JPS6028836A - Electric dust collector - Google Patents

Abstract

PURPOSE:To prevent deterioration of dielectric strength of insulator due to moisture satisfactorily by housing an insulator for supporting an electrode of a higher voltage side of an electric dust collector in an insulator housing chamber and interposing a dehumidifying means in an air purging line. CONSTITUTION:Purge source sucked from ambient atmosphere is compressed and fed to an insulator housing chamber 26 through an air purge line 27 and then blown out of an outlet 26a of the chamber to the outside of the chamber. Thus, invasion of suspended particles in the gas to be treated flowing through the casing of the electric dust collector during dust collecting running, and invasion of dust filling the inside of the casing generated by the air blow during purging off of the dust into the insulator chamber 26 are prevented. A dehumidifier 31 is provided in the midway of the air purging line 27 where the purge source is dried by dehumidification. Thus, the absolute humidity of the purge source to be fed to the insulator chamber 26 is decreased remarkably, and deterioration of dielectric strength of the insulator 25 due to moisture is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to an electrical industrial dust device that is applied to, for example, tunnel air cleaning and ventilation equipment that uses the air inside an automobile road tunnel as the gas to be treated.

[Prior art and its problems]

The air inside the tunnels of the abovementioned motorways is contaminated with many submicron-sized suspended particles such as soot emitted from automobiles and dust from tires and road asphalt abrasion generated as automobiles run. As a method to clean and ventilate the contaminated air inside the tunnel, ventilation equipment using an electric dust machine is installed in the detour road in the tunnel leading to the roadway, and the contaminated air extracted from the roadway is passed through the electric dust machine. A system has been developed that cleans the air and sends it back to the roadway.

Next, we will explain the outline of the ventilation equipment that uses this electric industrial dust machine in Part 1.
Let's talk about the diagram. In the figure, l is a soft detour road that leads to the road 1 in the tunnel described above, and an electrostatic precipitator 2 and a blower 3 are installed on the downstream side of the road. The electrostatic precipitator 2 is equipped with opening/closing dampers 5 and 6 on the inlet and outlet sides of a casing 4, and a charging unit 8 and a dust collection unit 9 that receive power from a high-voltage power supply 7 are housed inside the casing. . This results in
During operation, the electrostatic precipitator 2 is drawn from the upstream side by the blower 3.
As is well known, during the process of passing through the interior of the machine, suspended particles contained in the contaminated air A are collected as dust on the dust collection electrode of the dust collection unit 9.
The purified air A1 is sent to the downstream side through the blower 3. In order to separate and recover the dust collected on the dust collection electrode, on the one hand, multiple stages of air blow nozzles 10 for blowing off dust are arranged behind the dust collection unit 9 toward the dust collection electrode, and This air blower nozzle
On the other hand, a dust discharge plenum 13 is defined at the bottom of the casing of the dust collector, and a dust separation and recovery device 14 such as a bag filter or a cyclone is connected to the plenum 13 at the bottom of the casing of the dust collector. A dust collection line 16 including a suction fan 15 is connected thereto. In addition, the code 1 in the figure
7 is an opening/closing drive unit for the dampers 5 and 6, and 18 is an air roller R.
The main valve 2, 19, is an opening/closing damper provided on the outlet side of the exhaust plenum 13.

Next, the dust dust removal and dust collection operations with the above configuration will be explained with reference to FIGS. 2 and 3.

First, during dust collection operation, the compressor 11 of the air blower line 12 and the suction fan 15 of the dust collection line 16 are both stopped as shown in Fig. 2, and in this state, the electrostatic precipitator 2 opens the dampers 5 and 6. , and receives power from the power supply device 7 to collect dust from the gas to be treated. If this year's dust operation continues for a certain period and a considerable amount of dust has been collected and deposited on the dust collection electrode, the dust attached to the dust collection electrode will be removed based on the cleaning command. Dropping and collection will take place. In this case, first
After stopping power supply to the blower 3 and high-voltage power supply 7 shown in the figure, the compressor 11 and suction fan 15 are started as shown in FIG. 6 is closed, and furthermore, the main valve 18 of the air blow line and the opening/closing valve 19 of the dust discharge plenum are opened to start the dust dust removal and collection operation. That is, the gas that is pressurized and supplied from the air glow nozzle 10 through the air plow line 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 carried out through the dust discharge plenum 13 to the dust recovery line 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 is exhausted to the upstream side of the electrostatic precipitator 2 through the airflow suction fan 15, for example. On the other hand, the dust separated and collected from the conveying airflow is appropriately repacked into bags, etc., and then transported to a processing plant where it is disposed of. As shown in the figure, a plurality of dust collection units are housed in the electrostatic precipitator, and an air blower nozzle 10 is installed opposite to these dust collection units.
In a configuration where compressors 11. Since the capacity of the suction fan 15 becomes enormous and the equipment cost increases, as a countermeasure, the air blow nozzle 10 for each stage is connected in parallel to the air blow line 12 via the nozzle valve 20 and housed in the electrostatic precipitator. A method is adopted in which the above-described operation cycle of dust removal and collection is repeated in block units for a plurality of installed dust collection units. With the dust removal and collection method described above, the dust collected inside the dust collector can be smoothly discharged outside the machine and separated and collected without being scattered again outside the machine.

On the other hand, the high potential side electrodes constituting the charging unit 8 and dust collection unit 9 of the electrostatic precipitator 2 are supported via insulators, but during dust collection operation, the casing of the electric dust collector A part of the gas to be treated that flows into the insulator wraps around the insulator, and if this continues, floating particles in the gas to be treated may adhere to the surface of the insulator, reducing the dielectric strength of the insulator. From the above point of view, as a means of preventing floating particles from adhering to the insulator surface and maintaining insulation performance, the insulator that supports the high potential electrode is housed in an insulator housing chamber, and this insulator housing chamber is supplied with a purge source from the outside. Conventionally, an air purge method is known in which an insulating gas is supplied under pressure to create a gap in a chamber. In particular, with the method described above in which the dust collected in the dust collection unit is removed by air blowing, the dust will fly inside the casing and create a highly concentrated dust atmosphere, so this air purge method is It is considered to be an extremely effective method.

By the way, according to the test results of an electric industrial dust machine that adopted the air purge method described above actually installed inside a tunnel and operated using purified outside air inside the tunnel as a purge source, it was found that air purge caused the insulator to enter the insulator chamber. Despite efforts to prevent the intrusion of floating particles, the insulator's insulation performance 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 when the air inside the tunnel is used as a purge source and this air is pressurized and supplied to the insulator chamber through a compressor, the purge source must first pass through the compressor. During the process, it is heated and reaches a stagnation state, but as the air flows through the piping from the compressor to the electric industrial machine, the ambient temperature is low, so the temperature of the purge source also drops, and the relative humidity of the purge source decreases again. It increases. As a result, the purge source blown into the insulator chamber touches the insulator and condenses on its surface, reducing the creeping dielectric strength of the insulator.

[Purpose of the invention]

This invention was made in consideration of the above points, and aims to solve the above problems by creating a new air purge line that can stably maintain the dielectric strength of the insulator even when installed and operated in a tunnel. The purpose is to provide electrical industrial dust equipment with the following features.

[Key points of the invention]

In order to achieve the above object, the present invention houses an insulator that insulates and supports a high-potential electrode of an electric industrial machine in an insulator housing chamber, and this insulator housing chamber is equipped with an air pressure feeding means that uses outside air as a purge source. In addition to connecting and piping the air purge line, a dehumidifying means is further inserted into the air purge line, and the dehumidified purge source is supplied under pressure to the insulator storage chamber through the dehumidifying means, thereby improving the dielectric strength of the insulator. This is how it was done.

[Embodiments of the invention]

FIG. 4 shows the main structure of an embodiment of the present invention.
and high potential side dust collection electrodes 22 are arranged alternately to form left and right end plates 23.
The electrodes 22 on the high potential side are arranged on an electrode support rod 24, and the electrode support rod 24 passes through 23 holes in the left and right end plates and is pulled out to the side. It is insulated and supported by an insulator 25. On the other hand, the insulators 25 are each housed in an insulator housing chamber 26 attached to the side plate 23, and the electrode support rod 24 passes through the opening 26a of the insulator chamber 26.
The support rod that supports it is protruding.

In addition, each insulator storage chamber 26 has the following air purge line 27.
The piping is open connected. Said air purge line 2
7 is an air filter 28 as a dust removal means, a compressor 29 as an air pressure feeding means, and an oil separator 30 as an oil mist trap, for example. A dehumidifier 31 using, for example, silica gel as a dehumidifying agent is connected in this order and is connected to the insulator storage chamber 27 by piping. Although only the dust collection unit 9 is shown in the figure, the high potential electrode supporting insulator of the charging unit is similarly configured, and a line branching from the air purge line 27 is connected to the insulator storage chamber. Note that 32 is a discharge valve of the compressor. In addition, each of the devices shown in the figure with reference numerals 29 to 31 is generally installed in an auxiliary equipment room separated from the electric industrial machine.

With the above configuration, if the compressor 29 is operated during the dust collection operation of the electric industrial dust machine and when the collected dust is brushed off, the purge source sucked from the surrounding atmosphere is added to the insulator storage chamber 26 through the air purge line 27. After being supplied with pressure, it blows out from the opening 26a of the chamber. This prevents suspended particles in the gas to be processed flowing through the electric dust machine casing during dust collection operation and dust that fills the casing due to air blowing during dust removal from entering the insulator chamber 26. Note that the supply pressure of the purge source is set to a higher pressure than the internal pressure of the casing during the dusting latency period by air blowing. Moreover, the absolute humidity of the purge source that is pumped into the air purge line 27 decreases significantly, and the insulator 25 due to moisture
can prevent a decrease in dielectric strength. f, compressor 29
An oil mist trap 3 is installed between the outlet of the oil mist trap 3 and the dehumidifier 31.
By interposing the oil mist from the compressor 29, it is possible to prevent the oil mist discharged from the compressor 29 from penetrating into the dehumidifier and adhering to the surface of the dehumidifying material and deteriorating the dehumidifying performance. Although it is preferable that the dehumidifier 31 described above is connected to the electric industrial dust machine as close as possible to the piping, due to constraints on the on-site installation location, the dehumidifier 31 is installed in the electric industrial dust machine and the auxiliary equipment room.
If the piping distance between two stations is unavoidably long, a simple dehumidifying trap such as a dehumidifying trap, which requires almost no maintenance, should be installed in addition to the dehumidifier 31 immediately before the electrical industrial dust generator on the downstream side. It is preferable to additionally provide an auxiliary dehumidifier 32.

As a result, even if a small amount of moisture in the purge source that has passed through the dehumidifier 31 condenses while flowing through the low-temperature piping,
There is no intrusion into the insulator storage chamber 26, and the reliability of the chips can be further improved.

〔Effect of the invention〕

As described above, according to the present invention, the insulator supporting the high potential side electrode of the electric industrial dust machine is housed in the insulator housing chamber,
An air purge line that uses outside air as a purge source is connected here, and a dehumidifying means is inserted into this air purge line, so that it can be removed into the insulator storage chamber during dust collection operation and when dust is removed by air blowing. While preventing the intrusion of suspended particles, it is also possible to effectively prevent deterioration of the dielectric strength of the insulator due to moisture even if the insulating material is humid. It is possible to provide a highly reliable electrical industrial dust device that can be applied to clean ventilation equipment.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of a conventional electric industrial dust device, and FIGS. 2 and 3 are operation explanatory diagrams of the dust collection operation and dust collection state of the electric industrial dust machine in FIG. 1, respectively. FIG. 4 is a configuration circuit diagram of a main part of an embodiment of the present invention. 2... Electric industrial dust machine, 3... Blower, 7... High voltage power supply device, Death... Charging unit, 9... Dust collection unit, 10... Air blow nozzle, 12... Air blow - line, 14... dust separation and recovery device, 15... suction fan, 16... dust collection line, 22... high potential side electrode, 25... insulator, 26... insulator storage chamber,
27... Air tR-Siline, 28... Dust removal filter, 29... Compressor, 30... Oil separator,
31, 32... dehumidifier, A, AI... gas flow to be treated, B... dust conveying air flow.

Claims (1)

[Claims] 1) By passing the gas to be treated through an electric industrial dust machine, floating particulates in the gas to be treated are collected as dust on a dust collection electrode, and the particles are collected on the dust collection electrode. In an electric industrial dust machine, the dust is blown off by an air blower, carried on a dust conveying air stream, and carried to a dust recovery line outside the machine, and then separated and collected from the conveying air stream in the dust recovery line. An insulator that insulates and supports the potential side electrode is housed in an insulator housing chamber, and an air purge line equipped with air pressure feeding means that uses outside air as a purge source is connected to the insulator housing chamber, and a dehumidifying means is further connected to the air purge line. An electric industrial dust device characterized in that the dehumidified purge source is pressurized and supplied to the 41" single-child storage chamber through the dehumidifying means. 2. The collection according to claim 1. In the dust equipment,
1. An electrical industrial dust device, characterized in that the purge source pressure feeding means in the air purge line is a compressor, and an oil separator is interposed between the compressor and the dehumidifying means on the discharge side.