JPS6044977B2 - Dust collection electrode mounting structure of dry electrostatic precipitator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry electrostatic precipitator equipped with a discharge electrode and a vertically suspended dust collecting electrode plate, and particularly relates to various aspects of the mounting structure of the dust collecting electrode.

In a dry electrostatic precipitator, in order to maintain dust collection performance, it is necessary to remove collected dust adhering to the dust collection electrode plate.

For this reason, the dust collecting electrode plate is usually hammered at appropriate time intervals during operation or when charging is stopped. It is well known that the ability to remove dust by hammering has a large effect on the performance of a dust collector.

Particularly when collecting dust whose electrical resistance value is in a range unsuitable for electrostatic collection, the dust layer adhering to the dust collection electrode plate promotes re-scattering and reverse ionization, significantly reducing the dust collection performance. It is well known that it reduces Therefore, it is an important issue to effectively remove dust from the dust collecting electrode plate. Various attempts have been made to address this problem. First, regarding the hammering device, it is necessary to increase the hammering force, improve the frequency of hammering, or improve the timing of hammering. Secondly, regarding the dust collecting electrode plate, it is necessary to form a coating with good dust releasability and to devise a shape. In addition, attempts have been made to modify the adhesion of the dust itself and to employ dust removal means other than hammering devices. However, all of the above-mentioned attempts involve sacrifices such as complicating the structure of the electrostatic precipitator as a whole, which results in an increase in equipment costs and operating costs, so they are not necessarily satisfactory. It wasn't. SUMMARY OF THE INVENTION An object of the present invention is to provide a dust collection electrode mounting structure for a dry electrostatic precipitator that enables effective dust removal with a relatively small hammering force without using complicated means. In view of the above object, the present invention was developed from the viewpoint of whether there is a clue to solving the problem at the most primitive contact point between the hammering device and the dust collecting electrode plate.
This was done by focusing on the detailed mounting structure of the dust collection electrode plate, which has not been given much attention.

The dust collection electrode mounting structure according to the present invention is based on a rectangular dust collection electrode plate suspended in the vertical direction, and the upper and lower ends of this dust collection electrode plate are respectively connected to a pair of parallel upper edge members and It is assumed that a hammering device is provided between the lower edge members and for hammering one end of the lower edge member.

The above-mentioned dust collection electrode mounting structure is commonly used in large-scale dry electrostatic precipitators, but the present inventors discovered that when the dust collection electrode plate is sandwiched and fixed between the lower edge members, It was confirmed through experiments that there are significant differences in the propagation of hammering energy during hammering and the vibration response of the dust collection electrode plate depending on the mode of hammering, and based on the results of this experiment, the characteristics and requirements of the present invention were constructed. That is, the present invention provides the above-mentioned dust collection electrode mounting structure.
In this case, the lower end of the dust collecting electrode plate is formed to have one or more trapezoidal convex portions along the direction in which the lower edge member extends, and is in close contact with the inner and outer surfaces of the convex portions. The dust collecting electrode plate is fixed to the lower edge member via a liner that fits with the liner. A further feature is that the lower end portion of the dust collecting electrode plate other than the fixed convex portion is provided so as to be spaced apart from the lower edge member.

The present invention will be explained below based on comparative experimental examples.

Figure 1 shows the overall configuration of the dust collection electrode mounting structure used in the experiment. Four dust-collecting electrode plates 1 are arranged in series with intervals between them, and the upper ends of these dust-collecting electrode plates 1 are connected to a common pair of upper edge members 2, and the lower ends are connected to a common pair of lower edge members 3. It is sandwiched between and fixed by bolts and nuts 4 at two upper and lower places indicated by the cross marks, so that the whole structure is made into an integral structure, and is vertically suspended from a beam 5 by a hanging fitting 6.

A hammering rod 7 is attached to one end of the lower edge member, and the hammering rod 7 is hammered with a hammer 8, and the energy is transferred to each of the dust collecting electrode plates 1 through the lower edge member 3. The dust propagating and adhering to the dust collection electrode plate 1 is peeled off by impact vibration. The experimental equipment was similar to a normal dry electrostatic precipitator, with multiple sets of the above-mentioned dust collection electrode mounting structure arranged in parallel.
The dust-containing gas is passed through while generating corona discharge from a plurality of discharge electrodes arranged between these electrodes. The experimental equipment is equipped with a scale (not shown) to measure the overall weight of the dust collection electrode plate, and the weight before and after hammering is measured.
Dust removal rate can be calculated. FIGS. 2 and 3 show various aspects of the mounting structure between the lower end of the dust collecting electrode plate 1 and the lower edge member 3 used in the experiment.

FIG. 2 shows an embodiment of the present invention; FIG. 2A shows the overall structure thereof, and FIG.

The dust collection electrode plate 1 has a cross-section formed by a press process in which a trapezoidal shape is alternately continuous. The lower end of this dust collection electrode plate 1 is sandwiched between a pair of lower edge members 3, and the two trapezoidal convex portions thereof are fixed to the lower edge members with bolts and nuts 4 via a convex liner 10 and a concave liner 11. There is. By interposing the convex liner 10 and the concave liner, the lower end portion of the dust collecting electrode plate 1 other than the fixed convex portion is separated from the lower edge member, forming a gap g and a final part. The outer shape of the convex piece liner 10 is similar in size to the inner dimension of the trapezoidal convex portion of the dust collecting electrode plate 1, which is slightly larger. Therefore, when the pair of lower edge members 3 are tightened with the bolts and nuts 4,
The upper surface of the convex liner 10 forms a gap with the upper inner surface of the trapezoidal convex portion, and the outer side surface of the convex liner 10 and the inner side surface of the trapezoidal convex portion are in close contact with each other. Further, the outer shape of the concave piece liner 11 is similar in size to the outer surface dimension of the trapezoidal convex portion, which is slightly smaller. Therefore, when the bolts and nuts 4 are similarly tightened, the bottom inner surface of the concave liner 11 forms a gap with the upper outer surface of the trapezoidal convexity, and the inner surface of the concave liner 11 and the outer side surface of the trapezoidal convexity form a gap. strongly close. What is shown in FIGS. 3A to 3E is a mounting structure of a comparative example that does not belong to the present invention.

The features of these mounting structures that differ from those of the above embodiments are as follows. Fig. 3A: In the trapezoidal convex portion at the fixed location, there is no lyre that fits closely on the inner and outer surfaces of the convex portion. Figure 3 Port...Similar to Figure 3A, there is no liner that fits closely.

Further, the lower end portion of the dust collecting electrode plate 1 other than the fixed convex portion shall not be separated from the lower edge portion. Fig. 3 C... The convex part of the dust collecting electrode plate 1 is not trapezoidal but rectangular.
It has the same structure as the picture opening.

Fig. 3 2: The convex part of the dust collecting electrode plate 1 is similar to the embodiment of the present invention shown in Fig. 2 above, except that the convex part of the dust collecting electrode plate 1 is rectangular rather than trapezoidal. Due to its rectangular shape, it is difficult to bring the convex liner and concave liner into close contact with the inner and outer surfaces of the convex portion.

FIG. 3(e): The dust collecting electrode plate 1 has a flat plate shape without a trapezoidal convex portion.

Table 1 shows the experimental results of dust releasability regarding the above various aspects.

The experiments shown in Table 1 were conducted under experimental conditions other than the above-mentioned differences in the mounting structure, such as the amount of dust deposited on the dust collection electrode plate before hammering,
The average value was obtained from several repeated experiments with the hammering force and surrounding environment (temperature and humidity) being as similar as possible. It was used as collected dust. In addition, in the above experiment,
The structure for attaching the upper end of the dust collecting electrode plate 1 to the upper edge member was all the same as that for the lower end.

The average response acceleration in Table 1 means that accelerometers are installed at 12 points at the top, middle, and bottom of each of the four dust-collecting electrode plates shown in Figure 1, and the response acceleration during hammering is measured in the in-plane direction and in-plane direction. Measurements were taken in the outward direction, and these measured values were averaged.
From the experimental results shown in Table 1, the results according to the embodiments of the present invention are as follows:
It can be seen that it has excellent propagation of hammering energy and vibration response, and shows a good dust removal rate. The main reasons for the above results are: First, because the lower end part other than the lower end fixing part is separated from the lower edge member, there is less external restraining force on the dust collection electrode plate, which improves vibration response. It is presumed that he did.

Second, in this example, it is presumed that the propagation of hammering energy is improved because the convex liner, the concave liner, and the trapezoidal convex portion are in close contact with each other on the side surfaces. That is, the third
In each of the comparative examples shown in the figure, the hammering energy is propagated through the liner etc. by frictional resistance in the same direction as the hammering direction, so when hammering, there is a burr in this part and the hammering energy is lost. will be reduced. On the other hand, in the embodiment shown in FIG. 2, the hammering energy is propagated in a plane substantially perpendicular to the hammering direction, so it is presumed that the amount of reduction is small. In addition, in the configuration of the present invention, the convex portion of the dust collecting electrode plate and the concave piece liner inevitably produce a spring action, which is thought to improve the propagation of the hammering energy. Further, due to the above-mentioned spring action, there is an advantage that the bolts and nuts do not loosen even after long-term operation. In addition, in the experiments shown in Table 1 above, the mounting structure between the upper end of the dust collection electrode plate and the upper edge member was all the same as that of the lower end, but in other experiments, the structure of the upper and lower parts was changed. In this case, for example, a structure in which the lower end part had the structure shown in FIG. 2 and the upper end part had the structure shown in FIG. 3D was tried. However, as long as the structure of the lower end remained the same, no significant difference was observed in the dust removal rate even if the structure of the upper end was changed. From the above, it can be understood that with respect to the dust collection electrode structure that the present invention is based on, the structure at the lower end is dominant in the removability of dust, and the structure at the upper end has little effect. The present invention is not limited to the embodiment shown in FIG. 2, but may be, for example, as shown in FIG. 4.

Fig. 4A shows a case where one fixed part is provided at the lower end of one dust collection electrode plate, and the opening in Fig. 4 shows a case where the parts other than the fixed part are flat. As described above, the dust collecting electrode mounting structure of the dry electrostatic precipitator according to the present invention can effectively peel off dust with a relatively small hammering force without requiring complicated means.

[Brief explanation of drawings]

Figure 1 is an overall configuration diagram of the dust collection electrode mounting structure used in the experiment, Figure 2 is a diagram of the mounting structure of the lower end of the dust collection electrode plate showing an embodiment of the present invention, and Figure 3 is FIG. 4 is a diagram showing the mounting structure of the lower end of the dust collecting electrode plate showing various comparative examples that do not belong to the present invention, and FIG. 4 is a mounting structure diagram showing another embodiment of the present invention. 1... Dust collection electrode plate, 2... Upper edge member, 3... Lower edge member, 4... Bolt nut, 6... Hanging Metal fittings, 7... Hammer rod, 8... Hammer, 10... Convex liner,
11...Concave piece liner.

Claims (1)

[Claims] 1. A rectangular dust-collecting electrode plate whose upper and lower ends are sandwiched between a pair of upper and lower edge members, respectively, and which is suspended in the vertical direction, and a hammer for hammering one end of the lower edge member. In the dust collection electrode mounting structure of a dry electrostatic precipitator, the lower end of the dust collection electrode plate has one or more trapezoidal convex portions along the direction in which the lower edge member extends. It is fixed to the lower edge member through a liner that closely fits the inner and outer surfaces of this convex part, and the part of the dust collecting electrode plate other than the fixed convex part. A dust collection electrode mounting structure for a dry electrostatic precipitator, characterized in that a lower end portion is provided so as to be spaced apart from a lower edge member.