JPS6250188B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method in which a plurality of plate-like electrodes each consisting of a high voltage pole and a dust collecting electrode are arranged vertically at predetermined intervals alternately, and the high voltage poles and the dust collecting electrode are arranged vertically at predetermined intervals. In a two-stage electrostatic precipitator equipped with a charging section and a dust collection section each connected and supported by a plurality of studs, a through hole provided in electrodes facing each other in order to penetrate the studs of the dust collection section. Regarding the shape of the hole.

In general, this type of two-stage electrostatic precipitator is not used when collecting fluid dust containing fine particles of oil or fat, etc., or when collecting dust in high temperature and high humidity environments, and only one-stage electrostatic precipitator is used. A device (Kottrell) is used. The reason for this is that in a two-stage electrostatic precipitator, collected fluid dust or water droplets condensed on the electrode surface because the temperature of the precipitator is lower than the target gas drips from the through hole, causing the static This is because sparks were generated between the two and it was difficult to take measures to prevent such sparks.

In the one-stage type, for example, as shown in Fig. 1, the dust collecting electrode plate 10 is cut out, and the place where attached fluid dust or condensed water droplets drips is the corner part 30 of the rectangular cylindrical electrode. However, since the corner portion 30 of this electrode is located further away from the discharge wire 20 than the flat plate portion, a device has been devised to make sparks less likely to occur. Note that a weight 40 is suspended from the discharge wire 20.

Next, an example of the configuration of an electrode in a dust collection section of a conventional two-stage electrostatic precipitator will be described with reference to FIGS. 2 and 3.

In the figure, three dust collection electrodes 1A, 1B, 1C
and two high-voltage poles 2A, 2B are vertically arranged alternately at a predetermined interval, and each dust-collecting pole 1 passes approximately through the center of a circular through-hole 2H provided in each high-voltage pole 2. They are connected and supported by conductive support rods (studs) 3, and both ends of each stud 3 are fixed with nuts 4. Similarly, each high-voltage pole 2 has two conductive support rods (studs) 5 that pass through approximately the center of the circular through hole 1H provided in each dust collection pole 1.
Both ends of each stud 5 are fixed by a nut 7 via a support 6, and the support 6 is further fixed to the dust collection poles 1A and 1C by an insulator 8. In addition, the above-mentioned circular through hole 1H,
A predetermined insulating distance is set between the inner edge of 2H and the outer periphery of studs 5 and 3, respectively.

When a dust-containing airflow is introduced into the dust collection section with such a structure from the direction of the arrow P, the collected fluid dust flows down the surface of the dust collection electrode 1, and a part of it flows down as shown in Figure 3. Upper edge 1 of through hole 1H
When it reaches HU, gravity and gradient force act on it, causing it to drip onto the surface of the stud 5 for supporting the high-voltage electrode and spark. Furthermore, from the stud 5 to the through hole 1H
Even if it falls on the lower edge 1HL of the dust, sparks will be generated in the same way, resulting in a decrease in dust collection efficiency. In addition, if there is a temperature difference between the electrode and the target gas, dew condensation may occur on the electrode surface, and in that case, the above-mentioned phenomenon may also occur between the high-pressure electrode 2 and the stud 3 for supporting the dust collection electrode. This also reduces dust collection efficiency. In order to prevent such sparks, the through hole 1
Increasing H and 2H reduces the significant area of the electrode, which also leads to a decrease in dust collection efficiency, which is not preferable.

In view of the above-mentioned conventional drawbacks, this invention has developed a two-stage electrostatic precipitator that has stable dust collection efficiency and is suitable for collecting fluid dust by devising the shape of the through holes provided in each electrode. The purpose is to obtain electrodes of

According to the present invention, the above object is to penetrate conductive support rods (studs) that connect and support electrodes of the same potential in the dust collecting section of a two-stage electrostatic precipitator to create an insulating gap. The shape of the through hole provided in the electrode is such that the inner diameter in the vertical direction is larger than the inner diameter in the horizontal direction, and in the insulating gap from the support rod to the electrode, at least the uppermost part of the dust collection part in the vertical direction is This is achieved by making the air gap larger than the horizontal air gap.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a perspective view of the main part of the electrode of the two-stage electrostatic precipitator according to the present invention, which corresponds to FIGS. 2 and 3, and the same symbols are used for the parts corresponding to FIGS. Attached. In the figure, the difference from the conventional example is that the through holes 1H and 2H have an elliptical shape with a long axis in the vertical direction and a short axis with a predetermined insulation distance in the horizontal direction. be. As a result, although the collected fluid dust flows down the surface of the dust collection electrode 1 in the same way as in the conventional example, a part of it flows down the upper edge of the through hole 1H.
When it reaches the HU, it flows down along the periphery due to the drainage action of the upper edge 1HU. Also, in the unlikely event that
Even if fluid dust drips onto the high-voltage electrode support stud 5, or even if it drips from the stud 5 and adheres to the lower edge 1HL, there is no danger of sparks because the distance in the vertical direction is long. This also applies to the case of condensation due to the temperature difference between the electrode and the target gas, thus eliminating the risk of sparks between the high-pressure electrode 1 and the stud 3 for supporting the dust-collecting electrode. be done.

FIG. 5 is a diagram showing the shape of a through hole in another embodiment. In the figure, the differences from the above embodiment are as follows.
Through hole 1 provided in dust collection pole 1 (high voltage pole 2)
The shapes of H and 2H are semicircular with a predetermined insulation distance on the lower side of the horizontal plane including the stud 5 for supporting the high voltage pole (stud 3 for supporting the dust collection electrode), and semielliptical on the upper side. be. In this example, in the insulation gap from the stud to the electrode, the top vertical gap on the upstream side of dust flow and dew condensation water is larger than the horizontal gap, and the bottom vertical gap is horizontal. It is assumed that the gap in the direction is the same. In this case, although it is not as effective in preventing sparks as in the previous embodiment, if it is suitable for the target gas and the condensation conditions, part of the fluid dust and condensed water droplets that flowed on the electrode surface will be removed from the upper edge 1.
Most of the water flows downward along the periphery due to the draining effect of HU and 2HU, and there is little chance of dripping onto the supporting studs 5 and 3. In that case, the size of the through-hole may be smaller than the elliptical shape of the previous example. As the through-hole is smaller than that of the through-hole, the dust collection efficiency is increased and it is effective.
In this way, the shape of the upper half and the shape of the lower half of the through hole may be combined in various ways depending on the target gas and the state of dew condensation, so that there is no protrusion inside the through hole.

Furthermore, FIGS. 6 to 13 show examples of through holes having other shapes, and parts corresponding to those in the previous figures are given the same symbols. In addition, the shape of the through hole according to the above is an ellipse in which the ratio of the long axis (up and down) to the short axis (left and right) is 1.5:1 or more, and the shape is polygonal or some or all of the corners of the polygon are rounded. The shape with the mark is effective when the ratio of the internal diameter in the vertical direction to the horizontal direction is 18:1 or more and the opening angle of the upper and lower edges of the through hole is 90° or less.

As described above, according to the present invention, by devising the shape of the through holes provided in electrodes with different potentials in order to penetrate the studs supporting the electrodes between the same potentials, fluid dust can be removed from a high temperature and high humidity atmosphere. Among other things, it is possible to provide an electrode for an electrostatic precipitator that can stably collect dust.

[Brief explanation of the drawing]

Figure 1 is a perspective view of an electrode with a spark-proof structure in a single-stage electrostatic precipitator, Figure 2 is a perspective view of the electrode section of a conventional two-stage electrostatic precipitator, and Figure 3 is a perspective view of an electrode with a spark-proof structure in a single-stage electrostatic precipitator.
FIG. 4 is a perspective view of the main part of the electrode section of a two-stage electrostatic precipitator showing an embodiment of the present invention, and FIG. 5 is a through hole showing another embodiment of the present invention. A front view of the hole, and FIGS. 6 to 13 are front views of the through hole showing other embodiments. 1, 1A, 1B, 1C; Dust collection electrode, 2, 2A,
2B, 2C; High voltage pole, 3, 5; Stud, 1H,
2H: Stud through hole, 1HU: Upper edge of stud through hole, 1HL: Lower edge of stud through hole.

Claims (1)

[Claims] 1. In the dust collection section of a two-stage electrostatic precipitator,
In order to penetrate the conductive support rod that connects and supports electrodes of the same potential and create an insulating gap, the shape of the through hole provided in the electrode of another potential is made so that the inner diameter in the vertical direction is larger than the inner diameter in the horizontal direction. An electrode for fluid dust of an electrostatic precipitator, characterized in that, in the insulating gap from the support rod to the electrode, at least the gap at the top in the vertical direction of the dust collecting section is larger than the gap in the horizontal direction. 2. In the electrode according to claim 1,
A fluid dust electrode for an electrostatic precipitator, characterized in that the through hole has an oval shape. 3. In the electrode according to claim 2,
A fluid dust electrode for an electrostatic precipitator, characterized in that the ratio of the long axis to the short axis of the oval shape is 1.5:1 or more. 4. In the electrode according to claim 1,
A fluid dust electrode for an electrostatic precipitator, characterized in that the through hole has a polygonal shape or a polygon with some or all of its corners rounded. 5. In the electrode according to claim 4,
The ratio of the vertical inner diameter to the horizontal inner diameter of the through hole is
An electrode for fluid dust of an electrostatic precipitator, characterized in that the ratio is 1.8:1 or more, or the opening angle at the upper and lower edges of the through hole is 90° or less. 6. In the electrode according to any one of claims 2 to 5, the shape of the through hole is semicircle, semiellipse, or polygon below the horizontal plane including the support rod. Alternatively, the polygon may have a shape in which some or all of the corners are rounded, and the upper side of the horizontal plane may be a semi-ellipse, a polygon, or a part or all of the polygon may be rounded; 1. A fluid dust electrode for an electrostatic precipitator, characterized by having no protrusion inside a through hole.