JPH0822724B2 - Multi-phase AC multi-electrode corona discharge device and ozone generator using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-phase alternating current multi-electrode corona discharge device for generating a flat corona discharge between multiple electrodes by using a multi-phase alternating current, and to a flat corona discharge part of the corona discharge device to supply oxygen or The present invention relates to an ozone generator that generates ozone with high efficiency by circulating an oxygen-containing gas.

[0002]

2. Description of the Related Art In order to generate a large amount of ozone by using corona discharge, it is necessary to efficiently cause the discharge electrons due to corona discharge to collide with oxygen molecules. Therefore, in the past,
It goes without saying that the oxygen concentration of the oxygen-containing gas raw material is increased,
Various devices have been added to the device so that the corona discharge constantly moves on the electrode surface. For example, in an ozone generator in which flat electrodes are arranged in parallel, the flat electrodes are precisely arranged in parallel to finish the electrode surface uniformly, or the discharge electrode is made to be a rotary type to prevent local concentration of corona discharge. There is. In addition, attempts have also been made to make the shape of the discharge electrode cylindrical.

However, all the conventional ozone generators use a single-phase AC or DC as a discharge power source, and the discharge itself generated between the electrodes is a linear corona discharge. Therefore, even if the local concentration of the discharge is completely prevented by constantly moving the corona discharge, there is a limit to the improvement of the ozone generation efficiency due to the linear discharge.

The applicant of the present invention can easily select from a three-phase AC power source to 6
A 6-phase AC output device capable of obtaining a phase AC has already been completed, and when the 6-phase AC output device and the 6 electrodes arranged at the required positions are discharged by devising the connection order, It has been found that a voltage corresponding to the inter-electrode distance is applied to each electrode, and a plurality of arc discharges are not interrupted between the six electrodes and are generated while rotating at high speed while aligning the discharge directions. The present inventor has already applied for this 6-phase AC output device and 6-phase AC 6-electrode arc discharge device (Japanese Patent Application No. 4-2.
28984).

The Applicant has found that, in addition to the extremely high efficiency of the above-mentioned arc discharge device, the discharge is performed in a plane rather than the linear discharge as in the conventional device. We devised to use this planar discharge in an ozone generator using corona discharge, and finally completed an ozone generator using a multi-phase AC multi-electrode corona discharge.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a multi-phase AC multi-electrode corona discharge device for producing a uniform and stable planar discharge between multiple electrodes, and ozone is efficiently generated by utilizing this planar discharge. It is a technical object to provide an ozone generator capable of achieving the above.

[0007]

Means adopted to solve the problem The means adopted by the present applicant to solve the above problems are as follows. That is, an n-phase AC output device that outputs an n-phase AC and a discharge electrode T
_{1 to} T _n , and an electrode unit formed by arranging the tip end portions of the regular n-gon in the vicinity of the respective vertex positions of the regular n-gon, and the respective phase output terminals of the n-phase alternating current output device are arranged in the order of earlier phase of the electrode unit. By adopting the technical means of connecting the discharge electrodes T _{1 to} T _{n in the} order of right or left, a multi-phase AC multi-electrode corona discharge device which produces a uniform and stable planar discharge was constructed.

The technical problem described above has been solved by adopting a means of installing this multi-phase AC multi-electrode corona discharge device in an ozone generation tower through which oxygen or oxygen-containing gas flows.

Further, if necessary, in a 6-phase AC output device for outputting 6-phase AC, two sets of three transformers are connected in parallel for each output terminal of each phase of the 3-phase AC power supply to form a pair. None,
The winding end of one transformer secondary winding and the winding start of the other transformer secondary winding of each pair of transformers connected in parallel as these pairs are connected, and these three sets of connection portions are further connected to each other. We adopted the method of connecting and using the terminal of the transformer secondary winding on the side not connected in common as the output terminal.

[0010]

The present invention will be described below based on the first and second embodiments. Incidentally, FIG. 1 shows a sixth embodiment of the present invention.
2 is a schematic diagram of a 6-phase AC 6-electrode corona discharge device according to the first embodiment of the present invention. FIG. 3 is a schematic diagram of a 6-phase AC corona discharge device according to the first embodiment of the present invention. Exchange 6
A voltage vector diagram of alternating current applied between the electrodes in the electrode corona discharge device, FIG. 4 is a composite vector diagram of alternating current applied between the electrodes in the six-phase alternating current six-electrode corona discharge device of the first embodiment, and FIG. FIG. 6 is a schematic configuration diagram showing an entire ozone generator using the 6-phase AC 6-electrode corona discharge device of the first embodiment, and FIG. 6 is a schematic configuration connection of the 6-phase AC 6-electrode corona discharge device of the second embodiment of the present invention. It is a figure.

[First Embodiment] The first embodiment is an ozone generator using a 6-phase AC 6-electrode corona discharge device. First, a 6-phase AC 6-electrode corona discharge device will be described with reference to FIGS.

The reference numeral 1 in FIG. 1 indicates an electrode unit for generating a corona discharge.
Is composed of _six stainless steel rod-shaped discharge electrodes T _{1 to} T ₆ having a diameter of 2 mm and having a bent portion at the upper part thereof. These discharge electrodes T _{1 to} T ₆ are formed by an electrode holder (not shown) through an insulator. It is held in a state where its tip is brought close to the position of the regular hexagon apex. The electrode unit 1 is connected to a 6-phase AC output device described below.

In FIG. 1, reference numerals U-X, V-Y, and W-Z.
What is indicated by is a three-phase AC output terminal connected to a three-phase AC power source and a delta connection (or a star connection may be used). A transformer S ₁ · S ₄ is connected to the terminal U-X and a transformer is connected to the terminal V-Y. vessel S ₅ · S _2, and so on transformer S ₃ · S ₆ to the terminal W-Z, and the three sets of six single-phase transformer by two for each phase connected in parallel. Neon transformers are used for the transformers S _{1 to} S ₆ . Of these two transformers for each phase,
Two sets of connections in which the winding end of the secondary winding of one transformer and the winding start of the secondary winding of the other transformer are connected, and this connecting wire is further connected to another transformer in the same manner. Connect with a wire. Then, the six terminals of the secondary winding of the transformer that are not commonly connected are used as the output terminals of the six-phase AC.

Here, when the single-phase alternating currents output from the single-phase transformers S _{1 to} S ₆ are represented by symbols A _{1 to} A ₆ , respectively, the alternating currents output from the transformers S ₁ and S ₄ connected in parallel, respectively. A ₁ and alternating current A ₄ are in opposite phases to each other, and similarly alternating current A ₅
And AC A ₂ and AC A ₃ and AC A ₆ also have opposite phases.
Further, the alternating currents A ₁ , A ₅ , and A ₃ output from the transformers S ₁ , S ₅ , and S ₃ have a phase difference of 120 ° with each other, and the same applies to the alternating currents A ₄ , A ₂ , and A _6. is there. Due to the phase relationships of the alternating currents A _{1 to} A ₆ , the 6-phase alternating current output device outputs 6 single-phase alternating currents with a phase difference of 60 °.

The 6-phase AC output device may be constructed as shown in FIG. Three-phase AC output terminal U
In place of the two single-phase transformers S ₁ · S ₄ , S ₅ · S ₂ , S ₃ · S ₆ connected in parallel to −X, VY, WZ respectively, Using transformers S ₇ , S ₈ and S ₉ which also have terminals in the center, these transformers S ₇ , S ₈ and
The central terminal of S ₉ is connected. In this way, the transformer primary winding can be halved.

The 6-phase AC output device having the above configuration and the electrode unit 1 are connected by the connection method described below.

Six single-phase alternating currents A _{1 to} A ₆ output from the 6-phase alternating current output device are energized in the clockwise (or counterclockwise) order to the discharge electrodes T _{1 to} T ₆ of the electrode unit 1 in the order of their phases. . The phase sequence in the 6-phase AC output device is AC A ₁
→ A ₂ → A ₃ → A ₄ → A ₅ → A ₆ , so AC ₁
Is applied to the electrode T ₁ , and the alternating current A ₂ is applied to the electrode T ₁ next to the electrode T _1.
If the current is applied to ₂ , the alternating current A ₃ is applied to the electrode T ₃ and the alternating current A _{4 is applied.}
To electrode T ₄ AC A ₅ to electrode T ₅ , AC A ₆ to electrode T
Energize ₆ respectively (in clockwise order toward the drawing).

When the 6-phase AC output device and the electrode unit 1 are connected by this connection method to generate a corona discharge, a plurality of corona discharges are constantly generated between the electrodes, and moreover, they rotate at a high speed. Corona discharge is generated in a plane. The state of corona discharge generated in the electrode unit 1 will be described below with reference to FIGS. 3 and 4.

FIG. 3 shows the voltage vectors for the other electrodes T _{2 to} T ₆ of the electrode T ₁ . When the voltage applied to each of the electrodes T _{1 to} T ₆ by the 6-phase AC output device is electrode T ₁ ; sin θ, electrode T ₂ ; sin
(Θ + 2π / 6), electrode T ₃ ; sin (θ + 4π / 6), electrode T
₄ ; sin (θ + 6π / 6), electrode T ₅ ; sin (θ + 8π /)
6), electrode T ₆ ; can be represented by sin (θ + 10π / 6). Therefore, the voltage between the electrodes T _{1 and} T ₂ ; sin θ−sin (θ + 2
π / 6) = − cos (θ + π / 6), and similarly, the electrodes T ₁ −T
Voltage between ₃ ; -√3cos (θ + 2π / 6), voltage between electrodes T _{1 and} T ₄ ; -2cos (θ + 3π / 6), voltage between electrodes T _{1 and} T ₅ ;
−√3cos (θ + 4π / 6), voltage between electrodes T _{1 and} T ₆ ; −cos
(Θ + 5π / 6). FIG. 3 shows an inter-electrode voltage vector applied between the electrode T ₁ and the other electrodes T _{2 to} T ₆ at a certain moment. Then, FIG. 4 shows a combined vector of the electrode T ₁ obtained by combining the voltage vectors shown in FIG.

As shown in FIG. 4, the composite vector of the electrode T ₁ rotates in an elliptical locus. Since the combined vector at the moment shown in FIG. 4 is directed to the midpoint between the electrodes T ₄ and T ₅ , the discharge at this moment is bent while being divided and mainly reaches the electrodes T ₄ and T ₅ . Will be done. A planar discharge is generated by this divided discharge. Moreover, the above rotationally synthesized vector based on the electrode T ₁ also exists in the other electrodes T _{2 to} T ₆ as well.
As a whole, a uniform and stable planar discharge is generated between the six electrodes.

Next, an ozone generator using this 6-phase AC 6-electrode corona discharge device will be described with reference to FIG.

In FIG. 5, the reference numeral 7 designates a cylindrical (inner diameter 90 mm) ozone generation tower through which oxygen or oxygen-containing gas (hereinafter referred to as raw material gas) flows. An electrode unit 1 composed of discharge electrodes T _{1 to} T ₆ is installed in. By passing the raw material gas through the planar corona discharge part generated by the electrode unit 1, the discharge electrons are efficiently collided with oxygen molecules to generate ozone. Further, in the present embodiment, in addition to the diaphragm dryer 2 for drying the raw material gas and the drying tower 5 using CaO, the pressure and flow rate of the raw material gas sent to the ozone generating tower 7 are adjusted. Regulator for flow control valve 4,
And a flow meter 6 are installed. In addition, the ozone generation tower 7
The ozone concentration of the ozone gas generated in 1 is measured by the ozone concentration meter 8 and is used for various purposes. The 6-phase AC output device is not shown in FIG.

"Test" The results of the test conducted on the ozone generator using the six-phase AC six-electrode corona discharge of the first embodiment described above are shown below.

Adjacent electrode spacing: 10 mm, power consumption: 350
At W, a corona discharge was generated, and air (oxygen approximately 20%) was fed as a raw material gas to the ozone generator at 2 l / min, resulting in 160 mg / min (ozone concentration 80 g / m ³ ) of ozone. Occurrence was observed. At this time, the ozone generation efficiency is 0.
The value reached 46 mg / Wmin (27.4 g / KWH), which was comparable to the generation efficiency of 25 g / KWH of the conventional apparatus using 90% oxygen gas as the raw material gas. From these test results, it is clear that when the device of the present invention uses the gas of 90% oxygen as a raw material gas to generate ozone, the generation efficiency thereof exceeds the efficiency of the conventional device.

[Second Embodiment] The ozone generator of the second embodiment uses a three-phase AC four-electrode corona discharge device. The configuration other than the corona discharge device is the same as that of the first embodiment, and only for this three-phase AC four-electrode corona discharge device,
This will be described with reference to FIG.

The reference numeral 11 in FIG. 6 indicates an electrode unit for generating a corona discharge.
Are _three stainless steel rod-shaped discharge electrodes T _{1 to} T _{3 each} having a bent portion at a diameter of 2 mm and a diameter 2 having no bent portion.
mm ground electrode T ₀ made of stainless steel, and the electrodes T _{1 to} T ₃ are held in a state in which the tips of the electrodes T _{1 to} T ₃ are brought close to the equilateral triangular vertex positions by an electrode holder (not shown) via an insulator. The electrode T ₀ is held so that its tip is located near the center point of the equilateral triangle. The discharge electrodes T _{1 to} T _{3 of} this electrode unit 11 and the three-phase AC output terminals U-X, V-Y, and W-Z that are delta-connected (or star-connected) with the three-phase AC power supply are connected to a transformer. The connection is made through S _{1 to} S ₃ .

[0027] Here assumed, without installing a ground electrode T _0, the 3-phase AC three-electrode corona discharge device constituted by closely arranged only three electrodes T ₁ through T ₃ in an equilateral triangle around the vertex positions, Consider a rotational composite vector based on the electrode T ₁ as described in the first embodiment. This three-phase AC 3
Even in the case of the electrode device, there is a moment when the rotational combined vector is directed to the midpoint between the electrodes T ₂ and T ₃ , but in the discharge device, the electrode T ₁ viewed from the electrode T _1.
The angle between the _two directions and the direction of the electrode T ₃ , that is, ∠T ₂ T ₁ T ₃
Is too large (60 °, the largest among other multi-phase AC multi-electrode discharge devices. In the case of the above-mentioned 6-phase AC 6-electrode device ∠T ₄
(T ₁ T ₅ = 30 °), almost no discharge occurs at the center point portion of the equilateral triangle formed by the electrodes T _{1 to} T ₃ . Therefore, in the second embodiment, the ground electrode T ₀ is provided near the center point of the equilateral triangle formed by the discharge electrodes T _{1 to} T ₃ .

[0028]

As described above with reference to the embodiments, in the multi-phase AC multi-electrode corona discharge device according to the present invention, there is almost no relation to the placement accuracy of the discharge electrodes, and it is uniform and stable among the multiple electrodes. Since it is possible to obtain a flat planar corona discharge, according to the ozone generator using this multi-phase AC multi-electrode corona discharge device, it is possible to cause the discharge electrons to efficiently collide with oxygen molecules, resulting in extremely high efficiency of ozone discharge. Can be generated.

Further, since this planar discharge is formed by a plurality of discharges which rotate at high speed while aligning the directions, the discharge efficiency itself is remarkably improved as compared with the conventional device, and it is necessary to raise the discharge voltage to the limit. Therefore, it is not necessary to make a great effort to prevent leakage by applying a high voltage.

Furthermore, when a 6-phase AC 6-electrode corona discharge device is used, 6-phase AC can be obtained from a 3-phase AC power source with a simple structure without complicating the structure, so it is very easy. It is possible to obtain a large amount of ozone.

[Brief description of drawings]

FIG. 1 is a schematic configuration wiring diagram of a 6-phase AC 6-electrode corona discharge device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration wiring diagram of a modified example of the 6-phase AC 6-electrode corona discharge device of the first embodiment of the present invention.

FIG. 3 is a voltage vector diagram of an alternating current applied between each electrode in the six-phase alternating current six-electrode corona discharge device of the first embodiment.

FIG. 4 is a combined vector diagram of alternating currents applied between electrodes in the six-phase alternating current six-electrode corona discharge device of the first embodiment.

FIG. 5 is a schematic configuration diagram showing an entire ozone generator using the 6-phase AC 6-electrode corona discharge device of the first embodiment.

FIG. 6 is a schematic configuration wiring diagram of a three-phase AC four-electrode corona discharge device according to a second embodiment of the present invention.

[Explanation of symbols]

S _{1 to} S ₆ single-phase transformer T ₀ ground electrode T _{1 to} T ₆ discharge electrode 1, 11 electrode unit 7 ozone generator tower

Claims (8)

[Claims] 1. An n-phase alternating current output device for outputting n-phase alternating current,
An electrode unit in which the tip portions of the discharge electrodes T _{1 to} T _n are arranged in the vicinity of respective vertex positions of a regular n-sided polygon, and the respective phase output terminals of the n-phase AC output device are arranged in the order of earlier phases of the electrodes. A multi-phase AC multi-electrode corona discharge device, characterized in that discharge electrodes T _{1 to} T _{n of the} unit are connected in a clockwise or counterclockwise order. 2. A 6-phase AC output device for outputting 6-phase AC,
An electrode unit in which the tip portions of the discharge electrodes T _{1 to} T ₆ are closely arranged near the respective vertex positions of the regular hexagon, and the output terminals of the respective phases of the 6-phase AC output device are arranged in the order of earlier phases. A multi-phase AC multi-electrode corona discharge device, characterized in that the discharge electrodes T _{1 to} T ₆ are connected in the clockwise or counterclockwise order. _3. An electrode unit is constructed by disposing the tip ends of the discharge electrodes T _{1 to} T ₃ in proximity to the respective vertex positions of the equilateral triangle and providing a ground electrode T ₀ near the center point position of the equilateral triangle. multiphase alternating multiple electrode corona discharge device each phase output terminal of the phase AC power source, characterized in that allowed to connect to the discharge electrodes T ₁ through T ₃ of the electrode unit. 4. As a 6-phase AC output device for outputting 6-phase AC, three sets of transformers S ₁ · S ₄ and transformer S ₅ are provided in parallel for each output terminal of each phase of the 3-phase AC power supply.・ S ₂ and transformer S
₃ · S ₆ is connected to form a pair, and the winding end of one transformer secondary winding and the winding start of the other transformer secondary winding of each pair of transformers connected in parallel are connected. Then, a 6-phase AC output device is further used in which these three sets of connection parts are further connected to each other and the terminals of the secondary windings of the transformer not connected in common are used as output terminals. The described multi-phase AC multi-electrode corona discharge device. 5. An n-phase alternating current output device for outputting an n-phase alternating current, and the tips of the discharge electrodes T _{1 to} T _n are arranged in the vicinity of respective vertex positions of a regular n-sided polygon, and each of the n-phase alternating current output devices An electrode unit in which the phase output terminals are connected to the discharge electrodes T _{1 to} T _{n in the} order of their phases in the right or left order, and an ozone generation tower in which the electrode unit is built and through which oxygen or oxygen-containing gas flows An ozone generator using a multi-phase AC multi-electrode corona discharge characterized by including: 6. A 6-phase AC output device for outputting 6-phase AC, and the discharge electrodes T _{1 to} T ₆ are provided with their tips in the vicinity of respective vertex positions of a regular hexagon, and each phase of the 6-phase AC output device is arranged. An electrode unit in which the output terminals are connected to the discharge electrodes T _{1 to} T _{6 in the} order of their phases in the order of right or left, and an ozone generation tower in which the electrode unit is built and through which oxygen or oxygen-containing gas flows. An ozone generator using a multi-phase AC multi-electrode corona discharge characterized by including: 7. The tip of the discharge electrode T ₁ through T ₃ arranged close to the vicinity of the apexes of an equilateral triangle, the electrode unit comprising and a ground electrode T ₀ is provided in the vicinity of the center point position of an equilateral triangle, the An ozone generator using a multi-phase alternating current multi-electrode corona discharge, characterized in that it comprises an ozone generator tower containing an electrode unit therein and through which oxygen or an oxygen-containing gas flows. 8. As a 6-phase AC output device for outputting 6-phase AC, three sets of transformers S ₁ · S ₄ and transformer S ₅ are arranged in parallel for each output terminal of each phase of the 3-phase AC power supply.・ S ₂ and transformer S
₃ · S ₆ is connected to form a pair, and the winding end of one transformer secondary winding and the winding start of the other transformer secondary winding of each pair of transformers connected in parallel are connected. 7. A 6-phase AC output device is further used in which these three sets of connection parts are further connected to each other and the terminals of the transformer secondary windings not commonly connected are used as output terminals. An ozone generator using the described multi-phase AC multi-electrode corona discharge.