JP2009285561A - Electrostatic dust collecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problems that, in the case where a spark is generated in an electric dust collecting apparatus, airborne suspended matter already trapped and deposited on an electrode plate may possibly be ignited and that, where the dust collecting apparatus is used as a smoke discharge apparatus particularly in a kitchen or an oil mist removal apparatus in a plant, the trapped matter is a powder dust containing oil (edible oil or oil mist) and therefore smoking and firing tend to be caused easily due to the powder dust being a core. <P>SOLUTION: The electrostatic dust collecting apparatus comprises an ionization part for charging the airborne dust or the like in the air by generating corona discharge between an earth electrode plate and a discharge electrode plate, and a dust collection part installed downstream of the ionization part for collecting dust or the like charged in the ionization part, and ignition and fire spread can be prevented by increasing the passing velocity. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrostatic precipitator that collects dust that is airborne particles.

  Currently, air cleaners for home use and commercial use, smoke generators for kitchens, smoke separators, and industrial use as dust collectors and oil mist removers for tunnel ventilation are used as floating substances in the atmosphere (dust, oil mist, smoke). Etc.) is used to collect airborne dust (dust, oil mist, smoke, etc.) generated in the room, tunnel, or factory.

  And in the ionization part of the electrostatic precipitator for such use, a charge-release electrode plate having a plurality of protrusions, a discharge wire, and a needle-like discharge electrode in which a plurality of needles are arranged have been used as the discharge electrode of the ionization part. . However, as each method is used, sparks are likely to be generated through deposits and suspended matter, and sparks ignite the deposits and cause smoke. In particular, when used as a device for removing oil smoke or oil mist, the collected material is dust containing oil mist, so there is a high possibility of fuming and ignition, and a safe electric dust collector is required.

  Under such circumstances, smoke ignition is controlled by reducing the voltage applied to the ionization part to suppress the ignition of the smoke by suppressing the energy at the time of sparking, and the passing wind speed is set to the low passing wind speed for dust collection performance. Small items secured in (1) have been commercialized.

However, in the case of large-scale factories that manufacture parts such as machine tools and cars, the amount of airborne matter (dust, oil mist, smoke, etc.) generated is large, so a small electric dust collector cannot handle it. Or, a problem remains that a large number of units are required, and maintenance and maintenance becomes difficult.
JP-A-8-117639 Japanese Patent No. 3512251 Japanese Utility Model Publication No. 6-45648 JP-A-6-99097

  When a spark occurs in an electrostatic precipitator, it may ignite suspended matter in the atmosphere that has already been collected and deposited on the electrode plate. In particular, when used as a smoke evacuation device in a kitchen or an oil mist removal device in a factory, the collected matter is dust containing oil (edible oil / oil mist), so that the dust becomes the core and is likely to cause smoke ignition. was there.

  Therefore, an object of the present invention is to provide an electrostatic precipitator capable of suppressing smoke emission even when sparking in the electrostatic precipitator.

  In order to solve the above problems, the present invention includes an ionization unit that generates corona discharge between a ground electrode plate and a discharge electrode plate to charge dust in the air, and the ionization unit provided on the downstream side. In an electrostatic precipitator including a dust collecting unit that collects charged dust and the like, it is characterized in that ignition and fire spread due to sparks between different poles are prevented by increasing the passing wind speed.

  By this means, even if a spark occurs in the electrostatic precipitator, an electrostatic precipitator can be obtained that can prevent smoke and ignition due to the spark.

  Another means is characterized in that the passing wind speed is 5 m / sec or more.

  By this means, even if a spark occurs in the electrostatic precipitator, an electrostatic precipitator can be obtained that can prevent smoke and ignition due to the spark.

  Another means is characterized in that the passing wind speed is set to 10 m / sec or less.

  By this means, smoke and ignition can be prevented while maintaining practical dust collection performance, and deterioration of dust collection performance due to re-release of collected oil and dust, and deterioration due to noise and metal fatigue can be prevented. Therefore, the electrode plate can be made of a thin material or a weak material such as aluminum, and an electric dust collector capable of reducing the weight and cost can be obtained.

  Another means is that the applied voltage is 12 kV or less.

  By this means, since the ignition energy at the time of spark can be suppressed, an electric dust collector capable of preventing smoke and ignition can be obtained.

  According to the electrostatic precipitator of the present invention, the ionization unit that generates corona discharge between the ground electrode plate and the discharge electrode plate and charges the dust or the like in the air with the ionization unit provided on the downstream side. In an electrostatic precipitator that consists of a dust collector that collects charged dust, etc., by increasing the passing wind speed, it is possible to prevent ignition and fire spread by sparks between different poles. It is possible to provide an electric dust collector that can prevent smoke from being ignited by sparks even when sparks are generated.

  In addition, by setting the passing wind speed to 5 m / sec or more, it is possible to provide an electric dust collector that can prevent smoke and fire due to spark even if a spark occurs in the electric dust collector.

  In addition, by setting the passing wind speed to 10 m / sec or less, it is possible to prevent smoke and ignition while maintaining practical dust collection performance, and the dust collection performance deteriorates due to re-release of collected oil and dust. Therefore, it is possible to prevent deterioration due to noise and metal fatigue, and to provide an electrostatic precipitator that can use a thin plate material or a weak material such as aluminum so that the weight can be reduced and the cost can be reduced. it can.

  Moreover, since the ignition voltage can be suppressed when the applied voltage is set to 12 kV or less, an electric dust collector capable of preventing smoke and ignition can be provided.

  The invention described in claim 1 is charged by an ionization unit that generates corona discharge between the ground electrode plate and the discharge electrode plate to charge dust or the like in the air, and the ionization unit provided on the downstream side. In an electrostatic precipitator consisting of a dust collector that collects dust, etc., sparks are generated in the electrostatic precipitator by adopting a structure that prevents the fire from spreading by sparking between different poles by increasing the passing air speed. Even so, it is an electrostatic precipitator characterized in that it can prevent smoke and ignition due to sparks, and has the effect of suppressing smoke and ignition by the passing wind speed.

  The invention according to claim 2 is characterized in that, by setting the passing wind speed to 5 m / sec or more, even if a spark is generated in the electrostatic precipitator, it is possible to prevent smoke and ignition due to the spark. It is a dust device, and has the effect | action that the effect which suppresses smoke generation becomes high by making passage wind speed 5 m / sec or more.

  The invention according to claim 3 is an electrostatic precipitator characterized in that the passing wind speed is 10 m / sec or less, and by setting the passing wind speed to 10 m / sec or less, smoke is ignited by the passing wind. In addition to suppressing the deterioration of dust collection performance caused by excessively high passing wind speed and deterioration due to noise and metal fatigue, the electrode plate material can be used with thin materials or weak materials such as aluminum, It has the effect of reducing the weight and cost.

  The invention according to claim 4 is an electrostatic precipitator characterized in that the applied voltage is set to 12 kV or less, and the effect of suppressing smoke generation is increased by setting the applied voltage to 12 kV or less. Have

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
The electrostatic precipitator according to the first embodiment will be described with reference to FIGS.

  FIG. 1 is a schematic diagram of an electrostatic precipitator according to an embodiment of the present invention, showing a flow of wind, FIG. 2 is a perspective view of an ionization section of the apparatus, and FIG. 3 is a circuit diagram of an ionization section of the apparatus. FIG. 4 is a cross-sectional view showing a test apparatus for confirming an ignition state when sparking is performed in an air blowing environment, and FIG. 5 is a diagram showing a circuit and a positional relationship of the test apparatus.

  The electric dust collector 1 includes an upstream ionization unit 2 and a downstream dust collection unit 3 with respect to the air to be processed. In the ionization section 2, discharge electrode plates 4 having a plurality of barb (needle) electrodes 13 and ground electrodes 5 are alternately arranged.

  Next, the test device 8 that is assumed to be sparked (discharged) by the ionization unit 2 and forcibly sparked in the air blowing environment will be described.

  A fixed support base 11 with an arm 12 and a grounding base 15 are installed in a wind tunnel 9 provided with a blower 10 on the downstream side, and an insulator 14 is sandwiched between the tips of the arms 12 of the fixed support base 11 and needles (needles) ) The electrode 13 is provided downward. Further, the positional relationship between the grounding table 15 and the thorn (needle) electrode 13 is such that the thorn (needle) electrode 13 comes to the center upper part of the grounding table 15, and the flat part of the grounding table 15 and the thorn (needle) electrode 13 are arranged. The interval is adjusted by the arm 12 so as to be 8 mm. As the electrical connection, the thorn (needle) electrode 13 is connected to the high voltage generator 6, and the high voltage generator 6 and the grounding base 15 are connected to the ground 7.

  With the above configuration, when the air to be treated flows into the electrostatic precipitator 1, first, a corona discharge is generated in the ionization unit 2 to charge the suspended matter (dust, oil mist, smoke, etc.) in the atmosphere. Further, it is pulled and attracted / collected by the ground electrode plate 5 side of the dust collector 3 by the Coulomb force of the strong electrolysis space formed in the dust collector 3 on the downstream side.

  In the test apparatus 8, spark (discharge) can be generated between the grounding base 15 and the thorn (needle) electrode 13 by increasing the voltage of the high voltage generator 6. The generated voltage of the high voltage generator 6 was a positive voltage (so-called positive charge) in which the discharge electrode 4 has a higher potential than the ground electrode 5. This is because the discharge electrode 4 is less likely to generate ozone than a negative voltage (so-called negative charge) having a lower potential than the ground electrode 5. However, even if it is a positive voltage (so-called positive charge) or a negative voltage (so-called negative charge), if it is the same potential difference, it can be said that the effect on the ignition phenomenon does not change because the energy for ignition is the same. The material of the barb (needle) electrode 13 and the grounding base 15 is SUS304.

  Since spark (discharge) is generated between the thorn (needle) electrode 13 and the grounding base 5, machine oil that causes ignition is placed between the thorn (needle) electrode 13 and the grounding base 5. By the way, the machine oil was tested with oily oil: Cosmo Oil Lubricants Cosmo Pure Spin D, water-soluble oil: Aoki Scientific Laboratory Lubrone A-2225. However, even if only oil (oil-based oil / water-soluble oil) was dropped and sparked (discharged), ignition did not occur. Therefore, a test was conducted with machine oil soaked in cotton 16 (0.3 mg) on the assumption that not only oil but also atmospheric dust was included (cotton: cotton line Hasegawa Co., Ltd.) Made of cut cotton for medical use).

  The reason why the wind tunnel 9 is provided in the test apparatus 8 is to confirm the ignition state when the wind is flowing because a high voltage is applied to the electrostatic precipitator when the wind is always flowing. In addition, the air blower 10 of the wind tunnel 9 was provided in the downstream of the test apparatus 8, and let wind flow with the tension | tensile_strength which the wind speed stabilized.

  From here, the test results will be described.

  FIG. 6 shows a graph according to wind speed showing the relationship between the ignition level and the applied voltage when only the cotton 16 is used in the test apparatus 8. Only cotton 16 (0.3 mg) was crumbled and placed between the thorn (needle) electrode 13 and the grounding base 5, and the voltage was increased by 1 kV and confirmed to 15 kV. The wind speed environment was as follows: no wind speed (wind speed 0 m / sec), 3 m / sec, 4 m / sec, 5 m / sec, 7 m / sec, 9 m / sec, and the spark (discharge) and ignition status were confirmed. . In the test, the graph was divided into 8 levels from level 0 to level VII so that the level of spark (discharge) and ignition state could be easily understood.

・ Level 0: No sparking ・ Level I: Sparking but no ignition / burning ・ Level II: Sparking but burning but no ignition (combustion area φ5 or less)
・ Level III: Spark is generated and scorched but no ignition (combustion area φ6 or more)
・ Level IV: Spark is generated and only fire is generated
・ Level V: Sparking and ignition / burning (combustion area φ5 or less)
・ Level VI: Sparking, ignition and scorching (combustion area φ6 or more)
・ Level VII: Spark is generated and complete combustion (burns out)
In the case of cotton 16 alone, the level of the spark (discharge) / ignition state increased as the applied voltage increased. In addition, the lower the wind speed, the higher the level of spark (discharge) / ignition state.

  It was confirmed that the level VII was reached when the applied voltage was 13 kV or more and the wind speed was 4 m / sec or less. However, when the wind speed was 5 m / sec or higher, level VII was not reached even when the applied voltage was 13 kV or higher.

  Next, FIG. 7 shows a graph according to the wind speed of the relationship between the ignition level and the applied voltage when the oil 16 was soaked in the cotton 16 performed by the test apparatus 8. Under the test conditions of FIG. 6, not only the cotton 16 but also cotton 16 (0.3 mg) is soaked with oily oil (0.2 ml) and rubbed between the thorn (needle) electrode 13 and the grounding base 5. Carried out.

  If the cotton 16 is soaked with 0.2 ml of oily oil, it will be in the level III / IV state even at 11 kV to 12 kV. Also here, the lower the wind speed, the higher the level of spark (discharge) and ignition. However, level VI was not reached in any state.

  Next, FIG. 8 shows a graph according to the wind speed of the relationship between the ignition level and the applied voltage when the oil 16 is soaked in the cotton 16 used in the test apparatus. Under the test conditions of FIG. 7, cotton 16 (0.3 mg) was soaked with oily oil (0.4 ml) and demulsified and placed between the barb (needle) electrode 13 and the grounding table 5.

  When the cotton 16 was impregnated with 0.4 ml of oily oil, the result was not much different from that when the cotton 16 was filled with 0.2 ml of oily oil, but in any state it did not exceed level VI. Also here, the lower the wind speed, the higher the level of spark (discharge) and ignition.

  Next, FIG. 9 shows a graph according to the wind speed of the relationship between the ignition level and the applied voltage when 0.6 ml of oily oil is soaked in the cotton 16 used in the test apparatus 8. With respect to the test conditions of FIG. 8, cotton 16 (0.3 mg) was soaked with oily oil (0.6 ml), demulsified, and placed between the barb (needle) electrode 13 and the grounding stand 5.

  When cotton 16 was soaked with 0.6 ml of oily oil, it did not exceed level VI in any state. In addition, at 4 m / sec or less and 5 m / sec or more, the level of spark (discharge) / ignition state is clearly higher at 4 m / sec or less.

  Comparing FIGS. 6 to 9, it can be seen that the greater the content of oily oil, the more difficult it is to burn. This is related to the fact that it did not ignite when oil alone (no cotton), as mentioned before.

  Next, FIG. 10 shows a graph according to the wind speed of the relationship between the ignition level and the applied voltage when the water 16 is soaked in the cotton 16 used in the test apparatus 8. The test conditions of FIG. 7 were carried out by impregnating with water-soluble oil (0.2 ml) instead of oily oil and placing it between the barb (needle) electrode 13 and the grounding table 5.

  Even when 0.2 ml of water-soluble oil is soaked into cotton 16, the level of spark (discharge) / ignition state tends to increase as the wind speed slows down, but level IV only when the wind speed is 3 m / sec or 4 m / sec. The wind speed was 5 m / sec or higher and no wind (0 m / sec).

  It did not reach Level VI like oily oil, and was below Level IV in any state. Therefore, it turns out that it is hard to burn than oil-based oil. It is presumed that the water-soluble oil contains moisture and works in a direction that is difficult to ignite against ignition.

  Next, FIG. 11 shows a graph according to the wind speed of the relationship between the ignition level and the applied voltage when the water 16 is soaked in the cotton 16 used in the test apparatus 8. With respect to the test conditions of FIG. 10, cotton 16 (0.3 mg) was soaked with water-soluble oil (0.4 ml), demulsified, and placed between the barb (needle) electrode 13 and the grounding base 5. .

  Even when 0.4 ml of water-soluble oil is infiltrated into cotton 16, the result is not much different from that when 0.2 ml of water-soluble oil is in cotton 16. The lower the wind speed, the higher the level of spark (discharge) and ignition. However, it reached level IV only when the wind speed was 3 m / sec and 4 m / sec, and was below level II in a wind speed of 5 m / sec or higher and no wind (0 m / sec). It did not reach level V as in oily oils, and was below level IV in any state. Therefore, it turns out that it is harder to burn than oily oil here.

  Next, FIG. 12 shows a graph according to the wind speed of the relationship between the ignition level and the applied voltage when 0.6 ml of water-soluble oil is soaked in the cotton 16 used in the test apparatus 8. For the test conditions shown in FIG. 11, cotton 16 (0.3 mg) was soaked with water-soluble oil (0.6 ml), demulsified, and placed between the barb (needle) electrode 13 and the grounding base 5. .

  Even when 0.6 ml of water-soluble oil is soaked into the cotton 16, the result is not much different from that when the water-soluble oil is 0.2 ml or 0.4 ml in the cotton 16. The slower the wind speed, the higher the level of spark (discharge) and ignition. However, it reached level IV only at wind speeds of 3 m / sec and 4 m / sec, and was below level II in windless conditions (0 m / sec) and at wind speeds of 5 m / sec or higher. It did not reach level V as in oily oils, and was below level IV in any state. Therefore, it turns out that it is harder to burn than oily oil here.

  Next, FIG. 13 shows a graph according to the wind speed of the relationship between the ignition level and the applied voltage when the factory collected oil is 0.2 mg alone, which is performed by the test apparatus 8. For the test conditions shown in FIG. 7, a single oil (oil collected by a dust collector) collected at an actual machining (cutting / polishing) factory was placed between the thorn (needle) electrode 13 and the grounding base 5. .

  A comparison of the results of the oil collected at the actual machining (cutting / polishing) factory (oil collected by the dust collector) and the results of oil-based and water-soluble oils is characteristically similar to water-soluble oil There was a tendency. Therefore, as a result of confirmation with a machining factory, it was confirmed that water-soluble oil was actually used. However, as mentioned before, the oil alone has not burned until now. The reason for reaching Level IV without cotton 16 this time is presumed to be that oil once released into the atmosphere has been recovered, and that it includes clothes fibers and cotton dust. This factory-collected oil was dark and transparent in appearance, and was a semi-kneaded oil with a high viscosity. Moreover, although the level of the spark (discharge) / ignition state tends to increase as the wind speed is slow, the level IV was not exceeded under any conditions.

  Next, FIG. 14 shows a graph according to the wind speed of the relationship between the ignition level and the applied voltage when 0.2 ml of the factory-collected oil was kneaded into the cotton 16 performed by the test apparatus 8. With respect to the test conditions of FIG. 13, oil (oil collected by a dust collector) collected in an actual machining (cutting / polishing) factory is kneaded into cotton 16 (0.3 mg), and the thorn (needle) electrode 13 And was carried out between the grounding table 5.

  Even under this condition, the result is not much different from that of the oil collected at the actual machining (cutting / polishing) factory (oil collected by the dust collector) alone. The lower the wind speed, the higher the level of spark (discharge) / ignition state. Although there was a tendency to increase, level IV was not exceeded in any condition.

  From the above results, it was confirmed in a phenomenological manner that the fire spread can be suppressed by increasing the passing wind speed. Among them, when the passing wind speed is set to 5 m / sec or more, the ignition and fire spread suppressing effect is increased. In addition, the faster the passing wind speed, the higher the effect of suppressing the ignition and fire spread, but on the other hand, there is a risk of deterioration due to dust collection performance and noise, which are important as a dust collector, and metal fatigue of the discharge electrode plate 4 and the ground electrode plate 5. In this ignition and fire spreading test, it was confirmed up to 9 m / sec. However, considering the dust collection performance and noise, and the deterioration of the discharge electrode plate 4 and the ground electrode plate 5 due to metal fatigue, it is realistically established as the electric dust collector 1. Is considered to be limited to a wind speed of 10 m / sec. Moreover, since it tends to ignite when the applied voltage exceeds 12 kV, the fire spread can be suppressed by using it at 12 kV or less.

  The electrostatic precipitator of the present invention applies electric charges to the dust by corona discharge and charges the dust, and collects the charged dust by coulomb force. In industrial use, it can be used for electric dust collectors such as a dust collector for tunnel ventilation and an oil mist removing device.

The figure which showed the flow of the wind in the schematic of the electrostatic precipitator by embodiment of this invention Perspective view of the ionization part of the device Circuit diagram of ionization section of the device Cross-sectional view showing a test device for confirming the ignition state when sparking in an air blowing environment Diagram showing the circuit and positional relationship of the test equipment Graph by wind speed of the relationship between ignition level and applied voltage when only cotton was used in the test equipment Graph by wind speed of the relationship between ignition level and applied voltage when oil oil 0.2ml was soaked in cotton Graph by wind speed of the relationship between ignition level and applied voltage when oil oil 0.4ml was soaked in cotton Graph by wind speed of the relationship between ignition level and applied voltage when 0.6 ml of oily oil was soaked in cotton Graph by wind speed of relationship between ignition level and applied voltage when water-soluble oil 0.2ml was soaked in cotton Graph by wind speed of the relationship between ignition level and applied voltage when water-soluble oil 0.4ml was soaked in cotton Graph by wind speed of the relationship between ignition level and applied voltage when 0.6 ml of water-soluble oil was soaked in cotton Graph by wind speed of the relationship between the ignition level and applied voltage when the factory collected oil of 0.2 mg was used with the same test equipment Graph by wind speed of the relationship between ignition level and applied voltage when 0.2 ml of factory-collected oil was kneaded into cotton made using the same test equipment

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric dust collector 2 Ionization part 3 Dust collection part 4 Discharge electrode plate 5 Grounding electrode plate

Claims (4)

An ionization unit that generates corona discharge between the ground electrode plate and the discharge electrode plate to charge dust in the air, and a dust collection unit that collects dust and the like charged by the ionization unit provided on the downstream side The electrostatic precipitator which consists of a part WHEREIN: The ignition dust spread by the spark between different poles is prevented by making the passage wind speed of the air which passes between electrode plates faster, and is characterized by the above-mentioned. 2. The electrostatic precipitator according to claim 1, wherein the passing wind speed is 5 m / sec or more. 3. The electrostatic precipitator according to claim 1, wherein the passing wind speed is 10 m / sec or less. The electrostatic precipitator according to any one of claims 1 to 3, wherein the applied voltage is 12 kV or less.

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