JP3150431B2 - Electric dust collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a means for judging the quality of insulation resistance of a dust collecting portion and a charging portion in a control device of an electric dust collecting device.

[0002]

2. Description of the Related Art In recent years, an electric dust collector has been installed in a detour tunnel formed in a tunnel of an automobile road, and the electric dust collector purifies contaminated air in the tunnel.

FIG. 3 is a perspective view showing a basic configuration of an electric dust collecting apparatus, wherein 101 is a charging section, 102 is a dust collecting section,
103 is a high-voltage power supply unit.

[0004] The charging section 101 is provided between a plurality of discharge lines 101A for applying a high voltage of, for example, +11 kV from the high voltage power supply section 103, and a plurality of ground electrode plates 101B arranged between the discharge lines 101A. Then, a corona discharge is caused to occur, thereby charging the suspended particles contained in the contaminated air A passing through the gap during this period.

The dust collecting section 102 includes a plurality of high voltage side dust collecting electrodes 102A for applying a high voltage of, for example, +5.5 kV from the high voltage power supply section 103, and these high voltage side dust collecting electrodes 102A.
A, and a plurality of ground-side dust collecting electrode plates 102B disposed between the two electrode plates 102A and 1B.
02B, the electrode plate 102B
Then, the charged airborne particles in the contaminated air A are collected to obtain clean air B.

On the other hand, a high voltage charging unit to which a high voltage is applied,
That is, the discharge wire 101A and the high-pressure side dust collection electrode 102
A and a supporting conductor for guiding a high voltage from these high-voltage power supply units 103 are supported in the dust collector by a high-voltage insulator (not shown). Since it is difficult to completely isolate this insulator from the passage through which the contaminated air A passes, it is difficult to maintain electrical insulation between the discharge wire 101A, the high-pressure dust collecting electrode 102A, and the supporting conductor. Part of the wire goes around the insulator. For this reason, the suspended particles in the contaminated air A may adhere to the surface of the insulator as dust, and the dielectric strength (performance) may be reduced.

In consideration of the above points, as a means for preventing the suspended particles in the contaminated air from adhering to the surface of the insulator and maintaining the insulating performance, dust removal from the dust collecting portion by blowing compressed air is performed. A so-called air blow method, in which compressed air is blown onto the insulator at the same time as the work to remove dust deposited on the surface or in the vicinity thereof, and a so-called water washing method, in which water is blown instead of compressed air, have been conventionally proposed.

However, when the dust on the surface of the insulator or the vicinity thereof is removed by the above-described air blow method, if a large amount of moisture is mixed in the compressed air to be blown by the air, the dust on the surface of the insulator can be blown to some extent. Dust adheres to the surface of the insulator due to the moisture, and the insulation resistance tends to decrease. This is because the insulator is directly washed with water in the above-described water washing method, so that the insulation resistance value is further reduced as compared with the air blow method. Can be easily induced. Further, it is difficult to completely remove the dust on the surface of the insulator by both of the above methods, and the dust remaining on the surface of the insulator absorbs moisture from the surrounding atmosphere, resulting in a decrease in the insulation resistance value of the insulator.

In such an electric precipitator, when a voltage lower than the rated voltage is applied to the precipitating unit and the charging unit for a certain period of time when the electric precipitator is started, the insulation resistance value of the insulator is reduced due to moisture. However, a control means is employed in which the moisture-absorbed portion of the insulator is dried and the insulation resistance is recovered by Joule heat caused by a leakage current flowing through the moisture-absorbed portion on the insulator surface.

[0010]

In such a conventional electric precipitator, there is no function of detecting and judging the insulation resistance value (particularly at the time of start-up). It is not possible to determine whether the insulation resistance value has dropped due to a short circuit accident.If a short circuit has occurred, a high voltage will be applied after startup, resulting in a lack of safety and secondary damage to equipment. There is a problem in operation control that tends to cause inconvenience.

The present invention solves the above-mentioned problems, and provides an electric precipitator provided with control means for detecting an insulation resistance value of an insulator when starting up the electric precipitator and determining whether the insulator is good or not. It is intended to be.

[0012]

According to the present invention, there is provided a dust collecting section, a charging section, a voltage / current detecting mechanism of the dust collecting section, and a voltage / current detecting mechanism of the charging section. An electric precipitator is characterized in that it has means for determining whether or not the insulation resistance value of the precipitating unit and the charging unit is good.

[0013]

According to the present invention, when starting up the electric dust collector with the above-mentioned configuration, there is almost no possibility that secondary damage to the equipment will occur even if the electric dust collector is initially short-circuited by about 2 to 5% of the rated voltage. A low voltage is applied as a test voltage to the dust collecting portion and the charging portion, and the insulation resistance value of the insulator of the dust collecting portion and the charging portion is detected. If the value is, for example, 10 k to 300 k ohm, the insulation resistance value due to moisture absorption is obtained. Therefore, the apparatus is started up while drying with Joule heat, and if it is less than 10 kOhm, it is determined that the insulation resistance value is decreased due to a short circuit, and a failure is output without starting up the apparatus.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 2 is a control block diagram for implementing the present invention in the electric dust collecting apparatus, 11 is an output voltage signal of the dust collecting section, 12 is an output current signal of the dust collecting section, and 13 is an output of the charging section. A voltage signal, 14 is an output current signal of the charging unit, 15 is a differential amplifier unit, and 16 is a sequencer with an analog signal processing function.

Since the form of each of the signals 11 to 14 output from the high voltage power supply unit 103 is 0 to 1 mA, the signals are input to the differential amplifier unit 15 so as to be easily processed by the sequencer 16.
After being converted to a V output, it is input to the sequencer 16.

FIG. 1 shows that a test voltage is applied to the dust collecting portion and the charging portion when a start command of the dust collecting device is issued, and respective signals 11 to 14 as return analog signals corresponding to the test voltage are generated inside the sequencer 16. Fig. 3 shows an arithmetic processing flow to be processed. 1 and 6 are division units, 2 and 7 are judgment values of insulation resistance of the dust collection unit and the charging unit, 3 and 8 are comparison units, and 4 and 9 are start permission commands of the dust collection unit and the charging unit (that is, the dust collection unit). And a high voltage application permission command to the charging section),
Reference numerals 5 and 10 denote short-circuit alarms of the dust collecting unit and the charging unit.

In the divider 1, the output voltage signal 11 of the dust collector is divided by the output current signal 12 of the dust collector, and this value is used as the current insulation resistance value of the dust collector. The comparison unit 3 compares the insulation resistance determination level value 2 with the determination value, and if it is equal to or greater than the determination level value (Yes), the dust collection unit activation permission command 4
Is output, and if it is less than the determination level value (if No)
The short-circuit alarm 5 of the dust collecting section is output.

The above is the calculation processing flow of the insulation resistance judgment at the time of starting the dust collecting section.

Since the operation of the charging unit is exactly the same as that of the first embodiment, the description is omitted. The result of an experiment in which the control means of this embodiment was incorporated into a test electric precipitator will be described below.

A moisture absorbing state (an insulation resistance value of 25 k ohms for both the dust collecting unit and the charging unit) and a short-circuit state (0.1 k ohms for both the dust collecting unit and the charging unit) are set when the electric dust collecting apparatus is started. Attempting to start the dust collector confirmed that the moisture absorption state and the short-circuit state could be clearly distinguished.
That is, in the moisture absorbing state, when an analog-variable output voltage of the high-voltage power supply unit 103 that is [insulation resistance value] * [current of the maximum capacity of the high-voltage power supply unit 103] is applied to each of the dust collection unit and the charging unit. Since the insulation resistance value decreases due to the drying effect of Joule heat with the passage of time, the output power of the high-voltage power supply unit 103 continuously increases in an analog manner, and the operating voltage (rated voltage) can be safely increased without sparking. (A voltage) could be demonstrated (conventionally, the output voltage of the high-voltage power supply unit 103 could only be increased stepwise using a timer). In the short-circuit state, short-circuit alarms 5 and 10 for the dust collecting section and the charging section are immediately issued, so that the safe operation of the electric dust collecting apparatus is ensured.

As described above, according to the electrostatic precipitator of the embodiment of the present invention, when starting the electric precipitator, a low voltage is first applied to the dust collector and the charging unit as a test voltage. Further, since the insulation resistance value of the insulator of the charging section is detected and the quality of the insulation is determined, it is possible to take control means for preventing secondary damage to the equipment due to a decrease in insulation resistance value due to a short circuit accident.

[0023]

As is apparent from the above embodiment, according to the present invention, when starting the electric dust collecting apparatus, a low voltage is first applied to the dust collecting section and the charging section as a test voltage. In addition, it is possible to provide an electric precipitator capable of detecting the insulation resistance value of the insulator of the charging section and preventing secondary damage to equipment due to a decrease in insulation resistance value due to a short circuit accident.

[Brief description of the drawings]

FIG. 1 is a flowchart of an arithmetic process for detecting insulation resistance at the time of starting an electric dust collector according to an embodiment of the present invention.

FIG. 2 is a control block diagram of the insulation resistance detection.

FIG. 3 is a perspective view showing a basic configuration of a conventional electric dust collector.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Dividing part 2 Judgment level value of insulation resistance of dust collecting part 3 Comparison part 4 Command for permitting start of dust collecting part (that is, command for permitting application of high voltage to dust collecting part) 5 Short circuit alarm of dust collecting part 6 Dividing part 7 Charging Judgment level value of insulation resistance of unit 8 Comparator 9 Command to permit activation of belt transmission unit (that is, command to permit application of high voltage to charging unit) 10 Short circuit alarm of charging unit 11 Output voltage signal of dust collection unit 12 Dust collection unit Output current signal 13 Charger output voltage signal 14 Charger output current signal 15 Differential amplifier unit 16 Sequencer with analog signal processing function

Claims (4)

(57) [Claims] And 1. A dust collection unit includes a charging unit, a voltage-current detection mechanism of the dust collecting unit, a voltage-current detection mechanism of the charging unit, electrostatic
When starting up the air precipitator, first use 2-5% of the rated voltage.
Apply low voltage as test voltage to dust collection part and charging part
And an electric precipitator having means for recognizing an insulation resistance value of the precipitator and the charging unit. 2. An electric precipitator according to claim 1.
And the recognized insulation resistance is 10 to 300 kohm
If so, it is determined that the insulation resistance value has decreased due to moisture absorption,
There is a means to start up the device while drying with Joule heat
Electric dust collector. 3. An electric precipitator according to claim 1.
And the recognized insulation resistance is less than 10k ohms
If it is determined that the insulation resistance has decreased due to a short circuit,
Precipitator having means for outputting a failure without starting up
Place. 4. An electric precipitator according to claim 1.
And the recognized insulation resistance is 10 to 300 kohm
If so, it is determined that the insulation resistance value has decreased due to moisture absorption,
There is a means to start up the device while drying with Joule heat
If less than 10k ohms, insulation resistance due to short circuit
And output a failure without starting the equipment
An electrostatic precipitator having means for performing the following.