JPH10192734A - Method for cooling electrostatic precipitator and electrostatic precipitator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the thermal deformation of an electrode part and the damage to a blower on the downstream side due to the overheating when a high-temp. dust-contg. air is circulated. SOLUTION: This electrostatic precipitator 2 is set in a dust-contg. air passage 1 and contains the charging part 7 and dust collecting part 8 in a casing 5. In this case, when a high-temp. dust-contg. air is generated due to a fire, the inlet side and outlet side of the casing 5 is opened to circulate the high-temp. dust-contg. air through the precipitator 2, water is sprayed on the electrodes of the charging part 7 and dust collecting part 8 and into the air passage between the electrodes from an upper water spray nozzle 34 above the charging part 7 and collecting part 8 and from a side water spray nozzle 32 on the inlet side of the charging part 7, and the electrodes and high-temp. dust-contg. air are cooled by the water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cooling an electric precipitator for removing dust from dust-containing air in the event of a fire, and an electric precipitator for implementing the method.

[0002]

2. Description of the Related Art Generally, as a method for purifying dust-containing air in a tunnel for an automobile road, the dust-containing air is fed into a flow passage provided as a detour on the side of the tunnel or the like, and is introduced into the flow passage. 2. Description of the Related Art A purification method in which a dust collecting device is installed to collect dust and return the air after dust removal to a tunnel is widely used. Since the dust removal target is air having a large air volume in which fine particles are suspended, an electric dust collection device is often used as the dust collection device.

[0003] When installing the electrostatic precipitator, in order to prevent the hot dust-containing air from flowing through the electroprecipitator when a tunnel fire occurs, damage such as thermal deformation of the electrode plate is caused. As shown in FIG. 4, an air inlet 62 is provided upstream of an electrostatic precipitator 61 installed in the dust air flow passage 1, and a bypass air flow passage 64 having an outlet 63 downstream is provided. And the inlet 62
And a tunnel structure in which bypass dampers 65 and 66 are provided at the outlet 63. Reference numeral 3 denotes a blower for circulating dust.

[0004] When a tunnel fire occurs, the entrance damper 71 at the entrance of the casing 69 containing the charging unit 67 and the dust collection unit 68 of the electrostatic precipitator 61 and the exit damper 72 at the exit side are closed as shown in FIG. While preventing the flow of the dust-containing air into the electric precipitator 61, the bypass dampers 65 and 66 are opened to allow the high-temperature dust-containing air to flow through the bypass flow passage 64, and from the outlet 63 to the dust-containing air flow passage 1. The reflux protects the electrostatic precipitator 61 against high temperatures.

However, in order to form the bypass flow passage 64, construction costs such as digging work and finishing work are increased, equipment costs for the bypass damper are increased, and the downstream blower 3 is not used.
However, there is a problem in that overheating is caused by high temperature dust-containing air.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and can prevent the electrode plate portion from being thermally deformed in a high-temperature dust-containing air flow state. An object of the present invention is to provide a method of cooling an electrostatic precipitator which can be prevented, and an electric precipitator suitable for implementing the method.

[0007]

SUMMARY OF THE INVENTION A method of cooling an electrostatic precipitator according to the present invention involves a fire in an electric precipitator installed in a dust-containing air flow passage and containing a charging unit and a dust collecting unit in a casing. When high-temperature dust-containing air is generated, the inlet side and the outlet side of the casing are opened to allow the high-temperature dust-containing air to flow through the electrostatic precipitator, and the charging section and the upper section of the dust collecting section and the charging section Water is sprayed from an inlet side to the electrodes of the charging unit and the dust collecting unit and an air passage between the electrodes, and the water cools the electrodes and the high-temperature dust-containing air.

According to a second aspect of the present invention, there is provided an electric dust collecting apparatus, wherein an inlet damper is provided at an inlet of a casing accommodating a charging unit and a dust collecting unit, and an outlet damper is provided at an outlet of the casing. An upper water spray nozzle having a spout opening downwardly above the dust portion is provided, and a side water spray nozzle having a spout opening toward the charging portion is provided at an inlet side of the charging portion, and the casing is provided with a side water spray nozzle. A lower part is provided with a drainage part for draining jet water from each of the spray nozzles. At the time of inflow of high-temperature impregnated air, a damper opening command is given to the opening / closing drive of the inlet damper and the outlet damper, and An operation control device for giving a water supply command to a water supply device for supplying water to the water spray nozzle is provided.

According to a third aspect of the present invention, there is provided the electric dust collecting apparatus according to the second aspect, wherein the upper water spray nozzle and the side water spray nozzle are provided with an electrode cleaning device for the charging unit and the dust collecting unit. Is also used as a spray nozzle.

In the present invention, the charging section and the electrode of the dust collecting section collectively refer to the positive discharge electrode (discharge wire) of the charging section, the negative electrode plate, and the positive electrode plate and the dust collecting electrode plate of the dust collecting section.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. In FIG. 3, reference numeral 1 denotes a dust-containing air flow passage, which is provided on a side of an unillustrated motorway tunnel in a bypass shape with respect to the tunnel. Reference numeral 2 denotes an electrostatic precipitator, which is installed in a dust-containing air flow passage 1, and the dust-containing air flows in a direction indicated by an arrow by a blower 3 disposed downstream thereof, and is removed by the electric precipitator 2. .

FIGS. 1 and 2 show the detailed structure of the electrostatic precipitator 2. The electric precipitator 2 is provided in a casing 5 having outer walls 5a, 5b and an intermediate wall 5c, two rows vertically and two rows horizontally. In which four dust collection units 6 are accommodated. Each dust collection unit 6 has a charging unit 7 and a dust collection unit 8. The charging unit 7 includes a discharge wire (positive emission electrode) 11 and a negative electrode plate 12 opposed thereto. The dust collection unit 8 includes a positive electrode plate 13 and It has a known configuration in which a number of opposed dust collecting electrode plates 14 are alternately arranged, and the discharge wires 11 and the positive electrode plate 13 are connected to a high-voltage power supply (not shown). Reference numeral 15 denotes an air passage formed between the negative electrodes 12 and 12 with the discharge wire 11 interposed therebetween, and 16 denotes an air passage formed between the positive electrode 13 and the dust collecting electrode 14 and having a small width (for example, 6 mm).

Reference numeral 21 denotes an inlet damper provided at an inlet portion of the casing 5 through which dust-containing air flows, for shutting off dust-containing air flow.
The open / close drive unit 22 drives the open / close operation all at once. Also 23
Is an outlet damper provided at the outlet of the casing 5 through which the processed air after dust flows out for shutting off the dust-containing air flow.

Reference numeral 31 denotes a water pipe provided on the inlet side of the dust collecting unit 6, that is, in a front space 26 between the charging unit 7 and the inlet damper 21. A number of open side water spray nozzles 32 are mounted.

Reference numeral 33 denotes a water pipe provided in the top space 27 above the dust collecting unit 6 on the upper stage.
Are provided with a plurality of upper water spray nozzles 34 that open downward toward the charging unit 7 and the dust collection unit 8 of the dust collection unit 6 on the upper side.

The water supply pipes 35 and 36 connected to the water distribution pipes 31 and 33 are connected to a water supply pump 38 via an electromagnetic valve 37. 39 is a water storage tank.

A drain pipe 41 for washing the electrode is also provided on the outlet side of the dust collecting unit 6, that is, in the rear space 28 between the dust collecting section 8 and the outlet damper 23. A large number of cleaning water spray nozzles 42 that open laterally toward the dust portion 8 are attached. And the water pipe 41
Is connected to the water supply pump 38 via an electromagnetic on-off valve 44.

At the bottom of the casing 5, there is formed an inclined dish-shaped drain portion 5e for collecting the water jetted from each of the water spray nozzles and dust washed out by the jet water and discharging the collected dust to the outside through a drain port 5d. I have.

In FIG. 1, reference numeral 50 denotes an operation control device.
Issues a command signal S ₁ to S ₄ which will be described later as a cooling operation command in the event of a fire in the car tunnel, electrode cleaning electrostatic precipitator device (playback) sometimes issues a command signal S ₃ to S ₇ described later as a cleaning operation command Things.

In order to remove the dust-containing air flowing through the dust-containing air flow passage 1 by the electric dust collector 2 having the above-described structure, the inlet damper 21 and the outlet damper 23 are opened, and the discharge wire 11 and the positive electrode plate are removed. 13, a high voltage is applied, and the dust in the flowing dust-containing air is collected by the respective dust collection units 6.

Next, when a tunnel fire occurs in the automobile passage tunnel on the upstream side of the dust-containing air flow passage 1, operation control is performed in response to a fire occurrence signal from a fire alarm or a general equipment control device in the tunnel. The device 50 cancels the high voltage applied to the discharge wire 11 and the positive electrode plate 13 of each dust collecting unit 6 and then controls the opening and closing of the inlet damper 21 as damper opening command signals S ₁ and S ₂ as control signals during cooling operation. The pump operation command signal S ₃ is output to the water supply pump 38 as a water supply command to the water supply device for supplying water to the spray nozzles, while outputting the water to the water supply device for supplying water to the spray nozzles.
The valve opening command signal S ₄ is output to the solenoid valve 37.

As a result, the inlet damper 21 and the outlet damper 23 are maintained in an open state, and the high-temperature dust-containing air flows through the electrostatic precipitator 2.
4 and the side water spray nozzle 32, pressurized water is sprayed, so that the electrode (discharge wire 1) of each dust collection unit 6 is discharged.
1, the negative electrode plate 12, the positive electrode plate 13, and the dust collecting electrode plate 14) are cooled by the spray of the jet water, so that overheating of the electrodes and accompanying thermal deformation are prevented.

The high-temperature dust-containing air flowing through the air passages 15 and 16 is also cooled by the jet water blown into these air passages, and its temperature drops, so that the motor and the bearing of the blower 3 on the downstream side have high-temperature dust. This prevents overheating damage caused by air. After the fire is extinguished, the components may be returned to the original normal operation mode and the electric dust collection may be performed.

On the other hand, the dust collecting electrode plate 1
When dust accumulates on the surface of the dust collection unit 4, the operation control unit 50 releases the high voltage to the discharge wire 11 and the positive electrode plate 13 of each dust collection unit 6, and then removes the dust during cleaning operation. As control signals, damper closing command signals S ₅ and S ₆ are output to the opening / closing drive unit 22 of the inlet damper 21 and the opening / closing drive unit 24 of the outlet damper 23, and a valve opening command signal S ₇ is output to the electromagnetic opening / closing valve 44. Then, the same pump operation command signal S ₃ and valve opening command signal S ₄ as at the time of the fire occurrence are output to the water supply pump 38 and the solenoid on-off valve 37.

As a result, the inlet damper 21 and the outlet damper 23 are closed to prevent the flow of the dust-containing air during the washing, and the water sprayed from the upper water spray nozzle 34, the side water spray nozzle 32 and the washing water spray nozzle 42. As a result, each electrode is cleaned, and dust deposited on the dust collecting electrode plate 14 is effectively removed by the water jets from the front, rear, and upper three directions. In parallel with this, the insulator for supporting the electrode may be cleaned by a water spray nozzle (not shown), or air may be blown to each part after cleaning by an air blowing means (not shown) to promote drying.

The present invention is not limited to the above embodiment. For example, the number and arrangement of the dust collecting units 6 in the casing 5 may be other than those described above, and the inlet damper 21 and the outlet damper 23 may be of vertical type. It may be something. In addition, the upper water spray nozzle 34 and the side water spray nozzle 32 do not need to be used also as the spray nozzle of the electrode cleaning device, and the cleaning water spray nozzle 42 is not provided when another electrode regeneration method is used. May be.

[0027]

As described above, according to the present invention,
Spraying of water from above the charging unit and the dust collecting unit and from the inlet side of the charging unit can prevent overheating of the electrode and the accompanying thermal deformation in the high-temperature dust-containing air flow state. There is no need to provide a bypass flow passage with a damper for bypassing the dust collector on the side of the dust collecting device installation part of the air flow passage, which greatly increases civil engineering and equipment costs for installing the dust collector. And the construction period can be shortened.

Further, since the high-temperature dust-containing air is also cooled by the above-mentioned spraying of water, it is possible to prevent the blower located downstream of the electric precipitator from being overheated and damaged.

According to the third aspect of the present invention, in addition to the above effects, the upper water spray nozzle and the side water spray nozzle for cooling used when generating high-temperature dust-containing air are provided by the spray nozzle of the electrode cleaning device. Since it can be used also at the time of electrode cleaning, the effect that the spray device as a whole is simplified and the production cost can be reduced is obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electric precipitator showing one embodiment of the present invention.

FIG. 2 is a plan view of the inside of the electrostatic precipitator of FIG. 1;

FIG. 3 is a longitudinal sectional view showing an installed state of the electric dust collecting apparatus of FIG. 1;

FIG. 4 is a longitudinal sectional view showing an example of an installation state of a conventional electric dust collecting device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Dust-containing air flow path, 2 ... Electric dust collecting device, 5 ... Casing, 5e ... Drainage part, 6 ... Dust collecting unit, 7 ... Charging part, 8 ... Dust collecting part, 11 ... Discharge wire, 12 ... Negative electrode plate , 13
... Positive electrode plate, 14 ... Dust collecting electrode plate, 15 ... Air passage, 16 ...
Air passage, 21 ... Inlet damper, 22: Opening / closing drive, 23
... Outlet damper, 24 ... Open / close drive, 32 ... Side water spray nozzle, 34 ... Top water spray nozzle, 35 ... Water supply pipe, 36 ... Water supply pipe, 37 ... Electromagnetic on / off valve, 38 ... Water supply pump, 50 ... Operation control apparatus.

Claims (3)

[Claims] 1. An electric precipitator installed in a dust-containing air flow passage and containing a charging unit and a dust collecting unit in a casing, wherein when a high-temperature dust-containing air is generated due to a fire, the inlet side and the outlet side of the casing are connected to each other. Opening and allowing the high-temperature dust-containing air to flow through the electrostatic precipitator, and connecting the electrodes of the charging unit and the precipitating unit from above the charging unit and the precipitating unit and from the entrance side of the charging unit. Spraying water toward the air passage of (1), and cooling the electrode and the high-temperature dust-containing air with the water. 2. An inlet damper is provided at an inlet of a casing containing a charging unit and a dust collecting unit, and an outlet damper is provided at an outlet of the casing, and opens downward above the charging unit and the dust collecting unit. An upper water spray nozzle having a spout is provided, and a side water spray nozzle having a spout opening toward the charging unit is provided at an inlet side of the charging unit, and a spout from each of the spray nozzles is provided at a lower part of the casing. In addition to providing a drainage section for draining water, when a high-temperature dust-containing air flows in, a damper opening command is given to an opening / closing drive section of the inlet damper and the outlet damper, and a water supply device for supplying water to the upper water spray nozzle and the side water spray nozzle. An electric precipitator provided with an operation control device for giving a water supply command. 3. The electrostatic precipitator according to claim 2, wherein the upper water spray nozzle and the side water spray nozzle double as a spray nozzle of an electrode cleaning device in the charging unit and the dust collecting unit.