JPH05138071A - Electric dust collector control device - Google Patents

Abstract

PURPOSE:To achieve a specified dust collection efficiency in a state where safety is ensured by providing an output/air flow reduction means which reduces the voltage generated by a high voltage generation part and the air flow of a fan for a specified time in accordance with the detection of an arc discharge by an arc discharge detection part. CONSTITUTION:If the time length detected by a time detection means 51 is more than a reference time length set previously as a result of comparison of both time lengths, a time length comparison means 52 outputs a signal to the reduction signal output part 61 and the timer part 62 of an output/air flow reduction means 6. The reduction signal output part 61, receiving this signal, outputs a reduction signal to switching circuits 7, 8 to reduce a generated voltage to a low output at a high voltage generation part 4 as well as to reduce the air flow by a fan 2 to a low air flow level. Subsequently, it is possible to maintain a specified dust collection efficiency in a state where the generation of an arc discharge is restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electrostatic precipitator which is mounted on an electrostatic precipitator equipped with an arc discharge detector and controls the operation of the electrostatic precipitator.

[0002]

2. Description of the Related Art As is well known, an electrostatic precipitator used in an air purifier or the like passes air taken in by a fan through a corona discharge area to charge dust in the air and then passes through the corona discharge area. The generated air is caused to flow between the dust collecting plates to which a high voltage is applied by the high pressure generating unit, and the dust is attached to the dust collecting plates to collect the dust.

In such an electric dust collector, when a large amount of dust is deposited on the dust collecting element, arc discharge may occur between the dust collecting plate and the dust or between the dust. The collected dust includes non-combustible substances such as dust, and combustible substances such as cigarette tar and soot (carbon). The flammable dust may be ignited by sparks.

Therefore, there is provided a device for detecting arc discharge which causes ignition and stopping the voltage generation by the high voltage generator for a predetermined time (see Japanese Patent Laid-Open No. 168559/1987).

[0005]

However, in this device, since the voltage generation by the high voltage generator is stopped,
No dust is collected during this stop. Therefore, there is a problem that the dust collection efficiency per unit time is significantly reduced. Also, because the ventilation by the fan was not stopped while the voltage generation by the high-voltage generator was stopped, the dirty air containing oil mist etc. remained as it was due to the ventilation in the non-dust collecting state. After passing through the dust collecting element, the internal members of the electrostatic precipitator such as the fan and the control device located on the downstream side of the dust collecting element are soiled.

Therefore, an object of the present invention is to solve the above-mentioned technical problems, to obtain a predetermined dust collection efficiency while ensuring safety, and to obtain an electrostatic precipitator which occurs in a non-dust collecting state. An object of the present invention is to provide a control device for an electrostatic precipitator, which can prevent the inside of the interior from being soiled.

[0007]

SUMMARY OF THE INVENTION To achieve the above object, a controller for an electrostatic precipitator according to the present invention comprises a fan for ventilating a dust collecting element to which a high voltage is applied by a high voltage generating section, and the high voltage generating section. In the control device of the electrostatic precipitator mounted on the electrostatic precipitator provided with an arc discharge detection unit for detecting the arc discharge based on the time width of the output change, depending on the detection of the arc discharge by the arc discharge detection unit, It is characterized in that it is provided with an output / air volume lowering means for reducing the voltage generated by the high voltage generator and the air volume of the fan for a predetermined time.

[0008]

According to the above construction, when the arc discharge detecting section detects the arc discharge, the output / air volume lowering means reduces the voltage generated by the high voltage generating section for a predetermined time in response to the detection, and the fan Air volume is reduced. As a result, a predetermined dust collection efficiency can be secured while suppressing the occurrence of arc discharge.

[0009]

Embodiments will be described in detail below with reference to the accompanying drawings showing embodiments. FIG. 2 is a schematic configuration diagram of an electrostatic precipitator including a control device as an embodiment of the present invention. Referring to FIG. 1, this electric dust collector has a casing 1 having a suction port 1a formed at one end and a discharge port 1b formed at the other end,
Between the fan 2 arranged in the casing 1 in the vicinity of the outlet 1b, the dust collecting element 3 arranged in the casing 1 in the vicinity of the suction port 1a, and between the fan 2 and the dust collecting element 3. Is arranged on the inner wall of the casing 1 of
And a control device A for controlling the operation of the electric dust collector. A pre-filter 31 is arranged close to the upstream side of the dust collecting element 3 in the ventilation direction, and a deodorizing filter 32 is arranged close to the downstream side of the ventilation element in the ventilation direction.

The fan 2 and the controller A are arranged downstream of the dust collecting element 2 in the ventilation direction.
This is because the fan 2 and the control device A are less likely to get dirty. FIG. 1 is a schematic diagram showing a block diagram of the control device A. With reference to FIG. 1, the control device A is configured to detect an arc discharge in the dust collecting element 2 and a predetermined time period according to a detection signal from the arc discharge detection unit 5. During this period, there is provided output / air volume lowering means 6 for making the voltage generated by the high-voltage generator 4 low and making the air volume of the fan 2 low.

The arc discharge detector 5 is provided with a dust collecting element 3
Time detecting means 51 for detecting the time width of the output change of the high voltage generating part 4 which supplies a high voltage to the time, and the time comparing the time width detected by the time detecting means 51 with a predetermined reference time width. And a width comparing means 52. When an arc discharge occurs in the dust collecting element 3, the output level of the high voltage generator 4 changes in a pulse shape. The time width of this pulse-like change is detected by the time detecting means 51. And
The time width comparison means 52, to which the output of the time detection means 51 is given, compares the reference time defined in relation to the arc discharge that causes ignition and the time width detected by the time detection means 51. When the detected time width is longer than the reference time, a signal corresponding to the detected time width is output to the below-described decrease signal output unit 61 and the timer unit 62 of the output / air volume decrease unit 6.

The output / air volume lowering means 6 receives the signal from the time width comparing means 52 of the arc discharge detecting section 5 to lower the voltage generated by the high voltage generating section 4 and lower the air volume by the fan. The signal is sent to the switching circuit 7 (see FIG. 4).
And the drop signal output section 61 that outputs to the switching circuit 8 and the signal from the time width comparison means 6, and operates for the time T (FIG. 3).
Timer unit 6 that outputs a signal after reference (for example, 10 seconds)
2 and a return signal output unit 63 that outputs a return signal for returning the voltage generated by the high voltage generator 4 and the air volume by the fan 2 to the switching circuit 7 and the switching circuit 8 according to the signal from the timer unit 62. Is included. The switching circuit 7 includes a relay 71, a resistor 72 and a resistor 73.

FIG. 5 shows the relationship between the current and the voltage flowing in the ion portion of the dust collecting element 3. In the figure,
The standard output by the high voltage generator 4 is shown by a solid line, and the small output is shown by a dashed line. In the initial use of the dust collecting element 3, the state indicated by the point P1 is changed. However, when the dust collecting element 3 becomes dirty, the current decreases and the voltage increases with respect to the point P1. And the arc discharge occurs. Therefore, by making the output from the high voltage generator 4 small, the output is moved to the state of the point P3 and the arc discharge is suppressed.

FIG. 6 shows the relationship between the current flowing through the ionization section of the dust collecting element 3 and the dust collecting efficiency η.
The points P1, P2 and P3 correspond to those in FIG. In the state of high air volume, from point P1 (η = 80) to point P2
The efficiency drops significantly to (η = 50), but when the air volume is low, the dust collection efficiency of a predetermined level (η = 6 at P3)
5) can be secured.

According to this embodiment, the time width comparison means 52
However, the time width detected by the time detection means 51 is compared with a predetermined reference time width, and when the detected time width is longer than the reference time width, the output / air volume lowering means 6 A signal is output to the drop signal output unit 61 and the timer unit 62. When the drop signal output unit 61 receives this signal,
By outputting a drop signal to the switching circuits 7 and 8, the voltage generated by the high voltage generator 4 is made low and the air volume by the fan 2 is made low. On the other hand, the timer unit 62, which has received the signal from the time width comparison unit 52, starts its operation and, after the time T,
A signal is output to the return signal output unit 63. Upon receiving this signal, the restoration signal output unit 63 outputs a restoration signal to the switching circuits 7 and 8 to restore the voltage generated by the high voltage generator 4 and the air volume by the fan 2. As a result, as shown in FIG. 3, the voltage generated by the high-voltage generator 4 is kept low for a predetermined time T, and the air volume by the fan 2 is made low, so that the occurrence of arc discharge is suppressed. The dust collection efficiency of can be secured.

Further, it is possible to prevent the inside of the electrostatic precipitator from being contaminated, which has been conventionally caused by ventilation in a non-dust collecting state. The present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention.

[0017]

As described above, according to the control device of the electrostatic precipitator of the present invention, the output / air volume lowering means controls the high-voltage generating portion for a predetermined time in response to the detection of the arc discharge by the arc discharge detecting portion. The generated voltage is reduced and the air volume of the fan is reduced. As a result, it is possible to obtain a predetermined dust collection efficiency while suppressing the occurrence of arc discharge and ensuring safety. Further, it is possible to prevent the inside of the electrostatic precipitator from being contaminated, which has been conventionally caused by ventilation in a non-dust collecting state.

[Brief description of drawings]

FIG. 1 is a block diagram of a control device for an electrostatic precipitator according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an electric dust collector.

FIG. 3 is a diagram showing a time chart.

FIG. 4 is a block diagram including a high-voltage generator, a switching circuit, and a dust collecting element.

FIG. 5 is a diagram showing a relationship between current and voltage of an ionization section of the dust collecting element.

FIG. 6 is a diagram showing the relationship between the current in the ionization section of the dust collection element and the dust collection efficiency.

[Explanation of symbols]

 2 Fan 3 Dust collecting element 4 High-voltage generator 5 Arc discharge detector 6 Output / air flow reduction means

Claims (1)

[Claims] 1. An arc based on a fan (2) that ventilates a dust collecting element (3) to which a high voltage is applied by a high voltage generator (4) and the time width of the output change of the high voltage generator (4). In the control device of the electrostatic precipitator that is installed in the electrostatic precipitator equipped with the arc discharge detecting unit (5) for detecting the discharge and controls the operation of the electrostatic precipitator, the arc discharge detecting unit (5) detects the arc discharge. Output / air volume lowering means for lowering the voltage generated by the high voltage generator (4) and the air volume of the fan (2) for a predetermined time according to the
(6) A control device for an electrostatic precipitator, which is provided with.