US3793804A - Collector electrode for electrostatic precipitator - Google Patents

Collector electrode for electrostatic precipitator Download PDF

Info

Publication number
US3793804A
US3793804A US00244659A US3793804DA US3793804A US 3793804 A US3793804 A US 3793804A US 00244659 A US00244659 A US 00244659A US 3793804D A US3793804D A US 3793804DA US 3793804 A US3793804 A US 3793804A
Authority
US
United States
Prior art keywords
electrode
strips
channels
strip
legs
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00244659A
Other languages
English (en)
Inventor
W Steuernagel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
GEA Group AG
Original Assignee
Metallgesellschaft AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Metallgesellschaft AG filed Critical Metallgesellschaft AG
Application granted granted Critical
Publication of US3793804A publication Critical patent/US3793804A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
    • B03C3/00—Separating dispersed particles from gases or vapour, e.g. air, by electrostatic effect
    • B03C3/34—Constructional details or accessories or operation thereof
    • B03C3/40—Electrode constructions
    • B03C3/45—Collecting-electrodes
    • B03C3/47—Collecting-electrodes flat, e.g. plates, discs, gratings

Definitions

  • the present invention relates to electrostatic precipitators, filters and like particle-removing apparatus and, more particularly, to a collector-electrode arrangement for an electrostatic precipitator.
  • an electrostatic precipitator comprises an electrode system including corona-discharge electrodes and collector electrodes, the latter being spaced apart to define channels for a fluid traversing the system.
  • Means are provided for inducing a gas flow through the precipitator and along the electrode system and means may be provided for removing the collected particles.
  • the latter means may include a rapping device for imparting impulsive shocks to the collector electrodes thereby causing any accumulated materials to fall into collector bins or the like.
  • the corona discharge generated at the discharge electrodes ionizes the gases and an electric charge is thereby imparted to the solid particles contained therein, which particles cannot readily be removed by filtering, sedimentation and other methods.
  • the particles are attracted to and tend to accumulate upon the collector electrodes which have an opposite charge and induce adhesion by electrostatic forces.
  • the electrostatic precipitator follows or is downstream of a mechanical separator in which particles of larger size are recovered.
  • collector-electrode strips may be joined together contiguously along their longitudinal edges to form collector electrodes having a height of 8 to 12 meters and a relatively close spacing, the coronadischarge electrodes being arrayed between the cllector electrodes.
  • the particle-containing gas stream may pass horizontally through the spaces between the vertical collectorelec'trode panels whereby the particles contained in the gas, having received an ionic charge from the corona electrodes, are attracted to the panels and collect thereon.
  • the panels are subjected to periodic rapping or vibration, whereupon the accumulations of solids fall toward the collecting bins mentioned earlier, especially when the cascade of solids is not broken up or carried away by the gas. Ultimately the dust agglomerates and falls in relatively large flakes.
  • the collector electrodes have a shape which does not conform substantially to the requirements of the system, turbulence is induced in the gases and the rapping or dust-shedding process is interfered with. Dust from the cascade is entrained by the gas and carried through the precipitator channels and must be reprecipitated at considerable cost and reduction of efficiency.
  • the collector electrodes For efficient removal of the collector electrodes, moreover, the latter must be strips which are stiff and easily vibratable so that the vibrational energy applied by the rapping head is distributed throughout the collector-electrode panels without substantial damping.
  • the problem of vibrational damping stems from the fact that a thin sheet-metal member, engaged at two edges, constitutes a membrane capable of internal deformation to the extent that such rapping energy is converted to mechanical deformation. Therefore, this energy is lost as dust-shedding energy.
  • the collector electrodes are provided with a profiled configuration, i. e., are deformed to have channels, crests, corrugations or beads which stiffen the otherwise fiat central portion.
  • High vibratability and minimum damping of a collector-electrode strip is not, however, sufficient to insure high collecting power or efficiency because the rapping of the electrode may result in the formation of a dust cloud or agitation of the dust as noted earlier.
  • low-flow zones in the channels traversed by the gas between the collector plates and in which the velocity of the gas drops.
  • Such low-flow zones are able to prevent dynamic entrainment of the dust particles or to produce the necessary velocity reduction of the gas to allow sedimentation of any particles which may have been entrained.
  • the low-flow zones may be formed by chambers produced by deformation of the sheet-metal electrodes and can constitute dust-receiving compartments to facilitate removal of the dust. The profile of the electrodes forming such chambers, of course, further stiffens the electrode strips.
  • Adjacent collector-electrode strips are often locked together in tight hook joints as may be made, for example, in the sheet-metal art by clamping two hook portions in interfitting relationship. They also may be joined by welding or riveting or may be connected in some other rigid manner so that the, resulting collector electrode panel is continuous in the sense that no openings are provided and the array is as stiff as possible.
  • a close spacing of the collector electrode panels, as described above, has the disadvantage that a strictly straight or aligned arrangement of the electrodes is impossible in practice and assembly results in bends and distortions. There is, consequently, a tendency for certain portions of the collector-electrode panels of conventional construction to be closer or further from one another and from the array of corona discharge electrodes. This not only may adversely affect gas flow but may result in undesired arcing at certain locations.
  • the collector electrodes described in the aforementioned application generally are strip-shaped and are composed of sheet metal with a thickness of 1 to 1.5 mm and a hight in excess of the width of the panels which have generally flat or planar central portions and trapezoidal longitudinal-edge portions.
  • the edge portions are unitarily and integrally deformed in trapezoidal profiles along each edge of the strip with at least one freed leg forming part of each trapezoid.
  • the leg is formed with an outwardly bent flange or foot so that, when the collector strips are deposited in substantially contiguous relationship, side by side in a common plane, the legs of adjoining trapezoids reach toward each other and form an overlap with an air gap between them. The gap thus forms a labyrinth seal.
  • the longitudinal-edge portions of the collector electrodes thus define low-flow trapezoidal receiving chambers by means of which collected dust can be discharged to the bins without disturbances which might otherwise cause reentrainment of the dust with the gas stream.
  • the collector-electrode strips have a planar stiffened intermediate portion extending over the major part of the area of the strip and at the lateral edges are stiffened trapezoidally such that the outer legs of the trapezoidal stiffening profile extend below the base along of the trapezoid.
  • the outer angle portion or foot of a pair of adjoining strips overlap one another while the major portions of the legs lie parallel to one another but are spaced apart by distances slightly greater than the width of the feet.
  • a collector-electrode strip thus comprises three shallow trapezoids or troughs of trapezoidal profile which are geometrically congruent or similar and which are open at their broad bases while being oriented at offset between the adjacent troughs.
  • one trough opens at its broad base at one side of the strip
  • the adjoining troughs opens at the opposite side while the next trough opens again atthe first side.
  • the leg of the outer trapezoids (which open toward the same side) are bent at right angles to form feet, flanges or rims at or below the plane of the broad base mentioned earlier, the latter plane simultaneously including the flattened crest formed by the narrow base of the central trapezoidalsection trough.
  • this outwardly bent leg portion is preferably less than the length of the leg so that the angle portions of a pair of adjoining electrode strips, each of which is rotated in space through a 180 with respect to the other, cover almost completely an air gap between these trapezoids located substantially along the aforementioned base planes.
  • the collector-electrode strips constituted in this manner have the advantage that the flattened profiles formed by the three trapezoidal troughs increase the stability of the electrode panel and enable the gas flow to hug the surfaces of the electrode with less flow separation than is the case with earlier systems.
  • the higher stability and stiffness increases the ability of the electrode to vibrate and allows increased cleaning with low intensity rapping.
  • the angled portions of the trapezoidal legs along the opposite edges of the strip almost completely cover the air gaps, the plates remain free to expand and allow assembly of the electrode panel within greater manufacturing tolerances. It has been found to be advantageous, moreover, to produce the strips by rolling on a hot-strip mill to a thickness of l to 15 mm.
  • the electrode strips can be stacked or nested with facility. Shipping and storage space and costs are thereby reduced.
  • FIG. 1 is an end view of an electrode strip according to the present invention
  • FIG. 2 is a transverse cross-sectional view, partly in diagrammatic form, showing the relationship of two collector electrodes with other elements of an electrostatic precipitator;
  • FIG. 3 is a fragmentary elevational view of the lower edge of the array.
  • FIG. 4 is a detailed view illustrating the junction between adjacent elements according to the present invention.
  • Each collector-electrode strip thus comprises three open trapezoidal section shallow channels represented at 1a, 1b and 1c, the channels being indicated generically at 1 in FIG. 2.
  • Trapezoidal channels 1a and 1c are denominated outer channels and open codirectionally to the left in FIG. 1 while the channel lb is denominated a central or intermediate channel and opens to the right. All of the channels open in the direction of the broad base of the trapezoid.
  • the narrow bases of the channels la 1c lie in two planes P' and P" which define the opposite faces of the electrode strip.
  • the channels la 1c are separated by flanks 2 inclined at angles a of substantially 105(i with the narrow base or floor of the channel.
  • the outer legs 20 are similarly inclined to the narrow base but have angled outer portions or feet 3 including angles )8 with the legs 20 wherein B 90 (i 5).
  • the length p of the foot 3 will be equal to about W w where W is the width of the broad base and w is the width of the narrow base of the trapezoid.
  • the legs 2 and 2a have lengths L approximately equal to W w)/[2sin (a 90)] such that the junction between the foot 3 and the leg 2a lies substantially in the plane P".
  • the narrow bases of the trapezoidal channels are preferably formed with corrugations or parallel beads, represented generally at 10.
  • the depth of each of the recesses 10, which likewise is of trapezoidal configuration and extends the full length of the strip, may be equal to l 1.5 mm or greater and is approximately equal to 1 to 3 times the thickness of the electrode strip.
  • the transverse width of each of the corrugations 10 may be approximately 7 20 times the thickness t of the plate which is between 1 and 1.5 mm as indicated earlier.
  • troughs of such depths D may be approximately one third to one fifth of the narrow-base width w and approximately one quarter to one sixth of the width W of the broad base.
  • Two corrugations 10 may be provided along the narrow base of each of the trapezoidal channels.
  • FIG. 2 shows how the electrode strips may be positioned contiguously to form the panels 11 and 12 defining a gas channel 13 between them.
  • the coronadischarge electrodes 4 are disposed in a parallel array between the two electrode panels and are connected to a high voltage source 14 as represented in FIG. 2.
  • the collector electrodes may be at ground potential. Since the subsequent strips are rotated through 180 with respect to one another, the air spaces 5 between the adjacent strips are almost completely covered by the angled portions 3, the legs 2a and the outer trapezoid portions along the plane P and P".
  • the air flow along the collector electrode strips is not obstructed and no transverse flow between the adjacent collectorelectrode strips will develop. Because the strips can be made with large tolerances, one need only arrange the angled portions 3 and the legs 2a so that the latter do not extend into the gas space and do not protrude beyond the adjacent legs. We may recess the junction between angled portion 3 and leg 2a somewhat inwardly, e. g., by 5 to 10 mm, if desired, of the associated plan P'or P".
  • the electrostatic precipitator also may include a fan or like means represented at 15 for inducing a flow of air between the collector electrode panels and a rapping device which may comprise a motor 16 having an eccentric hammer 17 adapted to strike an anvil l8 affixed to the upper edge of the panel.
  • a rapping device which may comprise a motor 16 having an eccentric hammer 17 adapted to strike an anvil l8 affixed to the upper edge of the panel.
  • a fastening strip 19 to which the electrode strips 20, 21, 22 etc. are secured by bolts or rivets 23, the strips being constituted of the configuration previously described.
  • the rapper comprises an anvil 24 at the end of the bar or strip 19, a hammer 25 and an eccentric or crank arrangement 26 of the motor 27 carrying this hammer.
  • a collector electrode for an electrostatic precipitator comprising at least one sheet-metal strip uniformly subdivided along its width with a plurality of longitudinally extending trapezoidal cross section troughs alternately open in opposite directions along the broad bases of the trapezoid and of geometrically similar configuration, said troughs being of odd number and having depths smaller than the widths of the channels, said channels including at least two outer channels having outwardly divergent legs formed with outwardly angled portions at free extremities of said legs, the narrow bases of said channels defining respective planes along opposite surfaces of the strip, said legs lying within the region defined between said planes.
  • the electrode defined in claim 1, comprising a second electrode strip geometrically identical to the first mentioned electrode strip and rotated relatively thereto through and means securing said strips in laterally adjoining relationship with respective legs and angled portions in overlapping relationship whereby an air gap is defined between the overlapping legs and angled portions will be substantially completely covered thereby.
  • each of said electrode strips is provided with three such channels.
  • each of the trapezoidal cross-section channels is formed with a plurality of longitudinally extending corrugations.
  • electrode strips are composed of sheet-metal having a thickness of approximately 1 to 1.5 mm.

Landscapes

  • Electrostatic Separation (AREA)
US00244659A 1971-04-20 1972-04-17 Collector electrode for electrostatic precipitator Expired - Lifetime US3793804A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19717114982U DE7114982U (de) 1971-04-20 1971-04-20 Niederschlagselektrodenstreifen

Publications (1)

Publication Number Publication Date
US3793804A true US3793804A (en) 1974-02-26

Family

ID=6620650

Family Applications (1)

Application Number Title Priority Date Filing Date
US00244659A Expired - Lifetime US3793804A (en) 1971-04-20 1972-04-17 Collector electrode for electrostatic precipitator

Country Status (6)

Country Link
US (1) US3793804A (de)
JP (1) JPS551102B1 (de)
CS (1) CS164920B2 (de)
DE (1) DE7114982U (de)
GB (1) GB1358123A (de)
RO (1) RO59485A (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4526591A (en) * 1982-12-13 1985-07-02 Allis-Chalmers Corporation Electrode rapping arrangement
US4614526A (en) * 1984-03-10 1986-09-30 Metallgesellschaft Aktiengesellschaft Dust collector with improved collecting electrodes
EP1792659A1 (de) * 2005-11-30 2007-06-06 VTT Industrial Systems Entwurf eines elektrostatischen Abscheiders
US8414687B2 (en) 2010-09-23 2013-04-09 Chevron U.S.A. Inc. Method to control particulate matter emissions
CN108097466A (zh) * 2018-01-22 2018-06-01 佛山市科蓝环保科技股份有限公司 一种自动清洗阳极板的工业油烟净化设备
CN113634374A (zh) * 2021-09-14 2021-11-12 崔英福 环向复合除尘装置及除尘方法
RU2810475C1 (ru) * 2023-04-04 2023-12-27 Акционерное общество "Кондор-Эко" Способ изготовления элемента осадительного электрода электрофильтра

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6372440U (de) * 1986-10-29 1988-05-14

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1345790A (en) * 1920-05-10 1920-07-06 Lodge Fume Company Ltd Electrical deposition of particles from gases
GB747301A (en) * 1954-04-07 1956-04-04 Carves Simon Ltd Improvements relating to collecting electrodes for electrostatic precipitators
US2946400A (en) * 1956-08-27 1960-07-26 Svenska Flaektfabriken Ab Collecting electrode for electrofilter
GB963109A (en) * 1962-07-04 1964-07-08 Metallgesellschaft Ag A collecting electrode for an electrostatic precipitator
US3282029A (en) * 1963-06-19 1966-11-01 Metallgesellschaft Ag Emitting electrode construction for electrostatic separators
US3418792A (en) * 1967-06-26 1968-12-31 Koppers Co Inc Modular collector electrode for electrostatic precipitators

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1345790A (en) * 1920-05-10 1920-07-06 Lodge Fume Company Ltd Electrical deposition of particles from gases
GB747301A (en) * 1954-04-07 1956-04-04 Carves Simon Ltd Improvements relating to collecting electrodes for electrostatic precipitators
US2946400A (en) * 1956-08-27 1960-07-26 Svenska Flaektfabriken Ab Collecting electrode for electrofilter
GB963109A (en) * 1962-07-04 1964-07-08 Metallgesellschaft Ag A collecting electrode for an electrostatic precipitator
US3282029A (en) * 1963-06-19 1966-11-01 Metallgesellschaft Ag Emitting electrode construction for electrostatic separators
US3418792A (en) * 1967-06-26 1968-12-31 Koppers Co Inc Modular collector electrode for electrostatic precipitators

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4526591A (en) * 1982-12-13 1985-07-02 Allis-Chalmers Corporation Electrode rapping arrangement
US4614526A (en) * 1984-03-10 1986-09-30 Metallgesellschaft Aktiengesellschaft Dust collector with improved collecting electrodes
EP1792659A1 (de) * 2005-11-30 2007-06-06 VTT Industrial Systems Entwurf eines elektrostatischen Abscheiders
US8414687B2 (en) 2010-09-23 2013-04-09 Chevron U.S.A. Inc. Method to control particulate matter emissions
CN108097466A (zh) * 2018-01-22 2018-06-01 佛山市科蓝环保科技股份有限公司 一种自动清洗阳极板的工业油烟净化设备
CN108097466B (zh) * 2018-01-22 2024-03-12 佛山市科蓝环保科技股份有限公司 一种自动清洗阳极板的工业油烟净化设备
CN113634374A (zh) * 2021-09-14 2021-11-12 崔英福 环向复合除尘装置及除尘方法
CN113634374B (zh) * 2021-09-14 2024-04-02 崔英福 环向复合除尘装置及除尘方法
RU2810475C1 (ru) * 2023-04-04 2023-12-27 Акционерное общество "Кондор-Эко" Способ изготовления элемента осадительного электрода электрофильтра

Also Published As

Publication number Publication date
GB1358123A (en) 1974-06-26
CS164920B2 (de) 1975-11-28
DE7114982U (de) 1971-07-08
JPS551102B1 (de) 1980-01-11
RO59485A (de) 1976-02-15

Similar Documents

Publication Publication Date Title
US4175938A (en) Apparatus for the separation of liquid droplets from a gas stream entraining same
US5401301A (en) Device for the transport of materials and electrostatic precipitation
US3755991A (en) Collector electrode for electrostatic precipitator
EP0175945B1 (de) Kehrmaschine mit Vorreiniger und/oder Entnebelungsvorrichtung
EP2471602B1 (de) Elektrische Abschirm-Vorrichtung für Strukturen in der Nähe von Hochspannungsteilen elektrostatischer Filter
US3793804A (en) Collector electrode for electrostatic precipitator
US5076820A (en) Collector electrode structure and electrostatic precipitator including same
US4072478A (en) Mist remover
US3282029A (en) Emitting electrode construction for electrostatic separators
US3803809A (en) Electrostatic precipitator
US3418792A (en) Modular collector electrode for electrostatic precipitators
RU171615U1 (ru) Устройство для тонкой пылегазоочистки
US4848986A (en) Selfsupporting-corona-discharge electrode
US3807140A (en) Receiving electrode of plate-type electrostatic precipitator
US5759240A (en) Laminar flow electrostatic precipitator with sandwich structure electrodes
US2996144A (en) Collecting electrode
US3125426A (en) Collecting electrodes and electrode system
US4614526A (en) Dust collector with improved collecting electrodes
US3518813A (en) Extended discharge systems for electrostatic precipitators
JPS62277165A (ja) 静電集塵装置
US3514923A (en) Electrostatic prfcipitators
RU2036016C1 (ru) Электрофильтр
RU221867U1 (ru) Электрофильтр
US2529594A (en) Collecting electrode structure for electrical precipitators
US3200566A (en) Emission electrode for electrostatic precipitators