JP3355774B2 - Electric dust collector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic precipitator and, more particularly, to an electric precipitator capable of collecting dust from a processing gas containing dust by particle size.

[0002]

2. Description of the Related Art In an electrostatic precipitator, a high voltage is applied between a discharge electrode and a precipitating member, so that a corona discharge is generated between both parts to form a charged zone, and the charged zone is treated. The dust contained in the processing gas is charged by flowing the gas, and the charged dust is sucked and collected by a dust collecting member having an opposite potential.

FIG. 5 is a cut-away plan view showing an example of a conventional electric precipitator, and has a casing provided with a gas inlet duct 2 and a gas outlet duct 3 for guiding a processing gas 1 containing dust in the direction of the arrow. A discharge electrode 5 having a permeation structure of the processing gas 1 which is disposed in parallel with the flow direction of the processing gas 1 and is formed of a plate or the like having a net, a loose line, or a projection of a barb; Alternatively, a dust collecting member 6 having a structure such as a perforated plate and arranged in parallel with the discharge electrode 5
Are suspended so as to constitute a main part of the electric dust collecting apparatus 7.

[0004] In the electric dust collecting apparatus 7 having the above-described structure, the charged powder in the processing gas 1 can be removed because the discharge electrode 5 and the dust collecting member 6 are arranged in parallel to the flow direction of the processing gas 1. It is easy to flow as it passes without being sucked by the dust collecting member 6,
There is a problem that it is difficult to increase the dust collecting efficiency, and therefore, there is a problem that the size of the electric dust collecting device 7 is increased.

For this reason, recently, as shown in FIG. 6, a discharge electrode 5 and a dust collecting member 6 having a structure for permeable processing gas 1 are provided in a casing 4 in a direction intersecting the flow direction of the processing gas 1. An electric precipitator 8 having a structure in which is disposed is considered.

According to the electric dust collecting device 8, since the discharge electrode 5 and the dust collecting member 6 are disposed in a direction intersecting with the processing gas 1 flowing in the casing 4, dust caused by the discharge electrode 5 is prevented. By increasing the chances of dusting and dust suction to the dust collecting member 6, the effect of the dust passing as in the case of FIG. 5 is reduced, and the dust collecting efficiency can be greatly increased. .

[0007]

However, in general, the dust collection efficiency of an electrostatic precipitator is proportional to the strength of an electric field (electric field density). At the same electric field density, the larger the particle diameter of the dust, the higher the dust collection efficiency. However, in the above-mentioned conventional electrostatic precipitator 8, the discharge electrode 5
Since the distance between the dust collecting member 6 and the dust collecting member 6 is set to be uniform, the electric field density between each discharge electrode 5 and the dust collecting member 6 becomes the same. Most of the dust, which contains a large amount of dust with a large particle size, is collected unevenly.On the other hand, a small amount of dust with a small particle size cannot be collected completely and remains on the downstream side. There was a problem that the discharge electrode 5 and the dust collecting member 6 had to be increased on the downstream side due to a small amount of dust having a small particle diameter that could not be removed.

In order to increase the electric field density in order to quickly collect dust having a small particle diameter, it is conceivable to increase the applied voltage to increase the electric field density of the discharge. There is naturally a limit to increase it,
There is a problem that a new power supply device having a large capacity needs to be newly installed and the power supply device needs to be switched, or that power consumption increases significantly.

Further, it is conceivable to increase the electric field density by uniformly narrowing and setting the mutual interval between the discharge electrode 5 and the dust collecting member 6, but the upstream side has a large particle diameter which is originally liable to collect dust. Unnecessarily unnecessary charging is performed on the dust, so that there is a problem that electric energy loss increases.

The present invention has been made in view of such circumstances, and an electric precipitator capable of efficiently collecting dust by applying different electric fields to the dust in the processing gas without changing the voltage. It is intended to provide.

[0011]

According to the present invention, there is provided a casing for guiding a processing gas containing dust, a discharge electrode disposed in the casing in a direction intersecting a flow direction of the processing gas, and a processing gas. An electrostatic precipitator comprising a dust collecting member having a transmission structure and being disposed in parallel with the discharge electrode,
An electrostatic precipitator according to claim 1, wherein the discharge electrode and the dust collecting member are arranged such that a mutual interval between the discharge electrode and the dust collecting member is gradually reduced in a flow direction of the processing gas.

[0012] Further, a plurality of hoppers may be formed below the casing so as to be divided in the flow direction of the processing gas.

[0013]

Therefore, according to the present invention, when the electric dust collector is operated with, for example, the same voltage applied between each discharge electrode and the dust collecting member, the discharge electrode on the upstream side in the flow direction of the processing gas is collected. Since a relatively large mutual interval is set between the dust member and the dust member, the electric field density is lowered and a relatively weak electric field is formed. In this case, dust having a large particle diameter that is easily collected is collected from the processing gas.

Further, as the distance between the discharge electrode and the dust collecting member gradually decreases in the flow direction of the processing gas, the electric field density is increased, and an electric field stronger than the electric field on the upstream side is formed on the downstream side. Then, dust having a small particle diameter is gradually collected from the processing gas toward the downstream side. However, the voltage can be adjusted by increasing or decreasing as needed on the upstream side or the downstream side.

Further, a plurality of hoppers divided in the flow direction of the processing gas are formed at a lower portion of the casing, and the collected dust is wiped off and collected in each hopper. It becomes possible.

[0016]

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

FIGS. 1 to 3 show an embodiment of the present invention, in which a gas inflow duct 2 for guiding a processing gas 1 containing dust is provided on one side and the processing gas 1 after dust collection is discharged. The lower part of a casing 4 provided with a gas discharge duct 3 on the other side,
A plurality (three in the illustrated example) of hoppers 9, 10, 11 divided in the flow direction of the processing gas 1 are formed.

At a position directly above the entrance hopper 9 inside the casing 4, a discharge electrode 5 and a dust collecting member 6, which are oriented so as to intersect with the flow direction of the processing gas 1, are spaced apart from each other by a relatively large interval x. The discharge electrode 5 and the dust collecting member 6 form a coarse powder collection block 12 which are suspended and supported alternately.

At a position just above the intermediate hopper 10 inside the casing 4, a discharge electrode 5 and a dust collecting member 6 oriented to intersect with the flow direction of the processing gas 1 in the same manner as described above are provided with the mutual distance x. They are suspended and supported alternately with a smaller mutual interval y, and the discharge electrode 5 and the dust collecting member 6 form a medium powder collection block 13.

Further, at a position just above the outlet hopper 11 inside the casing 4, a discharge electrode 5 and a dust collecting member 6 which are directed to intersect with the flow direction of the processing gas 1 in the same manner as described above, are disposed at the above-mentioned interval. The discharge electrode 5 and the dust collecting member 6 form a fine powder collection block 14 which is suspended and supported with a mutual interval z smaller than y.

Any of the discharge electrodes 5 of the above-described coarse powder collecting block 12, medium powder collecting block 13, and fine powder collecting block 14.
As shown in FIG. 2, the suspension member 17 is also supported by a discharge electrode support beam 15, which extends in the width direction (the left-right direction in FIG. 2) in the upper part of the casing 4 via an insulating material 16. The discharge electrodes 5 are suspended and supported by the suspending members 17, and each discharge electrode 5 has a configuration in which loose-shaped electrode wires 5b are provided in a frame 5a.

Each of the dust collecting members 6 is suspended and supported as shown in FIG. 3, and a dust collecting member supporting beam erected in the upper part of the casing 4 in the width direction (left-right direction in FIG. 3). A mesh-shaped dust collecting member 6 is suspended from and supported by a suspending member 19 in parallel with the discharge electrode 5, and each dust collection member 6 is disposed so as to sandwich the discharge electrode 5. Has become.

In the figure, reference numeral 20 denotes a motor provided outside the casing 4 which vibrates the discharge electrode 5 and the dust collecting member 6 via a hammering rod 21 by a crank mechanism or a hammer, and the like. And a hammer 22 for removing dust adhering to the dust collecting member 6. The hammer 22 is provided to insulate the hammer bar 21 of the hammer 20 provided for the discharge electrode 5 from the penetrating portion of the casing 4. It is an insulating material provided in.

FIG. 4 is a front view showing an example of the above-mentioned hammering device 20. A hammering rod 21 fixed to the discharge electrode 5 and the dust collecting member 6 makes the casing 4 densely and slidably. It penetrates as much as possible and projects out of the casing 4. A collar portion 23 is integrally formed at the tip of the hammering bar 21, and between the collar portion 23 and the outer surface of the casing 4,
A spring 24 is provided. Hammering stick 2 for this
1 is urged by a spring 24 in a direction protruding from the casing 4 so that the collar portion 23 is pressed against the hammering cam 25.

The hammering cam 25 is fixed to the rotating shaft 26. When the hammering cam 25 rotates clockwise together with the rotating shaft 26, the collar 23 of the hammering cam 25 is rotated.
The contact portion of the casing gradually becomes larger in diameter, and the collar portion 23, the hammering rod 21, the discharge electrode 5 or the dust collecting member 6 is integrally moved inward of the casing 4 against the force of the spring 24. I will let you.

As the hammering cam 25 continues to rotate further clockwise, the portion of the hammering cam 25 that contacts the collar 23 suddenly becomes smaller in diameter, and the collar 23, the hammering rod 21,
The discharge electrode 5 or the dust collecting member 6 rapidly moves in a direction to protrude from the casing 4 by the force of the spring 24.
As the hammering cam 25 continues to rotate, the discharge electrode 5
Alternatively, the dust collecting member 6 is vibrated right and left. 27
Is the cover.

When the same voltage is applied between the discharge electrode 5 and the dust collecting member 6 in each of the blocks 12, 13, and 14 to operate the electric dust collecting apparatus, the coarse dust collecting block 12 Since the relatively large mutual distance x is provided between the discharge electrode 5 and the dust collecting member 6, the electric field density is reduced and a relatively weak electric field is formed. In, only coarse powder having a large particle diameter that is easily collected is collected from the processing gas 1.

Further, the electric field density is increased between the discharge electrode 5 and the dust collecting member 6 in the intermediate powder collecting block 13 by setting the mutual interval y smaller than the mutual interval x, so that the coarse powder collecting block 12 An electric field stronger than the electric field is generated, and only the medium powder that is easily collected from the processing gas 1 after the coarse powder is collected in the coarse powder collection block 12 is collected.

Further, the electric field density is increased between the discharge electrode 5 and the dust collecting member 6 in the fine powder collecting block 14 by setting the mutual interval z smaller than the mutual interval y. An electric field which is stronger than the electric field is generated, and fine powder having a small particle diameter remaining in the processing gas 1 after the medium powder is collected by the medium powder recovery block 13 is collected. .

The dust collected in each of the blocks 12, 13 and 14 falls by its own weight, or is blown off by a hammering rod 21 of a hammering device 20, and is removed by the hoppers 9, 10, and 1.
Collected in 1 each.

Therefore, according to the above embodiment, the coarse powder collecting block 12, the medium powder collecting block 13, and the fine powder collecting block 1
By setting the intervals x, y, and z to be narrower in the order of No. 4, dusts in the processing gas 1 can be applied to the dust in the processing gas 1 without changing the voltage, so that dust can be collected according to the particle size. However, it is possible to eliminate the disadvantage that the discharge electrode 5 and the dust collecting member 6 must be additionally provided on the downstream side due to a small amount of dust having a small particle diameter which is difficult to collect as in the related art. Dust can be collected efficiently by the discharge electrode 5 and the dust collecting member 6, and electric energy loss is minimized because unnecessary dust is not charged unnecessarily to dust having a large particle diameter which is easily collected. Can be suppressed.

The dust in the processing gas 1 is divided into coarse powder, medium powder,
Each hopper 9, 10, 11 is collected as fine powder by particle size.
Therefore, it can be used for the purpose of classifying dust in the processing gas 1.

It should be noted that the electric dust collecting apparatus of the present invention is not limited to the above embodiment, but the discharge electrode and the dust collecting member arranged in the casing are not necessarily mutually separated for each block as in the illustrated embodiment. It is not necessary to set the intervals to be narrow, and it may be set so that the intervals between the individual discharge electrodes and the dust collecting members are continuously reduced. Furthermore, the discharge electrodes and the dust collecting members need to be arranged alternately. However, for example, a plurality of sets may be formed in such a manner that one discharge electrode is sandwiched between two dust collection members before and after, and a plurality of sets may be connected. The voltage to be applied can be increased or decreased as needed at any position in the flow direction of the processing gas. If only the dust is collected, only one hopper at the bottom of the casing is required. It is good to put together That the discharge electrode may have a shape other than the loose electrode wire, that the dust collecting member may have a shape other than the mesh shape, and that various changes can be made without departing from the gist of the present invention. Of course.

[0034]

According to the above-described electric dust collecting apparatus of the present invention, various excellent effects as described below can be obtained.

(I) By arranging the discharge electrode and the dust collecting member so that the mutual distance between the discharge electrode and the dust collecting member is gradually reduced in the flow direction of the processing gas, the dust in the processing gas can be changed without changing the voltage. The dust can be collected according to the particle size by applying electric fields of different intensities to each other, so that dust can be collected efficiently with the minimum necessary discharge electrodes and dust collection members, and the particle size is easily collected. Electric power loss can be suppressed to a minimum since unnecessary useless charge is not performed on large dust particles.

(II) By adopting a structure in which a plurality of hoppers divided in the flow direction of the processing gas are formed at the lower part of the casing, dust in the processing gas can be collected by particle diameter and collected in each hopper. Therefore, an electric dust collector can be used for the purpose of classifying dust in the processing gas.

[Brief description of the drawings]

FIG. 1 is a cutaway side view showing one embodiment of the present invention.

FIG. 2 is a view taken in the direction of arrows II-II in FIG.

FIG. 3 is a view taken in the direction of arrows III-III in FIG. 1;

FIG. 4 is a front view showing an example of the hammering apparatus shown in FIGS. 2 and 3;

FIG. 5 is a cut-away plan view showing an example of a conventional electric precipitator.

FIG. 6 is a cut-away plan view showing another example of the conventional electric precipitator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing gas 4 Casing 5 Discharge electrode 6 Dust collection member 9 Inlet hopper 10 Intermediate hopper 11 Outlet hopper x Mutual interval y Mutual interval z Mutual interval

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Nobuyuki Abe 3-2-16-1 Toyosu, Koto-ku, Tokyo Ishikawa-jima-Harima Heavy Industries, Ltd. Toyosu General Office (56) References JP-A-63-171655 (JP, A) JP-A-7-232099 (JP, A) JP-A-3-232552 (JP, A) JP-A 7-155641 (JP, A) JP-A-53-30082 (JP, A) JP-A-62 −4451 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B03C 3/00-3/88

Claims (2)

(57) [Claims] 1. A casing for guiding a processing gas containing dust, a discharge electrode disposed in the casing in a direction intersecting with a flow direction of the processing gas, and a processing gas permeable structure. An electrostatic precipitator comprising: a discharge electrode and a dust collection member disposed in parallel with each other, wherein the discharge electrode and the dust collection member are arranged such that an interval between the discharge electrode and the dust collection member is gradually reduced in a flow direction of a processing gas. An electrostatic precipitator characterized by arranging. 2. The electrostatic precipitator according to claim 1, wherein a plurality of hoppers are formed at a lower portion of the casing and are divided in a flow direction of the processing gas.