US1793665A

US1793665A - Electrode for electrical precipitation apparatus

Info

Publication number: US1793665A
Application number: US398466A
Authority: US
Inventors: Anderson Evald
Original assignee: International Precipitation Co
Current assignee: International Precipitation Co
Priority date: 1929-10-09
Filing date: 1929-10-09
Publication date: 1931-02-24
Anticipated expiration: 1948-02-24

Description

Feb 24, wh.

E. ANDERsoN ELECTRODE FOR ELECTRICAL PRECIPITATION APPARATUS Filed Oct. 9. 1929 .Patented :Feel 24,1931 A UN111511)"js'rA i *I i fr EVM-ANDERSON, OF :z g-

CIPITTION COMPANY, FOBNIA ras P-'rsr o-Fsic* BRA, cALIroaNrA, Asistencia.V To mrEaNArIoNAL raaor Los ANGELES, CALIFORNIA. A CORPORATION or cALr-I ninc'raonnjroa nLE'c'rmcAL -rargcrrirArIoN -APPARATS Application mea amber a,-.192a. .serial No. 398,466.

ject-matter originally disclosed-in my 'application,"Ser. No.` 154,131, filed December 11, 1926,or Apparatus for electrical precipitation of suspended material from gases.

' lIt has'been found advantageous in certain 'I cases of electrical'precipitation to .use collecti g electrodes of 'emi-conducting material, :torv example', concrsete or cement material as set yforth in," m 'United States Patent No. '15V 1,541,67 7 issue June 9, 1925'. Such semiconducting electrodeshaveheretofore ordi'- narily'been madeinthe form 'of platesor slabs containing embedded metallic reenfor ing and conducting members.- Each collecte `20 ing electrode has been made either as asin' le integral slab .or plate of this type er as ap urality of sections mounted* and connecte together in suitable'manner. lIn'practlcefltis generally necessary 25 considerable height and width so that an electrode formed as a single integral plate is nec essari'ly of relatively great weight and there-` fore' diicult .to handle. Also,

, permit, mounting of such lateswithi'the 3c precipitating chambers an provide for subsequent removalthereof for repair or re lacement, it has been customary to provi ereto make the electrodes of' above the 'tops of the precipitating chambers'. This space is sometimes not available and in -'many mstances the space required for this purpose could be utilized to goodjadvantage for other purposes'.

A further objection to theseintegral plate Vcollecting'electrodes isfthat, due to the relatively smallv th'clness thereof, there isa tend-,f

ency for them to buckle or defoi'm under cer f.

tain conditions of v operation, particularly' where the gases to be treated, are at high tem\ perature .orv sulg'ectfto sudden iiuctuations A teper'ature. uchdeformations-of the electr'l es may lead to seriousdiculty de to irregularity in the 'space of different portions of the collecting electrode from the opposing discharge electrodes, whichA interferes with satisfactory operation of the precipitator.

The use of 'collect' electrode plates made up of relatively sma' sections or slabs has therefore been proposed, bothas a means of lesseing the tendency to buckling and deformation and in order to reduce the head 'room required above the top of the precipif 70 tator chambers for moving these sections to -an'd f rom their positions in the installation. Considerablediiiculty, however, has been ex- `in order to perienced in supporting andrconnecting together these plate sections, and furthermore the welght ofthe complete electrode is as eat in this case as though the sam'e were' ormed in one piece.

movable covers for the pregpitating cham-( An impOItIlt Object Q the present inventator's.v For example, for"- andling concrete c collecting electrode plates of 12 feet in height, 45 an equal height of clear space is required 'tion is to provide a type of semi-conductingY so collecting electrode construction which over comes the above mentioned objections, that' is, a construction in which only/ a relatively small` head roomy or free s ade is required above the tops ofI the col `ecting electrode chambers for moving' 'the elements of the collecting'V electrodes to a'nd from ltheir positions in the installation, in which the elements to be liandledare ofl relatively small size and weight andy ma be easily assembledV in placaftc form a comp eted electrode which i is of considerably less weight than the platesqY heretofore used and in which there is little or no opportunity for warping or buckling, smthat all portions of the collecting electrode are maintained at uniform Kspacing from the opposing discharge electrodes. -The collecting electrodeof this invention comprises essentially a plurality of closely' m and the supporting members for all. the ele'- -ments of eac collecting electrode are preferably secured at their upper ends toa common supporting member.A The elements of each co lecting electrode: are placed suiliciently '25 close together so asto approximate the eil'ect of a continuous surface, so that if a row of suitably spaced dischar e electrode elements* is-placed vatthe roper istance from the row of collecting e ectrode elements' there will 3c be substantially the same amount of electric discharge and, hence substantially the .same amount of electrical preci itatingaction as though a plate collecting e .ectrode having a continuous lane surface were' used. a5- Eacho'f t ese 'vertically extending collectl.ing electrode elements is also preferably rposed sectionsformed of av pluralityof su so as to reduce or entirely e mate the tend- -ency to' warpingor buckling thereof in a' 40 verticalplane. hese sections may either be secured tov the central-supporting and conducting'member, or they may. be loosely Astrung thereon, and the lowerm'ost section [supported upon said member in any suitable manner.- `Since the elements are hung sepa rately fromlone 4another there is of course substantially no'ftendency .tol buckling or deformation. ofthe assembled collecting electrde in 'a horizontal'plane, andY all parte of I' the electrode are, therefo `maintainedfsubstantially in alignment with thegfintende'd om the discharge electrodes.

lis a verticalsection of a portion df electrical precipitating 4apparatus showvention mounted thereim Fig.2 is atransverse section through two adaeentcOIIecting electrodes,'takenj on line. 2- 2inFig'.8. 3 is a horizontal online'- ingacollecting electrode according tomyingether 'to approxima electrically the eHect each electrode curtain.` re suiciently close totlata Each element is' ing electrode pxlane or surface andat the proper'distancegshulderx The com fanymg 'drawings illustratev em- Fig. 4 is a horizontal section of a modied formof'electrode construction accordin-g'to this invention.

Fig. 5 is allorizontalsection (if/another modification.

Fig..6 is a vertical' section of a modified construction 0f one of the electrode elements.

'.lhel precipitating apparatus shown in Fig.

l comprises suitable housing means 1 enclosing a precipitating chamber 2 through which the ases to be treated are passed, said bonsing ing also provided with suitable vmeans such as a hopper indicated in part at Y3, for

receiving the suspending material separated from the gases. Suitable collecting electrodes 4 and discharge electrodes 5' are mount ed within, said chamber.

The discharge electrodes comprise rows of suitablyspaced elongated mem ers of small diameter formed o f suitable conducting material such as metal, for example, iron wires orsmall diameter rods, mounted on suitable supporting frames 6 carriedby beams 7 w/vhich rest on insulating supports 8. Each collecting electrode Ais'shown as comprising a plurality f `eler'nents 9' of circularl 'cross section, formed of semiconducting material such 'as concrete, cement, terra cotta, etc., and extending vertically in closely spaced arrangementand substantially in asingle vertical plane so as to `rovide'a curtainlike electrode structure formed by a row of .i

these rod-shaped element/s'. Theelements of cfa smooth surfaced preferably also made up of a pluralit of sections l11`mounted contiguously one a Ive 'another. Atmetallie reenforcin andconducting member 12`extends'centra ythroughout the len' l1 of each element or of all the secinanysuitable manner on said supporti 'members For. example, shown, eac supportin meinbermay have'an'.

enlargement 18 `ower end providing a .shoulder14 and the lower end of each collectelement or o f thelowermost sec- .l as. at- 15'so as to tonthereofmaybe- ....-c

bndresbuponwd;

pass overthis'enlargeer'it ments, or. the sections thereof, may bemade in any suitable manner, as'by inmng or eastlos .tions t ereof and said elements orsections".` are supported iis e -remaining' strung on the central rodandrest'upon-one anothe'ng YThe rod-shaped collectingele- .'1-20 ceive. the supportingl.and feonductin trol-,metallic supporting 4 members -12 to the.

In order to prevent espesura of t e een- 1'25 -'electrical and thus amid -p' cof eleetrifV cul'- t' disrs mais semanalmente videlsg t scc'tlonill :11th. interloc A20,;overlapping one apother. Any suitable means may be provided or supporting all of the elements of each collecting electrode.

Such means isfshown, however, as comprising a common supporting member such as a channel16 supported at its ends on the housing in any suitable manner, the upper ends of the supporting rods 12 for the several. elements being removably supported on said channel Vas by means of nuts shown at 17. Said supporting rods are preferably secured 'td the common support 16 in such manner as to hang yprecipitating chamber is preferably formed 'as a removable cover plate 18, which may be removed to permit easy access thereto, for mounting and removal of the collecting electrodes, which may either be handled'bodily, or the individual elements or sections may be handled separately and assembled lin position.

This latter method of assembly is particularly advantageous, as the individual parts handled are small and do not require much free space above the top of the precipitator. l

As shown in' Fig. 4 the collecting electrode elements 9 which may, for example, be of the -same construction as above described may be disposed in circular arrangement about a central discharge electrode 5 so as to form a 'collecting electrode of a shape resembling the well known pipe or tube electrode.

Another modification is shown in Fig. 5 ,in

which the rodish'aped lsemi-conducting4 collecting electrode elements 9 are arranged in .rows extending in two perpendicular direc-y tions -so as to form square fiues or spaces 21 therebetween, the dischargeelectrodes 5 being in this casedisposed centrally\oi said flues.

In some cases, in order to provide for more uniform electrical contact of allpoitions of the elements or sections of semi-conducting material with the supporting and-conducting members extending centrally therethrough, I

may provide each section 11 of each element 9 with a metallic sleeve or pipe 22 as shown in Fig. 6, said sleeve being'prei'erably molded or embedded in the concrete or other semiconducting material andtting more'or less closely on the metallic supporting rod 124.'

It is to be understood that in each of the above forms of the invention means will beprovided for connecting the discharge electrodes to a source of high potential electric current. For example, -.the discharge electrode system may be connected to suitable rectifying apparatus forsupplying the, elec-- .paratus and being preferably also grounded.

trical precipitator with rectified alternating current, the collecting electrodes being connected to the other side of said rectifying ap- In the operation of the apparatus a. suitable potential difference, say 50,000 to 100.- .000 volts depending onthe spacingbetween the discharge and collecting electrodes and the nature of the gas to betreated, is maintained between said electrodes, and the gas is passed through the passages between the collecting electrodesand the discharge electrodes. With electrodes as shown in Fig. 1, f

the gas may VJpass either horizontally or vertically in a direction parallel to the plane of 'the electrode curtains, but the particular apparatus shown is intended for horizontal iiow,

for example incthe direction by the arrows in 'said figure. With electrodes of the form shown in Figs. 4 and 5, on the other hand,'the directionof gas flow is vertical, or longitudinally of the passages between the electrode curtains. The high potential diierence maintained between said electrodes produces electrical discharge .from the dischar e electrodes and vconsequent precipitation o suspended material by electrical action on the electrodes and particularly upon the collecting elec'- trodes. The particles so precipitated may either fall from the electrodes by gravity, or may be dislodged therefrom by any suitable semi-,conducting material surrounding and supported by the respective vertical support-- ing members,`each of said cylindrical' elements comprising a plurality of directly contiguous sections one above another andcoinpletely enclosin the correspond'in metallic member throug out the height o said elenient. 1

2. .A collecting electrode for electrical recipitating apparatus comprising a plura ity of separate closely spaced vertically extendingl elements of semi-conducting materialf each having a single metallic supporting and conducting member extending centrally throughout the height thereof, and each of said elements comprising a plurality of directly contiguous sections one above another and completely 'enclosing the corresponding means, and are collected in the hopper orl i ipotential difference therebe-v metallic member throughout the height of vsaid element. 3. In a collecting electrode for electrical precipitating apparatus, a vertically extend- 5 ing metallic supporting `and. conducting member and a plurality of directly eontiguous cylindrical sections of semi-conduca material mounted one above another and c pletelysurrounding said .metallic me ber lO and supported thereb In testimony whereof I have hereunto sub` v scribed my name this 27th day ofvSep'tember',

I i929. A `ILVALD ANDERSON. 15

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