JPH02106B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a method for starting an electrostatic precipitator.

[Prior art and its problems] An electrostatic precipitator is installed, for example, in a Ukai tunnel formed in a tunnel as a road for automobiles.
By using electrostatic precipitators installed at such locations, contaminated air extracted from the tunnel into the tunnel can be purified and re-supplied into the tunnel.

FIG. 1 is a perspective view showing the basic configuration of an electrostatic precipitator, in which 1 is a charging section, 2 is a dust collecting section,
3 is a power supply section.

The charging unit 1 receives, for example, + from the high voltage power supply unit 3.
Multiple 1A discharge lines applying a high voltage of 11kV,
It has a plurality of ground electrode plates 1B arranged between these discharge wires 1A, and has a plurality of ground electrode plates 1B arranged between the discharge wires 1A and the ground electrode plates 1B.
A corona discharge is caused between the two, and the suspended particles contained in the contaminated air A passing through the gap between the two are charged.

The dust collection unit 2 receives electricity from the high voltage power supply unit 3, for example, +
It has a plurality of high-voltage side dust collection electrode plates 2A that apply a high voltage of 5.5 kV, and a plurality of ground side dust collection electrode plates 2B arranged between these high voltage side dust collection electrode plates 2A, and has a charging part. By passing the contaminated air A, which has charged the suspended particles therein, between the electrode plates 2A and 2B, the charged suspended particles in the contaminated air A are transferred to the electrode plate 2B. is collected to obtain clean air B.

On the other hand, the high-voltage charging section to which a high voltage is applied, that is, the discharge wire 1A and the high-voltage side dust collection electrode 2A, and the support conductor for guiding the high voltage from the high-voltage power supply section 3 to these, are made of high-voltage insulators ( (not shown) within the dust collector. It is difficult to completely isolate this insulator from the path through which the contaminated air A flows, from the viewpoint of maintaining electrical insulation of the discharge wire 1A, the high voltage side dust collecting electrode 2A, and the supporting conductor. A part of it wraps around the insulator. Therefore, floating particles in the contaminated air A may adhere to the surface of the insulator as dust, reducing its dielectric strength (performance).

Taking the above points into consideration, as a means of preventing airborne particles in contaminated air from adhering to the surface of the insulator and maintaining its insulation performance, it is recommended to remove dust from the dust collection area by blowing compressed air. At the same time, the so-called air blow method, in which compressed air is blown onto the insulator to remove dust accumulated on its surface or its vicinity, and the so-called air blow method, in which the insulator is housed in an insulator chamber, and an insulating gas is applied from outside into the insulator chamber. supply pressure,
An air purge system has been proposed in the past that prevents floating particles from entering the insulator chamber from the outside by blowing out the gas from a gap formed in the insulator chamber.

However, when removing dust on or near the surface of the insulator using the air blow method described above, if the compressed air used for air blowing contains a large amount of moisture, the dust on the surface of the insulator may be blown away to some extent. The moisture causes dust to adhere to the surface of the insulator, reducing its insulation resistance. This also applies to the air purge method. In addition, if dust remains on the surface of the insulator despite the measures taken to maintain insulation performance as described above, the surrounding atmosphere (for example, installing an electrostatic precipitator in a bypass tunnel for automobiles) If the insulator is installed in a location where the insulator is installed), the dust on the surface of the insulator absorbs moisture, causing dew condensation on the surface of the insulator, which may reduce its insulation performance. As a result, if the insulating performance of the insulator deteriorates, leaks, partial arcs, sparks, etc. may occur on the surface of the insulator when starting up the electrostatic precipitator, resulting in a problem that the insulator cannot be started. .

[Object of the Invention] The object of the present invention is to solve the above-mentioned problems. For example, even when an electrostatic precipitator is installed and operated in a tunnel with high humidity, An object of the present invention is to provide a method for starting an electrostatic precipitator that can start the electrostatic precipitator while maintaining good insulation performance of an insulator.

[Summary of the Invention] In order to achieve the above object, the present invention applies a voltage that increases overall while changing its value to a high voltage electrode member of an electrostatic precipitator installed in a high humidity atmosphere. In particular, in a method for starting an electrostatic precipitator that applies a steady operating voltage to the high voltage electrode member, after applying a voltage of a predetermined value lower than the steady operating voltage to the high voltage electrode member for a predetermined period of time, the steady operating voltage is applied to the high voltage electrode member. It is characterized by applying

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

FIG. 2 shows an embodiment of a circuit of a high voltage power supply section for implementing the present invention in an electrostatic precipitator,
4 is a transformer, 5 is a rectifier connected to the secondary winding 4A of the transformer 4, 6 is a resistor provided between the cathode of the rectifier 5 and the output end 7, and 8 is provided between the output end 7 and the ground. It is a voltage dividing circuit.

The primary winding 4B of the transformer 4 has a plurality of taps 4.
The number of windings is changed by moving the contact 4C in contact with the tap 4BT by the drive of a motor (not shown), thereby changing the number of secondary windings 4A.
change the voltage induced in

The voltage divider circuit 8 is formed by connecting in series a parallel circuit of a resistor R1 and a capacitor C1, and a parallel circuit of a resistor R2 and a capacitor C2, and Take out the determined partial pressure value. This extracted voltage is input to the voltage/time judgment circuit 9, where it is applied to the primary winding 4B.
For example, a commercial power supply voltage is applied to the transformer 4 with the contact 4C connected to a predetermined tap 4BT of the output terminal 7.
The voltage obtained is a predetermined stable voltage, for example 3kV
Counting is started from the point at which 0 is reached, and after a predetermined time has elapsed, the motor that switches the tap of the primary winding 4B of the transformer 4 is controlled. This causes a (stable) voltage of, for example, 6 kV to be generated at the output 7 by switching the tap. In this way, in the voltage/time determining circuit 9, the voltage of the primary winding 4B of the transformer 4 is wound so that a voltage of a predetermined value is generated at the output end 7 for a predetermined time, and the value increases step by step. Control the number of times.

In addition to controlling the number of turns of the primary winding 4B, the voltage on the primary side of the transformer is changed by controlling the phase angle of a thyristor inserted in the primary winding circuit, so that the output terminal 7 You can also change the voltage. In this case, the voltage at the output end 7 can be changed continuously and arbitrarily.

A power supply cable for applying a voltage to, for example, a charging section of the electrostatic precipitator is connected to the output end 7. Note that the steady-state operating voltage of the charging section is, for example, 11 kV, but the insulating member that supports the discharge wire in the charging section can be composed of two insulators connected in series; in this case, 2
For example, a voltage of 5.5 kV for the dust collection section can be extracted from the connection between the two insulators. Therefore, only one power supply cable is required,
The secondary winding of the transformer also requires a simple configuration, and the rectifier is only required for 11kV.

Figure 3 shows an electrostatic precipitator installed in a humid environment with a humidity of approximately 90%, operating under the conditions of 11 kV at the charging part and 5.5 kV at the dust collecting part, and was activated by applying voltage to the charging part in three stages. An example of the voltage application mode is shown below.
By maintaining 6kV at , and from t3 to t4 for about 1 minute each, it was possible to enter continuous steady-state operation by applying 11kV thereafter. t1, t2 to t3 and t4 to t5 were about 1 second. In this way, by increasing the voltage value step by step until the steady operating voltage is reached, even if the dust adhering to the insulator surface has absorbed moisture and the surrounding atmosphere has become highly humid, Even if the insulation performance is degraded, the dust attached to the insulator surface is heated by the leakage current generated on the insulator surface without flashing when the applied voltage is relatively low. As a result, the insulation resistance of the insulator surface can be increased to a high value, and steady operation can be achieved without causing flashover or the like.

For comparison purposes, the charging part of the electrostatic precipitator under the same conditions as above (Figure 3) was started using the conventional method (sudden impression method) of instantaneously applying a voltage of 11 kV. As shown in Figure 4, 6kV
When the applied voltage rose, sparks were generated in the insulator, resulting in startup failure.

[Effects of the Invention] As explained above, according to the present invention, an electrostatic precipitator can be started safely without causing an accident such as a flashover.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the basic configuration of an electrostatic precipitator, FIG. 2 is a diagram showing an embodiment of a high-voltage power supply circuit for implementing the present invention in an electrostatic precipitator, and FIG. 4 is a diagram showing a voltage application mode to the charging section, and FIG. 4 is a diagram showing a voltage application mode according to a conventional method. 1... Charging section, 2... Dust collection section, 3... High voltage power supply section, 4... Transformer, 5... Rectifier, 8... Voltage dividing circuit, 9... Voltage/time judgment circuit.

Claims (1)

[Claims] 1 By applying a voltage that increases overall while changing the value to the voltage electrode member of an electrostatic precipitator installed in a high humidity atmosphere, a steady operating voltage is applied to the high voltage electrode member. A method for starting an electrostatic precipitator, the method comprising: applying a voltage of a predetermined value lower than a steady operating voltage to the high voltage electrode member for a predetermined period of time, and then applying a steady operating voltage.