JPS62273064A - Electrostatic type dust arresting apparatus - Google Patents

Abstract

PURPOSE:To perform dust collection safely and efficiently and to facilitate cleaning and maintenance, by forming an air passing route between electrode units constituted by arranging opposed electrodes through a solid insulator and mounting a filter element to said air passing route in a freely detachable manner. CONSTITUTION:Each of electrode units is constituted by arranging a first electrode 70 and a second electrode 71 so that the leading end part of the latter is set to a position retracted from that of the former and, by the end edge effect of the leading end parts of said units, an electric field is generated between the leading end parts of the conductive filter elements 75 electrically connected to both electrodes 70, 71. By the action of said electric field, the suspended particles in air forcibly sent to the air passing routes 7 between electrode units are physically caught by the conductive filter elements 75 and charged suspended particles are attracted to the filter element 75 having a wide area electrically connected to the second electrode 71 by electrostatic induction. The filter elements 75 can be detached from the air passing route 74 and replaced.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is an electrostatic type remover! ! 1! In particular, the present invention relates to an electrostatic dust removing device that does not cause short-circuit discharge due to high voltage, can efficiently collect fine dust, and has a filter that can be easily replaced.

(Conventional technology) Due to the development of industry and the development of overcrowded cities, urban air quality has become increasingly polluted, impeding productivity in industry and having a negative impact on the health and living environment of residential areas. It has become to. Therefore, while pollution prevention measures such as pollution source control are being considered and implemented, air purification of confined spaces has become an important issue in more advanced or broader fields. In particular, in the semiconductor industry, ultra-fine processing such as VLSI, and in the precision machinery industry, to improve the yield of ultra-precise products, and in order to improve the yield of ultra-precise products in the semiconductor industry, biotechnology in operating rooms, sterile rooms, bacterial experiments and food processing. As air purifiers become more sophisticated, air purifiers have become indispensable as environmental hygiene measures for homes, workplaces, recreational facilities, etc., including measures against dust, smoke, dust mites, and pollen.

For this reason, the required performance of high-performance filters has been improved to a target suspended particle size of 0.3 μm or 0.1 μm or more, and the results are gradually being achieved.

Incidentally, the dust collection mechanisms of conventional air purifiers are roughly divided into mechanical dust collection systems and electrical dust collection systems in terms of operating principles.

Generally speaking, mechanical dust collection methods have large particles that can be collected, and there are many difficulties in equipment installation and handling, so electrical dust collection methods are generally used today. .

The electrostatic precipitator that uses this electric precipitator method collects the dust electrostatically after ionizing it by corona discharge, and the electrostatic precipitator that collects the dust electrostatically after ionizing it by corona discharge. There are electrostatic dielectric air purifiers that collect electrostatically through the air.

First, the former type of conventional electrostatic precipitator will be explained with reference to FIGS. 4 and 5.

In FIG. 4, to explain the principle of dust collection of this electrostatic precipitator, suspended particles contained in contaminated air 1 pass through a pre-filter 2, and enter a charging section 3 having a discharge ka4 which performs corona discharge (+ ), and these (+) charged particles are repelled by the high-voltage electric seed plate 6 in the dust collection section 5,
It is collected on the ground electrode plate 7. Therefore, purified air 8 in which suspended particles are collected can be obtained.

FIG. 5 is a cross-sectional view showing an example of an electrostatic precipitator adopting such a dust collection principle, and shows a discharge with a positive potential''!Ii*10
, has a unit in which a discharge electrode plate 11 having a positive potential and a dust collection electrode plate 12 having a negative potential are assembled, and the holder part 13 has a front filter 14 on the front part and a rear filter on the rear part. 15 and an activated carbon filter 16 for deodorizing are set. The cented items are stored in the case body 17 through a grille 18 serving as a suction port. A fan 19 and an air outlet 20 are provided at the rear of the case body 17.

Therefore, suspended particles contained in lη-contaminated air sucked in from the suction port by the fan 19 pass through the front filter 14, and are charged to (+) by the discharge wire lO performing corona discharge, and this (+) The charged particles are repelled by the discharge electrode plate 11 which has a positive potential, and are repelled by the collection electrode plate 12 which has a negative potential.
is collected by. The purified air flow is passed through the rear filter 15.
It passes through the activated carbon filter 16 and is blown out from the outlet 20.

Next, a conventional electrostatic dielectric air purifier of the latter type has already been published as Japanese Patent Application Laid-open No. 1956-1956 filed by the same inventor as the present application. This will be explained in detail.

First, referring to FIG. 6, to explain the principle of dust collection, this electrostatic dielectric air purifier has electrodes 31.32 disposed on a porous dielectric material 30, and
A high DC voltage is applied between the porous dielectric 30 and the porous dielectric 30 to generate a strong electric field to collect floating particles that try to pass through the ventilation holes of the dielectric.

FIG. 7 is a sectional view of an electrostatic dielectric air purifier employing such a dust collection principle, and FIG. 8 is a configuration diagram of its filter element. In these figures, a filter element 41 is disposed in the center of a case 40, and air containing pollutant particles is drawn in by a fan 42 and sucked in through a suction port 43. In order to prevent clogging of the filter element 41, a filter bag 44 is provided to collect coarse dust. As shown in FIG. 8(a), the filter element 41 includes a porous dielectric material 47 such as urethane foam, and a thin metal film 48 such as Al that serves as one electrode on one side of the porous dielectric material 47.
Metal thin film 4 serving as the other electrode with porous dielectric material 47 in between
As shown in FIG. 8(b), a plurality of filter media having 9 formed thereon are wound into a cylindrical shape, and the adjacent electrodes 48, 4 are
9, a high voltage is applied from the DC high voltage power supply 45 via the terminals 49a, 49a. 47a is the filter element 41
It is a support network for

Therefore, the suspended particles inhaled through the suction port 43 are physically trapped in the vent holes of the filter medium, and a strong electrostatic field is generated by the dielectric material placed between the positive and negative electrodes, causing the suspended particles to become electrically charged. , charged airborne particles are trapped on the dielectric vent wall.

(Problems to be Solved by the Invention) However, the electrostatic collector shown in FIGS. 4 and 5 described above has the following problems.

(1) Cleaning and maintenance are difficult.

If a large amount of dust adheres to the dust collection plate, the dust collection effect will decrease, so prepare a weak alkaline detergent dissolved in lukewarm water at about 60°C, remove the dust collection unit from the grill 18, and clean it from the front filter 14. and rear filter 15
The electrostatic precipitator from which the activated carbon filter 16 has been removed is swamped in the cleaning solution and immersed for approximately 3 hours, depending on the degree of contamination. Then, while soaking in the cleaning solution, shake it back and forth and from side to side to remove dirt. In this case, avoid touching the thin discharge &110. In particular, if grass smoke or the like adheres to the dust collecting plate 12, it is difficult to remove the dirt, but care must be taken not to scrub the dust collecting plate with a brush or the like.

(2) In order to increase the re-scattering collection ability of the collected particles, the applied voltage must be increased (or the voltage application section must be lengthened), but the particles accumulated on the dust collection electrode plate 12 Due to the concentration of the electric field on the raised area, a discharge occurs and the collected particles are scattered again.

(3) Easy to cause radio wave interference.

When corona discharge occurs, high-frequency current flows through the ionized space, which causes noise interference to radios.

(4) Ozone is generated.

Because corona discharge is involved, ozone is generated, which can irritate or attack mucous membranes.

Next, in the electrostatic dielectric air purifier shown in FIGS. 6 to 8 described above, (1) the filter element equipped with the band-shaped ti is disposable, and it cannot be improved from an economic point of view; mosquito.

(2) Is it possible to make the device more compact?

(3) Is it possible to improve it so that it is suitable for use at high temperatures?

In order to meet these demands, the present invention has developed an electrostatic filter that does not cause short circuits due to high voltage, can efficiently collect fine dust, has easy filter element replacement, and has low maintenance costs. The purpose is to provide a pi device.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a first electrode to which a positive potential is applied, and a first electrode located at a position recessed from the tip of the first electrode. an electrode unit consisting of a second electrode to which a negative potential is applied, the tip of which is located and which faces oppositely across a solid insulator; a ventilation path formed on the outside of this second electrode; and this ventilation path. A conductive filter element is mounted on the filter element and contacts the second electrode, and a forced ventilation means for ventilating the gas to be purified is provided in the ventilation path.

(Function) According to the present invention, by adopting the above-mentioned configuration, a conductive electrode is electrically connected to the tip of the first electrode and the second electrode by an edge effect at the tip of the electrode unit. An electric field is generated between the tips of the filter element, and under the action of the electric field, airborne particles are guided to the filter element. Therefore, while being physically captured by the conductive filter element, the charged floating particles are caused by electrostatic induction.
It is attracted and captured by a filter element with a large surface area that is electrically connected to a second electrode.

Furthermore, the electrode unit is mechanically strong and electrically stable. Furthermore, when replacing the filter element, it is only necessary to insert it into the ventilation path, and the replacement can be easily performed.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of an electrostatic dust remover according to the present invention, FIG. 2 is an exploded perspective view of the electrostatic dust remover shown in FIG.
The figure is a perspective view of the filter element, FIG. 9 is a configuration diagram of the main parts of the dust removing device according to the present invention, and FIG. 10 is an electrostatic remover! showing another example of the present invention. Perspective view of the dust collection section of the J device, No. 11
The figure is a partially cutaway perspective view of FIG. 10, and the twelfth figure is a perspective view of the filter element.

First, the configuration of the main parts of the dust removal device of the present invention will be explained with reference to FIG.

A ceramic 56 as a solid insulator is provided around the first electrode 5o to which a positive DC high voltage is applied, and a second electrode 52 to which a negative potential is applied is placed between the ceramic 56. provided. These constitute an electrode unit. In this case, the tip of the second electrode is
The electrode is located at a position that is set back from the tip of the electrode. This is because an electric field is generated in that part due to the edge effect of that part, and the electric field guides floating particles to the filter element.

There is a ventilation path 6 between the electrode units configured in this way.
0 is formed, and a filter element 61 is attached to this ventilation path 6o. This filter element 61 is made of metal wool made of extremely thin metal wires, such as steel wool, AI wool, Cu wool, etc.

Therefore, when air containing suspended particles reaches the ventilation path 6o, the suspended particles are guided to the filter element by the electric field generated at the tip of the electrode unit. When the suspended particles reach the filter element 61, if the suspended particles are positively charged, they contact the second electrode to which a negative potential is applied, and are kept at a negative potential. Coulomb force acts due to the electrostatic induction between the hanging filter element 75 and the countless linear bodies having a large surface area, and is collected by the linear bodies. In addition, when the floating particles pass through the space in which the negative electrode is formed by the mesh-like filter element 75, they are apertured and repeatedly collide with or come into contact with each other, becoming electrically charged, and finally due to the Coulomb force described above. is collected on the linear body of the filter element. The collected particles are attached and retained as they are. The t-load for this is supplied from the second electrode.

Next, in FIGS. 1O to 12, 50 is a first electrode to which a positive DC high voltage is applied, and this electrode 50 is surrounded by a ceramic 56 and molded. A second electrode 52 is applied with a negative voltage on both sides of the ceramic 56.
A first electrode unit U+ is prepared. Here, the tip of the second electrode 52 is located at a position farther back than the tip of the first electrode 50, and an electric field is generated at these ends. Further, a second electrode unit U2 is prepared, which includes an electrode 50 to which a high positive voltage is applied to one side and a second electrode 52 to which a negative voltage is applied to the other side with a ceramic 56 in between. Here, connect each electrode unit 7) Ul, Lh to the ventilation path 6.
Assemble at a certain distance to form 0.

In that case, the second electrode unit U2 described above is used as the electrode unit located at the end.

A partition wall plate 57, a lower spacer [58], and an upper spacer plate 59 are provided between the electrode units assembled in this way to partition them and form a plurality of ventilation paths. Further, the electrode 50 is provided with a terminal 51 and the electrode 52 is provided with a terminal 53, and the electrodes having the same polarity are connected to each other by a connecting conductor 54.

In this case, the number of ventilation paths may be one at the minimum, and the number of ventilation paths can be appropriately designed depending on the capacity and purpose of the dust removal device. Further, as shown in FIG. 12(a), the filter element 61 is shaped in advance to match the shape of the ventilation path. Furthermore, as shown in FIG. 12(b), the filter element has linear bodies distributed coarsely at its tip, that is, at the entrance side of the ventilation path, and gradually distributed densely toward the outlet. With this configuration, it is possible to equalize the amount of dust collected over the entire area of the filter element.

Next, the electrostatic dust removal device according to the present invention will be explained in detail with reference to FIGS. 1 to 3.

In these figures, 70 is a first electrode to which a positive DC high voltage is applied, 71 is a second electrode to which a negative potential is applied, and 72 is a solid insulator formed surrounding the first electrode 70. These ceramics constitute the QCs unit. As mentioned above, the tip of the second electrode of this electrode unit is the! Place the electrode so that it is set back from the tip of the electrode. 73 is a side plate, 74 is a ventilation path, 75 is a filter element attached to the ventilation path, 76 is a pre-filter that collects coarse dirt to prevent clogging of this filter element 75, and 77 is a holder for an activated carbon filter. 78 is an activated carbon filter attached to the rear filter, 79 is a case body, 80 is a stop bar, 81 is a grill, 82 is a fan, and 83 is an air outlet.

Therefore, air containing suspended particles is sucked in by the fan 82 through the grille 81 serving as an inlet, and the air containing the suspended particles is sucked into the prefilter 76.
to the dust collection unit. This dust collection unit is
A first electrode 70 to which a positive potential is applied, a second electrode 71 to which a negative potential is applied, an electrode unit made of a ceramic 72 formed between these electrode units, and an electrode unit formed between these electrode units. It consists of a filter element 76 disposed in a ventilation path 74, a rear filter 77 at the end of the ventilation path 74, and an activated carbon filter. Here, as the filter element 76, steel, AI,
A metal wool such as Cu or a sponge made of conductive plastic can be used, and as shown in FIG. Make it easy to insert. The prepared filter element is passed through the ventilation path 74.
You can insert it into . The assembled dust collection unit is then pushed into the case body 79 by being pushed from the grille 81 until it abuts the stopper 80 inside the case body 79. A fan 82 and a purified air outlet 83 are provided at the rear of the case body 79.

Therefore, when air containing suspended particles is sucked in by the fan 82 from the grille 81 serving as the suction port, the coarse dust is collected by the pre-filter 76, and the suspended particles in the air that have passed through there are collected at the tips of the electrodes 70 and 71. The particles reach the filter element under the action of the electric field of the filter element 75, and are collected by the above-mentioned dust collecting action on the countless cotton-like bodies having a large surface area of the filter element 75, which is maintained at a negative potential. The purified air is deodorized by the activated carbon filter 78 and blown out from the outlet 83.

Here, when steel wool is used as the material for the filter element 75, it has the effect of chemically adsorbing SO, NOx, etc., and can further purify the gas passing through the filter.

Additionally, such filter elements are suitable for use at high temperatures.

Further, the strength and distribution of the electric field generated at the tip of the electrode unit described above depends on the voltage applied between the first electrode and the second electrode, the density of the linear body at the tip of the filter element, etc.

Although ceramic is used as an example of the solid insulator, the solid insulator is not limited to this, and any material with high dielectric strength and high mechanical strength may be used. For example, epoxy resin may also be used. good. In the case of epoxy resin, a thin electrode unit can be easily constructed by forming an electrode made of a thin metal film on the surface of an epoxy resin plate.

Furthermore, the thickness and shape of the solid insulator at the tip of the electrode unit can be appropriately designed depending on how the strength of the electric field and its distribution are selected.

Furthermore, the present invention is not limited to the above embodiments,
Various modifications are possible based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, according to the present invention, the following effects can be achieved.

(1) Even when a high DC voltage is applied between the electrodes, the ceramic and epoxy resin interposed between the electrodes have high insulation properties, and dust does not accumulate between the electrodes, preventing short-circuit discharge. It can also reduce radio interference and ozone.

(2) The filter element that is in contact with the dust collecting electrode is kept at the same potential as the dust collecting electrode, and its surface area is extremely large, and due to static induction with particles suspended in the air passing through it, Since the dust is collected, combined with the filtering action of the filter element itself as a physical filter material, higher dust collection efficiency can be achieved.

(3) The particles collected on the filter element can be maintained in an attached state by the electric charge supplied from the electrode unit 7).

(4) An electrode unit in which a counter electrode is disposed via a solid insulator is structurally strong and simple in structure;
Cost can be reduced.

(5) Each constituent material has high heat resistance, so it can withstand even high-temperature environments.

(6) The device can be made more compact.

(7) The filter element can be replaced very easily by simply removing it from the ventilation path and inserting a new filter element into the ventilation path before the dust collection efficiency decreases.

(8) The initial performance of the filter element can be updated by replacing it.

(9) Metal wool such as steel, AI, or Cu can be used for the filter element, and its price is low, and maintenance costs can be reduced.

In particular, these metal wools can secure a wide surface area in the ventilation path and can improve dust collection efficiency.

(10) When the material of the filter element is still wool, it has the effect of chemically adsorbing SO□, NOII, etc., and the gas passing through the filter can be further purified.

(11) If the replaced filter element is made of steel wool, even if it is disposed of as is, it will naturally oxidize and disappear due to oxygen and moisture in the air, and there is no risk of causing pollution.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electrostatic dust remover according to the present invention, FIG. 2 is an exploded perspective view of the electrostatic dust remover shown in FIG.
The figure is a perspective view of the filter element, Figure 4 is an explanatory diagram of the dust collection principle of a conventional electrostatic precipitator, and Figure 5 is a cross-sectional view showing an example of an electrostatic precipitator adopting the dust collection principle. , Figure 6 is an explanatory diagram of the dust collection principle of a static dielectric air purifier, and Figure 7 is an illustration of the dust collection principle of a static dielectric air purifier.
Figure 8 is a cross-sectional view of an electrostatic dielectric air purifier that adopts the dust collection principle shown in the figure, Figure 8 is a configuration diagram of its filter element, Figure 9 is a configuration diagram of main parts of a dust removal device according to the present invention, and Figure 10 is A first perspective view of a dust collection section of an electrostatic dust removal device showing another example of the present invention.
FIG. 1 is a partially cutaway perspective view of the dust collecting section shown in FIG. 10, and FIG. 12 is a perspective view of the filter element. 50, 70...First electrode, 52.71...Second electrode, 56°72...Ceramic, 57...Partition plate, 58...Lower spacing plate, 59...Lower part Spacing plate, 60
．． 74... Ventilation route, 51.53... Terminal, 54.
... Connection conductor, 61.62.75 ... Filter element, 73 ... Side plate, 76 ... Pre-filter, 7
7... Rear filter, 78... Activated carbon filter, 7
9...Case body, 80...Stopper, 81...
Grill, 82...Fan, 83...Air outlet.

Claims (12)

[Claims] (1) (a) A first electrode to which a positive potential is applied, the tip of which is located at a position set back from the tip of the first electrode, and a negative potential that faces across a solid insulator. (b) a ventilation path formed outside the second electrode;
c) a conductive filter element attached to the ventilation path and in contact with the second electrode; and (d) forced ventilation means for venting the gas to be purified into the ventilation path. Electrostatic dust removal device. (2) The electrostatic dust removal device according to claim 1, wherein a plurality of dust collection units each including the electrode unit, the ventilation path, and the filter element are arranged in parallel. (3) The electrode unit in the dust collection unit disposed inside of the plurality of dust collection units arranged in parallel is the first electrode unit.
3. The electrostatic dust removal device according to claim 2, wherein the electrode is surrounded by a solid insulator, and second electrodes are disposed on both sides of the solid insulator. (4) The electrostatic dust removal device according to claim 1, wherein the first electrode and the second electrode are arranged in a parallel plate shape. (5) The electrostatic dust removal device according to claim 1, wherein the filter element is formed in advance to match the shape of the ventilation path. (6) The electrostatic dust removal device according to claim 1, wherein the filter element is made of metallic wool. (7) The electrostatic dust removal device according to claim 6, wherein the metallic wool is steel wool. (8) The electrostatic dust removal device according to claim 1, wherein the forced ventilation means is a motor-driven fan provided at the rear end of the ventilation path. (9) The electrostatic dust removal device according to claim 1, characterized in that a pre-filter is provided at the front of the ventilation path. (10) The electrostatic dust removal device according to claim 1, characterized in that an activated carbon filter is provided at the rear of the ventilation path. (11) The electrostatic dust removal device according to claim 1, wherein the solid insulator is ceramic. (12) The electrostatic dust removal device according to claim 1, wherein the solid insulator is an epoxy resin.