Electric precipitator

Abstract: An electric precipitator comprising a plurality of discharge members (3) each having a plurality of spaced main discharge electrodes (3b) protruded from each longitudinal edge of the discharge member (3) and a plurality of spaced additional discharge electrodes (3c) protruded from each longitudinal edge of the discharge member (3) and arranged with the main discharge electrodes (3b) in an alternating manner, a plurality of charge members (4) each charge member having a plurality of spaced main charge electrodes (4a) formed at each longitudinal edge of the charge member (4) to have an arc groove shape and a plurality of spaced additional charge electrodes (4b) formed at each longitudinal edge of the charge member (4) to have an arc groove shape and arranged with the main charge electrodes (4a) in an alternating manner. Each additional discharge electrode (3c) has a length different from that of each main discharge electrode (3b). Each additional charge electrode (4b) has an arc length different from that of each main charge electrode (4a). An activated carbon filter is disposed to filter secondarily the charged dust particles and remove odor from the air.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an electric precipitator, and more particularly to an electrical precipitator with discharge and charge members and a dust collecting member. Description of the Prior Art Generally, such an electrical precipitator is a device for cleaning room air by electrically charging dust included in the room air sucked into the interior of precipitator by virtue of a rotation of a blowing fan driven by electric power with high voltage or naturally introduced into the interior of precipitator, attracting the charged dust to a precipitator member of the precipitator and then discharging the cleaned room air free of the dust out of the precipitator. As a conventional electrical precipitator, U.S. Patent No. 3,740,927 discloses an electrostatic precipitator comprising two electrostatic sections. The first section 10 includes one or more pairs of positively charged vertical plates between each pairs of which are positioned a plurality of negatively charged vertical wires, so that a Corona discharge may be developed between the vertical plates. The second section 20, which is contiguous to one end of the first section and constitutes an add-on for the first section, includes a plurality of metallic grids G21 to G26 which are parallel to each other, but perpendicular to the plates of the first section. The first and last grids G21 and G26 of the second section 20 may be connected to a source of voltage which does not create a Corona field, and the remaining grids G22 to G25 of the second section are floated between the first and last grids so as to become charged by voltage induced in such grids so that particles of matter entering the second section 20 and traversing the opening of the various grids will respond to the electric field between adjacent grids and to the aerodynamic flow pattern developed between all of the grids, so that the particulate matter may be collected and removed from the fluid medium. However, this electrical precipitator not only has a relatively complex and expensive construction, but also encounters a degradation in precipitation efficiency due to the floated metallic grids. Referring to FIGS. 2 and 3, there is illustrated another conventional electrical precipitator. As shown in FIGS. 2 and 3, the electrical precipitator to which electric power of high voltage level is applied comprises a discharge member 1 connected to a positive pole (not shown) and a charge member 2 connected to a negative pole (not shown). The discharge member 1 has a plurality of vertically extending sharp-pointed discharge protrusions 1a for electrically charging dust and deflecting the charged dust toward the charge member 2. On the other hand, the charge member 2 has a plurality of square holes 2a and a plurality of dust collecting portions 2b each extending vertically from one edge of each corresponding square hole 2a. The dust collecting portions 2b of charge member 2 are also connected to the negative pole. Each dust collecting portion 2b of the charge member 2 has the substantially same height as each discharge protrusion 1a of the discharge member 1. Each discharge protrusion 1a is centrally arranged in each corresponding square hole 2a of the charge member 2, as shown in FIG. 3. In the conventional electrical precipitator with the above-mentioned construction, dust included in air entering the precipitator is divided into particles by discharge waves emitted from the discharge protrusions 1a of discharge member 1 and simultaneously electrically charged to a positive polarity. The positively charged dust particles are attracted to and collected on the dust collecting portions 2b of charge member 2 to which a negative polarity is applied. In this electrical precipitator, however, dust passing through shaded corner portions of each square holes 2a of charge member 2, which portions are shown in FIG. 3, are discharged into a room, without being electrically charged. As a result, there are degradations in precipitation efficiency and room air cleaning effect. That is, the shaded portions of square holes 2a are called dead regions which are not affected by discharge waves emitted from the discharge protrusions 1a. Dust passing through these dead regions can not be electrically charged, so that air including dust is discharged into a room, without being cleaned. In the FR-A-745 621 an electric precipitator is disclosed which precipitator comprises the members as in the preamble of claim 1. This prior art precipitator, however, has still the disadvantage of discharging dust into a room without being electrically charged. SUMMARY OF THE INVENTION Therefore, the present invention has been made in view of the above-mentioned problems encountered in the prior arts and an object of the invention is to provide an electrical precipitator free of dead regions not affected by discharge waves and thus capable of maximizing the precipitation efficiency. In accordance with the present invention, this object can be accomplished by providing an electric precipitator comprising: a plurality of discharge members each having a plurality of spaced main discharge electrodes protruded from each longitudinal edge of the discharge member and a plurality of spaced additional discharge electrodes protruded from each longitudinal edge of the discharge member and arranged with the main discharge electrodes in an alternating manner, each of the additional discharge electrodes having a length different from that of each main discharge electrode; a plurality of charge members adapted to charge dust particles included in air entering the precipitator, together with the discharge members, each charge member having a plurality of spaced main charge electrodes formed at each longitudinal edge of the charge member to have an arc groove shape and a plurality of spaced additional charge electrodes formed at each longitudinal edge of the charge member to have an arc groove shape and arranged with the main charge electrodes in an alternating manner, each of the additional charge electrodes having an arc length different from that of each main charge electrode; a dust collecting member disposed rearwardly of the discharge and charge members and having a polarity different from that of the charged dust particles to collect the charged dust particles thereon; and an activated carbon filter disposed rearwardly of the dust collecting member and adapted to filter secondarily the charged dust particles and remove odor from the air. BRIEF DESCRIPTION OF THE DRAWINGS Other objects and aspects of the invention will become apparent from the following description of embodiments with reference to the accompanying drawings in which: FIG. 1 is a sectional view of a conventional electric precipitator; FIG. 2 is a partial perspective view of another conventional electric precipitator; FIG. 3 is a front view of the electric precipitator shown in FIG. 2; FIG. 4 is a front view of an electric precipitator according to the present invention; FIG. 5 is a cross-sectional view taken along the line A-A of FIG. 4; FIG. 6 is a partial perspective view of the electric precipitator according to the present invention; and FIG. 7 is a schematic front view of a part of the electric precipitator shown in FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 4 to 7, there is illustrated an electrical precipitator in accordance with the present invention. As shown in FIGS. 4 to 7, the electrical precipitator comprises a plurality of spaced discharge members 3. Each discharge member 3 comprises a discharge member body 3a connected to a source of voltage with positive polarity and provided with opposite stepped ends, a plurality of uniformly spaced main discharge electrodes 3b protruded from opposite longitudinal edges of the discharge member body 3a and a plurality of uniformly spaced additional discharge electrodes 3c protruded from opposite longitudinal edges of the discharge member body 3a. Each additional discharge electrode 3c is arranged between adjacent main discharge electrodes 3b so that the main and additional discharge electrodes 3b and 3c are arranged at each longitudinal edge of the discharge member body 3a in an alternating manner. The main and additional discharge electrodes 3b and 3c formed at the discharge member body 3a are disposed at a level higher than those of the opposite ends of the discharge member body 3a, by a height y. Each main discharge electrode 3b and each additional discharge electrode 3c formed at one longitudinal edge of the discharge member body 3a correspond to each additional discharge electrode 3c and each main discharge electrode 3b formed at the other longitudinal edge of the discharge member body 3a, respectively, to extend in an opposite manner. The main and additional discharge electrodes 3b and 3c have an Ω shape with a circular tip. The distance between adjacent main and additional discharge electrodes 3b and 3c is substantially uniform. The stepped opposite ends of discharge members 3 are coupled together. In accordance with the present invention, the electrical precipitator also comprises a plurality of charge members 4 each positioned at adjacent discharge members 3. Each charge member 4 comprises a charge member body 4c connected to a source of voltage with negative polarity, a plurality of uniformly spaced main charge electrodes 4a formed at opposite longitudinal edges of the charge member body 4c and a plurality of uniformly spaced additional charge electrodes 4b formed at opposite longitudinal edges of the charge member body 4c. Each main charge electrode 4a has an arc groove shape. Each additional charge electrode 4b also has an arc groove shape having a diameter substantially identical to that of each main charge electrode 4a, but an arc length smaller than that of the main charge electrode 4a. Each additional charge electrode 4b is arranged between adjacent main charge electrodes 4a so that the main and additional charge electrodes 4a and 4b are arranged at each longitudinal edge of the charge member body 4c in an alternating and contiguous manner. Each main charge electrode 4a and each additional charge electrode 4b formed at one longitudinal edge of the charge member body 4c correspond to each additional charge electrode 4b and each main charge electrode 4a formed at the other longitudinal edge of the charge member body 4c, respectively, to be arranged in an opposite manner. The discharge members 4 are coupled together at their opposite ends. The main and additional charge electrodes 4a and 4b of charge members 4 are disposed in flush with the main and additional discharge electrodes 3b and 3c of discharge members 3. After assembling the discharge and charge members 3 and 4 in a uniformly spaced manner, each main discharge electrode 3b and each additional discharge electrode 3c formed at each longitudinal edge of each discharge member 3 correspond to each main charge electrode 4a and each additional charge electrode 4b formed at the other longitudinal edge of each charge member 4 facing to the discharge member longitudinal edge, respectively, as shown in FIG. 6. With this arrangement, a plurality of uniformly spaced circular main electric fields can be developed in a line by main discharge electrodes 3b formed at each longitudinal edge of each discharge member 3 and main charge electrodes 4a facing to the main discharge electrodes 3b, as shown in FIG. 7. In similar, a plurality of uniformly spaced circular additional electric fields can be developed in a line by additional discharge electrodes 3c formed at each longitudinal edge of each discharge member 3 and additional charge electrodes 4b facing to the additional discharge electrodes 3c. Each additional electric field are arranged between adjacent main electric fields, to overlap therewith. Accordingly, there is no dead region which are not affected by discharge waves emitted from the discharge electrodes 3b and 3c. The distance X 1 between the curved surface of each main discharge electrode 3b and the curved surface of each corresponding main charge electrode 4a is identical to the distance X 2 between the curved surface of each additional discharge electrode 3c and the curved surface of each corresponding additional charge electrode 4b (FIG. 7). On the other hand, the height y of the main and additional discharge electrodes 3b and 3c of discharge members 3 should be larger than the distances X 1 and X 2 . Where the height y is smaller than the distance X 1 or X 2 (y < X 1 or X 2 ), a charge movement from discharge members 3 is not achieved toward charge members 4, but undesirably achieved toward a dust collecting member 5 disposed rearwardly of the discharge and charge members 3 and 4. As shown in FIG. 4 and 5, the dust collecting member 5 has a strip structure wound around protrusions 7 formed in two lines at each lateral portion of a precipitator case 6, in a zig-zag manner. At rear of the dust collecting member 5, an activated carbon filter 9 is fixedly attached to opposite ends of the precipitator case 6. The activated carbon filter 9 serves to secondarily filter air including dust not collected by the dust collecting member 5 and to remove odor from the air introduced therein and discharge the cleaned air into a room. Now, operation of the precipitator according to the present invention will be described. Air is introduced in the precipitator case 6, under a condition that voltage of positive polarity is applied to the discharge members 3 while voltage of negative polarity is applied to the charge members 4 and the dust collecting member 5. Accordingly, dust included in the introduced air is divided into particles by discharge waves continuously emitted from the main and additional discharge electrodes 3b and 3c of discharge members 3 and simultaneously electrically charged to positive polarity. At this time, most of dust particles included in the air introduced in the precipitator case 6 can be electrically charged to positive polarity, in that the effect of discharge waves with high voltage is large by virtue of the provision of a plurality of main and additional discharge electrodes 3b and 3c and a plurality of main and additional charge electrodes 4a and 4b. The positively charged dust particles are attracted to and collected on the dust collecting member 5 exhibiting negative polarity. On the other hand, the air including dust particles not collected by the dust collecting member 5 is filtered through the activated carbon filter 9 prior to its discharge into a room and simultaneously free of odor so that cleaned air can be discharged into the room. Thus, the room air can be effectively cleaned. As apparent from the above description, the present invention provides an electric precipitator capable of maximizing the discharge efficiency by a plurality of discharge electrodes and a plurality of charge electrodes developing a plurality of circular electric fields arranged in lines and maximizing the precipitation efficiency by a secondary filtering obtained by an activated carbon filter.

Claims: An electric precipitator comprising: a plurality of discharge members (3) each having a plurality of spaced main discharge electrodes (3b) protruded from each longitudinal edge of the discharge member (3) and a plurality of spaced additional discharge electrodes (3c) protruded from each longitudinal edge of the discharge member (3) and arranged with the main discharge electrodes (3b) in an alternating manner, each of the additional discharge electrodes (3c) having a length different from that of each main discharge electrode (3b); a plurality of charge members (4) adapted to charge dust particles included in air entering the precipitator, together with the discharge members (3), characterized in that each charge member (4) has a plurality of spaced main charge electrodes (4a) formed at each longitudinal edge of the charge member (4) to have an arc groove shape and a plurality of spaced additional charge electrodes (4b) formed at each longitudinal edge of the charge member (4) to have an arc groove shape and arranged with the main charge electrodes (4a) in an alternating manner, each of the additional charge electrodes (4b) has an arc length different from that of each main charge electrode (4a); a dust collecting member (5) is disposed rearwardly of the discharge and charge members (3, 4) and having a polarity different from that of the charged dust particles to collect the charged dust particles thereon; and an activated carbon filter (9) is disposed rearwardly of the dust collecting member (5) and adapted to filter secondarily the charged dust particles and remove odor from the air. An electric precipitator according to claim 1, wherein each of the main and additional discharge electrodes (3b, 3c) has a circular tip. An electric precipitator according to claim 1 or 2, wherein the discharge members (3) and the charge members (4) have the same height. An electric precipitator according to any of claims 1 to 3, wherein the main discharge electrodes (3b) formed at each longitudinal edge of each discharge member (3) and the main charge electrodes (4a) corresponding to the main discharge electrodes (3b) develop a plurality of uniformly spaced circular main electric fields in a line and additional discharge electrodes (3c) formed at each longitudinal edge of each discharge member (3) and additional charge electrodes (4b) corresponding to the additional discharge electrodes (3c) develop a plurality of uniformly spaced circular additional electric fields in a line, each additional electric field being arranged between adjacent main electric fields, to overlap therewith. An electric precipitator according to any of claims 1 to 4, wherein the distance between each main discharge electrode (3b) and each corresponding main charge electrode (4a) is identical to the distance between each additional discharge electrode (3c) and each corresponding additional charge electrode (4b). An electric precipitator according to any of claims 1 to 5, wherein each discharge member (3) has opposite stepped ends disposed at a level lower than those of the main and additional discharge electrodes (3b, 3c) thereof and the main and additional charge electrodes (4a, 4b) of each corresponding charge member (4), by a height larger than both the distance between each main discharge electrode (3b) and each corresponding main charge electrode (4a) and the distance between each additional discharge electrode (3c) and each corresponding additional charge electrode (4b). An electric precipitator according to any of claims 1 to 6, wherein the dust collecting member (5) has a strip structure wound around protrusions (7) formed in two lines at each lateral portion of a precipitator case (6), in a zigzag manner.

Inventors: YONG-HYUN GILL, YONG-HYUN, GILL
Applicants: SAMSUNG ELECTRONICS CO LTD, SAMSUNG ELECTRONICS CO. LTD.
Application year: 1993
Main classification: B03C3
IPC codes: B03C3