US2687780A - Gas cleaning apparatus - Google Patents

Description

g- 1954 F. R. CULHANE GAS CLEANING APPARATUS 3 Sheets-Sheet I Filed Dec. 28, 1951 lNvaN-roz I FIZANKR..CUL.HANE= BY )1 I .f I

ATTORNEYS s U Em Nm w WA m m GAS C Aug. 31, 1954 Filed Dec. 28, 1951 3 Sheets-Sheet 2 HNVENTQR FRANK R.C.UL.HANE- A ORNEYS 31, 1954 F. R. CULHANE 2,687,780

GAS CLEANING APPARATUS Filed Dec. 28, 1951 3 Sheets-Sheet 3 r INVENTOK B FRANK R. CUbHANE.

jaw, MELF ZYLW ATTORN 2Y5 Patented Aug. 31, 1954 UNITED STATES PATENT OFFICE GAS CLEANING APPARATUS Frank R. Cu lhane, Mishawaka, Ind.

ApplicationDecember 28, 1951, Serial No. 263,857

Claims. 1

The present invention relates to the purifying of air and other gases, and is particularly concerned with an apparatus for removing dust or other particulate matter from a moving stream of gas by causing said particulate matter to become entrainedin a liquid disposed in contact with the stream of gas.

Gas cleaning devices of this general type have been in general use in various forms, employing in their operation a variety of physical principles for presenting the liquid to the moving stream of gas or vice versa, in a manner calculated to cause the particulate matter carried by the gas to be assimilated by the liquid. Apart from the question of economic efliciency, gas cleaners of the wet or so-called scrubber types capable of treating large quantities of gas, have incommon the inability to remove from the gas, in substantial quantity, extremely fine particles of the order, for example, of two microns (2x10- meters) and less in size. The efficient removal of particles in this range of sizes, at the present time and on a commercial basis, is considered theprovince ofvarious types of truefilter-type devices. The latter, however, are not suited to the handling 'of large volumes of gases at high velocities.

Accordingly, it is theprimary object of the present invention to provide a gas cleaning apparatus of the wet or scrubber type of substantially increased efficiency in the removal from gas streams of extremely small particles. A further object of the invention is the provision of a highly efiicient wet type cleaner in which large quantities of gas can be cleaned at high velocities without objectionable entrainment of'the liquid by the gas leaving the cleaner. A still further object of the invention is to provide an improved gas cleaner which is capable of efficiently cleaning large quantities of gas at high velocities without the expenditure of unreasonable amounts of power.

Other objects and advantages will become apparent by reference to the following description and to the accompanying drawings, which illusrality of cleaner tubes forming part of the apparatus.

Figure4 is a plan view of the tube illustrated in Figure 3.

Figure 5 is a sectional view taken along the line AA of Figure 3.

Figure 6 is a fragmentary elevational view of that" portion of the cleaner apparatus through which the gas is discharged, and is partially broken away to show its inner construction in greater detail.

Figure 7 is a diagrammatic sectional view taken along the line CG of Figure 6, and

Figure 8' is an enlarged perspective view of a guide vane assembly disposed within the discharge conduit illustrated in Figures 1, 6 and 7.

Briefly, the preferred embodiment of the invention illustrated in the drawing comprises a plurality of upright scrubber tubes I l arranged in a cluster about a central discharge stack l3 to which the individual tubes are manifolded at their lower ends by means of a collection chamber IS. The individual scrubber tubes are closed at their upper ends, but are provided adjacent those ends with intake conduits or scoops ll which are arranged to admit gas to the interior of the tubes in. a tangential direction. The intake openings of the individual scrubber tubes II are in turn manifolded by an annular chamber l9 which surrounds the tube cluster, and into which the individual scrubber tube intake scoops I? extend with their openings presented tangentially to the inner wall of the manifold chamber. For conducting the gas to be cleaned into the apparatus, the annular intake manifold is provided with an intake conduit 2| which introduces the incoming gas tangentially into the annular manifold chamber from the direction opposite to that in which the individual tube intake scoops face. Disposed about the interior of the intake manifold chamber I9, is a plurality of spray nozzles 23 located slightly below the level of the tube intake scoops I"! and which, during the operation of the apparatus, provide a spray curtain through which the incoming gas spiralling upwardly through the intake manifold chamber must pass, and which direct a film of the spray liquid downwardly along Walls of the manifold chamber. Each of the individual scrubber tubes l l is similarly provided witha spray nozzle 25 disposed above the level of the intake scoops I! for directing a film of liquid downwardly along the inner surfaces of the tube. The spent liquid with its entrained particulate matter collects in the form of a slurry or sludge at the bottom of the intake and discharge manifold chambers from which it is continuously removed.

The streams of gas issuing from the lower ends of the scrubber tubes I l are reversed in direction 180 degrees through the discharge manifold chamber l5 to pass upwardly out of the apparatus through the central discharge stack l3. This abrupt change of direction is effective to remove from the gas the major portion of any liquid which mayhave been entrained: indroplet form in the intakemanifold and in the scrubber'tubes, but to complete the removal of these droplets, including what particulate matter they may contain, guide vanes 21 are provided at 11181132581) the discharge stack to impart a whirling motion to the gas entering the stack, s0 as-to remove'byi centrifugal action additionalliquid not removed in the discharge manifold chamber I5. The additional moisture and entrained particulate. mat-. ter thus removed is collected at the base of the stack by a novel construction, laterto bedescribed. in detail, and removed from the apparatus, while. the stream ofgas leaves the cleaner. apparatus in an upward direction through the discharge stack.

It will be understood,- of course, that. pump means, not forming part of the cleaner apparatus itself,,is provided for forcing. the gas into-the apparatus, or drawing the-gas through the apparatus, although it will usually be preferred to place the pump or fan on the, discharge side of the apparatus so as to handle the gasonlyafter it. hasbeen cleaned.

Referring initially to Figure l for a detailed description of the apparatus in preferred'form, the cleaner. comprises three upright concentric shells 29, 3| and.33 joined together at theirupper ends by means of a top plate to which the shells may be. secured by welding. The outer shell 29. and middle shell 31 are co-extensive andconnected together in similar fashion at their lower ends by a floor plate 31 soas to define between them the annular chamber l5, while the inner.- most shell 33 is somewhat shorter thanthe two outer. shells 29. and 3|, so as to define within the middle shell 3| beneath the inner shell, the. discharge manifold chamber [5, whichcommuni cates with the annular space between the inner shell 33 and middle shell 35, and with the space within the inner shell 33. The floor plate Blis preferably dished in itscentral portionandlpro vided with a. drain 39 for a purpose later to-be described, and the entire floor plate is slightly inclinedtoward'one side of the apparatus and providednear its lowermost point with a drain 4i leading. from the annular intake manifold chamber I9 between the two outer shells. Secured to the outer shell 29 in the lowerportion. thereof, is the intake conduit 2! through which. the dirt-laden gas enters tangentially into the manifold chamber I9.

Between the middle shell 3| and inner shell 33 are disposed the individual scrubber tubes IL (Figs. 1 to 5 inclusive), twelve in number in the particular apparatus illustrated, the tubes being secured to the adjacent. shells. 3| and 33. or-to. the top plate 35by any desired means. The tubesare closed at their top ends and. open at their. bottom ends, the latter being preferably trun-- cated at an angle tothe longitudinaliaxis' oftthe tube, and with theshorter sideof-each. tubeiad'ejacent to, andpreferably co-extensive with the innermost shell 33.. The intake scoop ll adjacent, the upper end of each tube H may be formedi of, curved plate, and extends tangentially into the annular. intake chamber i9, adj acentthe-mid dle shell 3| and having its mouth facing in the same rotative direction in which the intake conduit 2! extends from the outer shell 29 (Fig. 2), that is, presented to the generally spiral flow of the gas upwardly through the intake manifold chamber. The intake scoops l! merge tangentially with the cylindrical walls of the scrubber tubes ll (Fig. 5) and, in the operation of the device, skin the inner layer of gas spiralling on' alarge radius throughthe intake-chamber I9 and rapidly'accelerate it* to a high rotational velocity inside the scrubber tubes.

The spray nozzles 23 are distributed circumferentiallyl about the interior of the intake manifold chamber it below the level of the intake scoopslii of'the scrubber tubes, and are connected by means of conduits 42 extending upwardly through the top plate 35 to a source of pressureliquid (not shown). The nozzles 25 located within the tubes above the level of the intake scoopsl'iare similarlyconnectedbymeans of conduits-43; to thesource of pressure liquid. It. will bev understood, of course,. that the. liquid.

supply system would includeany suitable,mani-. fold for distributingthe liquid under pressure to the. nozzles, and one or more regulating. valves for controlling the pressure. of the liquid at the.

nozzle.

The eiiluent from theseveral scrubbertubesl l is combineddnthe discharge. manifoldchamber... H'rinto a. single stream of gas and discharged. from the apparatus throughthe stack. i3; which.

includesthe. inner shell 33. and acentral. dis.-

charge conduit 14 securedin the. toppl'ate. 35' of. Disposed.

the apparatusabove the inner shell. within the inner shell.33. and connectedtherewith at its lower end by. meansof. asuitable.v annular plate liis a. shorttubelll (Figs. Land. 6) having secured in its lowerv portionthecurved.

(Fig. 3) and. to prevent. the. formation of a. core in the gas stream, the.guidevanesextendl to the center of the tube 41 and are there joined.

to. an'uprightre-enforcingmember 49.which is positioned centrally of, thetube. and proyiddiat.

each of its endsw-ithaspider 5] to the.

edges. of the guide vanesZ'l. may be. securedby.

any suitable means.

The rotary. motion. imparted tothe. stream of gas flowing upwardly. through the inner. tube. 4-7" throws any, liquid entrained. in. droplet. form.

against the walls of. the. tube,-.and.in.order.to.

remove this liquid, aseries .ofvertical l'ouvres-Eili are provided. to. permit. the. liquid. to. pass out? wardly into the annular; space between.the,inner. tube; and, the shell 334-. It...has.been.foundlthat. the. removal of liquid, in, this. manner. is.more.. eiiective if a portion of the gas is also permitted.

to, escapethrough lthe. louvres :so .-asto.=s.w.eep lthe liquid with it, and: for. this purpose the: inner.- tube. preferably terminates? short .of..the top plate. 35 of; the. apparatusl (Fig, 11) so that=the mainstream of gas passing outwardly througliltherdisicharge.conduitcitrexertsean:aspirator: efiectatendiingtovreduce. the pressure; within theeannula'r: To: further assure that liquid entering..'thezannular.=i

space surrounding; the; louvredr; inner. tube:

space; about; the inner. tube -is-=- not-.agairr carried in the: main gas: streams, a: plurality of; radially; extending vanes or spoilers 52 (Figs. 6 and-.7); may; be provided on. .the;.inner.' surface: of; the

In. the. embodiment shown,

inner shell 33 to intercept the liquidand convey,

it down to the bottom of: the chamber.

The liquid and entrained particulate matter is collected at the bottom of the annular chamber surrounding the inner tube 41 and drainedthere: from in any suitable manner as, for example, by a drain 53 discharging directly into the discharge manifold chamber from whence it is conveyed outwardly through the drain 39.

The apparatus operates as follows: i H i A suitable liquid is suppliedunder pressure t the nozzles in each of the, scrubber tubes II and to the nozzles 23 in theannular intake mania foldi chamber |9,to direct a film of liquiddownwardly along the walls of said tubes and chamber, and to create in the latter a spray curtain.

A pressure head is created across the apparatus in any suitablemanner so as to causethe dirt- 1 laden gas to enter the intakeconduit 2|, from which it spirals upwardly throughtheannular curtain, into the upperregions ofthe chamber.

It will be apparent that a certainamount of chamber. A further amount of particulate matter collides with droplets of liquid as the gas passes upwardly through the spray curtain, and is carried with the liquid to the walls of the chamber and down. Furthermore, the introduction ofthe gasat substantial velocity from the relativelyrestricted intake conduit 2| into therelatively unrestricted space within the annular manifolding chamber I 9, reduces thevelocity of flow and per mits a certain amount of the entrained solid particles to settle out of thegas by gravity, as is well understood. The solid matter removed from the gas in the chamber I9 forms a sludgewith liquid and is removed from the apparatus through the drain 4 I.

In the upper part of the intake manifold cham- 120 manifoldin chamber 19 and through the spray fold chamber 19 and in ,the scrubber tubes H;

The liquid and entrained particulatematter flowing downwardly along the inner surfaces of the scrubber tubes is conveyed by the truncated lower 1'. edges of the tubes over to the shell 31, thus minimizing the opportunity for further liquid entrainment, and flows downwardly therealong to collect in the discharge manifold chamber from which .it is removed as a slurry or sludge by the drain 39. W

The gas then passes upwardly through the inner tube 41, in which any remaining liquid in droplet form is centrifuged, passing out of the tube through the louvres 50, in its side walls, and being collected in the annular space around the tube 47 and conveyed by means of the drain 53 to the discharge manifold chamber l5 Where it is co-mingled with the sludge and removed through the drain 39.

In the foregoingithere has been described an improved gas cleaner device employing known her IS, the layer of relatively cleaner gas circling along the inner wall 3| of the chamber is caught by the intake scoops I? of the scrubber tubes ll, 1

the radius of which may be of the order of /5 or less of the inner radius of the chamber I 9, whereupon the gas entering the scrubber tubes is instantaneously accelerated tohigh rotational velocities, substantially increasing the centrifugal force and causing the smaller, lighter particles to impinge upon the walls of the scrubber tubes where they become entrained in the descending film of liquid supplied from the spray nozzles 25. The spray nozzles .25, as previously indicated, are positioned above the intake scoops I! so that the film of liquid is supplied at a high enough level to have a lubricating effect in the scoop l1 and.

adjacent tube walls and to reduce the abrasive efiect of the solid particles impinging thereupon.

The whirling gas spirals downwardly through the, tubes II to enter the discharge manifold chamber I5, in which the individual streams of gas issuing from the scrubber tubes are combined and conveyed upwardly into the discharge stack 13. It will be noted that the gas, in passing through the discharge manifold chamber I5 is reversed in direction, this sudden change of direction being efiective to, remove from the gas by centrifugal force a major portion of any of the liquid in droplet form which may have become entrained by the gas in the intake maniphysical principles in amore efiective manner, and in which higher cleaning efficiencies are attained than have previously been known .in existing types of gas cleaners employing those principles. It has been found, furthermore, that the device of the invention is capable of handling substantial quantities of gas at relatively high velocities with minimum liquid entrainment, and

'that it requires the expenditure of only reasonable amounts of power.

Various features of the invention believed to be new and patentable are set forth in the appended claims. it 1 I claim:

, 1. An apparatus for removing particulate matter from a moving stream of gas, comprising means including a pair of upright concentric shells connected together at their ends to define an annular intake chamber having an intake opening for admitting gas generally tangentially to said chamber a plurality of upright scrubber tubes disposed about the interior of the inner one of said shells, each scrubber tube being closed at its upper end and having near its upper end an intake conduit connecting said tube and said chamber and having its ends presented tangentially tosaid inner shell and to said tube respectively, means for directing a film of liquid downwardly along the inner walls of said chamber and said tubes for entraining the particulate matter impinging upon said walls, means defining a manifold chamber connected to the lower ends of said tubes, venting means for said manifold chamber comprising a vertical stack located centrally of said plurality of tubes and having within its lowerportionan inner concentric shell connected with the lower end of the stack to define an annular chamber about said shell, said inner stack shell having interior guide vanes for imparting a whirling motion to the stream of gas entering said shell thereby to remove liquid and particulate matter from said gas by centrifugal 7? tl'ie rewith an central inner: chamber andi an an nular outer: chamber; an intake conduit: for: said"; apparatus-connected toxsaid: outer-{shell i to admit the gas; to .be cleaned tangentially to saidan-nular chamber, a plurality: of upright scrubber tubeswithin:andidisposedwabout the periphery: ofasaid inner chamber; each scrubberstube 1 being closed" attits; upper end and-having .near' its upper: end amintake conduit connecting said tubeiandisaidw outer chamber, said tube intake conduit'having itsien'ds presentedztangentially to the inner: one-cf said; shells and towsaidz. tubes. respectively, meansfor: directing azfilm of". liquid: downwardly along thfilWfilISiOf said iouter .chamberand saidltub'es for: entrainingztheparticulate matter; impinging upon I said; walls; .said' tubes-being; open at their bottom: ends: and iterminatingrshorta of said bottom covers memberrsoastovdischarge zinto: said inner. cham her, an exhaust conduit connected tovtheupper" end ofr. said: inner: chamber." for; discharging the ga'srfrom said-apparatus; saidinnervcharnbenseriringztoomam'f'old and reverse the-direction .of flow I of: theagas: discharging; from: said plurality of tubes;.and:means. for removing: thespent: liquid andfitszentrained. particulate matter collecting in theebott'oms' .oftsaidzchalnbers.

8:. Aniapparatus for removing particulate mate terr from: at. movinge'. stream of gas comprising meansnncludinga pair of upright.concentric2cy lindrical shells; .top: and". bottom; cover memberssecured to the ends of saidzshellsuand.defining therewith :a. central inner chamber. and an annular; cuter: chambenu an. intake; conduit" for said:

apparatus connected to said outef shell to admit" the gas to be cleaned tangentially to saidannular chain-bier;- a. plurality" of' upright. scrubber tubes w-ithiniandi: disposed aboutzthecperiphery. of: said 1 innerichamberr; each scrubber tubeEbeingrcloSedat-r itssupp er: end. and having: near: its upper: end an intake conduitconnectingsaid tube and said outer; chamber; saidrtubejntake: conduitrhaving; its lends presented tangentially" to: the inner? one. of" said: shells". and to; saidztube-respectively; means; fer. directingra film of: liquid. downwardly alongrthe: Walls of: said outerrchamber. andi-saiditubes f orrene training; the. particulate matterv impinging. upon:v saidwalls; saidzitubestbeing open-at theirbotttom:

ends amdsterminating ShOIi'GLOf saidia bottomucover;

sei'asrto dischargeinto:said;inner chambenimeans:v defining anzexhaustastack; extending pdcwnwardly thr.ough:said.;top: cover; member centrally of: said plurality-oi tubesean'diintosaidiinnertol'iamberrfor; discharging: the: gas flOIllT. said: apparatus; said inner;chamberrservicingatorrnanifoldand-reverse? the direction. of; flow ofithe gasrdischargingrfrom; saidzplurality ofrtubes and-totconveyxsame ;to *said; stack, ,liquidaeliminatorz'means:dmtheelower-pore- 8i; tionflotfs'aidi stacks-for removing entrained liquid'" from said gas; and means.forrremoving the spent liquidi and itsaentrained:particulate'matter from the hottomsioi said chambers-and fromsaid elim inators means;

4 Apparatus for: removing: entrained liquidfrom iamoving stream =of: gas. comprising-la cyli dricalconduit: for; receiving said gas.stream; a plurality of curved ig-uide vanesdisposed within:

said conduit touimpartza tw-hirling-imotion .toxsaid gas stream saidiconduit being perforatedidownstreamifromasaidivanes, a shell surrounding said conduitandzbeingi connected thereto: sodas to form an;. annular r chamber about. the perforated 1 portion; ofzsaid iconduit, a second conduilr spacedfrom ;the downstream-iendflofithefirst mentionedi. conduit; said; chamber: being. connected to said? second aconduitidownstream r from said. first men tioned conduit-etc: return to 4 said .second: conduit. theigassesoapingfrom saidfirst mentioned con-a tending; downstreambeyondithe discharge end of:

said:conduit.zandtbeinggconnected..by=-means of'an annular; ringgto a;s.econd' conduit of: lesser cross-'- sectional area: than said: shell, .said. second con duit; receiving; the:- discharge of: the first-mentioned conduit andztheportion of the gaseescaps mg. said: first-mentioned. conduit. thIOllghl said. slottopenings, and:means formemcving the liquid collecting in; said: chamber;

Referencess Cited in g the -fi1e-* of this patent;

UNIT-ED STATES PATENTS Number Name Date 952,308. B'owen .Mar. 27,.l934s FQREIGN PATENTS Number G'ountry Date" 117328"= Australia; Aug. 12, 1932 3441058- GreatBritain J an: 6; 1931" 433K185"- Germany- Sept. 15;" 1926' 4823594 Great'Britain l- Apr. .1 1938

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