JPS6347508B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an electrostatic precipitator, particularly a double cylindrical wet type electrostatic precipitator.

In general, electrostatic precipitators generate corona discharge using high-voltage direct current, charge particles in the exhaust gas (discharge electrode), and separate the charged particles from the exhaust gas by electric force in an electric field (collecting electrode). Part) Refers to a particle electrostatic collection device with a mechanism. As the above-mentioned DC voltage, a high voltage of tens of thousands to hundreds of thousands of volts is used.

A typical dust collector that has been used in the past includes a dust collection chamber and a high voltage generator, and there are usually two types of dust collection chambers: a single cylindrical type and a double cylindrical type.

A single cylindrical dust collector uses the inner surface of the cylinder as a dust collecting electrode, and discharge electrodes are arranged in an annular manner within the inner space of the cylinder at approximately equal distances from the inner wall surface of the cylinder, in close proximity to the inner wall surface of the cylinder. The electrodes are connected to a high voltage generator and a high voltage current is applied to create a discharge between the two electrodes. On the other hand, the exhaust gas enters from the lower part of the dust collection chamber and rises upward, and during the rise, the particles in the exhaust gas are separated by the above-mentioned discharge, and the structure is relatively simple.

However, in this type, the discharge occurs only near the inner wall surface of the cylinder, and the exhaust gas passing through the center of the cylinder rises with almost no charge, causing a so-called short pass, resulting in low flow path efficiency. In this case, since the pole spacing is constant, it is necessary to reduce the diameter of the annular discharge electrode in order to reduce the number of shot passes, which inevitably reduces the processing capacity of the dust collector. Therefore, when a large amount of exhaust gas is treated using a single cylindrical dust collector, a large number of devices are required, which increases costs and increases the installation area.

A double cylindrical dust collector, such as a wet electrostatic dust collector disclosed in Japanese Patent Publication No. 54-29753, can be used to compensate for the above drawbacks. In this device, a dust collection chamber is formed by an outer cylinder and an inner cylinder, a high voltage generator is arranged at the bottom of the inner space of the inner cylinder, the inner surface of the outer cylinder and the outer surface of the inner cylinder are used as dust collection electrodes, and both the inner and outer cylinders are connected. A ring-shaped discharge electrode is suspended in the space between the discharge electrodes, and a cable is connected to the discharge electrode from the high-voltage generating device.In this device, the inner tube also serves as a pillar for supporting the discharge electrode. This type of dust collector has a higher flow path efficiency and a larger exhaust gas throughput than a single cylindrical dust collector.

However, in the double cylindrical dust collector disclosed in Japanese Patent Publication No. 54-29753, the exhaust gas flow path and the internal space of the inner cylinder in which the high voltage generator is placed communicate, so for example, when the dust collector is used as a wet type, Washing water and exhaust gas easily enter, and if the high voltage generator is completely sealed to prevent this, maintenance and inspection will be extremely difficult due to the fact that the high voltage generator is located at the bottom of the inner cylinder and is difficult to access. It becomes difficult. Furthermore, if the insulation interval is made large to ensure complete hermetic protection, the internal space of the inner cylinder will have a large volume, which tends to increase the size of the entire device. Furthermore, since the discharge electrode is supported by the inner cylinder, the inner cylinder requires considerable structural strength.

In addition, there is a device in which a dust collection chamber is stacked on top of a high voltage generator, but like the device of Japanese Patent Publication No. 54-29753, it is difficult to insulate the high voltage device from exhaust gas and cleaning water. For this reason, the dust collection chamber and the high-voltage generator are sometimes isolated and connected by a cable, but dew condensation occurs within the cable coating and the conductivity deteriorates.

The present invention has been devised in view of the above-mentioned drawbacks of conventional devices and provides an essentially advanced double cylindrical dust collector.

The invention will now be described with reference to embodiments shown in the accompanying drawings.

As shown in FIG. 1, the wet electrostatic precipitator of the present invention includes a dust collection chamber 1, an insulator chamber 2 provided directly below the dust collection chamber 1, and a high voltage generator 3 placed outside the insulator chamber 2.
Equipped with.

The dust collection chamber 1 has an upright coaxial outer cylinder 4 and an inner cylinder 5, and the bottom of the inner cylinder 5 is closed. Outer cylinder 4
The inner surface 4A of the inner cylinder 5 and the outer surface 5A of the inner cylinder 5 are used as dust collecting electrodes, respectively, and the discharge electrode 7 is disposed in the annular gas flow path 6 between the two dust collecting electrodes, which is a so-called double cylindrical type. An exhaust gas inlet 8 is provided tangentially in the lower part of the dust collection chamber 1, and the exhaust gas entering from the inlet rises while swirling in an annular gas flow path 6 in a cyclone shape. on the other hand,
The high-voltage direct current sent from the high-voltage generator 3 generates a corona discharge in the pole spacings P and Q between the discharge electrode 7 and each dust collection electrode, charges particles in the exhaust gas, and charges the particles in the exhaust gas. The particles are further separated and attached to both dust collection electrodes 4A and 5A. Annular cleaning devices 9, 9' are provided near the top of the dust collection chamber 1.
Water is sprayed from nozzles drilled at important points in the cleaning device to wash away particles adhering to the dust collection electrodes 4A and 5A.

FIG. 2 shows that the cleaning water that has flowed along the outer surface 5A of the inner cylinder 5 enters the annular gutter 11 surrounding the base of the inner cylinder.
1 further flows through the radially inclined gutter 12 toward the inner surface 4A of the outer cylinder 4, and all of the cleaning water is transmitted to the inner surface 4A of the outer cylinder 4 and flows down. In this way, cleaning water is prevented from entering the insulator chamber.

Returning to FIG. 1, in the insulator chamber 2 there are a plurality of insulators 13 insulated from the grounded insulator chamber side.
is erected and a support shaft seat 14 is provided thereon, and the discharge electrode 7 is mounted on the support shaft seat 14 via a support shaft 15.
To be published. Further, the high voltage generator 3 is connected to the support shaft seat 14 via a high voltage path 16 made of a steel pipe or the like. The high voltage path 16 is led in a duct 17,
Air introduced by a fan 18 is heated by a heater 19 and then introduced into the duct 17. Since dry air is thus introduced into the duct 17 and a steel pipe is used for the high voltage path 16, no condensation occurs as with conventional cables.
Note that 20 is a bushing for connecting the high voltage path 16. An outside air intake port 21 is provided in the side wall of the insulator chamber 2. The intake port 21 introduces outside air, and the insulator 13
This prevents the exhaust gas wetted by the cleaning water from adhering to the insulator chamber 2, causing dew condensation due to the temperature difference between the inside and outside of the insulator chamber 2, and thereby preventing the insulation from deteriorating. When the internal pressure of the insulator chamber 2 becomes lower than the internal pressure of the dust collection chamber 1, exhaust gas easily enters the insulator chamber 2, so a bypass is made from the duct 17 (not shown).
or use a separate fan (not shown)
is installed to pressurize the insulator chamber.

A partition wall 22 through which the support shaft passes is provided at the boundary between the dust collection chamber 1 and the insulator chamber 2, and a labyrinth-like curved path 23 is formed around the through hole of the partition wall 22. . By providing this curved path, wet exhaust gas is prevented from entering into the insulator chamber 2, so that the insulation properties of the insulator 13 are not reduced.
In addition to the above, the partition wall 22 also serves as a receiving tray for the washing water that has flowed down along the wall of the dust collection chamber 1.

Next, the interelectrode adjustment mechanism will be described. In conventional dust collectors, the pole spacing between the discharge electrode and the dust collection electrode is constant. However, if the pole spacing does not change in response to changes in the amount of gas to be treated or the concentration of exhaust gas relative to the initially planned value, sufficient collection of particles will not be obtained in the former case, and sufficient charging will not be obtained in the latter case. In the present invention, as shown in FIG. 3, the discharge electrode 7 is provided with saw-toothed discharge electrode pieces 26, 26 pivoted at both ends of levers 25, 25 attached to an annular support 24, respectively. are opposed to both the dust collecting electrodes 4A, 5A, respectively, and the pole spacing P on the outer cylinder side and the pole spacing Q on the inner cylinder side can be adjusted and set by changing the mounting angle of the lever 25. The above-mentioned pole spacings P and Q are usually 150 to 450 mm, with a preferred range of use being 200 to 350 mm. In this embodiment, the individual discharge electrodes 7 are adjusted one by one.
If you connect them vertically as shown in the diagram, you can adjust them all at once with one hand.

The present invention is configured as described above, and an insulator chamber is provided at the lower part of the dust collection chamber, and the curved path and partition wall prevent wet exhaust gas from entering from the dust collection chamber toward the insulator chamber. The insulation of the device does not deteriorate, and since the high voltage generator is placed externally, it is easily accessible and maintenance and inspection is easy. Furthermore, since the inner cylinder of the dust collection chamber does not require any strength and can be made small in diameter, it has many advantages such as a compact device.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the entirety of the present invention, FIG. 2 is an enlarged cross-sectional view showing a cleaning water gutter, and FIG. 3 is a side view showing a discharge electrode. DESCRIPTION OF SYMBOLS 1...Dust collection chamber, 2...Insulator chamber, 3...High voltage generator, 4...Outer cylinder, 4A...Dust collection electrode of outer cylinder, 5...Inner cylinder, 5A...Dust collection electrode of inner cylinder, 6...Annular gas flow path,
7...Discharge electrode, 9...Annular cleaning device, 13...Insulator, 14...Support shaft seat, 15...Support shaft, 22...Partition wall, 23...Curved path, 25...Lever, 26...Discharge electrode piece, P, Q ...polar spacing.

Claims (1)

[Claims] 1. A collector that has a discharge electrode in an annular gas flow path between an upright coaxial inner and outer cylinder, uses the inner surface of the outer cylinder and the outer surface of the inner cylinder as dust collection electrodes, and has a cleaning device for cleaning the dust collection electrode. In a wet type electrostatic precipitator for exhaust gas that is equipped with a dust chamber and a high voltage generator connected to the discharge electrode, an insulator chamber 2 is provided at the lower part of the dust collection chamber 1, and the insulator is connected to the insulator through an insulator 13. The support shaft 15 of the discharge electrode 7 in the dust collection chamber is mounted on a support shaft seat 14 insulated from the bottom of the chamber, and a high voltage generator 3 is installed outside the insulator chamber to connect the generator and the above insulation. A support shaft seat of the insulator chamber is connected to the support shaft seat of the insulator chamber by a high voltage path, and a partition wall 22 through which the support shaft passes is provided at the boundary between the dust collection chamber and the insulator chamber, and a partition wall 22 is provided around the through hole of the partition wall. A curved path 23 is formed in the annular gas flow path 6 to prevent exhaust gas and cleaning water from entering the insulator chamber, and a discharge electrode provided in the annular gas flow path 6 is provided in a sawtooth shape pivoted at both ends of the levers 25, 25. Wet type electricity is characterized in that it has discharge electrode pieces 26, 26 and is formed so that the respective pole spacings P and Q between the two dust collecting electrodes 4A, 5A and the discharge electrode piece can be adjusted by operating the lever. Dust collector.