JPS6338919Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to improvement of an electrostatic precipitator.

The basic structure of an electrostatic precipitator is that a dust collection unit consisting of a discharge electrode and a collection electrode is placed inside a dust collector body of various shapes, such as a box or cylinder shape, and a gas collector is installed at one end of the body. Introduce gas into the main body from the inlet,
On the way to the gas outlet provided at the other end of the main body, a dust collection unit causes dust in the gas to adhere to the dust collection electrode.

FIG. 1 shows an example of a conventional electrostatic precipitator. In this figure, reference numeral 1 denotes a dust collector body which is box-shaped and has a gas inlet 2 at one end and a gas outlet 3 at the other end. Inside the main body 1, two dust collecting units 4, 4' are arranged in series in the direction from the gas inlet 2 to the gas outlet 3.

The dust collection unit 4, 4' has a structure in which plate-shaped dust collection electrodes 5, 5' and a linear discharge electrode are arranged along the air flow direction, and a voltage is applied between the discharge electrode and the dust collection electrode. The high voltage used in this process applies an electric charge to the dust in the gas to be treated, causing it to adhere to the dust collecting electrode. Further, between the dust collection unit 4 and the gas inlet 2 inside the main body 1, a perforated plate or a grid-shaped rectifying plate 6 is usually provided.

In the conventional electrostatic precipitator having such a configuration, the gas to be treated is introduced into the main body 1 from the gas inlet 2, and the dust collecting action is performed by the dust collecting units 4, 4' during the process of exhausting it from the gas outlet. However,
This is done when the gas to be treated passes through the dust collection units 4 and 4' as shown by a in the figure, and when the gas to be treated passes through the dust collection units 4 and 4' as shown by b in the figure.
Those passing through the side of 4' will not be processed.

The rectifying plate 6 is provided to prevent this, and has a certain function, but in reality, due to the principle of fluid diffusion, the introduced gas passes through the non-ionized part (side part). Not getting enough effect,
This caused the problems mentioned above. Therefore, in order to make the rectification effect of the rectifier plate 6 more complete, a large number of rectifier plates 6 are used, but this naturally increases the pressure loss, so a large induced fan or the like is required. becomes. Furthermore, if the number of rectifying plates is increased, problems such as dust clogging and blockage may occur, making it impossible to operate, or increasing resistance and decreasing the flow velocity, making it impossible to obtain complete rectification.

This idea was made in view of this point, and a shielding plate that forms an opening in the center and a plurality of through holes are provided between the dust collection units arranged in series inside the main body. By providing a rectifier plate, the untreated gas that has passed through the side of the dust collection unit at the front stage is mixed with the effective processing gas when passing through the opening, and passes through the dust collection unit at the rear stage. This is to prevent mistakes in dust collection.

An embodiment of this invention will be explained with reference to FIG. 2. In this case, between the dust collection units 4 and 4',
A shielding plate 7 is installed, the outer circumferential portion 7a of which is in contact with the inner wall of the main body 1, and the center portion of which is provided with an opening 7b. By arranging the shielding plate 7 in this way, the opening 7b of the shielding plate 7 (the inner peripheral part of the shielding plate 7) is located inward from the ends of the dust collecting electrodes 5, 5'. This is for the purpose of concentrating the gas flow at the center of the dust collection unit 5'. In addition, this shielding plate 7
A rectifying plate 6 is also provided. The purpose of installing this rectifying plate 8 along with the shielding plate 7 is that if only the shielding plate 7 were used, the gas flow would increase in flow velocity from the narrow opening 7b, pass through the inside of the dust collection unit 4' at high speed, and be collected. This is to prevent dust efficiency from decreasing.

In this electrostatic precipitator configured in this way, as shown by d in the figure, the untreated gas that has passed through the side of the dust collection unit 4 at the front stage is refracted toward the center by the shielding plate 7, and is then transferred to the dust collection unit at the rear stage. It will enter unit 4'. Therefore, the gas to be treated is not only effectively electrostatically collected within the dust collection unit, but also the gas that passes through the narrow center opening of the shielding plate is also subjected to the ventilating effect, so that the separation of dust particles is further improved. This results in the following effects. When operating in this way, the opening 7b (inner peripheral part) of the shielding plate 7 is located inward from the ends of the dust collecting electrodes 5, 5', so that the side part of the dust collecting unit 4' is The amount of gas passing through the non-ionizing part can be reduced, thereby providing an efficient dust collection effect.

In addition, by providing both the shield plate 7 and the straightening plate 8, the gas flow from the shield plate 7 is divided and made uniform by the straightening plate 8. Therefore, while the gas passes through the dust collection unit 5' at high speed when only the shield plate 7 is provided,
This does not occur, and the gas flow is converged and uniformed, the flow rate is optimized, and an excellent dust collection effect can be obtained. In this case, as described above, if only the straightening plate 8 is provided without the shield plate, a large number of straightening grids and straightening plates are arranged in a row, which increases the pressure loss, requires a large induced draft fan, and causes the straightening plate to become clogged. However, with the device of the present invention, which has both the shield plate 7 and the straightening plate 8, such problems do not occur.

Next, a theoretical comparison will be made between the electrostatic precipitator of this invention shown in FIG. 2 and the conventional one shown in FIG. In Fig. 1, the dust concentration of the gas to be treated is 1 g/ ^Nm3 at the gas inlet 2, the amount of the gas to be treated flowing through a is 90% of the total, the amount of gas flowing through b is 10%, Also, assuming that the efficiency (dust removal rate) of dust collection units 4 and 4' is 90% each, the dust concentration on line a is: Point A 1g/Nm ³ ×0.9×0.1 = 0.09g/Nm ³ Point B 0.09g/Nm ³ ×0.1=0.009g/Nm ³
...(1) The dust-containing concentration of the gas on the b line is 1g/Nm ³ ×0.1=0.1g/Nm ³ at point B ...(2) Therefore, the total dust-containing concentration at point B is (1) +(2)=0.109g/ ^Nm3 .

The one in Figure 2 is similar to Figure 1. If the dust concentration at the gas inlet 2 of the gas to be treated is 1 g/Nm ³ , then the dust concentration at point A' is c line 1 g/Nm ³ ×0.9× 0.1=0.09g/Nm ³ ...(3) d line 1g/Nm ³ ×0.1=0.1g/Nm ³ ...(4) (3)+(4)=0.19g/Nm ³ , so B' The dust concentration at the point is c′ line 0.19g/Nm ³ ×0.9×0.1=0.0171g/Nm ³
...(5) d' line 0.19g/Nm ³ ×0.1 = 0.019g/Nm ³ ...(6) (5) + (6) = 0.361g/Nm ³ .

From the above, in the conventional system shown in Figure 1, the dust concentration of the gas at the gas outlet is 0.109g/N.
^m3 , and the one of the present invention shown in Figure 2 is 0.0361g/N.
It can be seen that m ³ . This proves the effect of sufficiently lowering the dust concentration.

As explained in the embodiments above, this invention is applicable to an electrostatic precipitator in which a plurality of dust collecting units each consisting of a discharge electrode and a dust collecting electrode are arranged in series inside the main body of the electrostatic precipitator. Between the units, a shielding plate whose outer periphery is in contact with the inner wall of the main body and which forms an opening in the center, and a rectifying plate with a plurality of openings are installed, so it has the following advantages. have

Untreated gas that passes through the side without passing through the front stage dust collection unit is also guided to the rear stage dust collection unit by the shielding plate, so the amount of gas discharged without being collected becomes extremely small. , stable efficiency can be obtained.

By installing a shielding plate, not only effective electrostatic dust collection but also a ventilly effect can be obtained, which improves dust collection efficiency and allows simple rectifying plates and the like to be used.

Any type of electrostatic precipitator can be used, whether dry or wet, vertical, horizontal, or upright cylindrical.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view schematically showing a conventional electrostatic precipitator. FIG. 2 is a sectional view schematically showing an embodiment of this invention. 1...Main body, 2...Gas inlet, 3...Gas outlet, 4, 4'...Dust collection unit, 5, 5'...Dust collection pole, 6...Brighter plate, 7...Shielding plate, 7a ...outer periphery, 7b...door.

Claims (1)

[Scope of utility model registration request] In an electrostatic precipitator in which a plurality of dust collecting units each consisting of a discharge electrode and a dust collecting electrode are arranged in series inside the main body of the device, an outer peripheral portion is connected to the inner wall of the main body between the dust collecting units. A shielding plate whose inner periphery is located inward from the extreme part of the dust collection and forms a vent in the center of the gas flow path, and a rectifier plate with multiple through holes are installed at right angles to the gas flow path. An electrostatic precipitator characterized by being attached to.