surface of the electrode, and conversely, the lack of heating can sufficiently sterilize the food material. It is also possible to prevent the occurrence of a lack of cooking or a lack of cooking.

  Furthermore, if there is a leakage current as described above, the waveform of the AC voltage applied between the electrodes due to a slight phase difference or the like can be prevented from being broken. That is, when a high-frequency AC voltage is applied to a food material, it is known that the waveform has an effect on the sterilization effect, but if the waveform collapses due to leakage current, the sterilization effect will be reduced. Is also a concern. However, in the present embodiment, inflow of leakage current from the outside can be avoided, and there is no possibility that the preset high-frequency AC waveform will be destroyed, and the required sterilizing effect can be maintained.

  In addition, if the peak value of the high-frequency alternating current is abnormally high due to the leakage current from the outside, there is a concern that the abnormally high peak current flows into the transformer of the power supply device and the transformer is burned. However, in this embodiment, such a situation can be avoided.

  In actual continuous energization heating of fluid food materials, the current, voltage, and AC waveform are appropriately controlled according to the type of food material (mainly resistance value), flow rate, viscosity, and inlet temperature. However, as described above, by preventing leakage current from flowing in from outside, abnormal fluctuations in current, voltage, and alternating current waveform can be prevented, so that there is little possibility of hindering control.

  In the power supply device 23 shown in FIG. 2, a plurality of (three in the illustrated example) output terminals on the alternating potential side (three in the illustrated example) are provided from different tap positions of the secondary side (high voltage side) winding 232 </ b> A of the output transformer 232. First to third output terminals) 23B to 23D are drawn out so that high-frequency waves having different potential differences can be extracted. Therefore, the output terminal on the alternating potential side connected to the second voltage application wiring 29 according to the type and properties of the food material to be heated, the flow rate and flow rate in the pipeline, and the target heating temperature. Can be changed. In some cases, a changeover switch (not shown) is provided between the voltage application wiring 29 and the output terminals (first to third output terminals) 23B to 23D on the alternating potential side. The output terminal on the alternating potential side connected to the second voltage application wiring 29 may be selectively switched.

Further, in some cases, the voltage applied between the annular electrodes for voltage application may be applied to the food material supply side (inflow side) zone, the food material discharge side zone, or the intermediate zone in one energization heating unit 3. It may be required to be different. For example, in general, the temperature of a food material flowing from one end side (food material supply side) of the energization heating conduit 15 increases as it moves toward the other end side (food material discharge side). And if temperature rises, an electrical resistance will fall in the normal fluid food material. If therefore the voltage is the same applied between mutual voltage applying annular electrode 5 _{1-5 7,} in the food material discharge side where the electrical resistance is lowered, the current flowing between the electrodes than the inflow side is increased As a result, the amount of generated Joule heat increases and the temperature may rise excessively. In this case, on the food material discharge side, the temperature of the food material suddenly increases, and there is a possibility that the temperature cannot be controlled appropriately. Therefore, it may be necessary to set the voltage between the electrodes lower in the zone on the food material discharge side than in the zone on the food material inflow side. An example of an energization heating unit in which the present invention is applied to such a case is shown in FIG.

The example of the energization heating unit shown in FIG. 5 is obtained by changing the wiring connection relationship of each voltage application electrode to the power supply device based on the example shown in FIG. That is, among the even-numbered voltage application annular electrodes 5 ₂ , 5 ₄ , 5 ₆ counted from the inflow side, the electrodes 5 ₂ , 5 ₄ are output terminals 23 C on the relatively high potential V ₂ side in the power supply device 23. to be connected via a voltage applying wire 29A, the electrode 5 ₆ are connected through a voltage application line 29B to an output terminal 23B of a relatively low potential V ₁ side of the power supply 23. On the other hand, the odd-numbered voltage application annular electrodes 5 ₁ , 5 ₃ , 5 ₅ , 5 ₇ counted from the food material supply side are connected to the power supply device 23 via the voltage application wiring 27 as in the case of FIG. It is connected to the output terminal 23A on the reference potential side.

In such a configuration, among the voltage application electrode 5 _{1-5 7,} from the electrode 5 ₁ on the inflow side to the fifth electrode 5 _5, a relatively high voltage is applied between the electrodes, the 5 th from the electrode 5 ₅ to the electrode 5 ₇ on the outflow side, a relatively low voltage is applied between the electrodes. Therefore, it is avoided that the temperature rises excessively in the outflow side zone as described above.

And in such instances, as in the example shown in FIG. 2, the voltage applying annular electrode 5 ₁ and the food material discharge side of the voltage applying annular electrode 5 ₇ food material supply side are both the reference potential side from being connected to the terminal 23A, which is also at the timing, the potential of the voltage application annular electrode 5 ₇ for voltage application of the food material supply side annular electrode 5 ₁ and the food material discharge side are _equal. Therefore, one end side of the voltage applying annular electrode 5 ₁ (food material supply side) and the potential difference between the grounding ring electrode 9A of the adjacent, voltage application annular electrode 5 on the other end side (food material discharge side) ₇ and the potential difference between the adjacent grounding annular electrode 9B are substantially equal at any timing. Therefore, at any timing, the potential difference between the grounding annular electrode 9A on one end side and the grounding annular electrode 9B on the other end side is substantially zero, and the grounding annular electrode on the other end side is connected to the grounding annular electrode on the other end side. It is avoided that leakage current flows into the electrode from the outside.

  Here, the current heating unit 3 shown in FIGS. 1 to 3 or the current heating unit shown in FIG. 5 can be used alone as a continuous current heating device, but in actual food factories, etc. In many cases, a continuous energization heating apparatus is configured by combining a plurality of energization heating units. Therefore, the entire configuration of the continuous energization heating apparatus 1 configured using three energization heating units is shown in FIGS. For convenience, in order to distinguish each energizing heating unit, each energizing heating unit is given the symbols 3A, 3B, and 3C in order from the lower one. FIG. 6 shows the continuous energization heating device 1 with the mechanical connection as a main component, omitting the electrical connection / wiring structure, and FIG. 7 shows the electric connection / wiring structure as a main component. As shown.

  In FIG. 6, the frame 5 is assembled into a frame structure along each line of a rectangular box as a whole by using, for example, a metal channel material or bar material such as steel or aluminum. Inside the frame body, the three energization heating units 3A, 3B, 3C are parallel to each other so that each of them is slightly inclined with respect to the horizontal plane (so that the discharge side is positioned higher than the food material inflow side). Is arranged.

  And between each electric heating unit 3A, 3B, 3C, it connects in series by intermediate | middle piping 40A, 40B, and supply piping 43 is connected to the entrance side (left end side) of the lowermost electric heating unit 3A. Further, a discharge pipe 45 is connected to the discharge side (right end) of the uppermost conduction heating unit 3C. The electric heating units 3A, 3B, 3C and the pipes 40A, 40B, 43, 45 are fixed inside the frame 5 by support portions 47A, 47B mainly made of steel, aluminum, or the like.

  As shown in FIG. 7, the grounding annular electrodes 9 </ b> A, 9 </ b> B of the energization heating units 3 </ b> A, 3 </ b> B, 3 </ b> C are grounded terminals 49 attached to the frame of the frame 5 by grounding wires (upstream side grounding wires) 31, 33. In addition, another ground wiring (downstream ground wiring) 51 is connected to an appropriate portion of the frame 5, and the downstream ground wiring 33 is inserted into a ground potential member, for example, the ground GN. It is connected to the ground bar 33.

Further, in this example, a single power supply device 23 common to each unit is used as a power supply device that supplies power (high-frequency current) for current heating to each of the current heating units 3A, 3B, and 3C. And each electrical heating units 3A, 3B, 3C definitive voltage applying annular electrode 5 _{1-5 7,} like the electric heating unit 3 described with reference to FIG. 2, respectively, odd-numbered voltage applying annular electrode 5 ₁ 5 ₃ , 5 ₅ , 5 ₇ are connected to the output terminal 23 A on the reference potential side of the power supply device 23 via the first voltage application wiring 27, and the even-numbered voltage application annular electrodes 5 ₂ , 5 _4. , _{5 6} are respectively connected to a second alternating potential different output terminal 23B~23D voltage application wiring 29 through the power supply 23. That is, the even-numbered voltage application annular electrodes 5 ₂ , 5 ₄ , 5 ₆ in the lowermost stage (food material supply side) current heating unit 3A are connected to the output terminal 23D of the relatively high potential V ₃ , respectively. The even-numbered voltage application annular electrodes 5 ₂ , 5 ₄ , 5 ₆ in the middle stage heating unit 3B are respectively connected to the output terminal 23C of the intermediate potential V ₂ , and further on the uppermost stage (food material discharge side). The even-numbered voltage application annular electrodes 5 ₂ , 5 ₄ , 5 ₆ in the energization heating unit 3C are connected to the output terminal 23B having a relatively low potential V ₁ , respectively.

  In the continuous energization heating apparatus 1 incorporating a plurality of, for example, three energization heating units 3A, 3B, and 3C as described above, the fluid food material supplied from outside the apparatus is first supplied to the lower energization heating unit 3A. Then, it is energized and heated, then led to the middle-stage energization heating unit 3B, and again energized and heated, and further led to the upper-stage energization heating unit 3A, and then again energized and heated, and then the apparatus It is discharged outside.

In the continuous electrical heating device 1 as described above, the electric heating units 3A, 3B, if you look at every 3C, as already described with reference to FIG. 2, the voltage applying annular electrode 5 ₁ of each both end sides, 5 and ₇ always have the same reference potential. Therefore, as already described, in the same energization heating unit, inflow of leakage current due to a shortcut of the external electric path between the grounding annular electrodes 9A and 9B at both ends is avoided.

Further, when viewed between the upper and lower electric heating units, the grounding annular electrodes 9A and 9B at both ends of the respective electric heating units 3A, 3B and 3C are all electrically connected via the ground wiring 33. Since the voltage application annular electrodes 5 ₁ , 5 ₇ of the both ends of the current heating units 3A, 3B, 3C are always at the reference potential, that is, the same potential, It is also avoided that leakage current flows from the grounding annular electrode to the grounding annular electrode of another energization heating unit. Therefore, it is possible to prevent an abnormal phenomenon similar to that described above from occurring due to leakage current flowing between the plurality of energization heating units.

  In the example shown in FIG. 7, the voltage applied between the voltage application electrodes is different for each of the current heating units 3A, 3B, 3C (the voltage on the discharge side unit is higher than that on the inflow side current heating unit). Although the connection is made to the power supply device so that the voltage between the electrodes for application is low), depending on the case, the unit may be connected so that the voltage between the electrodes for voltage application is the same. Of course.

  In the above embodiment, the grounding annular electrodes 9A and 9B are provided separately from the flange members 11A and 11B on both ends of the current heating conduit 15 in each current heating unit 3 (3A, 3B, 3C). ing. However, when the flange members 11A and 11B are made of a conductive metal, the ground members are connected to the flange members 11A and 11B without providing the ground annular electrodes 9A and 9B. 11B itself may have the same function as the annular electrode for grounding. That is, you may comprise the earth functional member of the both ends of a pipe line by the flange members 11A and 11B.

  The preferred embodiment of the present invention has been described above. However, the above-described embodiment is merely an example within the scope of the gist of the present invention. Omissions, substitutions, and other changes are possible. That is, the present invention is not limited by the above description, is limited only by the scope of the appended claims, and can be appropriately changed within the scope.

1 ... Continuous current heating device 3, 3A, 3B, 3C ... Current heating unit
5 _{1, 5 2,} 5 _{3, 5} 4, _{5 5,} 5 _{6, 5} 7 ... voltage applying annular electrodes _{7 1,} 7 _{2, 7 3,} 7 4, _{7 5,} 7 _{6, 7} 7, 7 ₈ ... Insulating tube bodies 9A, 9B ... Grounding annular electrode 15 as grounding functional member ... Current-carrying heating conduit 23 ... Power supply device 232 ... Output transformer 23A ... Reference potential side Output terminals 23B, 23C, 23D ... output terminals on the alternating potential side

Claims (6)

Three or more voltage application annular electrodes having at least an inner peripheral surface made of a conductive material and four or more insulating tubes having at least an inner peripheral surface made of an electrically insulating material are alternately arranged along a common axis. An electrode for applying voltage adjacent to each other by an AC power supply device while forming a current-carrying heating pipeline and continuously fluidly transferring a fluid food material in the lengthwise direction in the current-heating channel. In a continuous energization heating device for fluid food material that is heated by energizing the fluid food material in the pipeline continuously in the length direction of the pipeline by applying an alternating voltage between
An annular grounding functional member having at least an inner peripheral surface made of a conductive material on both sides in the pipe extension direction from the two voltage application electrodes located on both ends of the energization heating pipe via an insulating pipe. Disposed, and those grounding functional members are electrically grounded,
Further, in the AC power supply apparatus, the output terminal on the reference potential side and one or more output terminals on the alternating potential side whose potential is inverted to positive and negative with respect to the reference potential are drawn from the secondary winding of the output transformer. And
Among the voltage application annular electrodes, the two voltage application electrodes located on both ends of the current heating conduit are commonly connected to a reference potential side output terminal of the output transformer. A continuous energization heating device for fluid food materials. In the continuous electric heating apparatus of the fluid food material according to claim 1,
The grounding functional member on one end side and the grounding functional member on the other end side of the energization heating conduit are electrically connected by a wiring connecting between them, and the ground wiring is drawn from at least one grounding functional member. A continuous energization heating device for fluid food material, characterized in that it is electrically grounded. In the continuous energization heating apparatus of the fluid food material according to any one of claims 1 and 2,
The energization heating pipe is divided into a plurality of zones in the length direction, and a voltage applied between the voltage application ring electrodes in one zone and a voltage application ring electrode in another zone. A continuous energization heating device for fluid food material, wherein each voltage application annular electrode is connected to an output transformer of the power supply device so that a voltage to be applied is different. Three or more voltage application annular electrodes having at least an inner peripheral surface made of a conductive material and four or more insulating tubes having at least an inner peripheral surface made of an electrically insulating material are alternately arranged along a common axis. An AC power source is disposed between adjacent voltage application electrodes while forming a current-carrying heating conduit and continuously fluidly transferring the fluid food material in the length direction in the current-heating conduit. A plurality of energization heating units are provided that are heated by energizing the fluid food material in the pipeline continuously in the length direction of the pipeline by applying an alternating voltage by the apparatus,
An annular structure in which at least the inner peripheral surface is made of a conductive material on both sides in the pipe extension direction from the two voltage application electrodes located at both ends of the electric heating heating pipe in each of the electric heating units. The grounding functional members are arranged, and those grounding functional members are electrically grounded,
In the AC power supply device, an output terminal on the reference potential side and one or more output terminals on the alternating potential side in which the potential is inverted positively and negatively with respect to the reference potential are drawn from the secondary winding of the output transformer. ,
In addition, a plurality of current heating units are connected in series,
Moreover, there are two voltage application electrodes located on both ends of the current heating conduit in one current heating unit, and two voltage application electrodes located on both ends of the current heating conduit in the other current heating unit. A continuous energization heating device for fluid food material, characterized in that it is commonly connected to an output terminal on the reference potential side in the output transformer. In the continuous electric heating apparatus of the fluid food material according to claim 4,
The grounding functional member on one end side of the current heating conduit in each of the current heating units and the grounding functional member on the other end side are electrically connected by a wiring connecting between them, and at least one grounding functional member A continuous energization heating device for fluid food material, characterized in that the ground wiring is drawn out from the ground and electrically grounded. In the continuous energization heating device for fluid food material according to any one of claims 4 and 5,
Each voltage application annular electrode is connected to the power source so that the voltage applied between the voltage application annular electrodes in one energization heating unit is different from the voltage applied between the voltage application annular electrodes in another energization heating unit. A continuous energization heating device for fluid food material, characterized in that it is connected to an output transformer of the device.

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