JPS6154463B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting the dust collection limit of a dust collection electrode for an electrostatic precipitator for removing pollutants such as dust and smoke floating in the air.

An electric precipitator cleans the air by electrifying particulates such as dust and smoke floating in the air by corona discharge or the like, and collecting the charged particulates on a dust collecting electrode. There are many types of electrostatic precipitators in practical use, ranging from large ones for industrial use to extremely small ones for homes, offices, and even vehicles.

Generally, in an electrostatic precipitator, as the amount of dust accumulated on the dust collection electrode increases, the dust collection effect decreases, eventually becoming unable to collect the dust, and furthermore, the collected dust begins to scatter again. Therefore, when the amount of dust collected exceeds a predetermined value, the dust collection electrode must be cleaned or replaced. Large-scale equipment is inevitably equipped with auxiliary equipment that can completely control the amount of dust collected and the effectiveness of dust collection, and furthermore, because it is handled by specialized engineers, the equipment is always operated appropriately. It will be done. On the other hand, in the case of small and medium-sized appliances, incidental equipment is often omitted as much as possible to avoid complexity, and the scope of management left to the user tends to increase. However, in reality, it is often handled by multiple users without special expertise, and sufficient management cannot be expected in many cases. Therefore, in order to maintain a certain level of dust collection performance in small and medium-sized dust collectors, the average usage time is set in advance, and when this time is reached, the dust collection electrodes are cleaned or replaced. There are many things that are.

However, the degree of air pollution in actual installation locations varies widely, and management based solely on operating time is often insufficient. In other words, in places with a low degree of pollution, the dust collection electrodes are cleaned or replaced even though they can still exhibit sufficient dust collection effects. On the other hand, in places with a high degree of pollution, the dust collection effect decreases even though the operating time limit has not yet been reached, and in extreme cases, re-scattering may occur. Furthermore, in many systems that specify the usage limit time, special warnings etc. cannot be issued, so there are many cases where the timing for cleaning or replacement is missed.

An object of the present invention is to provide a dust collection limit detection device for a dust collection electrode for an electrostatic precipitator that can appropriately detect the actual dust collection state, that is, the dust collection limit, of the dust collection electrode in an electrostatic precipitator. be.

This object is achieved by a dust collection limit detection device for a dust collection electrode for an electrostatic precipitator as set forth in the claims.

According to the dust collection limit detection device according to the present invention, it is possible to clearly grasp the state of the actual amount of dust collected on the dust collection electrode. Since this detection result is an electrical signal, it is possible to arbitrarily activate audible, light, or other ordinary indicating/warning devices. By managing the dust collection electrode based on such instructions and warnings,
The performance of the electrostatic precipitator can be economically and fully demonstrated.

The invention will now be described in detail with reference to the accompanying drawings, which illustrate examples.

Figure 1 shows the principle of an electrostatic precipitator, in which fine particles in the air are collected by corona discharge from a corona electrode 1 placed upstream of the air flow path as shown by the white arrow W. Negatively charged. These charged fine particles are collected on the dust collecting electrode 2 by the action of the electric field formed by the dust collecting electrodes 2 disposed above and below and the repelling electrode 3 disposed in the air flow path, and are collected on the dust collecting electrode 2 as shown in numeral 4. accumulate. Due to the collection effect, the amount of this accumulation is large on the upstream side of the air flow path and decreases toward the downstream side. In other words, particulate contaminants charged by corona discharge vary depending on the amount of charge, electric field strength,
The particles approach the dust collection electrode and are captured according to the moving speed determined by the particle diameter, etc., and these factors are influenced by the amount of the fine particles 4 deposited on the dust collection electrode. Naturally, when fine particles are captured and deposited near the air flow path outlet of the dust collection electrode,
Particulates that are not captured and scattered will be generated, resulting in a reduction in the dust collection effect and, therefore, in the air purification performance.

Therefore, by monitoring the particulate contaminants captured and deposited on the dust collecting electrode near the air flow path outlet, the usage limit of the dust collecting electrode can be detected. As a result, it is possible to appropriately grasp the timing of cleaning or replacing the dust collecting electrode, and to operate the electrostatic precipitator economically and effectively.

FIG. 2 shows two flat dust collecting electrodes 12 of the present invention,
12 is a sectional view showing an example in which a fine wire corona electrode 11 is used to charge fine particles in an air flow W. Openings 15, 16 and 17 are provided at transparent positions near the exits of the air flow paths of the dust collection electrode 12 and the repulsion electrode 13, respectively. Among these openings, at least the dust collection electrode 12
The openings 15 and 16 of the transparent conductive coatings 18 and 1
covered by 9. The opening 17 of the repulsion electrode 13 can be left as it is, or in some cases it can be covered with a transparent conductive film like the dust collecting electrode. In any case, these openings and the transparent conductive coating are all arranged in a line, and a light source 20 and a photodetector 21 are arranged outside both dust collecting electrodes 12. Therefore, the light beam from the light source 20 passes through the transparent conductive coatings 18 and 19 and the aperture 17, and reaches the photodetector 21.

When the dust collector is operated in such a configuration, the trapped fine particles 14 on the dust collection electrode 12 gradually develop from the upstream side of the air flow path. When the captured particles 14 finally reach the transparent conductive coatings 18 and 19, the transparency of the coatings will inevitably be impaired. Therefore, the light beam that passes through the conductive film is absorbed and scattered by the deposited particles, reducing the amount of light that reaches the photodetector. Since such a state means the usage limit of the dust collecting electrode as described above, the degree of fine particle accumulation on the transparent conductive coating is determined by comparing the output of the photodetector 21 with an appropriate reference value. , it is possible to ultimately confirm the usage limit of the dust collecting electrode.

It goes without saying that such a principle can be similarly applied to the case where two or more dust collecting electrodes are used as shown in FIG. In this embodiment, the minimum objective can be achieved by providing the transparent conductive coatings 181 and 191 only on both outer dust collecting electrodes 121. Naturally, by providing a transparent conductive film in the opening of the dust collection electrode 12 located in the middle, it becomes possible to detect an appropriate amount of dust collection.

FIG. 4 shows an embodiment using a needle-like electrode 31 and a cylindrical dust-collecting electrode 32. In this example,
Fine particles charged by the electric field generated by the needle electrode 31 are deposited inside the dust collecting electrode 32 as indicated by reference numeral 34. An opening 35 is provided at the air flow path outlet of the needle electrode 31 and the cylindrical dust collecting electrode 32, respectively.
36 is provided and further covered with a transparent conductive coating 37. By arranging the light source 38 and the photodetector 39 on both sides of the conductive film 37, that is, on the inside of the base 33 of the needle electrode 31 and on the outside of the dust collecting electrode 32, the desired purpose can be achieved. In addition, in such a form, as shown in FIG.
It is also possible to cover the transparent conductive film 57 with a light source 58 and a photodetector 59 sandwiching these.

FIG. 6 shows still another embodiment, which has the same configuration as FIG. 3, but in which an optical fiber 70 is disposed between the light source 68, the photodetector 69, and the conductive film 67. . As is well known, since optical fibers have sufficient flexibility, it is possible to adopt an advantageous configuration when there are restrictions on the placement of a light source or a photodetector. It should be noted that such an optical fiber can be used for either one of them, and it goes without saying that it can also be used for one or both of the light source and the photodetector as appropriate in the other embodiments described above.

According to the dust collection limit detection device for a dust collection electrode according to the present invention, since the amount of captured particles on the dust collection electrode can be accurately grasped, the usage limit of the dust collection electrode can be easily lowered. As a result, the time to clean or replace the dust collection electrode is clearly indicated, and the dust collector can be operated economically while always maintaining high dust collection efficiency.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electrode arrangement showing the principle of an electrostatic precipitator. FIG. 2 is a sectional view showing a first embodiment of a dust collection limit detection device for a dust collection electrode according to the present invention. 3 to 6 are sectional views showing other embodiments. In the figure, the correspondence of main reference symbols is as follows. 11; Thin wire corona electrode, 31, 51, 61;
Needle electrode, 12, 121, 32, 52, 62; Dust collection electrode, 15, 16, 17, 35, 36, 55,
56, 65, 66; opening, 18, 19, 181,
191, 37, 57, 67; transparent conductive coating, 2
0, 38, 58, 68; light source, 21, 39, 5
9, 69; photodetector; 70; optical fiber.

Claims (1)

[Scope of Claims] 1. Apertures arranged so as to be visible near the air outlet side of a plurality of dust collecting electrodes are provided, and a light source and a photodetector for detecting the amount of collected dust are provided on both sides of the openings, In the dust collection limit detection device for a dust collection electrode for an electrostatic precipitator, at least one of the dust collection electrodes 12; 121;
32; 52; 62 said openings 15, 16; 36;
56; 66 with transparent conductive coatings 18, 19; 181,
191, 37; 57; 67, and a light source 20; 38; 58;
8, and a photodetector 21 for detecting the transmitted light flux;
39; 59; 69. A dust collection limit detection device. 2. The dust collection limit detection device according to claim 1, wherein the light source is a light emitting diode. 3. The dust collection limit detection device according to claim 1, wherein the photodetector is a phototransistor. 4. The dust collection limit detection device according to claim 1, wherein a light beam between the light source or photodetector and the transparent conductive coating is transmitted by an optical fiber 70.