JPS60118258A - Electric dust collecting apparatus - Google Patents

Abstract

PURPOSE:To make it possible to maintain the stable dielectric strength of an insulator even in a tunnel for a driveway, by receiving the insulator for supporting a high potential electrode in an insulator receiving chamber and using a dust separating means for purifying gas supplied into the insulator receiving chamber. CONSTITUTION:The insulator 25 for supporting the high potential electrode of an electric dust collector is received in an insulator receiving chamber 26 and a dust separating means 14 used in shaking off collected dust is availably utilized in purifying gas supplied into the insulator receiving chamber 26. By this mechanism, floated particles are availably prevented from penetrating into the insulator receiving chamber and the deterioration in the dielectric strength of the insulator is well prevented. Because air purifying equipment is not provided for exclusive use, the electric dust collector becomes inexpensive.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to an electrostatic precipitator 6 in which the dielectric strength of an insulator supporting a high-voltage side electrode is increased.

[Prior art and its problems] Electrostatic precipitators are applied, for example, to equipment for purifying and exchanging air in tunnels in which the air in tunnels of motorways is used as the gas to be treated. The air inside a motorway tunnel is made up of smoke emitted from cars, tires generated as the car travels,
It is contaminated with many submicron-sized suspended particles such as dust from road asphalt wear. As a method to purify the contaminated air inside such tunnels, an electrostatic precipitator is installed inside the detour barrier in the tunnel leading to the roadway.
A system has been developed in which contaminated air is extracted from the roadway, purified using an electrostatic precipitator, and then sent back to the roadway.

Next, an outline of ventilation equipment employing this electrostatic precipitator will be explained with reference to FIG. In the figure, l is a detour that leads to a roadway in the tunnel, and an electrostatic precipitator main body 2 and a blower 3 are installed in the roadway 1 on the downstream side thereof. The electrostatic precipitator main body 2 has a casing 4,
Opening/closing dampers 5.6 are provided at the inlet and outlet sides of the casing 4, and a charging unit 8 and a dust collection unit 9 which receive power from a high-voltage power supply 7 are housed inside the casing 4. As a result, during operation, the contaminated air A that is sucked into the electrostatic precipitator main body 2 from the upstream side by the blower 3 is mixed into the contaminated air A during the process of passing through the electrostatic precipitator main body 2, as is well known. The contained suspended particles are collected as dust on the dust collection electrode of the dust collection unit 9, and as a result, the purified air A' is sent downstream through the air blower a3. Here, in order to separate and recover the dust collected on the east dust electrode, on the downstream side of the dust collection unit 9, there are a plurality of air blow nozzles that inject compressed air for dust removal toward the dust collection electrode. A pipe 12 coupled to a compressor 11 is connected to the air blow nozzle 10 in the bracket, and a dust discharge plenum 13 is defined at the bottom of the casing of the electrostatic precipitator main body 2, and a dust discharge plenum 13 is formed in the plenum 13. Connect one end of a pipe 16 with a dust separation and recovery device 14 such as a bag filter or cyclone installed in the middle,
A suction end of a suction fan 15 is connected to the other end of this piping 16. In addition, the reference numeral 17 in the figure is an opening/closing driving part for the dampers 5 and 6, 18 is a main valve provided in a connecting section of the pipe 12, and 18 is an opening/closing damper provided on the outlet side of the dust discharge plenum 13.

Next, the dust dust removal and dust collection operations with the above configuration will be explained based on FIGS. 2 and 3. First, during dust collection operation, the compressor 11 of the pipe 12 and the suction fan 15 of the pipe 16 are both stopped as shown in FIG.
is opened and receives power from the power supply device 7 to collect dust from the gas to be treated. If this dust collection operation continues for a certain period and a considerable amount of dust has been collected and deposited on the dust collection electrode, the dust adhering to the dust collection electrode will be brushed off based on the cleaning command. Collection takes place. In this case, first stop the power supply to the blower 3 and high-voltage power supply device 7 shown in FIG. 1, then start the compressor 11 and suction fan 15 as shown in FIG. The dampers 5 and 8 on the inlet and outlet sides of the casing No. 2 are closed, and the main valve 18 of the pipe 12 and the opening/closing damper 19 of the dust discharge plenum 13 are opened to start the dust dust removal and collection operation. That is, the gas that is pressurized and sent from the air blow nozzle 10 through the piping 12 is ejected at a wind speed close to the speed of sound toward the dust collection electrode that constitutes the dust collection unit 9, and is deposited on the electrode. Brush off any dust that may be present. Here, the dust collected on the dust collection electrode is aggregated and coarsened, and the coarse particle dust brushed off from the electrode is transferred to the carrier airflow B using the airflow ejected into the casing from the air blower nozzle 10. The dust is dispersed in the carrier airflow and is sucked and discharged through the dust exhaust plenum 13 into the piping 16 outside the machine. Furthermore, the dust riding on the carrier airflow enters the dust separation and recovery device 14, where it is separated from the carrier airflow, and only the airflow is exhausted to the downstream side of the electrostatic precipitator body 2 through the suction fan 15, for example. On the other hand, the dust separated and collected from the conveying airflow in the dust separation and recovery device 14 is packed into bags or the like as appropriate and transported to a processing plant where it is disposed of. In addition, in a configuration where multiple sets of dust collection units are housed in an electrostatic precipitator as shown in the figure, and these dust collection units have opposing city air blow nozzles 1O arranged in multiple stages above and below, air blow is simultaneously performed from all nozzles. - The compressor 11. Since the capacity of the suction fan 15 becomes enormous and the equipment cost increases, as a countermeasure, air blow nozzles 10 are connected in parallel to the piping 12 at each stage via nozzle valves 20 and housed in the electrostatic precipitator body 2. A method is adopted in which the dust removal and collection operation cycle described above is repeated in block units for a plurality of installed dust collection units. With the dust dust removal and collection method described above, the dust collected within the electrostatic precipitator main body 2 can be smoothly discharged outside the machine and separated and collected without being scattered again outside the machine.

- The high potential side electrodes that constitute the charging unit 8 and the dust collection unit 9 in the electric dust collection wooden body 2 are supported via an insulator, but the dust collection operation is Sometimes, a part of the gas to be treated that flows into the casing of the electrostatic precipitator body 2 gets around the insulator, and if this continues, suspended particles in the gas to be treated will adhere to the surface of the insulator, reducing the dielectric strength of the insulator. There is a risk. From the above point of view, as a means to prevent floating particles from adhering to the insulator surface and maintain insulation performance, the insulator that supports the high potential electrode is housed in an insulator housing chamber, and this insulator housing chamber is insulated from the outside as a purge source. A secondary purge method has been known in the past, which prevents floating particles from entering the room from the outside by supplying a pressurized gas and blowing out the purge source from the gap in the room to the outside. . This air purge method is especially effective when using an air blower to blow off the dust collected in the dust collection unit as described above, as the dust flies inside the casing and creates a highly concentrated dust atmosphere. It can be considered as a suitable method.

By the way, according to the test results of actually installing a nine-mounted air dust collector in a tunnel using the air purge method described above and operating the machine using purified air from the tunnel as a purge source, it was found that air purge Despite efforts to prevent floating particles from entering the insulator chamber,
A phenomenon was observed in which the insulation performance of the insulator deteriorated and leakage current increased over a relatively short period of time. After considering this point, it was found that the cause lies in the following points. In other words, the atmosphere inside the tunnel is relatively humid, so the air inside the tunnel is used directly as a purge source.
When this air is pressurized and supplied to the child chamber 17 through the compressor, the purge source is heated during the process of passing through the compressor and becomes a low humidity state, but the inside of the piping from the compressor to the electrostatic precipitator is heated. During the flow, the temperature of the purge source also decreases due to the low ambient temperature, and the relative humidity of the purge source increases again. As a result, the purge source blown into the insulator chamber touches the insulator and spreads on its surface, reducing the creeping dielectric strength of the insulator.

[Objective of the Invention] The object of the present invention has been made in view of the above-mentioned problems, and is to provide an electric collector that can maintain stable dielectric strength of an insulator even when installed and operated in a tunnel. The purpose of this company is to provide dust equipment.

[Summary of the Invention] In order to achieve the above object, the present invention provides a dust collector housing chamber containing an insulator that supports a high-voltage side electrode in the dust collector main body, a dust separating means, and a dust collector main body. a switching means provided between the dust discharge section and the dust separation means and configured to communicate the inlet section of the dust separation means with the dust discharge section or open it to the outside air; and a dehumidification means; The apparatus includes a suction blowing means whose suction side is connected to the outlet side of the dust separation means and whose blowing side is connected to the insulator storage chamber via the dehumidification means.

[Embodiment of the invention] FIG. 4 is a schematic configuration diagram showing an embodiment of the invention,
Components similar to those in FIG. 1 are designated by the same reference numerals. In FIG. 4, the dust collection unit 9 is arranged between left and right end plates 23 by alternately arranging grounded uneven dust collection electrodes 21 and high potential uneven dust collection electrodes 22, of which the high potential uneven dust collection electrodes 22 are The electrode support rod 24 is installed on the support rod 24, and the electrode support rod 24 is connected to the left and right end plates 23.
It penetrates through the hole, projects outward, and is insulated and supported by the insulator 25. On the other hand, the insulators 25 are each accommodated in several insulator storage chambers 28 formed in the side plate 23, and a support rod that supports the electrode support rod 24 protrudes through the opening 213a of the insulator storage chamber 28.

Each insulator storage chamber 26 is connected to one end of the pipe 27A.

Piping 2? The other end of A is connected to the outlet end of the dehumidifier 28.

One end of the pipe 27B is connected to a suction fan 1 as a suction blowing means.
5, and the other end is connected to the inlet end of the dehumidifier 28.

One end of the pipe 18A is connected to the dust discharge blemish 13 (not shown; see FIG. 1) of the electrostatic precipitator main body 2, and the other end is connected to the inlet end of the dust separation and recovery device 14. Piping 18
One end of B is connected to the outlet end of the dust separation and recovery device 14, and the other end is connected to the suction end of the suction fan 15.

A first on-off valve 28 is provided in the middle of the 1 ftA pipe.

Furthermore, a second on-off valve 30 is provided in the middle of the pipe 18A between the first on-off valve 2B, the dust separation port, and the collection container 14.
is provided, and the other end of a branch pipe 31, one end of which is open to the atmosphere surrounding the dust separation and recovery device 14, is connected. First on-off valve 2
8 and the second on-off valve 30 are controlled by a control device (not shown) as described later.

With the above configuration, first, during dust collection operation,
The first on-off valve 28 is closed and the second on-off valve 3o is opened to operate the suction fan 15. As a result, the atmosphere surrounding the dust separation and recovery device 14 is removed from the second on-off valve 30. It is sucked into the dust separation and recovery device 14 through the branch pipe 31 and the pipe 18A,
There, the dust is separated and becomes clean air. The clean air thus obtained is passed through the pipe 18B and the suction fan 15. The air is sent to the dehumidifier 28 through the pipe 27B, where it is dehumidified to become dry air, and then supplied under pressure into the insulator storage chamber 28 through the pipe 27A, and blown out from the opening 28a of the insulator storage chamber 26 to the outside.

On the other hand, during the work of brushing off the collected dust, the first on-off valve 2
8 is opened, the second on-off valve 30 is closed, and the suction fan 15 is operated. As a result, the pipe 18A is connected from the dust discharge blemish 13 of the electric dust collector main body 2, and the first on-off valve 2
8, the air containing dust that has been brushed off from the electrodes in the electropulverizer main body 2 is transferred to a dust separation and recovery device 14.
The air is sucked into the air, where the dust is separated and becomes clean air. The clean air thus obtained is dehumidified in the same manner as described above and is supplied under pressure into the insulator storage chamber 28.

In this way, suspended particles in the gas to be treated flowing inside the casing of the electric dust bundler main body 2 during dust collection operation and dust filling the recasing due to air blowing during dust removal are removed from the insulator storage chamber 26. It is effective to infiltrate 1
This will be prevented. Moreover, since dry air is supplied into the insulator storage chamber 28, it is possible to effectively prevent the dielectric strength of the insulator 25 from decreasing. The supply pressure of the virgin air is set to a higher pressure than the internal pressure of the casing when dust is removed by air blowing.

[Effects of the Invention] As described above, according to the present invention, the insulators supporting the high potential electrodes of the electric dust duster are housed in the insulator storage chamber, and clean and dry air is supplied thereto. It is possible to effectively prevent floating ultraparticles from entering the insulator storage chamber during dust collection operation and when the collected dust is removed by air blowing, and to effectively prevent deterioration of the dielectric strength of the insulator. It is possible to provide a highly reliable electric flux device that can be applied to ventilation equipment for cleaning contaminated air in tunnels. Further, according to the present invention, since the dust separation means used when brushing off the collected dust is effectively used to dry and purify the gas supplied into the insulator storage chamber, for example, a dedicated air purifying device is installed in the same insulator storage chamber. It is possible to provide an electric dust bundling device at a much lower cost than when supplying clean air using a

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a conventional electric dust bundler, and FIGS. 2 and 3 are operation explanatory diagrams of the dust collection operation and dust collection state of the electric dust bundler in FIG. 1, respectively. FIG. 4 is a schematic diagram showing an embodiment of the present invention. 2...Electric dust bundle machine body, 3...Blower, 7...High voltage power supply, 8...Charging unit, 9...Dust collection unit, 1O...Air blow nozzle, 12.1B , 18A, 18B, 27A, 27B... Piping, 14... Dust separation and recovery device, 15... Suction fan, 22... High potential side electrode, 25... Insulator, 26... Insulator storage Chamber, 28... Dehumidifier, 29... fiS1 on-off valve, 30... Second on-off valve, 31... Branch pipe, A, A'... Gas flow to be treated, B... Dust conveying airflow. Patent applicant Fuji Electric Manufacturing Co., Ltd. Figure 2

Claims (1)

[Scope of Claims] An insulator storage chamber housing an insulator that supports a high-voltage side electrode in a dust collector plate main body, a dust separation means, a dust discharge part of the dust collector main body, and the dust hA separation means. and an inlet portion of the dust separation means,
A car communicating with the dust discharge section or a switching means for switching to open to the outside air, a dehumidifying means, the suction side of which is connected to the outlet side of the dust separation means, and the air blowing side of the car connected to the outlet side of the dust separating means. An electrostatic precipitator comprising: a suction blower means connected to the insulator storage chamber. (Hereafter, margin)