US2601906A - Discharge electrode system for electrical precipitators - Google Patents

Description

y 1952 H. A. WINTERMUTE 2,601,906

DISCHARGE ELECTRODE SYSTEM 'F'OR ELECTRICAL PRECIP ITATORS Filed Jan. 29, 1952 3 Sheets-Sheet 1 I 2o i l8 v I2 I Tfl--fl I uiluu nu EIUUU 22 29 3a 32 34 "134 INVENTOR HARRY A. WINTERMUTE ATTORNEYS July 1, 1952 H. A. WlNTERMUTE DISCHARGE ELECTRODE SYSTEM FOR ELECTRICAL PRECIPITATORS Filed Jan. 29, 1951 3 Sheets-Sheet 2 1 -1 I L I I I I I I 1 I I I I I I I I I ATTORNEY y 1,1952 H. A. WINTERMUTEL 2,601,906

DISCHARGE ELECTRODE SYSTEM FOR ELECTRICAL PRECIPITATORS Filed Jan. 29, 1951 '3 Sheets-Sheet 5 I ('1 I24 I I (a) (0 I: I, i 1' I00 (5?) (1 I24 (E) (j (5E v INVENTOR HARRY A. WINTERMUTE MQ W ATTORNEYS Patented July 1, 1952 U ITED. STATES. PATENT OFF-ICE DISCHARGE ELECTRODE SYSTEM FOR ELEo'rn-IoAL PREoIrrrAToRs Harry A. Wintermute', Plainfield, N. J., assignor to Research Corporation, New corporation of New York York, N. Y., a

Application'January 29, 1951,Serial No. 208,327

This invention relates to electrical precipita'-- tion apparatus for the separation of suspended materials from gases. I s

More particularly the invention relates to means for substantially eliminating or damping oscillation and swinging of flexible discharge electrodes in Cottrell type precipitators.

In most Cottrell type precipitators the discharge electrodes are long flexible electrical conductive members suspended from their upper ends between collecting electrodes Theseflexible discharge electrode members are held taut by a weight at their lower ends, and commonly, where there are a plurality of discharge. electrodes, they are tied together by means of a spacing framework or bar loosely engaging each.

of the electrodes just above the weights.

While this construction affords a very satis-. factory arrangement of supporting and centering discharge electrodes, the combination of long flexible electrodes with heavy weights at their lower ends will swing as a pendulum unless restrained.

Swinging of the electrodes appears to be caused by gas flow, changes in gas conditions and in the relative humidity or moisture content of the ,7 Claims. (01. 183-7) .2573. electrical operation. For example, .a change in gases to be cleaned has been found to initiate swinging, or the swinging may be started by the combined action of movement of gas through the treating zone of the precipitator and the electrical field maintained between the discharge and collecting electrodes. Generally the oscillation of the electrode system starts with a low amplie tude and gradually increases until a heavy arcing condition has been established between the.

discharge and collectingelectrodes thus greatly lowering the efiiciency of the precipitator.

In the past insulating supports have been used,

between the precipitator wall and the spacing framework, or the discharge electrodes have been made of stiff material to damp oscillation. ever, neither of these methods have proved very satisfactory, as the stiff electrodeshave a tendency, to act as springs and maintain rather than I damp the oscillation, and .when insulators are usedfor steadying they are adjacent the point of maximum fall of precipitatewhich often forms,

a conductive layer upon theinsulators.

It is therefore a principalobject of the inverttion to provide means for substantially preventing and damping the periodic swinging and oscillation of flexible discharge electrodes, thus permitting the electrical precipitation apparatus to be operated with greater efliciency and at a, higher potential than heretofore possible.

prise: aplurality of weight'members or a single elongated weight member flexibly suspended from at least two spaced points.

Theinvention will. be more particularly described fwith reference to the illustrative embodimerits-of the. invention shown in the accompanying drawings, in which: L

Fig. .1 is a fragmentary, vertical section of a horizontal fiowiplate type precipitator employ- {ing discharge electrode damping means constructedin accordance with the principles of the invention; V Fig. 2 is avertical section of a vertical fioW tubular type precipitator having discharge electrodedamping means similar to those shownin Fig..-1 of the drawings; and v Fig. 3 is a section on line 33 of Fig. 2 to inore clearly showthe electrode spacing. frame and=oscillation damping weights. 7

With, reference to the drawings, and in particular to Fig. 1, I0 is the shell or casing of the precipitator having a horizontal gas inlet l2,

gas outlet l4, and dust storage hopper l5.

Within'the casingare a plurality of plate type collecting electrodes l8, supported from the side Walls of the casing, for example, by brackets '20.

The flexible discharge electrodes 22 are suspended between'the collecting plates from the insulated electrode frame. Frame 24 in turn is szupported by the high tension insulatedleadin V 5.

At the lower endof each electrode are indi- 45 yidual tension weights 28, and a spacing bar or guide frame 29. The guide frame 23 is loosely supported by the wire electrodes and prevents the electrodes from independently swinging or oscillating. Frame 29, however, has no restrain ing force to prevent free swinging of the en- 'tire'groupelectrodes, weights, and frame-in a straight line ororbital path, the limits of which are .the collecting electrodes or the precipitator casing.

.It has been found that auxiliary weights 3!) flexibly suspended by cables 32 from the lower spacing frame below the center of mass of the system will substantially eliminate and damp both linear and arcuate swinging of the discharge electrode system. As shown in the drawings, at least two damping weights spaced a substantial distance apart are necessary. One weight suspended below the centerof mass of the discharge electrode group will only damp linear oscillation, as the single suspended weight will form a pivot point around which the electrode system will oscillate in an arcuate path.

The greater the distance between" the neatly:

suspended damping weights the greater will be their damping effect on the .torsionaliipendula-i tion of the system. The point about .Which'the system will tend to rotate will lie midway between the damping weights, thusby increasing.

the radius of swing of the damping weights, the force required to set them in motion is increased.

On installations where the forcescreating the pendulation'of the discharge electrodes is great or where additional steadying 7 means :are -requirecl it has been found that'if an electric held.

a conductive member secured'to the .precipitator is formed between the dampingweights and frame even less oscillation will occur in the electrode system.

In the form of the invention showninFig. l-

of the drawing, adjacent eachof-the damping of the dust hopper. weights 3i. and bars 34 is greater'thanithearcing distance of the highest electricalpotential.

adapt-ed to he used in a given installation; Thus while no arcing occurs between bars. 34 and.

weights 36a strong electrostatic-field is :developed there-between whichtends to. resist'any relative movement between these members.

Referring. to Figs. 2 and 3 of the illustrative. embodiments of the invention thereisshown a:. vertical flow tubular type electrical:precipitator;

in which i536 is the casing of the apparatus, comprising a precipitated material storage zone 02, gas treating zone 48d and the header zone-lilfi- Opening into the casingare the-collected mate-.

rial outlet I98, gas inlet 1 l0 and clean: gasoutlet Within the casing are a plurality of tubular collecting electrodes H4 supported from a plate H6 which separates the gas treating and outlet zones of the precipitator; v

Centrally disposed within each collecting electrode is aflexi'ole wire discharge electrode H8 suspended from the electrodesupport and bus bar i2 3. trode frame 125 is loosely supported by-the wire else-- trodes. The form of the spacing frame is more clearly shown in Fig. 3 of the drawing:

As hereinbefore mentioned in relation to the form of the invention shown in Fig; 1 of the drawings, the entire discharge assembly-comprising electrodes weights and frame are free to swing in a straight line-or path" and any direct restraining means for the system presents a difficult problem'of insulation due to the high electrical potential maintained in an electro* static precipitator between the discharge and collecting electrcdes.= In accordance with the principles of the invention this difficulty is obvia ed by flexibly suspendingat least two spaced" weights below the center of mass-of the discharge At the lower end of :each-wireelec- H8 are individual tensionweights I221 Adjacent the weightsa tie and spacingbar or' .30. weights 38 are grounded bars1'34 supported, for example, by a frame 36 carried by'the side walls.

The distance: between the a electrode system and where needed providing an electrostatic field between the suspended damping weights and an adjacent grounded member.

The damping weights, designated I26, are supported by electrically conductive cables I28 attached to the electrode spacing frame I24. Adjacent each of the.damping- ;Weights.I26 there may be placed agroundedbar- I35 supported, for example, by a frame I32 carried by the side walls oi the dust hopper, when added damping is desired by means of the electrostatic field developedbetween'the grounded bars and the damping weights.

From-the foregoing description it will be seen that thespresent'invention provides a novel electrode-oscillation damping means, whereby the aims, objectsand advantages of the invention are fully accomplished.

Itzwill. be evident that various modifications may be made in the construction of the device. For example, it is contemplated that the electrostatic fielddamping device may be used with or without the primary damping weights and that additional damping of the electrode system will' .beobtainable by employment of an electrostatic from; at :spaced points below the planerof the electrode. holding means; whereby the center of mass of theufiexiblysuspended weight means is below .the center of gravity of the discharge elec-' trode system.

2.'A discharge electrode system-for electrical precipitators comprisinga plurality of discharge electrodes movably suspended from a support, means for holding the electrodes in spaced :relation, and a plurality of weightsflexibly suspended therefrom at. spaced points. below the lower active. ends .of "the.'dischargeelectrodes, whereby the. center of.mass 0f. the flexibly suspended weights is belowthe centerof gravityof the discharge electrode system.

3; A discharge electrode systenrxfor electrical. precipitatorsrcomprising a plurality ofzdischarge'i electrodes movably" suspended from a support; a spacing frame :near. therlower end of the electrodes for holding thelelectrodes in spaced relation, andat least two weights flexibly suspended at spaced points from the .spacingirame below, thev plane of saidspacing frame whereby the cen-.

ter of mass :of :the. flexibly suspended weightsis 1 below-the center. of ;gravity of the electrode system;

4;. A discharge electrode system for electrical.

precipitat-ors .comprisingia plurality 'of discharge electrodes movably suspended from a*support;.a-: spacing frame'suspended near the lower end :of: the electrodes for holding the electrodes in spaced relation, tension weights attachedat the lower ends of the electrodes, and at-least two damp-'- ing weights flexibly suspended at spaced points from the spacing frame below: the tension weights, whereby the center ofmassof the damping weights isbelow the centerofgravity of the electrode-system.

5.'-A discharge electrodesystem for electrical precipitators comprising a plurality of discharge electrodes movablyfsuspended from. a support.

means for holding the electrodes in spaced relation, a plurality of weights flexibly suspended at spaced points from the spacing frame below the center of gravity of the electrode system, and conductive grounded members spaced from said weights by a distance greater than the spacing between the discharge and collecting electrodes of the electrical precipitator.

6. A discharge electrode system for electrical precipitators comprising a plurality of discharge electrodes movably suspended from a support, a spacing frame near the lower end of the electrodes for holding the electrodes in spaced relation, at least two weights flexibly suspended at spaced points from the spacing frame below the center of gravity of the electrode system, and conductive grounded members spaced from said weights by a distance greater than the spacing between the discharge and collecting electrodes of the electrical precipitator.

7. A discharge electrode system for electrical precipitators comprising a plurality of discharge electrodes movably suspended from a support, a

6 spacing frame suspended near the lower end of the electrodes for holding the electrodes in spaced relation, tension weights attached at the lower ends of the electrodes, at least two damping HARRY A. WINTERMUTE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,409,508 Wintermute Mar. 14, 1922 1,810,614 Knight -June 16, 1931 1,882,949 Ruder Oct. 18, 1932

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