JP3605206B2 - Electric dust collector - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electric precipitator comprising a pre-stage ionization section for ionizing sucked dust and a post-stage dust collection section for adsorbing and collecting the ionized dust, while ensuring the dust collection capability and safety while maintaining ventilation. It relates to an improvement for reducing the thickness in the direction.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an electric precipitator including an upstream ionization section and a downstream dust collection section, for example, in an ionization section, the respective electrodes are arranged in parallel with each other and arranged in parallel with the ventilation direction. The same applies to the electrodes of the dust collecting section. In order to improve the ionization efficiency of the ionization section and the dust collection efficiency of the dust collection section, it is good to stabilize the discharge after increasing the discharge voltage of each section. It is necessary to increase the area (relative to the positive electrode), and conventionally, the area was expanded by extending the ground electrode in the ventilation direction. Further, in the dust collecting section, a certain depth in the ventilation direction is required to sufficiently collect the ionized dust.
[0003]
Each electrode of the ionization section is a needle-shaped electrode provided with a discharge protrusion for discharging a discharge current toward the windward in the ventilation direction, but a short electrode is provided in the ventilation direction in order to face the discharge protrusion to the facing electrode. Even so, when each electrode was arranged so that the discharge protrusion was substantially at the center of the ground electrode, the rear end of the positive electrode in particular tended to fall backward, but between the ionization part and the dust collection part. In order to suppress the abnormal discharge that occurs, it is necessary to keep the entire ionization section away from the dust collection section. Further, if the assembling relation of each part is displaced or deformed due to an external impact, the ionized part and the dust collecting part may come close to each other and abnormal discharge may occur between the two parts. Has become wider, and the conventional electric precipitator has become considerably thicker in the ventilation direction.
[0004]
[Problems to be solved by the invention]
As an electric precipitator for installation in houses, buildings, warehouses, etc., even if the thickness increases in the ventilation direction, even if it is unavoidable to increase dust collection efficiency or ensure safety, it is suitable for vehicles etc. Since the installed electrostatic precipitator must effectively use a limited space, it is preferable that the electric precipitator be as small as possible, and in particular be thin in the direction of ventilation. Therefore, in order to reduce the thickness of the electric precipitator in the ventilation direction while securing the dust collection efficiency and safety, a study was made by paying particular attention to the electrode of the ionization part.
[0005]
[Means for Solving the Problems]
As a result of the study, we developed an electric precipitator consisting of a pre-stage ionization unit and a post-stage dust collection unit. is there. In the present invention, the electrode in the ionization section is inclined in the ventilation direction, thereby reducing the length in the ventilation direction, that is, the thickness of the ionization section, while keeping the area of the electrode the same as the conventional one.
[0006]
Also, in the same electrostatic precipitator, when the electrode of the ionization part is folded in an arc shape, the sharp end face becomes a gentle continuous surface, and the larger the radius of curvature of this continuous surface, the more difficult the discharge at the end face to occur. Therefore, it is possible to increase the discharge voltage while reducing the thickness of the ionized portion. To increase the discharge voltage, it is preferable to increase the radius of the arc at the folded end of the electrode, that is, to fold the electrode back.
[0007]
Further, as a countermeasure for abnormal discharge, the electrode of the ionization section having a different polarity from the ground electrode of the dust collection section is narrowed in the ventilation direction, and the rear end of the electrode of the ionization section is separated from the ground electrode of the dust collection section. Among the electrodes of the ionization section having the discharge protrusion, the electrode having a different polarity from the dust collection section is shortened, and the rear end of this electrode is kept away from the dust collection section, thereby reducing the risk of abnormal discharge. For example, when the discharge protrusion of the A electrode is opposed to the middle point of the B electrode, conventionally, even if the A electrode is shortened, the rear end of the A electrode approaches the dust collecting portion. It was necessary to keep the entire ionization section away from the dust collection section to separate from the dust collection section. In the present invention, since the electrodes of the ionization section are inclined in the ventilation direction, even if the front ends of both electrodes are aligned, the discharge protrusion of the A electrode can be opposed to the middle point of the B electrode.
[0008]
Also, in the same electrostatic precipitator, if the electrode of the ionizing part and the electrode of the dust collecting part are brought close to each other via the insulating rib, even if the assembling relationship between them may be shifted or each part may be deformed, the insulation may be performed. Since the rib secures a certain distance between the two, the two do not approach each other excessively and do not cause abnormal discharge. It is better to fix the position of the electrode of each part by bringing the insulating rib into close contact with the rear end of the electrode of the ionization part and the front end of the electrode of the dust collecting part and supporting each electrode.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a partially cutaway perspective view of an electric precipitator according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. In FIG. 1, an ionization unit 1 is arranged at an upper stage and a dust collection unit 2 is arranged at a lower stage with respect to a ventilation direction from above to below. In this example, as seen in FIGS. 1 and 2, the ionization unit 1 inclines the wide ground electrode 3 in the ventilation direction and the positive electrode 4 narrow in the ventilation direction by 45 degrees with respect to the ventilation direction. The electrodes are arranged alternately and in parallel with their leading edges aligned. Each of the ground electrode 3 and the positive electrode 4 of the ionized portion has discharge protrusions 5 and 6 at the front edge, and the rear edge is folded in an arc shape in cross section. The dust collecting section 2 spirally winds a ground electrode 7 and a positive electrode 8 laminated with a plastic film.
[0010]
As shown in FIG. 2, the ionization unit 1 discharges from the discharge projection 5 of the ground electrode 3 toward the facing positive electrode 4 or from the discharge projection 6 of the positive electrode 4 toward the facing ground electrode 3. The dust passing between the ground electrode 3 and the positive electrode 4 together with the sucked air is ionized negatively or positively. Since the electrodes 3 and 4 have the same leading edge but are inclined with respect to the ventilation direction, the discharge can be reliably discharged from the discharge projections 5 and 6 toward the positive electrode 4 or the ground electrode 3.
[0011]
In addition, since the rear edges of the electrodes 3 and 4 are folded back in a circular arc shape, the withstand voltage is increased because the originally sharp rear edge has a smooth continuous surface, and the withstand voltage is increased. A higher voltage can be applied as compared with a conventional positive electrode. Then, the positive electrode 4 is shortened in the ventilation direction, the leading edge is aligned with the ground electrode 3, the trailing edge is separated from the dust collecting section 2, and the distance between the positive electrode 4 of the ionizing section 1 and the dust collecting section 2 is reduced. By ensuring this sufficiently, the occurrence of abnormal discharge is prevented. In this case, if the positive electrode of the ionization unit is a line electrode such as a wire and arranged in alignment with the front edge of the ground electrode, the distance from the dust collection unit can be further increased, and safety can be improved.
[0012]
In addition, as described above, even if the arrangement of each electrode is devised to prevent abnormal discharge occurring between the ionization part and the dust collection part, if the thickness as an electric precipitator is to be reduced, ionization is inevitable. When the part and the dust collecting part are close to each other and the positional relationship between the ionized part and the dust collecting part is broken due to an external impact or the like, the possibility of abnormal discharge increases. Therefore, in this example, as shown in FIG. 1 or FIG. 2, an insulating rib 9 is provided between the ionization unit 1 and the dust collection unit 2, and particularly, the ground electrode 3 of the ionization unit 1 which is long in the ventilation direction. By supporting the rear end with the insulating ribs 9 and fixing the position, the occurrence of danger due to the ionization unit 1 and the dust collection unit 2 being excessively close to each other due to displacement is prevented.
[0013]
In this example, by arranging the ground electrode 7 and the positive electrode 8 in the dust collecting portion 2 in a spiral shape, the total dust collecting area is increased, and the thickness of the dust collecting portion 2 in the ventilation direction is reduced. Thus, in combination with the above-described thinning of the ionization section 1, the electric dust collector of the present invention brings the ionization section and the dust collection section into close contact, and achieves a considerable reduction in thickness. In the conventional electrostatic precipitator, it is about 80 mm, whereas in the present invention, for example, the electric precipitator having the structure as shown in the above example, the thickness can be reduced to about 25 mm. In this way, the electric dust collector of the present invention can be installed with a margin in a design that has a sufficient space when it is installed in a vehicle or the like, which is limited by the installation place.
[0014]
【Example】
Regarding the withstand voltage of the electrode of the ionization part, the trailing edge where the sharp end face is left as in the related art (refer to the measurement circuit in FIG. 3) and the trailing edge where the end face is folded in an arc shape based on the present invention (see FIG. Measurement circuit). The distance between the positive electrode 2 and the ground electrode is 6 mm, and the ground electrode is made of aluminum. As a result, the withstand voltage of the conventional electrode was 9.7 kV, whereas the withstand voltage of the positive electrode having the trailing edge whose end face was folded in an arc shape based on the present invention was 12 kV, which was about 24%. The voltage is high. Thus, it is understood that abnormal discharge is less likely to occur in the present invention than in the related art, and that the electric precipitator can be operated more safely.
[0015]
Folding the rear edge of the electrode into an arc shape is to form a sharp end face into a continuous face so as not to form an edge where abnormal discharge is likely to occur. From this, if the radius of curvature of the folded portion is increased, the withstand voltage can be further increased. The radius of curvature of the turn is determined from the balance of the above.
[0016]
【The invention's effect】
The electric precipitator of the present invention has the advantage that it can be provided as a thinner and safer product if it has the same performance as the conventional one, and particularly can be easily installed in a place such as a vehicle where installation space is limited. For this reason, it does not have a structure different from the conventional one, nor does it have any special mechanism, so that it can be assembled, assembled, or attached in the same process as the conventional electric dust collector. Conventionally, there is a structure in which the thickness is reduced by using a linear electrode as the positive electrode, but the linear electrode has low mechanical strength. The positive electrode of the present invention has high mechanical strength by being integrally molded from a metal plate, and can be manufactured at low cost. The effect of the present invention makes it difficult for abnormal discharge from the rear end to occur, and ideally discharges only from the discharge protrusion. It is a positive electrode.
[0017]
As can be seen in the previous example, it can not be simply compared that the thickness in the ventilation direction can be reduced to 以下 or less, but it is possible to construct an electric dust collector with the same thickness and significantly improved dust collection efficiency. Means In this case, it is clear that the electric precipitator of the present invention in consideration of safety for suppressing abnormal discharge is more excellent, and has a characteristic that the performance as an electric precipitator can be improved.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view of an electric precipitator according to an embodiment of the present invention.
FIG. 2 is a sectional view taken along the line AA in FIG.
FIG. 3 is a connection diagram of a conventional positive electrode withstand voltage measurement circuit.
FIG. 4 is a connection diagram of a circuit for measuring a withstand voltage of a positive electrode according to the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 ionization section 2 dust collection section 3 ionization section ground electrode 4 positive electrode of ionization section 5 discharge projection of ionization section ground electrode 6 discharge projection of positive electrode of ionization section 7 ground electrode of dust collection section 8 positive electrode of dust collection section 9 Insulation rib

Claims (4)

In sucked dust and comprising a subsequent dust collection unit for collecting the adsorbed dust ionized portion and ionization of preceding ionizing electrostatic precipitator, electrodes of the ionization section provided with discharge projections integrally molded to the metal plate An electrostatic precipitator that is arranged at an angle to the ventilation direction. In an electric precipitator comprising an ionization part at the preceding stage for ionizing the sucked dust and a dust collection part at the latter stage for adsorbing and collecting the ionized dust, the rear edge of the electrode of the ionization part is arranged by folding back in a circular arc shape in cross section. Electric dust collector. Ionization section, narrowing the ground electrode and the polarity of the different Do that electrodes of the particulate collection portion in the airflow direction, and electrostatic precipitator of claim 1, wherein formed by separating the rear end of the electrode from the dust collection unit. In an electric precipitator comprising an ionization section at a preceding stage for ionizing sucked dust and a dust collection section at a later stage for adsorbing and collecting the ionized dust, an insulating rib is provided between an electrode of the ionization section and an electrode of the dust collection section. An electrostatic precipitator comprising: a rear end of a ground electrode of an ionization section supported by the insulating ribs and fixed in position .

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