High conversion electrostatic precipitator

• US 4,725,289 A
• Filed: 11/28/1986
• Issued: 02/16/1988
• Est. Priority Date: 11/28/1986
• Status: Expired due to Fees

• Current Assignee: Quintilian B. Frank
• Original Assignee: Quintilian B. Frank
• Inventors: Quintilian, B. Frank
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/935,972
• Time in Patent Office: 445 Days
• Field of Search: 55/2, 55/128-130, 55/133, 55/136, 55/137, 55/149, 55/113, 55/154
• US Class Current: 95/76
• CPC Class Codes: B03C 3/09 characterised by presence of stationary flat electrodes arranged with their flat surfaces at right angles to the gas stream
• CPC Class Codes: B03C 3/36 Controlling flow of gases or vapour

Abstract

An electrostatic precipitator with an inlet and outlet duct having corona forming discharge electrodes to ionize the particulate in the gas stream, and multi-lateral stages of collecting zones to collect particulate from the gas stream by impingement and polarity action. The collecting zones are isolated from the flowing gas so the collected particulate can fall away from the gas stream and avoid intermixing with the gas during the normal cycle of operation and during rapping, to minimize particulate re-entrainment. An improved system of balancing the gas stream as it enters the precipitator and during the course of movement through the collecting zones includes flow dividers located between the edges of the collecting electrodes and movable downstream to provide larger flow openings and movable upstream to provide smaller flow openings, thus producing desired flow control. The flow dividers can be set in desired position by making an adjustment at attaching brackets either locally or by remote control through a bell-crank linkage. These features produce uniform flow and gas cleaning through all collecting zones.

Claims

1. A system for electrostatic precipitator deposition of material from a stream of gas flowing in a direction from upstream to downstream in a housing, comprising:

means for producing a swaying deposition path of said stream of gas, including a plurality of rows of alternately first and second negative electrodes, said first and second negative electrodes and said rows being transverse to said flow direction and defining respective spacings between said first and second negative electrodes, the first and second negative electrodes having first and second edges respectively and in each row being staggered with respect to the first and second negative electrodes of next adjacent rows upstream and downstream from it, a plurality of positive electrodes in rectangular-grid disposition, each positive electrode being located in-line between a first edge of a first negative electrode and a second edge of a first negative electrode adjacently downstream from the first edge of the first negative electrode, thereby producing said swaying deposition path.

2. A system as recited in claim 1, wherein each of the first and the second negative electrodes comprises an elongate member with a respective width, and wherein said width of the first negative electrodes is substantially greater than the width of the second negative electrodes.

3. A system as recited in claim 2, wherein each of the first negative electrodes has a prow-like protrusion symmetrical to the width thereof and extending upstream and having on either side thereof flat portions terminating in said first and second edges, and said first and second edges being rounded.

4. A system as recited in claim 3, wherein each of said second negative electrodes has a body shaped like a "V", with the apex of the "V" facing upstream and with first and second edges curved in said upstream direction.

5. A system as recited in claim 4, wherein means is provided for adjusting flow of gas through said spacings, comprising means for adjusting in upstream/downstream direction the location of a plurality of said second negative electrodes.

6. A system as recited in claim 4, wherein means is provided for adjusting flow of gas through said spacings, comprising means for adjusting the angular disposition in upstream/downstream direction of a plurality of said second negative electrodes.

7. A system as recited in claim 2, wherein each of the first negative electrodes has a prow-like protrusion in the form of a plate protruding in an upstream direction centrally therefrom, and wherein said prow-like protrusion has a rounded edge in said upstream direction.

8. In an electrostatic precipitator system for collecting suspended matter from a primary flowing gas stream comprising a housing with inlet and outlet openings, a plurality of discharge electrodes for ionizing suspended matter, a plurality of collecting electrodes with rounded edges for resisting arcing and re-enforced by respective central trough-shaped depressions, said plurality of collecting electrodes located at said housing in parallel row arrangement with gas stream flow spaces between them forming a plurality of collection zones, said collecting electrodes including first negative electrodes and second negative electrodes, the second negative electrodes comprising a plurality of flow dividers, each said row having a plurality of said flow dividers in the respective flow spaces, said flow dividers and first negative electrodes being staggered in each row relative to adjacent rows, thereby breaking up said primary flowing gas stream into a plurality of smaller gas streams, said plurality of smaller gas streams being directed to flow in a swaying manner and always in downstream direction, alternately contracting and expanding and forming hour-glass patterns in combination with adjoining said smaller gas streams of said plurality.

9. A system as recited in claim 8, wherein is provided a first plurality of corona discharge electrodes spaced upstream of said collecting electrodes, and a second plurality of corona discharge electrodes spaced midway between said parallel rows of first negative electrodes and flow dividers and within said smaller gas streams for ionizing gas both before the gas enters the collection zones and after the gas enters the collection zones.

10. A system as recited in claim 9, wherein each plurality of collection zones, starts with a respective pair of impingement collection zones on the upstream side of each first negative electrode and of each flow divider followed by a pair of eddy zones on the downstream side of each first negative electrode and each flow divider, thereby producing four zones of collection per corona discharge electrode.

11. An improved method of creating flow resistance and balance at an inlet flow end of a flowing gas purifying electrostatic precipitator system having said inlet flow end and downstream therefrom a plurality of rows of laterally spaced plates transverse to the flow of gas, and in each row between said laterally spaced plates locating respective flow dividers for forming inlet flow apertures for improving gas distribution thereinto and stratification downstream therefrom, comprising the steps:

(a) moving flow dividers at the inlet flow end to vary said inlet flow apertures; and

(b) moving flow dividers spaced from said inlet flow apertures within rows of said plurality of rows and thereby creating flow resistance and breaking up stratification.

12. A method of producing desired flow resistance and balance in selected locations in a path of flowing gas in an electrostatic precipitator that is subject to rapping, and providing quiescent zones clear of the flowing gas for receiving collected particulate and minimizing particulate re-entrainment during said rapping, comprising the steps:

(a) interposing in the flowing gas a first row of collecting electrode plates having spaces between them and disposed transverse to the flowing gas, (b) diverting from selected locations the flowing gas by interposing a second row of collecting electrode plates downstream from the first row of collecting electrode plates and staggered laterally with respect thereto, thereby providing said quiescent zones;

(c) interspersing a respective flow divider between collecting electrode plates in each said row and (d) repeating steps (a) (b) and (c) above.

13. A method as recited in claim 12, having the additional steps of:

(e) moving all said flow dividers in a direction perpendicular to said rows and thereby changing said spaces, while (f) observing said flow resistance and balance to select locations for fastening said flow dividers, and (g) fastening all said flow dividers in said selected locations.

14. A system for balancing flow resistance in a gas-flow purifying electrostatic precipitator having a plurality of electrostatic elements having lateral spacings in a row transverse to said gas flow, characterized by:

every alternate electrostatic element being a flow divider and having an adjustment means permitting moving all said flow dividers in a direction transverse to said row and changing said spacings, and a bellcrank mechanism for holding said flow dividers for movement together when moved.