JP3592893B2 - Electric precipitator and method of operating electric precipitator - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric precipitator installed in a high humidity atmosphere and a method of operating the electric precipitator in a high humidity atmosphere.
[0002]
[Prior art]
In recent years, for example, as a method of purifying contaminated air in a tunnel on an automobile road, a method using an electric dust collector has been used. In this method using an electric dust collector, a detour tunnel is formed in a tunnel, an electric dust collector is installed, contaminated air extracted from the tunnel into the tunnel is cleaned by the electric dust collector, and then sent to the tunnel again. This is to purify the contaminated air in the tunnel by taking care.
[0003]
By installing the electric precipitator in the detour tunnel in the tunnel as described above, the contaminated air in the tunnel can be purified. However, in the electric dust collecting device, dust adheres to the electrode portion and the insulator portion supporting the electrode by the dust collecting process, and thus it is necessary to clean the electric dust collecting device, for example, about once a day.
[0004]
When the air in the place where the electric precipitator is installed is dry, it can be cleaned by blowing compressed air on the dirty part. However, in places with high humidity such as in a tunnel, dust adheres firmly to the surface of the insulator or the like due to the moisture, so that cleaning cannot be sufficiently performed only by blowing compressed air.
[0005]
In such a case, a water washing method of removing dust by spraying pressurized water instead of air is used.
The above-mentioned water cleaning method can provide a large cleaning power, but since the electrode portion and the insulator portion to which a high voltage is applied are wet with water, the inside of the electrostatic precipitator is dried before the operation is restarted. There is a need.
[0006]
For this reason, in the past, a method of drying electrodes, insulators, and the like by using a blower installed to guide contaminated air to an electric dust collector, and further, applying a very low voltage to the dust collecting electrode. A method of gradually increasing this voltage to a rated voltage is used.
[0007]
[Problems to be solved by the invention]
However, when using the method of applying a voltage to the dust collecting electrode as described above, it is dangerous to increase the applied voltage to the dust collecting electrode in a short time, and the applied voltage must be increased very slowly. Therefore, it takes time to restart the operation of the electric precipitator. At this time, the number of spark discharges caused by the wetting of the electrodes must be counted, and the voltage must be controlled so that the number of times per unit time falls within an allowable range that does not damage the electrodes. is there. In addition, when a spark discharge or overcurrent occurs during operation, the charging of a plurality of dust collection units that are charged by one DC high-voltage power supply is temporarily reduced every time, causing a reduction in dust collection efficiency. Become.
[0008]
SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and when restarting the operation of an electric dust collector in a high-humidity atmosphere, an electric collector capable of restarting the operation in a short time and safely. It is an object of the present invention to provide an operation method for reducing a decrease in dust collection efficiency due to spark discharge or overcurrent during operation of a dust device and an electric dust collector.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 is a method of operating an electric precipitator in which one direct current high voltage is applied to one or a plurality of electrode units in the electric precipitator installed in a high humidity atmosphere. A coil is provided in series with a DC high voltage application circuit to the electrode unit, and a rated DC high voltage is immediately applied upon startup, and the voltage applied to the electrode unit of the electrostatic precipitator is adjusted by the action of the coil. It is characterized by shifting to a steady operation state.
[0010]
The invention according to claim 2 is an electric precipitator provided in a high-humidity atmosphere and having a plurality of electrode units to which a DC high voltage is applied, wherein a damper for controlling inflow of air into each of the electrode units is provided. A DC high-voltage power supply for supplying a DC high voltage to each of the electrode units, a coil provided in series with a DC high-voltage application circuit from the DC high-voltage power supply to the electrode unit, with the damper closed at startup. A rated DC high voltage is supplied from the DC high voltage power supply to the electrode unit through the coil, and the applied voltage of the electrode unit is normal after an overcurrent generation section due to a current leak accompanying the application of the DC high voltage has passed. And control means for opening the damper and returning to normal operation when the voltage returns to the normal state.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an entire electric precipitator according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a dust collecting unit, which is installed, for example, in a detour tunnel formed in a tunnel of an automobile road. The dust collector unit 1 includes a dust collecting electrode unit 2, a damper 3 for controlling the flow of contaminated air, a washing for washing the dust collecting electrode unit 2, an insulator supporting the electrode unit 2, and the like with water. It consists of a nozzle 4. The electrode unit 2 has a structure in which a plurality of discharge plates and dust collection plates are alternately and horizontally arranged.
[0012]
A DC high voltage is applied to the electrode unit 2 from the DC high voltage power supply 5 via the coil 11. The DC high-voltage power supply 5 applies a predetermined voltage to the electrode unit 2 according to a control command from the control device 6. Although not shown, the DC high-voltage power supply 5 boosts an AC voltage by a high-voltage transformer and rectifies a high voltage generated in a secondary coil thereof to obtain a DC high voltage. The voltage and current of the DC high-voltage power supply 5 are detected as a secondary-side converted value of a voltage of a voltage-dividing resistor provided on the secondary side of the transformer and a primary-side current, and input to the control device 6. When activating the electric dust collector, the controller 6 generates a high voltage from the DC high voltage power supply 5 and applies it to the electrode unit 2, detects an applied voltage and a supply current to the electrode unit 2, The operating status of the dust collector is monitored.
[0013]
An air pipe 7 is connected to the damper 3, and an electromagnetic valve 8 is provided in the air pipe 7. The solenoid valve 8 is on / off controlled by a control command from the control device 6, and the damper 3 is opened and closed accordingly.
[0014]
Further, a water pipe 9 is connected to the washing nozzle 4, and an electromagnetic valve 10 is provided in the water pipe 9. The solenoid valve 10 is turned on / off by a control command from the control device 6. When the electromagnetic valve 10 is turned on, water is sprayed from the cleaning nozzle 4 to perform cleaning. The control device 6 controls the on / off time of the solenoid valves 8 and 10 by, for example, setting a program in the sequence control device and controlling the on / off time of the relay.
[0015]
Next, the cleaning operation and the restarting operation of the electric precipitator in the embodiment will be described with reference to a timing chart shown in FIG.
When an operation for instructing cleaning of the electric precipitator is performed by a worker or by automatic operation, the controller 6 first outputs a “close command” to the solenoid valve 8 at time t0 as shown in FIG. Then, the damper 3 is closed and the electromagnetic valve 10 is opened as shown in FIG. 3B, and water is sprayed from the cleaning nozzle 4 to start cleaning the electrode unit 2 and the insulator portion. Further, the controller 6 stops the application of the voltage from the DC high-voltage power supply 5 to the electrode unit 2 at the same time as the cleaning start operation is performed as shown in FIG.
[0016]
Then, after performing the above-described cleaning operation for a predetermined time, the control device 6 outputs a “close command” to the solenoid valve 10 at time t1 as shown in FIG. 2B, and stops the supply of water to the cleaning nozzle 4. Then, the cleaning operation is completed.
[0017]
Further, the control device 6 outputs a rated DC high voltage from the DC high voltage power supply 5 and applies it to the electrode unit 2 at a time t1 when the cleaning operation is completed, as shown in FIG.
[0018]
Immediately after the cleaning of the electrostatic precipitator is performed as described above, the insulation of the insulator portion is reduced. When a high DC voltage is applied to the electrode unit 2, an overcurrent due to leakage flows through the coil 11. . When an overcurrent flows through the coil 11, the potential of "L (di / dt)" (L: inductance of the coil 11, i: current, t: time) is applied to both ends of the coil 11 as shown in FIG. Therefore, the voltage applied to the electrode unit 2 is automatically controlled as shown in FIG. 2E while the output voltage of the DC high-voltage power supply 5 is kept constant.
[0019]
When a high DC voltage is applied to the electrode unit 2 at the time of restarting the electrostatic precipitator as described above, a current flows through the electrode unit 2 to generate Joule heat, and drying of the electrode and the insulator is promoted. Accordingly, the insulation of the electrodes and the insulator is restored. When the insulation between the electrode and the insulator is restored, the voltage applied to the electrode unit 2 is restored as shown in FIG. That is, after the voltage application at the time of restart (time t1), when the overcurrent occurrence section T due to the leakage of the insulator or the like elapses, the applied voltage of the electrode unit 2 returns to the normal voltage, so that the control device 6 At t2, the electromagnetic valve 8 is turned on, the damper 3 is opened, and the operation shifts to the normal operation state.
[0020]
Also, as shown in FIG. 3, usually, in order to charge a plurality of, for example, two to four dust collector units 1 with one DC high-voltage power supply 5, by providing a coil 11 to each unit 1, Even if a spark or overcurrent occurs in one dust collector unit, only the voltage of that unit is reduced by the action of the coil 11, and the other units can maintain the normal charged state. . Therefore, when the coil 11 is provided in each of the electrode units, the dust collection efficiency at the time of spark generation or overcurrent generation with respect to the DC high-voltage power supply 5 is compared to the case where one coil 11 is provided. Reduction can be suppressed.
[0021]
If the supply current to the electrode unit 2 does not become lower than the rated value even after a predetermined time has elapsed after the restart of the electric precipitator, the control device 6 regards the failure as a failure, and The application of voltage to the electrode unit 2 is stopped, and if necessary, the occurrence of a failure is indicated by a warning light or the like.
[0022]
In the above embodiment, the case where the electrostatic precipitator is restarted after washing with water has been described. However, when the electric precipitator is restarted in a high-humidity atmosphere, it can be carried out in the same manner as the above embodiment.
[0023]
【The invention's effect】
As described above in detail, according to the present invention, a coil is provided in a DC high voltage application circuit to an electrode of an electrostatic precipitator, and a rated DC high voltage is immediately applied at the time of start-up, and the electric action is performed by the coil. Since the operation is shifted to the steady operation state while adjusting the voltage applied to the electrode of the dust collector, Joule heat is generated due to the leak current of the electrode and the insulator part, and the drying of the electrode and the insulator part is promoted. It is possible to shift to the steady operation state in a short time. In addition, since the overcurrent can be suppressed by the action of the coil provided in the DC high voltage application circuit, the restart operation can be performed safely.
[0024]
Also, even if a spark discharge or an overcurrent occurs during operation, the current applied to the coil is reduced by increasing the voltage applied to the coil, so that the spark discharge and the overcurrent can be suppressed, and one DC high voltage If multiple dust collection units are charged by the power supply, install a coil for each unit to reduce the charge of only the unit where spark discharge or overcurrent is occurring, and to charge other units normally. The state can be maintained.
[Brief description of the drawings]
FIG. 1 is an overall schematic configuration diagram of an electric precipitator according to an embodiment of the present invention.
FIG. 2 is a timing chart for explaining an operation at the time of startup in the embodiment.
FIG. 3 is a timing chart for explaining the operation of the embodiment when a spark occurs during normal operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Dust collection unit 2 Electrode unit 3 Damper 4 Cleaning nozzle 5 DC high voltage power supply 6 Control device 7 Air piping 8 Solenoid valve 9 Water piping 10 Solenoid valve 11 Coil

Claims (2)

In the operation method of the electric dust collector, which applies one DC high voltage to one or more electrode units in the electric dust collector installed in the high humidity atmosphere,
A coil is provided in series with a DC high voltage applying circuit to the electrode unit of the electrostatic precipitator, and a rated direct high voltage is immediately applied at the time of startup, and the action of the coil is applied to the electrode unit of the electric precipitator. An operation method of an electric precipitator in which a transition is made to a steady operation state while adjusting an applied voltage. In an electric precipitator equipped with a plurality of electrode units installed in a high humidity atmosphere and applied with a DC high voltage,
A damper that controls the inflow of air into each of the electrode units, a DC high-voltage power supply that supplies a DC high voltage to each of the electrode units, and a DC high-voltage application circuit from the DC high-voltage power supply to the electrode unit in series. A coil provided, and a rated DC high voltage is supplied from the DC high voltage power supply to the electrode unit via the coil in a state where the damper is closed at startup, and an overcurrent due to a current leak accompanying the application of the DC high voltage is provided. electric dust collecting apparatus characterized by open the damper when the applied voltage of the electrode unit has passed the generation interval is returned to the voltage of the normal and control means to shift to normal operation.

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