US1396811A - Electrical precipitating system - Google Patents

Description

l L. w. cHu'B. ELECTRiCAL PRECIPITATING SYSTEM. APPLICATION FILED MAR. I4, |918.

Patented Nov. 15, i921;

\ ew/1s warf/Wm; 671mb,

' Y BY AT'FRMEV L UNITED STATES' PATEN T 4orrlcs.-

Y .LEWIS WARRINGTON CH'UBB, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOB T0 WEST I IN'GHOUSE ELECTRIC MANUFACTURING VCOHPANY, A CORPORATION OF PENN- Patented Nov. '15, 1921.

BYLVNIA. ELECTRICAL PBECIPITATING mm. 1,396,811. spegmcmen of remi-g ramt.

Application tied' Iaroh 14, 1918. lSerial No. 222,491. T o allwhomitmayconcem:

partlcles from Be it known that I, LEwI-s WARRINGTON CHUBB, a citizen Allegheny and State o Pennsylvania, invented a new and useful Improvement in Electrical Precipitating Systems, of'whieh .the followingis -a speclfication.

My invention relates to electrical precipitating systems and particularly to those systems which are emplo edy for precipitating finely divided suspen ed matter or smoke bodies of gases or vapors by the passage therethrough of electrical discharges.

In systems of the above-mentioned character, it is usual to provide a' discharge electrode capable of emitting non-disruptive dis- Impress on t the electrode.

the-.use ofa mechan '45 v value of 'may have imp opposed to a collecting electrode, and

to a apt the discharge electrode for the impression thereon of a .high negative potential.

It is likewise the usual practlce to collecting electrode a positive potential, whereupon the particles which are charged by the aforementioned electrical discharges are attracted to said collecting Such collecting electrode is usulally thewall of a. llue For the service conditions indicated and to obtain the nondisruptive discharges, it is therefore necessary to employ a very high potential, and this is generallyobtained bythe use of an alternating-current system. Inlorder, therefore, to Iprovide the required negative potential for the discharge electrode, it has been the usual practice to "employ a. mechanical rectifier. culties attendant upon the use of a mechani- Cal rectifierv in connection with potentials of extremely high values are numerous and wen known., Y

My invention, therefore, `proposes to avoid h 'cal rectifierby posit-lonf in the treating `the gas or vapor 1s; '1:

. potentials' of a value, without .the necese fore'been-psed fo ticks-,Xtrem sity ofinitially through a rectifying of the United States, and .a resident of Pittsburgh, in the countyl7 of or treating chamber.

at a predetermined later The difr' chamber, throu' h"which'th`e treating chamber, taken on line B--B d, electro eswhicli" Referring more'l stack or treatingv ing the precipitated particles that, after their dislodgment from the wall` of the collecting electrodes to which'they lhave been attracted, they will not be the stream of gas or vapor.

By the use of my device, means are 'provided whereby, after the particles are precipitated and attracted to the collecting electrode, they are urged in a direction opposite to that of the `stream of gas o r vapor passing through the treating chamber and are carried out of the path of said gas or vapor and deposited at the bottom of said treating chamber. V l

Furthermore, `my means wh-ereby the gas is constrained to passaforementioned `non again drawn into discharges several times before emerging i from the treating chamber: tremely advantageous\ in that it prevents particles from being forcedupward through the treating chamberliiy an extremely heavy draft without being acted upon by the nondisruptive discharges emitted from the dis- This is excharge electrode.

For a better understanding of a specific construction which embodies m invention, reference may be had to the rawings in which Figure lis a view, partially in elevation .and partially in section, of apparatus constructed in accordance with my invention. Fig. 2 is a cross sectional View taken on line AA of Fig. l and Fig. 3 is a like view showing the positions of the electrodes time period; Fig. 41s a cross sectional view also taken online AA of Fig. 1 but illustrating electrodes of a different construction in Fi 2 and 3 which will hereinafter be .desem ed,"and whiclr'constitute a vpreferred embodiment. of my invention. Fig. 5 isa `longitudinalsectional view of a portion of of AFig.A 4. l

es'beingmounted on shafts 6 and li',respectively.v At the lower from those shown.

particularly to Fig.`l, a

Posi- A winding 14 of portion of the rings 8 and 9 upon which bear brushes 10 and 11, said brushes being attached by lead wires 12 and 13, respectively, to a secondary indicated.

At 17 is shown a motor that may be energized from the same current sourceas the primary winding 16. A bevel gear 18 is attached to the shaft of the motor 17.and meshes with a similar gear 19 attached to the end of the shaft 7. One-to-one gears 20 and 21 are mounted on the shafts 6 and 7 respectively, in such manner that, upon rotation of the sha-ft ofthe motor 17, the delectrodes 4 and 5 are caused to rotate in opposite directions.

Referring to Fig. 2, the specific construction of the electrodes and the manner of their rotation are set forth. Since the electrodes 4 and 5 are alike, only one of'them will be described. Y A spider 22 is mounted on the shaft 6 of the electrode 4,l and, attached thereto, are channel portions 23 composed of conducting material.` The channel portions 23 are so attached to said spider 22 extending rib portions shown.

- The electrodes 4 and 5 are initially mounted in such manner that a channel portion of one electrode is disposed opposite to the rib opposed electrode.

Fig. 3 sho-ws the positions of the electrodes 4 and 5 after each of them has been rotated through a` 30o angle. It will be seen that, whereas, in Fi 2, a channel portion on the electrode 4 is disposed opposite a rib portion of the electrode 5, in this figure, a. rib portion on the electrode 4 is disposed opposite a channel portion of the electrode 5.

In this-connection, it will be observed that the rib portions formed on the electrodes are adapted for use as discharge electrodes, while'the` channels formed on said electrodes are adapted for use as collecting electrodes. It will further be observed in this connection that, by suitable rotation of the electrodes 4 and 5, a rib portion of a discharge electrode vmay always be maintained subthat longitudinally 24 are formed, as

stantially opposite -a channel portion or a' collecting electrode and vice versa.

Although I have shown my dimorphous electrodes as composed of two or more rib and channeled sections and capable of being rotated in synchronous relationship, it is apparent that said electrodes may comprise one rib section and one section of optimum shape for use as a collecting electrode and that said electrodes may be either oscillated or rotated in synchronism.

In Figs. '4 and 5 is shown a preferred ernbodiment of my invention in which an interiorly mounted ribbon member 25 is so twista transformer 15. A primarywinding 16 of `thetransformer 15 is at-` tached toa source of alternating current, asv

ed as to have helical convolutions formed on its surface and is so positioned, that when the same is rotated, any particle impinging thereon will be urged in the direction of the convolutions thereof. The helical member 25 is mounted on the shaft 6 and is further secured in the desired position by means of rings 26 which are uniformly spaced along the electrode structure 4. In this embodiment of my invention, the yrib portions V27 are secured to the rings 26 in any suitable manner, and theintermediate channel portions 28 are reticulated in order that suspended particles may readily pass therethrough when having a velocity suoli as may be imparted thereto by reason of being charged by the non-disruptive discharges taking place from the rib portions of the opposite electrode but will be restrained from passing therethrough when possessing only the upward velocity imparted to it by the natural draft of the stack.

The operation of my device is as follows:

The electrodes 4 and 5 are rotated, in synchronous relationship to the potential impressed thereon, by means of the motor 17 and the gear train 18, 19, 20, 21.' It will be apparent that, if a higlh negative potential is impressed upon,` eit er one of the electrodes 4 and 5 when one of the rib portions of one of them is opposed to one of the channel portions of the other, silent non-disruptive discharges will take place from the rib portion. If a Gas or vapor is admitted to the treating cham er 1 by means of the fines 2 and 3, the rotation of electrodes 4 and 5, in the directions indicated, will cause the aforesaid gas or vapor to move in substantially helical paths during its passage through the treating chamber 1. The gas will, therefore, be brought into the path of said silent discharges several times before its emergence from the treating chamber, and all of the particles therein will be charged and deposited thereby.

Assuming that the electrodes are in the positions shown in Fig. 2 and a stream of gas or vapor is led therebetween, a silent nondisruptive discharge will take place from the rib portion of the electrode 5, and particles suspended in the gas or vapor will thereupon be charged negatively'. If, as shown,

the opposed channel portion of the electrode 4 has residing thereon a positive charge, the aforementioned negatively-charged particles will be attracted thereto, and, when a suflicient number of them have lodged thereon, the resultant inass will detach itself and Ityill fall'to the bottom of the treating chamer. In Fig. 3, the electrodes 4 and 5 are shown after they have been rotated through 30 from the positions shown in Fig. 2. It will be noted that a rib portion of the electrode 4 is opposed to a channel portion of the elecimpressed thereon a v passing through electrode.'

y electrode 25.

rection oppositeA to being treated. y

Furthermore, said screen member 28 isV lof such a character that, a particle, having a velocity imparted to it the treatingl chamber.

fthrough the screen,

opositely char ed electrode.

ofV my device I am 1n`one treating chamber,

trode 5 and that the particlesI will, therefore, be precipitated on electrode 5 1n contra-distinction. to theirl collection. on electrode 4, as shown in Fig. 2.

It will readily be apparent, therefore, that the electrodes 4 and 5 are of a dimorlions-character and alternately perform the unctions of a `discharge electrode and of acollecting electrode.

As has been hereinbefore set forth, it is exceedingly ditiicult to prevent the mass of smokeparticles vwhich collect on the collecting electrode from falling back into the stream of va or or gas being treated, 'and thereby nullif; the desired effect of the cipitator. In the electrodes shown in 4, I provide means Vfor the avoidance of thls .dimcuay the same period that ,the rib portionv of the opposed siding on The screen the purposes of illustration, as composed of heavy wire gauze, is of Such character that, when a smoke particle impinges thereon with sufficient velocity, it will pass therethrough and collect on the helical, collecting The helical portion 25 is so rotated that a particle impingng thereon is urged in a downwardy directlon, or a dithat ofthe gas or vapor whilel it will allow by the silent electrical discharge, to pass therethrough, it' will not admit gas or vapor the treating chamber, to the interior of the electrode. This is because the gas or vapor is 4flowing upwardly durin substantially the entire 'time that it is within Therefore, little or no'tendency will exist for the same to ass however, are ropelled in a direction perpendicular to e screen by reason of the attraction exerted upon the particles by the will be o served, therefore, that, by able to maintain, two oppositely-directedstreams of particles, one stream carrythus 'fgive the desired draft.

.the combination ith portion 28, shown hereln, for w g fluid being treated since the flow is at right` angles to the perforations in the screen member. Ihe smoke particles which are charged,

ing finely divided and suspended material in a spiral path and on its way to treatment, while the other stream `is cipitated particles which are finally'deposited at the bottom of the treating chamber and may be withdrawn therefrom by any lsuitable method. Y p

While I have shown, for. convenience, the

helically shaped interior member 25 as fas-- tened to the outer portion of electrode 5 and, therefore, rotating at the same speed, it is obvious that, if a reater counter draft is desired, said helic v rately mounted vin the interior of theelectrode structure and than that of the containing structure and will be observed that,in the appended claims, I have not confined myself to this specific composed of prel so connected to a gear. train that it may be rotatedat a speed higher member may be Sepaf oreover, it

method of inducinga counter draft in the treating chamber, slnce it is obvious that other means may be employed to accomplish the same result withoutdepartingfrom the sctpe of myinvention.

t will be understood also that many further modifications may be made in my invention without departing from the spirit and scoIpe of the appendedfclaims.

claim as my invention:

1. In an electrical precipitating system, a treating chamber, of dimorphous electrodes positioned therein, a

source -of current vsupply therefor, l and means whereby each electrodeis constrained to yalternately perform the functions Aof either a discharge electrode or of a collecting electrode onl 2. YIn an e ectrical precipitating s stem, the combination with a treating cham er, of relativelyl movable dimorphous electrodes positioned therein, a source of current supply therefor, and means whereby said electrodes are constrained to alternately perv form the functions of a dischargeelectrode and of a collectingv electrode.

3. In anelectrical precipitating system, the

combination with` atreating chamber, of rotatingelectrodes therein which are so positioned that, by their rotary movement, the

substantially helical paths, and between said electrodes several times, during its passage throulgh the treatingchamber. i

4. n an electrical f precipitating system. the 'combination with rotatable electrodes source of fluctuating a treating chamber, of

current supply therefor, and means for moving said electrodes in i synchronous relationship to said current is cpnstrained to move in positioned therein, 'a

supplly. l l

5. n an electrical precipitating system,

the combination with a treating chamber, of

rotatable lectrodes positioned therein, a

source of fluctuating current supply thereree for, and' means for rotating said electrodes in such synchronous relationship to the our; rent in said supply circuit that'one of said rotatable electrodes periorms the function 'oi afdischarge during the period in which Y source of iiuctuating-current supply therecuit, sai

adapted to emit -raised to positive and negative or, andv means for rotating saidelectrodes in synchronous relationship to the current in said supply circuit, said electrodes being so constructed that, when they are rotated,

the gas or Vapor being treated is constrained to -move in substantially helical paths while passing through said treating chamber, and

l is thereby caused to pass repeatedly between said electrodes.' A

7 ln an electrical precipitating system the combination with a treating chamber, o a pair of 4rotatable electrodes positioned therein, 'a source of fluctuating-current sup ply therefor, each of said electrodes being silent non-disruptive discharges and to function as a collecting electrode for the other electrode, whereby the f suspended particles,

during their passage between said electrodes, are charged and thereafter attracted by the electrode having'an opposite char e to that which has been imparted to 'sai Iparticles. l

' V8. In an electrical precipitating system, thecombinatio'n with a treating chamber, of a pair of.l rotatable electrodesJ positioned therein, a source of uctuating-current suppliy therefor, each of said electrodes being a apted to' emit silent non-disruptive discharges and to function asa collecting electrode onthe other electrede, and means for v rotatin said electrodes 1n synchronous relations i to the current in said supply cirelectrodes being so constructed that, u on rotation of 'the same, a as or vapor, uring its passage through sai ltreating chamber, is constrained to move across the .path of said non-disruptive discharges, whereby the particles suspended in-said gas or vapor are charged' by said non-disruptive discharges. .y v .A

9. An electrical precipitator including, inA combination, a pair of electrodes, .means whereby said'electrodes may be alterntelv potentials,each of said electrodes being provided with 'rib portions and channel` portions, said electrodes bei disposed 1 1n cooperative relat-ionshi suc th the rib portions of each one wil cooperate with the channel portions l of the other, whereby an electric dlscharge .will be given off from the .respectiveribportions andthe charged ,particles will be attracted toward the respective channel portions.

cci

l0. ln an electrical precipitating system, the combination with a treating chamber, oi rotatable electrodes positioned therein, a source of current supply therefor, said electrodes being' provided with longitudinally extending rib and channel portions, said rib portions being adapted 'for use as discharge electrodes and said channel portions being adapted for use as collecting electrodes, and means `tor rotating said electrodes so that they alternately assume the functions of a discharge electrode and of a collecting electrede.

ll. in an electrical precipitating system. the combination with a treating chamber, oi rotatable electrodes positioned "therein, a source of current supply therefor, said cleo- 'trodes being provided with longitudinally extending rib yand channel portions, said rib portions being'adaptcd for use as digscharge electrodes and said channel portions being adapted for use as collecting elec-- trodes; and means Afor rotating said electrodes, said electrodes being so positioned and sorotated that said rib portions are opposed to said channel portions in synchronous relationship to said current supply. I

12. In an electrical precipitating system the combination with a treating chamber, o rotatable electrodes positioned therein, a source -of current su ply therefor, said electrodes beingv provi ed with longitudinali extending rib and channel portions, said ri portions being ada ted for use as discharge electrodes and sai channel portions bein adapted for use as collecting electrodes; an means for rotating said electrodes, said electrodes bein so positioned and so lrotated that said rib portions are o posed to said channel ortions during su stantially the same-period that a negative potential is impressed on said rib portions from said source of currentsupply.

13, In an electrical precipitating system the combination with a treating chamber, o electrodes positioned therein and a source of current su' ply therefor, said 'electrodes being provi ed with longitudinall extending rib and channel portions, tions comprising screen members Iexten ing between said rib portions.

14. In an electrical precipitating s stem i the combination with a treating cham r o .a pair of hollow, relatively movable e ectrodes positioned therein, and a souroe of current supply therefor, said electrodes be- 1n rig and channel portions, said tions comprisin -between said ri portions, andthe rib portions of each electrode being so ener zed from said source Aof current supply that silent electricdischarges are emitted therefrom during substantially the same riod thatthe screen portions of the other e ectrode are c annel provided with longitudinally extending -n r. screen members exten ing said current source that opposed to said rib portions, whereby particles passing between said lelectrodes are charged and thereafter forced through said screen into the interior of said electrode.

15. In an electrical precipitating system, the combination with'a treating chamber, of dimorphousV electrodes positioned therein, and a source of current su ply therefor, said electrodes being provided) nally extending rib and channel portions, said rib portions being so energized from silent electric discharges are emitted therefrom, said channel and a source of current portions consisting of screen members ex# tending between said rib portions, and said electrodes being 'further provided withJ an interior conducting member which is adapted to have a potential impressed thereon from said current source.

16. In an electrical precipitating system,

the combination with a treatingchamber, ofv

positioned therein, supply therefor, said provided with longitudiib and channel portions,

dimorphous electrodeselectrodes being nally extending`^\\ said rib portions ,being so` composed and be,-

ing so energized from said currentf source that silent electric 'discharges are emitted therefrom, said channel'portions consisting of screen me bers extending between said rib portions and saidelectrodes being further provided with an interior conducting member which is adapxted to have a positive potential'impressedt ereon from said current source, said interior member. having said positive .potential impressed thereon during substantially the same period. that said ri portion ofthe opposed electrode is emitting electric dischar s, thereby charging particles passing4 tween said opposed electrodes and attracting the same tothe positive or collecting electrode.l

17.- In an electrical precipitating s stem the'combination with'a treating cham r, oit' ,dimorphous electrodes l positioned therein,

and a source of current su ply therefor, said electrodes being provide with longitudinally extending r1b and: channel portions, said rib portions being so composed and being so energized from saidcurrent sourcethat` silent electric discharges are emitted therefrom, said channel Vportions consisting of screen members extending between said rib portions; and said electrodesbeing further provided with interior conducting members which are adapted tohave a positive` potential impressed thereon from said current source, said interior members having said 'positive potential impressed. .thereon during substantially the same period that said rib portion of the opposed electrode is emitting electric discharges, thereby charg-A ing particles passing between said op electrodes and attractingl the same to the positive or collecting electrode throughsaid with longitudi-4 screen members; said interior members further 'having such convolutions that, when said particles are attracted thereto, they are vcharge residing thereon; and means integral with said electrodes to urge' said collected particles in a direction opposite to the direction of flow of the gas or vapor being treated.

19. In an electrical precipitating system,

the combination with a treating chamber, of

electrodes therein, means for directly cons necting an alternating potential thereto, and means for causing ythe respective electrodes to emit corona of the same polarity irrespective of the impression thereupon of said alternating potential.

whereby particles passingfbetween `urged in a direction opposite to that of the ,Y

20. A precipitator as specified claim 9,

Vin combination with means for rendering the rib portions of each electrode relatively inactive `during the intervals when said electrode is positivel charged with respect to the other. electro e.

21. The method of ed particles fromv a charging said suspended particles by a corona discharge, attracting said charged parV ticles to collecting surface and thereatercausing said particles to move in a direction opposite to that of the fluid in which they are suspended.

22. The method of electrically precipitat ing suspended particles from a fluid which consists in establishin field, repeatedl passing said fluid through said field and t ereby charging the' particles suspended therein, attracting said charged particles recipitating suspendto a collecting surface and thereafter urging said particles in a direction subuid which consists in g an active electric stantially opposite to thatn which the fluid being treated is movin 23. In an apparatus or separating suspended particles from gases, a pair of spaced electrodes,

the discharge-emitting portions of eachone channel means for causing'` saidv gases to pass in the space between said elec- .pended partielles 'Eom gases,

will cooperate with the screen portions of the other, each eiectrode having changed por tions placed beck of seid screen portions, whereby paiticies passing between said eiecti'odes are charged and thereafter oced through said screen port-ions out of the mein path of said gases.

24%. in apparatus es specied in claim 23, in combination with means for urging said removed particies in a, direction oppositeto the ges stream.

25. in en eppeetns for separating susa channel tinrough which scifi gases pass, the side Weils of seid channels having scieen portions,

. oi' causing seid suspended partices to be attracted through seid screen portions Leeeii out of the main ges stream end mechanical means" foi' urging" seid removed particles in edirection cfpposite'to the ges stream.

26. ln an electrical pecipitating system, the combination 1with '.1 treating chamber, oi dimorphous electrodes positioned therein, :i source of current supply therefor, und means whereby said electrodes are constrained to alternately perform the functions of e discharge electrode and of :i collecting; electrode, each discheige portion of :in eiectfode being reiatively inactive Whiie a portion of that electrode is active es e, collecting; electrode.

in testimony ivhereoi.J l have hereunto subsciibed'niy neme this 12th dey of March,

LEY/VIS VVARRFNGFON CHUBB.

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