JPWO2016136270A1 - Electric dust collector - Google Patents

Abstract

The dust collection unit (11) of the electrostatic precipitator is composed of a plurality of charged portion load electrode plates (15) having conductive fiber portions (20) made of conductive fibers on at least one side and conductive fibers on at least one side. A plurality of charging portion grounding electrode plates (14) having the conductive fiber portions (20). In addition, the charging parts alternately arranged in parallel so as to have conductive fiber parts (20) made of conductive fibers between the electrodes of the charging part load electrode plate (15) and the charging part ground electrode plate (14). (12) is provided. In addition, the dust collector (13) in which the dust collector ground electrode plate and the dust collector electrode plate (17) are arranged in parallel, the charging unit high-voltage power source (18) for charging the charging unit electrode plate (15), the collector A dust collector high-voltage power supply (19) for charging the dust electrode (17) is provided. Further, a charging unit (12) is disposed on the leeward side, and a dust collecting unit (13) is disposed on the leeward side.

Description

  The present invention relates to an electrostatic precipitator that charges airborne particles in air and collects them by electrostatic force.

  Conventionally, this type of electrostatic precipitator applies a DC high voltage to the discharge electrode of the charging unit, generates a positive corona or a negative corona, and imparts a positive or negative charge to the dust passing through the charging unit. Is charged. There is a technology to collect this charged dust on the surface of the grounding electrode plate with electrostatic force by a high electric field between the load electrode to which a DC high voltage is applied and the dust collecting part having the grounding electrode plate connected to the ground. Widely known in general (for example, see Patent Document 1).

  Hereinafter, the principle of electrostatic dust collection will be described with reference to FIG.

  FIG. 20 schematically shows the electrode arrangement of the dust collection unit of the electric dust collector. As shown in FIG. 20, the electrostatic precipitator includes a charging unit 104 and a dust collecting unit 105. The ventilation direction is the direction from the charging unit 104 to the dust collection unit 105 (from left to right in FIG. 20). A DC high voltage of +11 kV and +8.3 kV is supplied from the DC high voltage power source 109 to the charging unit 104 and the dust collecting unit 105, respectively. The charging unit 104 includes a protruding discharge electrode 104A and a ground electrode plate 104B. A DC high voltage of +11 kV is applied to the discharge electrode 104A, and a positive corona discharge is generated in the space between the discharge electrode 104A and the ground electrode plate 104B. Positive ions generated by the positive corona give a positive charge to dust (not shown) in the space, and the dust is positively charged. The charged dust is collected on the ground electrode plate 105B by electrostatic force due to a strong electric field formed between the load electrode plate 105A and the ground electrode plate 105B in the dust collection unit 105 in the subsequent stage (dust collection principle).

A general dust collector for a tunnel ventilation facility using corona discharge has a power consumption per air volume of about 110 W / (m ³ / s). As a result, the power consumption per 1 m ³ / min is about 2 W.

Further, in other conventional air purifiers, the power consumption is 3.5 W when the processing air volume is 0.3 m ³ / min, and the power consumption per 1 m ³ / min is about 12 W (for example, Patent Document 2).

JP-A-9-225340 JP-A-9-239289

  In the charging unit 104 of such an electrostatic precipitator, power consumption due to corona discharge occurs, and thus there is a problem that the electricity cost associated with power consumption increases.

  In view of this, the present invention does not generate corona discharge or generates minute corona discharge to charge dust, thereby reducing power generation at the charging unit and reducing the electricity cost associated with power consumption. Provide a dust device.

  In the electrostatic precipitator according to the present invention, a plurality of load electrodes and a plurality of ground electrodes are alternately arranged in parallel between the inflow portion and the outflow portion of the gas containing dust. In addition, a conductive fiber is provided on one side of the load electrode or one side of the ground electrode, the conductive fiber is provided between each electrode plate of the load electrode and the ground electrode, and a charging unit that applies a high voltage to the load electrode is provided.

  With such a configuration, dust is deposited on the conductive fiber by a gradient force, and the accumulated dust is charged by induction charging to the same polarity as the conductive fiber deposited at the time of scattering, and the scattered charged dust is different in polarity. Dust can be collected by the opposing ground electrode or load electrode.

  Further, it is possible to reduce the generation of electric power in the charging unit and reduce the electricity cost associated with power consumption.

In addition, the electrostatic precipitator according to the present invention generates a discharge from the end of the conductive fiber by applying a high voltage to the load electrode, and discharges the charged portion to the area of the electrode by 3 per 1 mm ^2. It is good also as the range of * 10 < ^-5 > -60 * 10 < ^-5 > μA.

  Further, the ratio of the length of the conductive fibers to the electrode plate interval between the load electrode and the ground electrode is set to 0.01 to 0.3, and the electric field strength between the electrode plate between the load electrode and the ground electrode is set to 0.3 to 0.3. It may be 1 kV / mm.

  The conductive fiber may be carbon fiber.

  In addition, a plurality of dust collector load electrode plates and a plurality of dust collector ground electrode plates are alternately arranged in parallel between the inflow and outflow portions of the gas containing dust, and a high voltage is applied to the dust collector load electrode plates. A plurality of dust collecting portion load electrode plates and a plurality of dust collecting portion ground electrode plates may be used as the dust collecting portion, and the dust collecting portion may be provided on the downstream side of the charging portion.

  Moreover, it is good also as what does not generate | occur | produce discharge from the edge part of an electroconductive fiber, even if a high voltage is applied to a load electrode.

FIG. 1 is a perspective view of the inside of a tunnel ventilation facility using an electrostatic precipitator according to the first embodiment of the present invention. FIG. 2 is a view showing a section 2-2 in FIG. FIG. 3 is a view showing a 3-3 cross section of FIG. FIG. 4 is an internal perspective view of the upper surface of the tunnel ventilation facility using the electrostatic precipitator according to the first embodiment of the present invention. FIG. 5 is a configuration diagram of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 6 is a conceptual diagram showing the electrode plate arrangement of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 7 is a graph showing the current with respect to the applied voltage of the charging unit of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 8 is a conceptual diagram showing the electric field region of the charging unit of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 9A is a conceptual diagram illustrating the movement of dust accumulation in the charging unit of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 9B is a conceptual diagram showing the movement of dust re-scattering in the charging unit of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 10 is a graph showing the dust collection rate of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 11 is a graph showing the dust collection rate when the applied voltage of the electrostatic precipitator according to the first embodiment of the present invention is zero. FIG. 12 is a graph showing the dust collection rate when the voltage application of the electrostatic precipitator according to the first embodiment of the present invention is applied only to the charging unit. FIG. 13 is a graph showing the dust collection rate when the voltage application of the electrostatic precipitator according to the first embodiment of the present invention is limited to the dust collection unit. FIG. 14 is a graph showing a comparison of the dust collection rates of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 15 is a graph showing the dust collection rate with respect to the charging unit applied voltage of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 16 is a graph showing the dust collection rate with respect to the charged portion discharge current of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 17 is a graph showing the dust collection rate with respect to the power consumption of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 18 is a perspective view illustrating the configuration of the charging unit of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 19 is a perspective view illustrating the configuration of the electrostatic precipitator according to the first embodiment of the present invention. FIG. 20 is a configuration diagram of a charging unit and a dust collection unit of a conventional electric dust collector.

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

(First embodiment)
First, as an example of installation of the electric dust collector in the present embodiment, a configuration used for a tunnel ventilation facility will be described with reference to FIGS.

  As shown in FIGS. 1-4, the electrostatic precipitator 3 of this Embodiment is installed in the ventilation air path 4 from the ventilation inlet port 2 to the ventilation discharge port 6 in the upper part of the tunnel main line 1, and is ventilated. A ventilation fan 5 is installed on the downstream side of the air passage 4. In the present embodiment, there are three ventilation air passages 4, and as shown in FIG. 4, the ventilation inlet 2, the electric dust collector 3, the ventilation air passage 4, and the ventilation fan 5 constitute one system. Although not all are shown, a ventilation air passage having a similar configuration is provided on both sides of the ventilation air passage 4 shown in FIG. 4, and the common ventilation outlet 6 is an outlet in which three systems are combined. Yes.

  On the side of the electrostatic precipitator 3, as shown in FIG. 1, an electrostatic precipitator 7 and a high pressure generating panel 8 and a control panel 9 for operating the precipitator 3 and the electrostatic precipitator 7 are installed. Has been.

  As shown in FIG. 5, the electric dust collector 3 includes a dust collection unit 11 including a charging unit 12 and a dust collection unit 13 in a casing 10, and a damper 31 on the windward side of the dust collection unit 11. A cleaning pipe 32 is provided in the upper part on the leeward side, and a wiring terminal box 33 is provided in the lower part on the leeward side. As shown in FIG. 2, a plurality of dust collection units 11 are provided in the casing 10.

  The damper 31 is closed when the electrode plates constituting the charging unit 12 and the dust collecting unit 13 are washed with water, and has a function of preventing water scattering to the outside of the casing 10. In-machine piping for cleaning, which is made of stainless steel or resin.

  The wiring terminal box 33 is a box that temporarily receives the wiring from the high voltage generating board 8 and applies a high voltage from the terminal of the box to the charging unit 12 and the dust collecting unit 13.

  Next, the configuration of the charging unit 12 of the dust collection unit 11 that is a feature of the present embodiment will be described.

  As shown in FIG. 6, the dust collecting unit 11 includes a charging unit 12 in which charging unit grounding electrode plates 14 as grounding electrodes and charging unit load electrode plates 15 as load electrodes are alternately arranged in parallel, and a dust collecting unit grounding. A dust collector 13 in which electrode plates 16 and dust collector electrode plates 17 are alternately arranged in parallel, a charging unit high-voltage power supply 18 for charging the charger unit electrode plate 15, and a collector unit for charging the dust collector unit electrode plate 17. It consists of a dust part high-voltage power supply 19. A charging unit 12 is disposed on the windward side, and a dust collecting unit 13 is disposed on the leeward side.

  For example, the charging unit 12 has a depth (length) L1 of 40 mm and a height (not shown) of 32 mm between the charging unit ground electrode plate 14 and the charging unit load electrode plate 15. The electrode plate interval D1 of the partial electrode plate 15 is 10 mm.

  For example, the dust collection unit 13 has a dust collection unit ground electrode plate 16 and a dust collection unit load electrode plate 17 having a depth (length) L2 of 280 mm and a height (not shown) of 90 mm. The electrode plate interval D2 between the plate 16 and the dust collecting portion load electrode plate 17 is 10 mm. Further, six dust collecting portion grounding electrode plates 16 and six dust collecting portion load electrode plates 17 are used.

  The electrode plate material of the charging unit 12 and the dust collecting unit 13 is, for example, SUS304, the plate thickness is about 0.4 to 0.6 mm, and any material can be used as long as it is a conductor.

  The charging unit ground electrode plate 14 and the charging unit load electrode plate 15 are provided with a conductive fiber portion 20 in which a large number of conductive fibers are implanted on one side, and either the charging unit ground electrode plate 14 or the charging unit load electrode plate 15 facing each other. One of them is arranged so as to have the conductive fiber portion 20.

  The conductive fiber portion 20 is composed of a large number of activated carbon fibers having a wire diameter of about 5 to 10 μm and a length of about 0.1 to 3 mm, for example, and using a conductive adhesive, the charging portion grounding electrode 14 and the charging portion load are formed. Bonded to the electrode plate 15.

  The ratio of the length of the conductive fiber portion 20 to the electrode plate interval D1 between the charging portion load electrode plate 15 and the charging portion ground electrode plate 14 is preferably 0.01 to 0.3. If this ratio is 0.01 or more, that is, if the length of the conductive fiber portion 20 in this embodiment is 0.1 mm or more, the gradient force generated at the end of the conductive fiber portion 20 becomes strong, and the dust collection rate Can be high. Further, if the ratio of the length of the conductive fiber portion 20 to the electrode plate interval D1 is 0.3 or less, that is, the length of the conductive fiber portion 20 in this embodiment is 3 mm or less, the charging portion grounding electrode plate 14 Since the frequency of occurrence of a spark (local short circuit) between the charging part load electrode plates 15 is reduced, the dust collection rate can be increased.

  The conductive fiber portion 20 is preferably carbon fiber. According to this configuration, since the specific gravity is lighter than that of metal or the like while having conductivity, the apparatus can be reduced in weight.

  Planting hair using electrostatic force. The charging portion ground electrode plate 14 and the charging portion load electrode plate 15 coated with the conductive adhesive are arranged to face each other at an interval of about 20 to 30 mm, and a high voltage of about DC-5 kV is applied to the charging portion load electrode plate 15.

  When air containing a large number of conductive fibers is introduced in this state, one end of the conductive fibers is fixed on the charging portion ground electrode plate 14 and the charging portion load electrode plate 15 coated with a conductive adhesive by dielectric polarization.

  In the present embodiment, the conductive fibers are implanted, but a method other than the implantation may be used. For example, what processed the conductive fiber part 20 into the nonwoven fabric form may be adhered and fixed.

  Further, in the present embodiment, the conductive fiber portion 20 is composed of activated carbon fibers having fine pores on the surface. However, the conductive fiber portion 20 may not be activated carbon fibers as long as it has a conductive fibrous shape. For example, a resin fiber mixed with a conductive material such as carbon, a fine metal wire, or a resin fiber plated with a conductive material such as metal.

The conductive adhesive is composed mainly of, for example, silver as a conductive material and silicon as a binder, and is cured at about 180 ° C. The volume resistivity after curing is 2.5 × 10 ⁻⁶ Ω · cm. It is.

  The conductive material may be other than silver as long as it has conductivity. For example, gold or copper.

  The binder may be other than silicon as long as it has thermosetting properties. For example, epoxy resin, urethane resin, acrylic resin and the like.

  Further, in the present embodiment, the charging unit 12 is divided into two in the wind flow direction, and six charging unit grounding electrode plates 14 and six charging unit load electrode plates 15 are used in the front stage and the rear stage, respectively. In addition, the conductive fiber portions 20 of the charging portion grounding electrode plate 14 and the charging portion load electrode plate 15 are arranged in opposite directions in the former stage and the latter stage.

  The distance B between the two divisions is, for example, 40 mm.

  FIG. 7 shows a current value with respect to an applied voltage of the charging unit 12 when the conductive fiber portion 20 is present (solid line in ●) and when it is not present (dotted line in ▲).

  As shown in FIG. 7, when there is no conductive fiber part 20, the current increased at −10.5 kV or more (absolute value 10.5 kV or more), whereas when the conductive fiber part 20 exists, − An increase in current is observed at 6 kV or more (absolute value of 6 kV or more).

  In addition, the electric current value shown in FIG. 7 is a value after performing aging (time which passed in the state which applied the high voltage | pressure) for 3 hours. Since the charging unit grounding electrode plate 14, the charging unit load electrode plate 15, and the conductive fiber unit 20 have burrs at the end of processing, the current value changes due to the influence of the burrs. Due to aging, the current value decreases with time, and after a certain time has elapsed, the current also settles to a substantially constant value.

  In the present embodiment, the applied voltage of the dust collection unit 13 without the conductive fiber unit 20 is set to -9 kV in order to suppress power consumption in the dust collection unit.

  In such a configuration, the tunnel main line 1 operates the ventilation fan 5 and sucks contaminated air containing dust from the ventilation suction port 2 in order to prevent contamination caused by dust generated by traveling of the vehicle, and the ventilation air passage 4. The air is collected by the electric dust collector 3 and the air from which the dust is removed from the ventilation discharge port 6 is discharged out of the tunnel main line 1 (see FIG. 1).

  The electrostatic precipitator 3 charges the dust in the contaminated air sucked from the ventilation inlet 2 by the charging unit 12 of the dust collecting unit 11, and the dust collecting unit grounding electrode 16 and the dust collecting unit load electrode of the dust collecting unit 13. It adheres to the plate 17 and removes dust from the contaminated air (see FIG. 6).

  The feature of the present embodiment is that the charging unit high-voltage power supply 18 is used, but the corona discharge is not generated or the fine corona discharge is used to attach and charge the dust by the gradient force and the induction charging. This will be described with reference to FIGS.

  FIG. 8 is an enlarged view of a portion X in FIG. 6. As shown in FIG. 8, the charging unit high-voltage power supply 18 applies a negative high voltage to the charging unit load electrode plate 15 to charge the charging unit ground electrode plate 14. Electric lines of force directed toward the part load electrode plate 15 act. The electric lines of force are curved so that the conductive fiber portions 20 on the charging portion ground electrode plate 14 and the charging portion load electrode plate 15 are dense, thereby forming an unequal electric field.

  Here, the gradient force refers to a force that the dielectric receives so as to move in the direction of a stronger electric field in an unequal electric field, and the charged portion grounding electrode plate 14 in which the electric lines of force are dense in FIG. And acts toward the conductive fiber portion 20 on the charging portion load electrode plate 15.

  The behavior of the dust flying in the unequal electric field will be described with reference to FIGS. 9A and 9B.

  9A, the conductive fibers 20a and the conductive fibers 20b from the windward side (left side of FIG. 9A) of the conductive fiber portion 20 of the charging portion ground electrode plate 14 and the charging portion load electrode plate 15 shown in FIG. The conductive fibers 20c and the conductive fibers 20d will be described.

  9A schematically shows the behavior of dust in the conductive fiber portion 20 of the charging portion ground electrode plate 14, but the dust also has the same behavior in the conductive fiber portion 20 of the charging portion load electrode plate 15. FIG. do.

  As shown in FIG. 9A, the dust flying to the charging unit 12 is attracted to the conductive fiber 20a on the windward side of the conductive fiber unit 20 of the charging unit ground electrode plate 14 and the charging unit load electrode plate 15 by a gradient force. Is deposited.

  Further, the dust that has not been attracted to the conductive fibers 20a of the charging unit ground electrode plate 14 and the charging unit load electrode plate 15 passes through the region of the first unequal electric field, and the charging unit ground electrode plate 14 and the charging unit load electrode. The conductive fibers 20a of the plate 15 are attracted to the conductive fibers 20b on the leeward side (right side in FIG. 9A) and are deposited.

  Further, the dust that has not been attracted to the conductive fiber 20b of the charging unit ground electrode plate 14 and the charging unit load electrode plate 15 passes through the region of the second unequal electric field, and the charging unit ground electrode plate 14 and the charging unit load. The conductive fibers 20b of the electrode plate 15 are attracted and deposited on the conductive fibers 20c on the leeward side.

  Further, the dust that has not been attracted to the conductive fiber 20c of the charging unit ground electrode plate 14 and the charging unit load electrode plate 15 passes through the third unequal electric field region, and the charging unit ground electrode plate 14 and the charging unit load. The conductive fibers 20c of the electrode plate 15 are attracted to the conductive fibers 20d on the leeward side and are deposited.

  That is, the charged portion grounding electrode plate 14 and the charged portion load electrode plate 15 shown in FIG. 6 have a dense electric field in the vicinity of the conductive fiber portion 20 to form an unequal electric field. Attract and deposit.

  The dust deposited on the conductive fiber portion 20 of the charging portion grounding electrode plate 14 and the charging portion load electrode plate 15 peels off when a large amount of dust is deposited, and at this time, it is charged with the same electric polarity as the attached electrode plate ( This charging is called induction charging) and re-scatters.

  Specifically, as shown in FIG. 9B, the dust deposited on the conductive fiber portion 20 of the charging portion ground electrode plate 14 is deposited on the conductive fiber portion 20 of the positive polarity, charging portion load electrode plate 15. The dust that had been charged is negatively charged and re-scatters.

  The re-scattered and charged particles are collected by electrostatic force on the surface of the dust collecting portion ground electrode plate 16 or the dust collecting portion load electrode plate 17 of the dust collecting portion 13 shown in FIG.

  As described above, the charging unit ground electrode plates 14 and the charging unit load electrode plates 15 having the conductive fiber portions 20 on at least one side are alternately arranged in parallel, whereby the dust can be charged by induction charging. Here, “parallel” includes substantially parallel inclined several degrees.

  That is, as described with reference to FIG. 8, by providing the conductive fiber portion 20 on at least one surface of the charging portion ground electrode plate 14 and the charging portion load electrode plate 15, electric lines of force are generated in the conductive fiber portion 20 of each electrode plate. Can be bent and dense, and a large number of unequal electric field regions can be formed.

  And, by the gradient force acting in the direction of a stronger electric field, the dust is attracted and deposited on the conductive fiber portion 20 of the charging portion ground electrode plate 14 and the charging portion load electrode plate 15, and a large amount of dust is accumulated at the time of scattering. The charged portion ground electrode plate 14 or the charged portion load electrode plate 15 can be charged by induction charging to the same polarity.

  The scattered charged dust can be collected by the dust collector grounding electrode plate 16 or the dust collector electrode plate 17 having different polarities of the dust collector 13. As a result, dust can be charged and collected without generating corona discharge only by applying a high voltage between the charging portion ground electrode plate 14 and the charging portion load electrode plate 15 or by minute corona discharge. Therefore, it is possible to reduce the generation of electric power in the charging unit 12 and to reduce the electricity cost associated with power consumption.

  In the present embodiment, as shown in FIG. 7, the dust collection unit 13 uses electrostatic force generated in parallel plates, which has a lower pressure loss than a filter type by physical contact and also has a dust collection rate. high.

  In addition, since a stronger electric field can be obtained than in the electrostatic filter type in which a high voltage is applied to the filter, there are effects that the pressure loss is small and the dust collection rate is high.

  The dust collection effect when no corona discharge is generated in the present embodiment will be described with reference to FIGS. The results shown in FIGS. 10 to 14 are those in which the aging of the charging unit 12 is not performed.

  FIG. 10 is a graph showing the dust collection rate with respect to the wind speed when the applied voltage of the charging unit 12 in the present embodiment is −2.4 kV.

  The dust collection rate was determined by measuring the number concentration of dust in the air with a particle counter, and the dust collection rate was calculated from the concentration ratio between the inlet side and the outlet side of the dust collection unit 11 by the following formula.

Dust collection rate = (1-outlet side number concentration / inlet side number concentration) x 100 (%)
As shown in FIG. 10, it has a dust collection rate of 10% or more without consuming electric power at a wind speed of 11 m / s or less, and particularly a dust collection rate of 40% or more at a wind speed of 2 m / s.

  FIG. 11 is a graph showing the dust collection rate when the applied voltage of the charging unit 12 and the dust collection unit 13 is 0 kV for comparison.

  As shown in FIG. 11, the dust collection rate when no voltage is applied is less than 5%.

  When no voltage is applied, no gradient force is generated in the vicinity of the conductive fiber portion 20, so that dust cannot be charged by induction charging, and the dust collection rate is considered to be low.

  FIG. 12 is a graph showing the dust collection rate when a voltage is applied only to the charging unit 12. FIG. 13 is a graph showing the dust collection rate when a voltage is applied only to the dust collection unit 13.

  In general, the combined dust collection rate c% in the case where the charging unit 12 with the dust collection rate a% and the dust collection unit 13 with the dust collection rate b% are arranged in series is as follows. It can be calculated by the formula.

Dust collection rate c = (1- (1-a / 100) × (1-b / 100)) × 100 (%)
FIG. 14 shows the combined dust collection rate (dotted line) and charging obtained from the dust collection rate when the voltage is applied only to the charging unit 12 and the dust collection rate when the voltage is applied only to the dust collection unit 13 using the above formula. It is the graph which compared the dust collection rate (solid line) at the time of applying a voltage to both the part 12 and the dust collection part 13. FIG.

  As shown in FIG. 14, the measured dust collection rate is higher than the synthetic dust collection rate obtained by calculation.

  This is because the dust collecting unit 13 applies a high voltage to the parallel plate, so that the dust once contacted or collected by the charging unit 12 is re-scattered in a state of being charged by induction charging, and this is the subsequent dust collecting unit. This is thought to be due to the effect of electrostatically collecting by the strong electric field in 13 parallel plates.

  Thus, the synergistic effect with the charging part 12 of the structure mentioned above can be created by comprising the dust collection part 13 as shown in FIG. 7 by a parallel plate, and applying a high voltage.

  Next, the dust collection effect when the minute corona discharge in this embodiment is used will be described with reference to FIGS. Note that the results shown in FIGS. 15 to 17 are those in which the charging unit 12 is aged.

  FIG. 15 is a graph showing the dust collection rate with respect to the applied voltage of the charging unit 12 in the present embodiment. The wind speed is 2 m / s, and the solid line in FIG. 15 represents the average value during five measurements.

  As shown in FIG. 15, the increasing tendency of the dust collection rate is seen when the applied voltage of the charging unit 12 is around -3 kV. Further, the dust collection rate is significantly increased at −4 kV or more (absolute value of 4 kV or more), and at −7 kV, the dust collection rate is 80% or more. In this embodiment, the electric field strength of the charging unit 12 at -3 kV is 0.3 kV / mm because the electrode plate interval D1 between the charging unit ground electrode plate 14 and the charging unit load electrode plate 15 is 10 mm. . Further, the electric field strength of the charging unit 12 at −4 kV in the present embodiment is 0.4 kV / mm.

  The electric field strength between the electrode plates of the charging portion load electrode plate 15 and the charging portion ground electrode plate 14 is preferably 0.3 to 1 kV / mm. If the electric field strength is 0.3 kV / mm or more, an improvement in the dust collection rate due to the gradient force can be expected. Further, if the electric field strength is 1 kV / mm or less, the frequency of occurrence of a spark (local short circuit) between the charging unit grounding electrode plate 14 and the charging unit load electrode plate 15 is reduced, so that the dust collection rate can be increased. it can.

  FIG. 16 is a graph showing the dust collection rate with respect to the discharge current of the charging unit 12 in the present embodiment. The wind speed is 2 m / s, and the discharge current is changed by slightly varying the voltage applied to the charging unit 12 in the vicinity of −7 kV.

As shown in FIG. 16, when the discharge current of the charging unit 12 is 1 μA, the dust collection rate is 70% or more, and when the discharge current is 2 μA or more, the dust collection rate is 80% or more. The discharge 1 μA of the charging unit 12 in the present embodiment is 3 × 10 ⁻⁵ μA when converted per 1 mm ^{2 of} electrode area (electrode area = area per electrode (40 mm × 32 mm) × number of electrodes ( 6 ground electrode plates + 6 load electrode plates) × 2 layers = 30,720 mm ² ).

In this embodiment, since the discharge current when the electrode plate interval D1 (see FIG. 6) of the charging unit 12 is 10 mm is about 20 μA, the discharging current of the charging unit 12 is 1 to ²⁰ μA, that is, per 1 mm ^{2 of the} electrode area. The discharge current is preferably 3 × 10 ^{−5 to} 60 × 10 ⁻⁵ μA.

If the discharge current per 1 mm ^{2 of} electrode area is 3 × 10 ⁻⁵ μA or more, that is, if the discharge current of the charging unit 12 is 1 μA or more in this embodiment, the gradient force generated at the end of the conductive fiber portion 20 is strong. Thus, the dust collection rate can be increased.

If the discharge current per 1 mm ^{2 of} electrode area is 60 × 10 ⁻⁵ μA or less, that is, if the discharge current of the charging unit 12 is 20 μA or less in this embodiment, the charging unit ground electrode plate 14 and the charging unit load electrode plate Since the frequency of occurrence of sparks (local short circuit) between 15 is reduced, the dust collection rate can be increased.

Further, it is more preferable that the discharge current per 1 mm ^{2 of} the electrode area is 3 × 10 ⁻⁵ to 15 × 10 ⁻⁵ μA, that is, the discharge current of the charging unit 12 in the present embodiment is 1 to ⁵ μA. According to this configuration, power consumption is extremely small, and the dust collection rate can be set to 70% or more.

  FIG. 17 is a graph showing the dust collection rate with respect to the power consumption in the present embodiment. The wind speed is 2 m / s, and the power consumption is changed by slightly varying the voltage applied to the charging unit 12 in the vicinity of −7 kV.

  As shown in FIG. 17, in this embodiment, the power consumption is 15 mW or more and the dust collection rate is 80% or more.

The processing air volume in the present embodiment is 0.46 m ³ / min from the cross-sectional area (height 32 mm × electrode plate interval 10 mm × electrode plate number 12 sheets) × wind speed (2 m / s). As a result, the power consumption per 1 m ³ / min is about 0.03 W, which is about 1 / 100th of the power consumption of the electrostatic precipitator of the prior art document 2, for example.

  Next, how to assemble the charging unit 12 and the dust collecting unit 13 will be described with reference to FIGS.

  As shown in FIG. 18, the charging unit 12 has a plurality of charging unit grounding electrode plates 14 and charging unit load electrode plates 15 arranged at regular intervals by an electrode plate interval holding tube 22. Each electrode plate is penetrated by a plurality of electrode plate holding rods 23 and supported and fixed in parallel between the charging unit frames 21 at both ends.

  In addition, the charging unit frame 21 is provided with an insulator 24, which supports a voltage applying component including the charging unit load electrode plate 15 and is electrically insulated from a grounding component including the charging unit grounding electrode plate 14.

  As shown in FIG. 6, the dust collecting unit 13 includes the dust collecting unit ground electrode plate 16 and the dust collecting unit electrode plate 17 having approximately the same number as the charging unit ground electrode plate 14 and the charging unit load electrode plate 15. Are arranged in parallel.

  In addition, as shown in FIG. 19, the dust collector 13 has a plurality of dust collector grounding electrode plates 16 and dust collector load electrode plates 17 between the dust collector frames 25 at both ends, similarly to the charging unit 12. It is arranged at a constant interval by a plate interval holding tube 22 and is supported and fixed in parallel by using four electrode plate holding bars 23 for each electrode plate.

  In this embodiment, the charging unit 12 and the dust collecting unit 13 are provided. However, the dust collecting unit 13 may not be provided and only the charging unit 12 may be configured.

  In addition, when high dust collection efficiency is required, sharp projections are provided at opposite positions of the charging part load electrode plate 15 and the charging part grounding electrode plate 14, respectively, and dust that flows in by using corona discharge is supplementarily supplied. It may be configured to promote charging.

  In the present embodiment, the grounding electrode and the load electrode of the charging unit 12 and the dust collecting unit 13 are flat plate plates, but a fiber or rod-shaped electrode may be used.

  As described above, the electrostatic precipitator according to the present invention does not generate corona discharge or generates minute corona discharge, thereby reducing power generation in the charging unit and enabling power saving. It is useful in a wide range.

DESCRIPTION OF SYMBOLS 1 Tunnel main line 2 Ventilation suction inlet 3 Electric dust collector 4 Ventilation air path 5 Ventilation fan 6 Ventilation discharge port 7 Electric dust collection auxiliary machine 8 High pressure generation panel 9 Control panel 10 Casing 11 Dust collection unit 12,104 Charging part 13,105 Dust collection unit 14 Charging unit ground electrode plate 15 Charging unit load electrode plate 16 Dust collection unit ground electrode plate 17 Dust collection unit load electrode plate 18 Charging unit high voltage power source 19 Dust collection unit high voltage power source 20 Conductive fiber unit 21 Charging unit frame 22 Electrode plate holding tube 23 Electrode plate holding rod 24 Insulator 25 Dust collector frame 31 Damper 32 Cleaning pipe 33 Wiring terminal box

Claims (10)

Between the inflow part and the outflow part of the gas containing dust, a plurality of load electrodes and a plurality of grounding electrodes are alternately arranged in parallel,
Conductive fibers are provided on one side of the load electrode or one side of the ground electrode,
The conductive fiber is provided between each electrode plate of the load electrode and the ground electrode,
An electrostatic precipitator comprising a charging unit that applies a high voltage to the load electrode. By applying a high voltage to the load electrode to generate a discharge from the end of the conductive fiber,
2. The electrostatic precipitator according to claim 1, wherein the discharge of the charging unit is in a range of 3 × 10 ^{−5 to} 60 × 10 ⁻⁵ μA per 1 mm ^{2 with} respect to the area of the electrode. The ratio of the length of the conductive fiber to the electrode plate interval between the load electrode and the ground electrode is 0.01 to 0.3,
2. The electrostatic precipitator according to claim 1, wherein an electric field strength between electrode plates of the load electrode and the ground electrode is 0.3 to 1 kV / mm. The ratio of the length of the conductive fiber to the electrode plate interval between the load electrode and the ground electrode is 0.01 to 0.3,
The electric dust collector according to claim 2, wherein an electric field strength between electrode plates of the load electrode and the ground electrode is set to 0.3 to 1 kV / mm. The electrostatic precipitator according to claim 1, wherein the conductive fiber is a carbon fiber. The electrostatic precipitator according to claim 2, wherein the conductive fiber is a carbon fiber. The electric dust collector according to claim 3, wherein the conductive fiber is a carbon fiber. The electrostatic precipitator according to claim 4, wherein the conductive fiber is a carbon fiber. A plurality of dust collecting portion load electrode plates and a plurality of dust collecting portion grounding electrode plates are alternately arranged in parallel between the inflow portion and the outflow portion of the gas containing dust,
Applying a high voltage to the dust collector load electrode plate,
The plurality of dust collecting portion load electrode plates and the plurality of dust collecting portion grounding electrode plates as dust collecting portions,
The electrostatic precipitator according to claim 1, wherein the dust collector is provided on the downstream side of the charging unit. 2. The electrostatic precipitator according to claim 1, wherein a discharge is not generated from an end of the conductive fiber even when a high voltage is applied to the load electrode.

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