SPARK TOLERANT ELECTROSTATIC PRECIPITATOR

Abstract

An electrostatic precipitator particle collection unit with a particle collecting electrode and a repelling electrode fabricated with static dissipative materials. The static dissipative material may be a polymer, may be a synthetic polymer, and may be a moldable polymer. The electrode plates may be formed from thermoplastic or thermoset polymer.

Claims

1. An electrostatic precipitator electrode pair comprising a 1.sup.st electrostatic precipitator electrode element arranged parallel to a second electrostatic precipitator electrode element, wherein said first electrode element is configured for connection at a first connection location to a first electrical potential and said second electrostatic precipitator electrode element is configured for connection at a second connection location to a second electrical potential and where a difference between said first electrical potential and said second electrical potential is a high voltage sufficient to create an electrostatic field to repel charged particles away from one of said electrostatic precipitator electrode elements and attract said charged particles toward another electrostatic precipitator electrode element; wherein said first connection location is remote from said second connection location; and wherein said first electrostatic precipitator electrode element resistivity along a current flow path between said first connection location and a location corresponding to said second connection location is at a level sufficient dissipate spark events.

2. The electrostatic precipitator electrode pair according to claim 1 wherein said first electrostatic precipitator electrode includes an interruption which extends said current flow path.

3. The electrostatic precipitator electrode pair according to claim 2 wherein said interruption is a nonconductive segment arranged between said first connection location and a position corresponding to said second connection location.

4. The electrostatic precipitator electrode pair according to claim 3 wherein said first connection location and said second connection location define a medial axis of said first electrostatic precipitator electrode element and said nonconductive segment transects said medial axis.

5. The electrostatic precipitator electrode pair according to claim 4 wherein said nonconductive segment extends from a first lateral edge of said first electrostatic precipitator electrode element.

6. The electrostatic precipitator electrode pair according to claim 5 further comprising a second nonconductive segment extending from a second lateral edge opposing said first lateral edge wherein said second non-conductive segment transects said medial axis further extending said current flow path.

7. The electrostatic precipitator electrode pair according to claim 6 wherein said first non-conductive segment and said second non-conductive segment established an S-shaped electrode element.

8. The electrostatic precipitator electrode pair according to claim 5 wherein said first non-conductive segment establishes a C-shaped electrode element.

9. The electrostatic precipitator electrode pair according to claim 2 wherein said first electrostatic precipitator electrode element comprises a static dissipative material.

10. The electrostatic precipitator electrode pair according to claim 9 wherein said static dissipative material is a moldable synthetic polymer.

11. The electrostatic precipitator electrode pair according to claim 10 further comprising a non-conductive segment of an electrostatic precipitator electrode element transecting a medial axis defined by said first connection location and said second connection location wherein said non-conductive segment is defined by absence of material forming said first electrostatic precipitator electrode element.

12. The electrostatic precipitator electrode pair according to claim 11 further comprising a stabilizing element in at least a portion of a region of said electrode element nonconductive segment wherein said stabilizing element is nonconductive.

13. The electrostatic precipitator electrode pair according to claim 10 further comprising a nonconductive segment of an electrostatic precipitator electrode element transecting said medial axis defied by said first connection location and said second connection location wherein said nonconductive segment is defined by insulating material molded into said first electrostatic precipitator electrode element.

14. The electrostatic precipitator electrode pair according to claim 10 further comprising a nonconductive segment of an electrostatic precipitator electrode element transecting a medial axis defied by said first connection location and said second connection location wherein said nonconductive segment is defined by treating said static dissipative material to locally increase resistance.

15. The electrostatic precipitator electrode pair according to claim 2 wherein said second electrostatic precipitator electrode element is configured to correspond to a configuration of said first electrostatic precipitator electrode element.

16. The electrostatic precipitator electrode pair according to claim 15 wherein said electrostatic precipitator electrode plates further comprising multiple interleaved non-conductive segments extending in opposing directions to define a switch back current path.

17. The electrostatic precipitator electrode pair according to claim 16 wherein said electrostatic precipitator electrode plates further comprising multiple interleaved non-conductive segments extending in opposing directions to define a switchback current path having at least 2 switchbacks.

18. The electrostatic precipitator electrode pair according to claim 17 wherein said electrostatic precipitator electrode plates further comprising multiple interleaved non-conductive segments extending in opposing directions to define a switchback current path having 2 to 10 switchbacks.

19. The electrostatic precipitator electrode pair according to claim 18 wherein said electrostatic precipitator electrode plates further comprising multiple interleaved non-conductive segments extending in opposing directions to define a switchback current path having 10 switchbacks.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0070] FIG. 1 shows the exploded mechanical schematics of an embodiment of an electrostatic air cleaner.

[0071] FIG. 2 shows the electrical schematics of an embodiment of an electrostatic air cleaner.

[0072] FIG. 3 shows an embodiment of an electrode plate and a connection configuration.

[0073] FIG. 4 shows an alternative embodiment of an electrode plate configuration.

[0074] FIG. 5 shows another alternative embodiment of an electrode plate configuration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0075] Before the present invention is described in further detail, it is to be understood that the invention is not limited to the embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing embodiments only, and is not intended to be limiting, since the scope of the present invention will be limited only by the appended claims.

[0076] Where a range of values is provided, it is understood that each intervening value, unless the context clearly dictates otherwise, between the upper and lower limit of that range is encompassed within the disclosure. Where the stated range includes one or both limits, ranges excluding either or both of those included limits are also included in the disclosure.

[0077] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, a limited number of the exemplary methods and materials are described herein.

[0078] It must be noted that as used herein and in the appended claims, the singular forms a, an, and the include plural referents unless the context clearly dictates otherwise.

[0079] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. Further, the dates of publication provided may be different from the actual publication dates, which may need to be independently confirmed.

[0080] The invention is described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art that changes, and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the claims, is intended to cover all such changes and modifications that fall within the true spirit of the invention.

[0081] FIG. 1 schematically shows an exploded view of an electrostatic air cleaner 101 shown. The exploded view of FIG. 1 shows side panels 102 of a case and a top panel 107. An ionizer assembly 103 may be in the front portion of the electrostatic air cleaner 101. A particle collection assembly 106 may be in the main body of the electrostatic air cleaner 101. The ionizer assembly 103 may include emitting wires (not shown in FIG. 1, see FIG. 2). The emitting wires are referred to as corona wire(s) or corona electrode(s). A mesh-like exciting electrode 104 is shown as part of the ionizer assembly 103. The exciting electrode 104 is arranged to cooperate with the corona electrode in establishing a corona field and generating ions. One mounting arrangement for the exciting electrode may include a slot 108 to receive the exciting electrode 104. The exciting electrode 104 (which is preferably earth grounded) may be easily removed through slot 108 for periodic cleaning. A topside panel 107 may include a handle. A high voltage power supply and controls may be mounted in the topside panel. The air cleaner 101 need not be configured with separate ionizer and particle collection assemblies. The components may be installed in a housing without being separated into assemblies.

[0082] The particle collection structure 106 may include a particle collecting electrode assembly 109 and a particle repelling electrode assembly 110. When the particle collecting electrode assembly 109 is inserted into the particle collecting structure housing 119, rails 111 may slidably engage slots 112. The particle repelling electrode assembly 110 may be secured on the opposite side of the collecting structure housing 119 from the mounting end of the particle collecting electrode assembly 109. The particle collecting electrode assembly 109 is preferably mounted to the particle collection structure housing 119 at the end opposite the ionizer assembly 103. A fan assembly 113, may be included in the electrostatic air cleaner 101 if needed. The fan assembly may not be needed if the ionizer assembly 103 and the particle collection structure 106 of the electrostatic air cleaner 101 is in a constrained airflow path such as HVAC ductwork, in an HVAC vent, or an exhaust vent. The intended airflow direction during normal operation is shown by arrow 120.

[0083] The collecting electrode assembly 109 may include a set of parallel collecting electrode plates 115 mounted to a collecting electrode mounting structure 116. The embodiment illustrated in FIG. 1 has the collecting electrode plates 115 connected at one edge and extending from the collecting electrode mounting structure 116. The repelling electrode assembly 110 may have a similar but reversed configuration having a plurality of repelling electrode plates 117 connected to a repelling electrode mounting structure 114.

[0084] The collecting electrode assembly 109 may include a mounting rail 111.

[0085] FIG. 2 schematically shows a simplified view of the electrode geometry of an electrostatic air cleaner 201. One or more fans 200 may be provided to control airflow. An ionizing stage 202 may be provided to generate ions. The intended airflow direction during normal operation is shown from left to right by arrow 210. The ionizing stage 202 may include one or more corona electrodes 203 which may be provided near an intake 211 of the electrostatic air cleaner 201. One or more exciting electrodes 204 may be provided near an intake 211 of the electrostatic air cleaner 201 and positioned to co-act with the corona electrode(s) 203. The corona electrode 203 may be a wire which is routed across the airflow path several times for example in front of each collecting electrode plate 212. The exciting electrode 204 may be a conductive grid that is connected to the ground or a ground side of a high-voltage power supply in the high-voltage power system 207. The high-voltage power system 207 may also include a controller and one or more sensors or other controls.

[0086] A particle collection stage 206 may be located downstream from the ionizing stage 202. The particle collection stage 206 may include a repelling electrode assembly 205 having one or more repelling electrode plates 205a and a collecting electrode assembly 209 having one or more collecting electrode plates 212. The collecting electrode assembly 209 is positioned to co-act with the repelling electrode assembly 205 so that charged particles move away from the repelling electrode and land on the collecting electrode plates 212. The collecting electrode plates 212 may alternate with parallel repelling electrode plates 205a in the particle collection stage 206. The ionizing stage 202 and the particle collection stage 206 are in an airflow path. The electrostatic air cleaner 201 may include one or more fans 200 to induce or affect airflow or the electrostatic air cleaner 201 may be in a constrained space with an externally induced airflow.

[0087] The airflow path may be selectively blocked by closing a blocking structure 214, such as shutters or a blast gate under the control of the high-voltage power system 207 or another controller.

[0088] An Amphenol SM-PWM-01A SMART Dust Sensor or a Waveshare Dust Sensor Detector Module with Sharp GP2Y1010AU0F are examples of the type of sensors that may be employed. The control system may also detect or use other environmental parameters including, but not limited to, elevation, air humidity, etc. Additional measures of environmental parameters or conditions allow for complicated and comprehensive power source control.

[0089] FIG. 3 shows an embodiment of an electrode plate in connection configuration. The electrode plates 301 and 302, for illustrative purposes, are shown separately from the other electrode plates and components of the electrode assemblies. The collecting electrode plate 301 is arranged adjacent and generally parallel to repelling electrode plate 302. In an actual device collecting several electrode plates 301 are interleaved with several repelling electrode plates 302. The high voltage output of high voltage power supply 303 may be connected to repelling electrode plate 302. It is understood that the connection to repelling electrode plate 302 may be via a connection to an assembled repelling electrode structure exhibiting multiple repelling electrode plates. The high voltage power supply 303 may be connected to the collecting electrode plate 301. Advantageously, the high voltage power supply 303 connection to collecting electrode plate 301 is spaced apart from and opposing the location of the connection of high voltage power supply 303 to the repelling electrode plate 302. The current permitted by a spark between collecting electrode plate 301 and repelling electrode plate 302 may be dissipated by the resistivity of the plates. The current flow path would be from the high voltage power supply through one of the electrode plates to the point of a spark and from the point of a spark on the other electrode plate to an opposing side of the high voltage power supply. Because voltage is related to current and resistance, the voltage drop across the adjacent plates during a spark will be at its lowest at the location of the spark and will increase along the current flow paths extending from the location of the spark. FIG. 3 shows that regardless of the location of a spark, the current flow path will be at least as long as the distance between the high voltage power supply connections to the respective electrode plates.

[0090] FIGS. 4 and 5 show alternative embodiments of electrode plate configurations intended to increase the length of the current flow path in the event of a spark. Current dissipation attributable to a spark will be dependent upon the resistivity of the electrodes. Increasing the current flow path will allow dissipation of current in electrodes having lower resistivity.

[0091] FIG. 4 shows a collecting electrode plate 401 which may be arranged adjacent to and parallel with repelling electrode plate 402. FIG. 4 shows that the connections of the respective electrode plates 401 and 402 to the high voltage power supply 403 are spaced from each other. The repelling electrode plate 402 has slots or cut-outs 404 so that it has a serpentine configuration. In order to add mechanical strength, the repelling electrode may include braces 405 of insulating material spanning each of the slots 404, illustrated as defining the serpentine structure of the repelling electrode plate. The collecting electrode plate 401 may also exhibit a serpentine configuration established by slots and may optionally have insulating braces to mechanically reinforced the collecting electrode plates at the location of the slots. The serpentine structure of the collecting plate need not match a serpentine structure of the repelling electrode plate 402. The serpentine configuration of the collecting electrode plate 401 may match the serpentine configuration of the repelling electrode plate 302. Alternatively, the serpentine structure of the collecting plate 401 may mirror the serpentine structure of the repelling electrode plate 402. If the structures of the respective plates match, insulating braces 405 may be utilized to mechanically reinforce 2 or more adjacent electrode plates. This has the advantage of mechanical simplicity, but the disadvantage of allowing creeping voltage leaks to particle deposits over a much shorter mechanical length. Having mirroring serpentine configurations, allows common mechanical braces to be used or the set of collecting electrode plates and different insulating braces to be used for the repelling electrodes. This will have the effect of facilitating a longer creeping voltage leak path.

[0092] FIG. 5 shows an electrode plate 501. The electrode plate 501 may be a collecting electrode plate or a repelling electrode plate. The electrode plate 501 may have a medium resistive segment 502 in a serpentine configuration integrated with insulating segments 503 filling the gaps between the switchbacks of the medium resistive segments 502 to define a serpentine configuration. The insulating segments 503 may be integrated with the medium resistance material of the medium resistive segment 502. The electrode plate 501 may be fabricated by various methods. One fabrication technique may be by injection, molding the serpentine structure 502 and subsequently placed in a second mold which permits injection of the insulating material 503. Alternatively, the same injection mold may be used but with gates in the areas designated for the insulating material followed by withdrawal of those gates and injection of insulated material in the spaces vacated by the gates. Another fabrication method may be by first molding a plate as a sheet and mechanically removing the areas where insulating material 503 will be inserted by a separate injection process. Another fabrication method may be by forming a unitary sheet and treating portions of the material of the sheet to increase or decrease resistivity to establish an extended flow path on a serpentine structure of highly resistive material. Medium resistive material may have surface resistivity greater than 10.sup.4 Ohms/sq., in the range of 10.sup.4 to 10.sup.12 Ohms/sq., in the range of 10.sup.6 to 10.sup.12 Ohms/sq., or in the range of 10.sup.10 to 10.sup.12 Ohms/sq.

[0093] The techniques, processes, and apparatus described may be utilized to control the operation of any device and conserve the use of resources based on conditions detected or applicable to the device.

[0094] The invention is described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and the invention, therefore, as defined in the claims, is intended to cover all such changes and modifications that fall within the true spirit of the invention.

[0095] Thus, specific apparatus for and methods of air cleaning devices have been disclosed. It should be apparent, however, to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the disclosure. Moreover, in interpreting the disclosure, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms comprises and comprising should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced.