JP2987310B2 - Electrode for electrostatic precipitator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge electrode for an electrostatic precipitator.

[0002]

2. Description of the Related Art Conventionally, in an electric precipitator, a gas containing dust (hereinafter referred to as "gas to be treated") is introduced into an electric field formed between a discharge electrode and a precipitating electrode. In an electric field, dust is attracted to the collection electrode. FIG. 2 is a conceptual diagram of a conventional cylindrical electric precipitator, and FIG. 3 is a conceptual diagram of a conventional parallel plate electric precipitator.

In FIG. 2, reference numeral 11 denotes a cylindrical collection electrode,
Reference numeral 2 denotes a discharge electrode located at the center of the dust collection electrode 11. In this case, a DC high voltage of negative polarity is applied to the discharge electrode 12 by the power supply device 13 to form an electric field between the dust collection electrode 11 and the discharge electrode 12. Then, a corona discharge occurs between the dust collecting electrode 11 and the discharge electrode 12, and the dust is charged by the corona discharge, and the dust is collected on the dust collecting electrode 11 by the Coulomb force.

[0004] In FIG. 3, reference numeral 11 denotes a pair of plate-shaped dust collecting electrodes arranged in parallel with each other, and 12 denotes the dust collecting electrode 11.
It is a plurality of discharge electrodes arranged at a predetermined interval therebetween.
This type of electrostatic precipitator is widely used because of its simple structure and easy scale-up and maintenance. The electrostatic precipitators are classified into a dry electric precipitator and a wet electric precipitator, depending on whether a cleaning liquid is used to collect dust collected on the dust collecting electrode 11. Normally, a dry electric precipitator is used, and a wet electric precipitator is used when the gas to be treated contains a combustible component or when mist dust is collected.

By the way, the discharge electrode 12 has a shape capable of lowering the corona discharge starting voltage and generating a strong corona discharge, and peeling off the adhered dust. It has good mechanical properties, has sufficient mechanical strength against vibration due to corona discharge, and has a structure that is less likely to cause electrolytic corrosion when spark discharge occurs. The discharge electrode 12 has a component of the gas to be treated, and an apparent electric resistance and specific gravity of dust contained in the gas to be treated.
The selection is made in consideration of density, fluidity, adhesion, particle size distribution, cohesiveness, and the like.

Next, the types of the discharge electrodes 12 used in the dry type electrostatic precipitator will be described. FIG. 4 is a diagram showing an example of a conventional discharge electrode. In the figure, (a) shows a round discharge electrode, (b) shows a sawtooth discharge electrode, (c) shows a barbed discharge electrode, and (d) shows a punctured discharge electrode. A round rod-shaped discharge electrode with
(E) shows a spring linear discharge electrode, and (f) shows a mast discharge electrode.

First, a circular discharge electrode 12a shown in FIG.
Is the basic form and has been used more often than before.
It is not used in coal-fired electric precipitators for the reasons described below. Next, the sawtooth discharge electrode 1 shown in FIG.
2b, a plurality of pricks 21 are provided at set intervals.
Are formed to protrude. In this case, since the discharge electrode 12b can be fixed by the frame, the size of the electric dust collector can be easily increased, and stable corona discharge can be generated.

Subsequently, a barbed discharge electrode 1 shown in FIG.
2c is effective when treating a gas to be treated having a large particle size of dust and a large amount of dust (dust). And
In the pierced rod-shaped discharge electrode 12d shown in (d),
Since the plurality of piercing portions 22 are formed so as to protrude at set intervals, it is effective when processing a gas to be processed at a high flow rate.

Further, the spring-shaped discharge electrode 12e shown in (e) is supported by a frame, and has high durability against thermal distortion (distortion). Further, in the mast-shaped discharge electrode 12f shown in (f), the tubular portion 23 and the tubular portion 2
3 and a plurality of notches 25 at each set interval.
Is formed.

In this case, since the same voltage is applied to portions other than the portion where corona discharge is generated, the voltage can be set high and a large corona current can flow.

[0011]

However, in the conventional discharge electrode for an electrostatic precipitator, in the case of the round discharge electrode 12a, a corona discharge is generated to secure a necessary corona current. It is necessary to make the discharge electrode 12a thicker, but it is generally about φ2 to φ3, and cannot be made thicker than that. Therefore, vibration, spark discharge,
In addition, the discharge electrode 12a is disconnected due to electrolytic corrosion based on these.

When the discharge electrode 12a is lengthened in order to increase the size of the electrostatic precipitator, it is necessary to increase the weight of the discharge electrode 12a in order to keep the discharge electrode 12a vertical. Therefore, the discharge electrode 12a is easily broken by the weight. Next, in the case of the sawtooth discharge electrode 12b,
When the discharge electrode 12b is enlarged, the piercing portion 21 is covered with dust, and it becomes difficult to generate corona discharge. That is, normally, a voltage having a negative polarity is applied from the discharge electrode 12b to a dust collecting electrode (not shown), and the dust charged to the negative polarity is caused to adhere to the dust collecting electrode. However, a voltage of a positive polarity is applied to a part of the dust by an electrostatic force according to Coulomb's law (reverse charging phenomenon), and the dust charged to a positive polarity adheres to the discharge electrode 12b. In this case, the discharge electrode 12b is covered with dust, the discharge electrode 12b enlarges in a short time, and the corona current stops flowing. As a result, the dust collection efficiency decreases.

Subsequently, in the case of the barbed discharge electrode 12c,
The wire breaks due to vibration, spark discharge, and electrolytic corrosion based on these. Further, the cost for assembling the discharge electrode 12c is high. In the case of the pierced rod-shaped discharge electrode 12d, it is effective when processing a gas to be processed at a high flow rate, but the cost for enlarging the electric dust collector is high.

In the case of the spring-shaped discharge electrode 12e, the wire is easily broken by spark discharge. Further, in the case of the mast-shaped discharge electrode 12f, since the discharge electrode 12f is heavy, a supporting insulator (insulator) for supporting the discharge electrode 12f becomes large,
The cost of the entire apparatus is increased.

The present invention solves the above-mentioned problems of the conventional discharge electrode for an electrostatic precipitator, so that the electric precipitator can be improved in dust collection characteristics without disconnection, and can be reduced in cost. An object of the present invention is to provide a discharge electrode for a device.

[0016]

For this purpose, the discharge electrode for an electric precipitator according to the present invention has a support pipe and a reticulated barb supported by the support pipe. The reticulated portion includes a band group including a plurality of bands, and a discharge portion including a branch protrusion is formed on an outer band.

[0017] In another discharge electrode for an electric precipitator according to the present invention, the branch projection is formed toward the precipitating electrode. In still another discharge electrode for an electrostatic precipitator of the present invention, the mesh-like piercing portion is made of expanded metal.

[0018]

According to the present invention, as described above, the discharge electrode for an electrostatic precipitator has a support pipe and a reticulated barb supported by the support pipe. The reticulated portion includes a band group including a plurality of bands, and a discharge portion including a branch protrusion is formed on an outer band.

In this case, when a power supply device is connected between the discharge electrode and the dust collection electrode, and a negative polarity voltage is applied to the discharge electrode,
Corona discharge is generated between the branch protrusion and the dust collection electrode,
The dust is charged to a negative polarity and adheres to the dust collection electrode. In another discharge electrode for an electrostatic precipitator of the present invention,
Further, the branch protrusion is formed toward the dust collecting electrode. In this case, corona discharge can be easily generated.

In still another discharge electrode for an electrostatic precipitator according to the present invention, the mesh-like piercing portion is made of expanded metal. In this case, the expanded metal is cut into a set shape and welded to the support pipe.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an enlarged view of a main part of a discharge electrode according to a first embodiment of the present invention, FIG. 5 is a sectional view of a main part of a discharge electrode according to the first embodiment of the present invention, and FIG. 6 is a plan view of an expanded metal. FIG. 7 is a cross-sectional view of a main part of the electric precipitator according to the first embodiment of the present invention, and FIG. 8 is a diagram showing the arrangement of discharge electrodes in the first embodiment of the present invention.

In FIG. 7, reference numeral 11 denotes a distance L parallel to each other.
A pair of flat plate-shaped dust collecting electrodes 30 arranged with 1 are a plurality of discharge electrodes arranged at a predetermined interval between the dust collecting electrodes 11 and fixed by a support frame (not shown). The gas to be treated flows through the passage formed by the dust collecting electrode 11 in the direction of the arrow. In FIG. 8, reference numeral 30 denotes a discharge electrode, 31 denotes a cylindrical support pipe,
Reference numeral 2 denotes a net-like piercing portion fixed to the support pipe 31 by welding. The reticulated piercing portion 32 is formed by cutting an expanded metal (JIS G 3351 (Japanese Standards Association, steel)) shown in FIG. 6 into a set shape, and is disposed symmetrically about the support pipe 31. Is done.

The expanded metal is formed by processing a steel sheet by a cold rolling method. The steel sheet is made of JIS G 3101 (rolled steel material for general structure),
ISG 3131 (Hot rolled mild steel and rope) and JI
It has the chemical components specified in SG 3141 (cold rolled steel plate and steel strip) and has the mechanical properties specified therein.

The type of expanded metal used for the discharge electrode 30 is a standard type, and the symbol XS is used. The support pipe 31
L2 between the tips of the reticulated punctures 32 fixed to both sides of
And the distance L3 between the tips of the reticulated punctures 32 of the discharge electrodes 30 adjacent to each other is equal, and the distance L4 between the support pipes 31 of the discharge electrodes 30 adjacent to each other is set to twice the distance L2.

Normally, the electrostatic precipitator is divided into 1 to 4 chambers, each of which has an individual power supply unit and is charged. If even one of the discharge electrodes 30 is disconnected, charging of the entire chamber becomes impossible, and the dust collection efficiency is extremely reduced. However, in the discharge electrode 30 having the above-described configuration, the corona current not only flows through the support pipe 31, but also
Since a pipe of 15 to 25 [A] is used as the support pipe 31, there is no disconnection. The diameter of the support pipe 31 is determined by the length and strength of the discharge electrode 30 or the diameter of the dust collection electrode 1.
It is set by the relationship with 1.

The reticulated piercing portion 32 is provided on the support pipe 31.
A plurality of bands 35 at a distance L5 from the center line CN of
And a second band group including a plurality of bands 36 at a distance L6. Then, a pair of branch protruding pieces 38 are formed radially inward of each of the bands 35 and are welded to the support pipe 31. Further, a strand 39 is formed between each of the bands 35 and each of the bands 36, and a pair of branch protrusions 40 are formed as a discharge portion on a radially outer side of each of the bands 36. Since the branch protrusion 40 shown in FIG. 5 extends toward the dust collecting electrode 11, corona discharge is easily generated. In addition, since each of the strands 39 has a ridge line portion 39a, corona discharge easily occurs.

For example, if the distance L1 is 200
In the case of [mm], if the distance L7 is set to 20 [mm] and the distance L8 is set to 50 [mm], a large amount of corona current can flow through the support pipe 31. The ratio between the distance L2 and the distance L1 is set to 0.7 to 1.0. Therefore, if the distance L1 is 300 [mm], the distance L2 is 200 to
If it is 300 [mm] and the distance L1 is 400 [mm], the distance L2 is 250 to 400 [mm]. Then, half of the value obtained by subtracting the outer diameter of the support pipe 31 from the distance L2 is the distance L8. At this time, if the distance L7 is L7 = (0.15−0.3) × 2 · L1, the dust collection is performed. Efficiency can be increased.

The distances L9 and L10 are the distances L7 and L7.
It can be set by selecting the expanded metal corresponding to the value of 8. Thus, the reticulated puncture 3
Since an expanded metal is used as 2, the discharge electrode 30 can be reduced in weight. For example, when the plate thickness is 3.2
[Mm] plate steel plate weighs 25.1 [kg /
m ² ], and the weight of the expanded metal having the same thickness is 2.7 [kg / m ² ] for the XS-81 type, and 4.0 [kg / m ² ] for the XS-72 type. The weight can be 11 to 16% when a plate steel plate is used. As a result, the weight of the support pipe 31 for supporting the expanded metal is similarly reduced, so that the discharge electrode 30 can be further reduced in weight.

Therefore, the entire discharge electrode 30 can be mounted on a pipe frame (not shown). Also,
Since press work is not required to form the reticulated piercing portion 32, the cost can be reduced. Next, the relationship between the voltage applied to the discharge electrode 30 and the corona current will be described.

FIG. 9 is a conceptual diagram of a test apparatus for comparing the embodiment of the present invention with the conventional technology, FIG. 10 is a first comparison diagram between the embodiment of the present invention and the conventional technology, and FIG. FIG. 6 is a second comparison diagram between the embodiment of the present invention and the conventional technology. 10 and 11, the horizontal axis represents the voltage applied to the discharge electrode 30, and the vertical axis represents the corona current. FIG.
FIG. 11 shows a case where the distance L1 is set to 300 [mm].
Indicates the relationship between the voltage and the corona current when the distance L1 is set to 400 [mm].

In FIG. 9, reference numeral 50 denotes a test device. In the test device 50, two dust collecting electrodes 11 (having a height of 40) are provided.
00 [mm] × length 6000 [mm]) are arranged in parallel. In this case, the distance L1 between the two dust collection electrodes 11 is set to 300
[Mm] and 400 [mm] were set, and the test was performed under two conditions. In addition, three discharge electrodes 30 are disposed at the center between the dust collecting electrodes 11, and the distance L4 between the discharge electrodes 30 is set to 25.
It was set to 0 [mm]. Then, a power supply 13 is connected between the dust collecting electrode 11 and the discharge electrode 30, and the power supply 13
Thus, a voltage of negative polarity was applied between the dust collecting electrode 11 and the discharge electrode 30, and the corona current flowing at this time was measured.
In addition, the test apparatus 50 was operated in the air and at normal temperature.

10 and 11, m1 is a line showing the dust collection characteristics when the discharge electrode 30 of this embodiment (FIG. 1) is used, and m2 is a sawtooth discharge electrode 12b of FIG. A line indicating dust collection characteristics when used, m3 is a line indicating dust collection characteristics when the mast-shaped discharge electrode 12f of (f) in FIG. 4 is used, and m4 is a circular line shape of (a) in FIG. 7 is a line showing dust collection characteristics when the discharge electrode 12a of FIG.

In this case, the distance between the piercing portions 21 in the longitudinal direction of the sawtooth discharge electrode 12b in FIG.
[Mm], the angle of the piercing portion 21 is 90 [°], and the distance between the piercing portions 21 of the adjacent discharge electrodes 12b is 13
[Mm]. The round discharge electrode 12a shown in FIG. 4A was a piano wire having a diameter of 2 mm.

As can be seen from FIG. 10, the distance L
1 is set to 300 [mm], the discharge electrode 3 of the present embodiment is set.
When 0 is used, the corona current per unit length can be made larger than when using the sawtooth discharge electrode 12b, the mast discharge electrode 12f, and the round wire discharge electrode 12a. Further, as can be seen from FIG.
Even when the discharge electrode 30 is set to 00 [mm], when the discharge electrode 30 of this embodiment is used, compared to when the sawtooth discharge electrode 12b, the mast discharge electrode 12f, and the round wire discharge electrode 12a are used, The corona current per unit length can be increased.

When the distance L1 is set to be long, the dust collection characteristics of the saw-toothed discharge electrode 12b, the mast-shaped discharge electrode 12f, and the round-shaped discharge electrode 12a other than the discharge electrode 30 of the present embodiment differ. It turns out that disappears. As described above, when the corona current per unit length is increased by using the discharge electrode 30 of the present embodiment, the electric field strength [k
V / cm] can be increased, and strong ion wind (electron movement) can be generated between the dust collection electrodes 11.
As a result, the dust collection efficiency can be increased.

Further, since the discharge electrode 30 is provided with the reticulated piercing portion 32, it has a structure in which two conventional discharge electrodes are integrated into one. Therefore, a high voltage is applied to the discharge electrode 30 over the distance L2 in FIG. That is, the discharge electrode 30
Is high in the electric field, so that the dust collection efficiency can be increased. By the way, normally, a voltage having a negative polarity is applied from the discharge electrode 30 to the dust collecting electrode 11, and the dust charged to the negative polarity is caused to adhere to the dust collecting electrode 11. However, a voltage of a positive polarity is applied to a part of the dust by an electrostatic force according to Coulomb's law (reverse charging phenomenon), and the dust charged to a positive polarity is discharged to the discharge electrode 3.
0.

However, since the discharge electrode 30 has a larger surface area than a normal discharge electrode, the dust charged to a positive polarity does not adhere to the branch protrusion 40 but adheres to a portion other than the branch protrusion 40. Therefore, the dust collection efficiency can be increased, and the hammering cycle can be lengthened. Further, the discharge electrode 30 needs to be centered with respect to the dust collecting electrode 11. Generally, when the distance L1 is 300 [mm], the centering target is ± 3 [mm]. Since the reticulated piercing portion 32 is formed of expanded metal, it is curved in the longitudinal direction. When the expanded metal is cut, distortion occurs due to residual stress.
In this embodiment, since the reticulated piercing portion 32 is fixed to the support pipe 31, it is possible to eliminate bending, distortion, and the like.
Therefore, centering of the discharge electrode 30 with respect to the dust collecting electrode 11 can be easily performed.

Further, since the support pipe 31 is cylindrical, the surface area of the discharge electrode 30 can be increased. Therefore, the dust charged to the positive polarity becomes the branch projection 4.
Since concentration on zero is suppressed, stable charging can be performed. When the discharge electrode 30 is hammered, the support pipe 31 transmits the impact force well, so that dust can be sufficiently removed.

FIG. 12 is a front view of the electrostatic precipitator in the embodiment of the present invention, FIG. 13 is a side view of the electric precipitator in the embodiment of the present invention, and FIG. 14 is an electric precipitator in the embodiment of the present invention. FIG. 15 is a longitudinal sectional view of the electrostatic precipitator according to the embodiment of the present invention, and FIG. 16 is a cross sectional view of the electric precipitator according to the embodiment of the present invention. In the figure, 13 is a power supply device, 61 is an electric dust collecting device, 62 is a device main body, 63
Is a rectifying plate for rectifying the gas to be treated, 64 is a hopper for collecting the collected dust, 65 is an insulator chamber, 66 is a heater, 67 is a discharge electrode hammer for exfoliating dust adhered to the discharge electrode 30 by vibration. Reference numeral 68 denotes a cone flue for supplying a gas to be treated, and reference numeral 72 denotes a dust collecting pole hammer which separates dust adhered to the dust collecting electrode 11 by vibration.

In this embodiment, a dust collecting electrode 11 and a discharge electrode 30 are provided in the apparatus main body 62, and the dust collecting electrode 11 has a height of 635 [mm] and a length of 2550 [m].
m], and the distance L1 between the dust collection electrodes 11 is 400
[Mm] are arranged in parallel with each other. The discharge electrode 30 is located at the center between the dust collecting electrodes 11.
It is arranged in parallel with.

The electric dust collector 61 is divided into one section and one section.
In addition to the structure of the duct (one gas passage), conditions are set so that the temperature of the gas to be treated is 135 ° C. and the moisture content of the gas to be treated is 8%, and the inlet of the coal ash is set. The gas to be treated was supplied so that the dust amount was 5 [g / m ³ N], and the dust collection characteristics were examined. In addition, with respect to the electrostatic precipitator 61 having the above-described structure, the amount of dust at the entrance was 15 g / m ^3.
N] was also examined.

FIG. 17 shows the relationship between the embodiment of the present invention and the prior art.
FIG. 18 shows a third comparative example, and FIG.
FIG. 14 is a fourth comparative diagram of FIG. 17 and 18
The horizontal axis shows the current density and the vertical axis shows the moving speed ratio.
You. FIG. 17 shows that the amount of dust contained at the inlet is 5 g / Nm.^Three]
FIG. 18 shows that the amount of dust contained at the inlet is 15 [g / N
m ^ThreeBetween current density and travel speed ratio when
Is shown.

In this case, the moving speed ratio is calculated as shown in FIG.
Using a circular discharge electrode 12a (φ2.6)
It represents the ratio when the moving speed of dust when dust is collected at a current density of [mA / m] is 1. Incidentally, there is a dust moving speed ω as an index for evaluating the dust collection characteristics, and the dust moving speed ω can be expressed by the following equation.

[0044]

(Equation 1)

Where ω is the apparent dust moving speed, Q
Is the flow rate of the gas to be treated, and A is all the dust collection electrodes 11 (FIG. 16).
Is the dust collection efficiency. Then, it can be seen that the larger the value of the dust moving speed ω, the better the dust collection characteristics. 17 and 18, m5 is a line showing the dust collection characteristics when the discharge electrode 30 of this embodiment is used, and m6 is a dust collection when the round discharge electrode 12a of FIG. 4A is used. This is a line showing characteristics.

As shown in the figure, when the discharge electrode 30 of the present embodiment is used, the discharge electrode 12a having a round wire shape shown in FIG.
The value of the moving speed ratio is 20 to 30 [%] than when using
growing. When the dust content at the inlet is increased, the value of the moving speed ratio is further increased. This relationship does not change even if the current density is changed. The discharge electrode 30 can be used not only for a dry electric precipitator but also for a wet electric precipitator.

Next, a second embodiment of the present invention will be described. FIG. 19 is a sectional view of the discharge electrode according to the second embodiment of the present invention, and FIG. 20 is a front view of the discharge electrode according to the second embodiment of the present invention. In the drawing, 30 is an electrode, 45 is a rectangular tubular support pipe, and 46 is the support pipe 4 by welding.
5 is a reticulated piercing portion fixed to 5. The reticulated piercing portion 46 has a band group including a plurality of bands 47, and each band 47
A pair of branch projecting pieces 48 are formed on the outside in the radial direction as discharge portions.

Next, a third embodiment of the present invention will be described. FIG. 21 is a sectional view of a discharge electrode according to the third embodiment of the present invention, and FIG. 22 is a front view of the discharge electrode according to the third embodiment of the present invention. In the figure, 30 is an electrode, 31 is a cylindrical support pipe, and 49 is the support pipe 3 by welding.
1 is a reticulated puncture fixed to 1. The reticulated piercing portion 49 has a band group including a plurality of bands 50, and each band 50
A pair of branch protruding pieces 51 are formed on the outside in the radial direction as discharge portions.

Next, a fourth embodiment of the present invention will be described. FIG. 23 is an enlarged view of a main part of a discharge electrode according to a fourth embodiment of the present invention. In the figure, reference numeral 30 denotes a discharge electrode, reference numeral 31 denotes a cylindrical support pipe, and reference numeral 52 denotes a mesh piercing portion fixed to the support pipe 31 by welding. The reticulated stub 52
6 is formed by cutting the expanded metal shown in FIG. 6 into a set shape, and is disposed symmetrically about the support pipe 31.

The reticulated portion 52 has a first band group including a plurality of bands 35 and a second band group including a plurality of bands 36. A pair of branch protrusions 38 are formed inward of the respective bands 35 in the radial direction, and are welded to the support pipe 31. The band 35
A strand 39 is formed between the first and second bands 36, and a pair of branch protrusions 40 are formed on the radially outer side of each band 36 as a discharge portion. The branch projection 40
Spreads toward the dust collecting electrode 11, and an acute angle portion 53 is formed facing the dust collecting electrode 11.

The acute angle portion 53 is formed by a grinder or the like with its tip facing the dust collecting electrode 11. In the present embodiment, when the same voltage as in the first embodiment is applied to the discharge electrode 30, more corona current can flow through the support pipe 31 than in the first embodiment, and the dust collection characteristics are improved. be able to. It should be noted that the present invention is not limited to the above-described embodiments, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0052]

As described above in detail, according to the present invention, the discharge electrode for an electrostatic precipitator has a support pipe and a mesh bar supported by the support pipe. The reticulated portion includes a band group including a plurality of bands, and a discharge portion including a branch protrusion is formed on an outer band.

In this case, since the support pipe is used to support the reticulated piercing portion, the discharge electrode does not break. In addition, since a discharge portion composed of a branch projection is formed in a band outside the reticulated portion, the electric field intensity can be increased, and a strong ion wind can be generated between the dust collection electrodes. As a result, the corona current per unit length can be increased, and the dust collection efficiency can be increased.

Further, since the surface area of the discharge electrode can be increased, dust charged to a positive polarity adheres to portions other than the discharge portion. Therefore, the dust collection efficiency can be increased, and the hammering cycle can be lengthened. In another discharge electrode for an electrostatic precipitator of the present invention,
Further, the branch protrusion is formed toward the dust collecting electrode. In this case, corona discharge can be easily generated.

In still another discharge electrode for an electrostatic precipitator of the present invention, the mesh-like piercing portion is made of expanded metal. In this case, the weight of the reticulated piercing portion can be reduced. Also, the entire discharge electrode can be attached to a pipe frame. Furthermore, since a press work is not required to form the reticulated piercing portion, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a main part of a discharge electrode according to a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of a conventional cylindrical electric precipitator.

FIG. 3 is a conceptual diagram of a conventional parallel plate type electric dust collector.

FIG. 4 is a diagram showing an example of a conventional discharge electrode.

FIG. 5 is a sectional view of a main part of a discharge electrode according to the first embodiment of the present invention.

FIG. 6 is a plan view of an expanded metal.

FIG. 7 is a sectional view of a main part of the electric precipitator according to the first embodiment of the present invention.

FIG. 8 is a view showing the arrangement of discharge electrodes according to the first embodiment of the present invention.

FIG. 9 is a conceptual diagram of a test apparatus for comparing an embodiment of the present invention with a conventional technique.

FIG. 10 is a first comparison diagram between an embodiment of the present invention and a conventional technique.

FIG. 11 is a second comparison diagram between the embodiment of the present invention and the conventional technology.

FIG. 12 is a front view of the electric precipitator according to the embodiment of the present invention.

FIG. 13 is a side view of the electric precipitator according to the embodiment of the present invention.

FIG. 14 is a plan view of the electric precipitator according to the embodiment of the present invention.

FIG. 15 is a longitudinal sectional view of the electric precipitator according to the embodiment of the present invention.

FIG. 16 is a cross-sectional view of the electric precipitator according to the embodiment of the present invention.

FIG. 17 is a third comparison diagram between the embodiment of the present invention and the conventional technology.

FIG. 18 is a fourth comparison diagram between the embodiment of the present invention and the conventional technology.

FIG. 19 is a sectional view of a discharge electrode according to a second embodiment of the present invention.

FIG. 20 is a front view of a discharge electrode according to a second embodiment of the present invention.

FIG. 21 is a sectional view of a discharge electrode according to a third embodiment of the present invention.

FIG. 22 is a front view of a discharge electrode according to a third embodiment of the present invention.

FIG. 23 is an enlarged view of a main part of a discharge electrode according to a fourth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Dust collection electrode 30 Discharge electrode 31 Support pipe 32 Reticulated stab 35, 36 Band 38, 40 Branch projection 61 Electric dust collector

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-52-131272 (JP, A) JP-A-51-126577 (JP, A) JP-A-2-134186 (JP, U) (58) Survey Field (Int.Cl. ⁶ , DB name) B03C 3/00-3/88

Claims (3)

(57) [Claims] [1 claim] (a) a support pipe, which has a net-like barbs portion supported by (b) the support pipe, comprising a band group consisting of (c) net-like thorns portion includes a plurality of bands, the outer electric dust collector for discharge electrode, characterized in that the discharge portion made of branches protruding piece in a square bands is formed. 2. The discharge electrode for an electrostatic precipitator according to claim 1, wherein the branch protrusion is formed toward a dust collection electrode. 3. The discharge electrode for an electrostatic precipitator according to claim 1, wherein the mesh-like piercing portion is made of expanded metal.