US2011330A - Boiler tube cleaner - Google Patents

Description

2 Sheets-Sheet l L. N. WHEELOCK BOILER TUBE CLEANER Filed Aug. 5, 1953 Am@ m, w35.

ATTORNEYS ZaU/SNWHEELNK INVENTOR Aug, 13, 1935. L. N. WHEELOCK BOILER TUBE CLEANER 2 Sheets-Sheet 2 Filed Aug. 5

oooomooooo OOOOOOOOOO INVENTOR Loa/5 MWHEUMK OOOOOOOOO ATTORNEYS Patented Aug. 13, 1935 UNITED STATES 2,011,330 n n l Y BoILERv'rUBE vCLEANER Louis` N. Wheelock, North Amherst, Mass.,

assignor to Boiler Equipment Trust, North Amherst', Mass., a'trust association of Massachusetts Application "August a, 193s, serial No. 683,455

4 claims. Y(c1. 122-391) This invention relates to boiler tube cleaners of the general class in which a series of nozzles arev used to. direct jets of steam, or other fluid under pressure, into the rfire tubes of a` boiler for the purpose of blowing out the soot or other accumulation therein, and in' which saidfnozzles are movable'back .and forth to traverse the ends of the lentire series of tubes of the boiler.

One object of the invention is toprovide an improved tube cleaning means of this general type by which the `time required for cleaning the boiler may be materially reduced, characterized by the use of a plurality rather than a single series of nozzles, eachseries traversing a different group of re tubes 'of the boiler.

Another object of the invention is to provide a tube cleaning means having as rigidly connected parts of the movable unit thereof, two laterally spaced manifold pipes, each carrying a series of nozzles axially spaced thereon and each depending from a point above vthe uppermost row of fire tubes of the boiler to the lowermostv Another object is to provide i'na tube cleanerl of the type just described, lower endportions, one for each manifold pipe, which are bent in-r wardly and disposed in downwardlyconverging relation, each such end portion'being sobent as to clear the water column connection `of the boiler and the inwardly curving wall of the smoke box when its manifold pipe lies inlits outermost extreme position. .y Y' l v yAnother object of the Vinvention isto .provid-o in a cleaner of the general class described and not necessarily only in the particular type; de-

, scribed, a novel spacing of the outersendsof the nozzles from the openends of the viiretubes into which the nozzles are adapted to inject steam or other fluid under pressuracharacterized in that such ends of the nozzles are spaced from the open ends of the vfire tubes by a distance greater than.;

the internal diameter of such tubes and not greater than one and one--half times such diameter. By such spacing the optimum results, insofar as the cleaning effect is concerned, are obtained,V having in mind not only thevolume of air `en-l trained by the steam jets but also the velocity thereofn A further object of the invention is the provision of a reciprocable tube cleaner hung from a support and operated by mechanism, both of 5 which are located very close to the outer wall of the smoke box inV a zone of relatively low tempcrature and also as far aspossible out of the path of the hot gases `rising in the smokeV box. A y 'Another object of the invention is to provide 10 a tubecleaner which is free from flexible pipe jointsa'n'd other relatively movable .parts likely to warp and cause binding when subjected to the heat prevailing in the smoke box.

A further object is to provide a tube cleaner l5* of simplifiedY and improved construction which is relatively inexpensive to manufacture in that there are comparatively few parts requiring ma-` chining and careful fitting, and which isbetter adapted to operate satisfactorily over along period of service because of the elimination'of parts which may Warp and cause binding when subjected to the `heat of the re box.

Other objects will appear as the detailed description proceedsY and will be pointed out in the 25,

appended claims.

The invention will be disclosed for illustrative purposes in connection with the accompanying drawings, in which:

Fig. ,l is an end 'elevational view of a boiler, '30

part of the `outer wall of the smoke box being broken away to reveal the tubes and tube shee and tube cleaner ,of this invention; f

Fig. v2Y is a fragmentary `sectional plan -view thereof taken on the line 2-2 of Fig. 1; 35`

meet the needs of each such arrangement. 45"

In Figs. .1 to 3 of these drawings, I have shown by'wa'y of illustrative example, one standard form of re 'tube boilerk and the manner in which my invention may beY applied thereto. The invention is equally applicableto Yother forms of fire tube 50" boilers, as I have attempted to showin part andy moreor less diagrammatically in Figs. 5 -to 14, inclusive; and it is infact readily .applicable to" anystandard form of fire'tube boiler now known tome; f f j Referring erst to Figs. 1 to 3 inclusive, the` boiler illustrated includes a. shell I5, a `tube sheet It, Vfire tubes i1 and smoke box I8, the outer wall of which is marked `I and is usually provided with a suitable doorsurch as 20. A feed water connection is indicated at 2I, and 22 is a pipe communicating withthe water space of the boiler andV extending from the'tube sheet I6 to and through the wall IS]l for connection to the water V column (notshown) of the boiler.

Y The tube ,cleaner of this invention includes two sets of nozzles 23 and 23', each arranged approxi- Y.

mately in vertical series and designed to blow steam into the open ends offthe tubes I1. nozzles 23 and 23 project from manifolds or pipes 24and V2li which are substantially vertically dis*- `posed except for bent lower ends 25 and 25", the lower extremitiesof which are closed. The upper ends of the pipes 24 and 24 `are connected by horizontal pipes 26 and 26l which extend horizontally away Vfrom tube sheet ltoward the wall I9 and which, near this wall, lare connected to opposite ends'of"Y a'h'orizontally and trans-VV Y versely` disposedV pipe 21.

inletV rconnected byaflexible hose 29 to a'steam supplypipe 39, which extends outsidethe shell I5..and is there provided witha ysuitableicontrol valve 3i. `The pipe'sections 24, 25, 216, 21 and 28l Y are preferably welded together buti'nanyY event tributed to the several nozzles of the two seriesthey: are connected to formone rigid unit to which'steam or: othersuitable fluid under pres-` enrolls supplied, and by which suchfluid is 'dis-i described.

This rigid fluidA conducting'and` distributing unit is mounted'to move back Vand forth in asubstantially horizontal pathdisposed at right Iangles to the axes of the tubes I1 'for the pur- `36, extends horizontally across the Ysmoke boxv near the upper part thereof and isr suitablyvfixed `ventedby '.pin 4t. .Fixedto the. outer: end'of' the pose of canning the nozzles of one set to traverse "l the open ends of half the tubes I1.and the nozzles of the other set to traversemthe open ends of the remaining tubes, so that all thereof aresubjected tothe action of jets of steam which issue rfrom l a the nozzles during each stroke in the.reciproca asbylthe .brackets 31 to such wall'. The vertical leg of angle iron 3.5 has fixed thereto two bear# ings'g38 and 39'. Y The rod 35 is. supported at'i`ts ends Vin said .baringslbeing suitablyxed, as by the set screws 40, thereto. ,Asfshown' in Fig; gli, thesbearing 38 not `only receives "an end' oflrod k35 Vbut also rotatably receives the inner and unthreaded end portion Aof *thefeed screw 34.;

Apin 4I, passingthrough this bearing 3S, sepa-y rates the, parts 341` and35 and'. forms a; lthrust bearing for theffeed screw 34. g

:.The feed screw hasV anxouter: unthi'eadedend portion 'which extends outwardly through shell l5 and is'rotatably supported in aV bearing 42, fixed toca; bracket 43, secured toV shell 15.? A collar 44 fixed tosaid portion, cooperates with one. end of bearing 42to prevent outward axial* movement of the feed screw, inner axial movement being prefeed screw is a pulley 45 vor` any other suitable Pipe21 has a centralV means for turning screw 34 first in one and then in the other direction. Ordinarily, a chain 46 .islooped over pulley 45 and serves asa suitable means for turning the.screW,-,such chain extending downwardly far enough so that it may be conveniently pulled by the operator. Y C

It willi be clear that the rigid distributor unit may be moved back and forth in a straight line by rotating shaft 34 rst inr one and then inthe other direction. The unit is limited in.v its travel by the abutment of one ortheother of the ears 32 and 33 with the bearing 39. The' unit, supported as thus described, can swing about the axis of shafts 34 and 35.Y To hold the unit so that pipe' sections 24 and 24 lie substantially verticaLa cross bar 41 extends acrossr the smoke box, near the lower'part thereof, and is suitably fixed at its ends thereto.v The pipes 24 rand 24. Y

slidably engage this'bar, the `weight of the'distributor unit tending to maintain the engagement as doesalso the reaction of the steam'fjets issuing from nozzles 23 and 23.

It is to be noted that the distributor unit slidably supported by means of the simplest char-Vr acter, viz., the ears 32 and 33, from which it'is suspended with freedom to swing, and the bar 41 which limits its outward swinging movement- The engagementof these ears 32 and 33 with the. members 34 and 35, respectively, isa looseone.

That is, the parts are purposely4 engaged with" what is usually termed a sloppy .,t, so that bind-` ,Y

ing of the parts under heat is` avoided andiisoY that even should the members 34 and 35,warp,the

device will still operate. Thedistributor, being free to swing away from bar 41, is unlikely to ably secured by'w'elding. The entire device "may be manufactured at lowcost. Y

It is to be noted that the distributor unit `is slidably supported and operated by means located closely adjacent the front wall I9 of the smoke box. The shaft 35 andthe feed screw ,34 are located very close to the wall I9. There are sev-v eral advantages to this location. First, thefparts are located in a zone of relatively low temperature, being removed as far as is feasible fromrthe tube sheet I6. The temperature adjacentwall I9 is at least 100 degreescooler than that adjacent the tube sheet I6. Consequently, with fthe relatively movable parts located'in the 4,coolest available zone', there is much less liability of any bind as it might if it were mounted Yon. a carriage riding on tracks.`

41511y .y Y

soffbinding of the parts dueto the effects of heat,V f

as for example because of warping Vof the screw 34 or shaft 35. Second,v` the relatively movable parts are removed from the direct,A path ofg'the hot gases which issuev from tubes I1V and pass up-'V tovheat and, in addition, it minimizes fthe sooting':

up of the parts. Third, it enables the distributor unit to be mounted in place VinV theV smoke box without necessitating any change inthe'location``4 of thefeedrwater pipe 2|. Aswill be seen from Fig. 3, thereis noty room for supporting-the unit by means located directly above the upper ends of ,the manifolds 24 and 24. Any support placed there lwould'interfere with pipe 2 land necessitate the labor and expense of taking down such pipe and relocating it.

rows vof firetubes which are at that time alined The spacing of the nozzles 23' from tubes I1, as shown herein, is important in that it materially enhances the efficiency lof the cleaningoperation. Cleaning of the tubes is effected by the wiping actionof the gases forced therethrough and not by rthe-direct action of the steam jets from the nozzles.V The volume of the gases entrained by thesejets and the velocity of such gases are most important factors insofar as the efficiency of the cleaning operation is concerned. Experiments showthat the greatest volume of gasesis entrained by thejet issuing from a nozzle of any given characteristics and under any given pressure, by spacing the tip of the nozzle from the open end of the vlire tube with which it isalined, by an axial distance equal in length to the internal diameter of the tube. An increase in this spacing will cause a diminution in the volume of the entrained gases but, up to a certain point at least, such increase will result in an increase in the velocity of the gases. vBy experiment, I have found that as said spacing is increased there' is a point where the optimum results arey obtained,- that is theggain by an increase in velocity more than offsets the loss by diminished volume of the gases. `To secure such optimum results, the tips ofthe nozzles should be spacedfrom the open endsy of the fire tubes by a distance which is greater than the internal diameter Aof the fire tubes and no greater than one and one-half ltimes such diameter.

The operation of the invention should be largely obvious from the foregoing description. When the fire tubes of the boiler are to be cleaned, the operator opens valve 3|, admitting steam tothe distributor unit including the manifold pipes 24 and 24'. 23 and 23 into the open yends of the two vertical therewith. The Vtubes are usually cleaned while the boiler is in operation, and this may be doneA without any drop in pressure in the boiler because the gases, entrained by the steam jets and blown into two vertical rows of tubes for cleaning the v same, are derived from the smoke box and hence are drawn through other rows of tubes, which are not then being cleaned, from the fire box. any loss due to temporary inactivity of two rows of tubes is compensated for by the increased velocity of the gases drawn from the fire box through the other tubes. turned on the steam as described, pulls on chain 45 and in this or any other suitable way causes the feed screw 34 to rotate, thus advancing the manifold pipes to the right, as viewed in Fig. l. In this way, the two series of nozzles are moved successively into alinement with the several vertical rows of tubes. The unit may be reciprocated as many times as is necessary to secure the desired cleaning action, after which valve 3l is closed.

It will be appreciated that the cleaning operation may be effected in half the time ordinarily consumed. Usually, there is only one manifoldy pipe with a single set of nozzles. Here, there are Y two working at the same time andthe time is cut in two. Also, the operator does not have to do as much work, as the distributor unit has to be Steam issues in jets from the nozzles The operator, having moved` only half the usual distance. SoA also a feed screw of half the usual length can behemployed. This makes possible the convenient as-- sembly of `the vparts from within the smoke box l'whiledoor 2li is open. The `short feed screw 34, and the shortshaft 35 will readily entersaid The shaft 35 maybe box through said door. first put in place in its bearings 33 and 39'. Then with the distributor unitv in its extremo, right hand position, thev feed screw may be pushed out through Jtheholein the v:wall of the;smokebox Y until its inner end canbe ,',threadedintognut 32 and finally into', bearingv 39. A long -feed screw,y such as has been heretofore employed,.could not be assembledin as convenient a manners It is obvious that other pipes, similar-to24 and v treme position in which its nozzles line up with the fire tubes H of an outer row. It has been proposed to cureathis difliculty by having the lower `end of the manifold pipe pivotally mounted so that ity can yield when it strikes such wall or` such connection. This means a swingv joint whichl is not desirable in zones of high temperature. I overcome the difliculty by the use of two manifold pipes, theV lower ends of which ar-e bent inwardly, asshown, in downwardly converging relation. 'I'he part 25 of pipe lLwhenA the latter isv in its extreme .left hand position with .its nozzles A'alined with theouter row `-of tubes il, will clear the water column connection 22 and one of the nozzles will aline with the lower tube in the next adjacent row. As the manifold is moved to the right, nozzles in the part 25 will successively aline with pairs of tubes Il, one tube of each such pair being 'in one row and theother in thel next adjacent row and below the first tube. With the use of a bent end, such as 25, which is rigidly fixed to the manifold pipe, two such pipes are necessary, as will be obvious.

I have found that the best angle for they part 25 is 25 degrees, as shown herein, although the practical range available varies from perhaps a minimum of about 22 degrees to a maximum of about V33 degrees. With the lower end 25 .bent at 25 degrees to the vertical pipe 24, a cleaner constructed as described, can be adapted to any usual fire tube boiler with which I am familiar. For example, the described arrangement will work with any of the standard layouts shown in Figs. 5 to 14 inclusive. These figures are copies of standard tube sheet layouts taken from a manual cn boiler making. The manifolds 211 and 25 have beenindicated conventionally by a single line.Y These figures do not show all the standard layouts but they do show enough of them to prove the point that the particular angle is suitedto meet a wide range of conditions. It is a fact that the same angle will work with other layouts ofv tubes and with'all standard layouts with which IA am familiar.

The invention thus provides a tube cleaner of greatly simplified yet improved construction which is relatively inexpensive to manufacture Vand yetiextremelyeifective and reliable in operation. 1

" w'Ifhe vinvention has been disclosed herein, in an embodiment at presentl preferred, for illustrative purposes, but the scope of. the `invention is de- Vlined by( the appended claims rather than by the foregoing de'scription.

.-71. The combination in aY boiler,with the smoke box includingA its outer wall,'the tube sheet which formsthe inner wall thereof, and the fire tubes whichopen at one end into said box; of a support clocatedcloselyadjacentsaid outer wall, a reciprocating-'unit including a part Vslidably mounted on said support and extending therefrom toward said tubesheet and a pipe portion whichextends from the 'inner end of said part downwardly in Vparallel and closelyadjacentrelation with said tube sheet; meansV to supply uid under.v pressure to said pipe portion,.nozz1es on said pipe portion adapted to. successively aline with rows of said Vtub'e'sas said unitis moved along saidsupport andthrough which nuid under pressure is ejected int'olthe open ends of said re tubes, andv means for moving said-unit back and'- forth .along said support.v Y

, 2. The combination in a boiler with the smoke box including its outer wall, the tubesheet which forms the inner Wall. thereof, and the re tubes "Whicheopen at one end into said box; of a support located closely adjacent said outer wall, a reciprocating unit including a part slidably mounted and Vpivotally hung on4 said` support andfextending therefrom toward said tube'sheet and a pipe portion which` extends from the innerV end of said lpart downwardly in parallel and closely adjacent relation with said tube sheet, 'means to supplyV iluid undertpressureY tok said pipe portion, nozzles on said pipe portion adapted tosuccessively aline with rows of said tubes as said unit is moved along said support and through which fluid under pressure is ejected into the open ends of said iire tubes, means for .moving said unit back and forth along 'said support, and a cross bar extending transversely of the smokebox ata substantially lower levelr than said support to restrain pivotal movement of said" unit relative to,saidfsupportv` in a'direction away Vfrom-'the tube sheet;v 3.' A boiler tube cleaner, comprising, af`pair 'of manifold pipes each equipped rwith nozzlesanl J disposed in laterally spaced and parallel relation; 5

a pipe rigidly interconnecting said manifold pipes andhaving an inlet for fluid under pressurdfaz support adapted to be fixed in the smoke box of a boiler 'and to extend transversely across thefsame, a pair of bearings fixed to'sa'i'd support one near one end and one nearthe center thereof, a frod having its ends mounted in said'bearings, an ear on the second named pipe near one endfthereof'- mounted to slide on said rod between said bear? ings, a nut fixed to the second namedV pipe nearl the other end thereof, a'fee'dscrew threadedYthi'ouglfl"` said nut and extendingv from the other end of said support along the same in axial alignment with said rod,` said freed screw having its inner end l received in the centrally'located bearinggfiandla bearing for supporting the feed screw near'its outer end from a Wall of the smoke box; Y

4, A boiler tube cleaner, comprising, a fpairV V manifold pipes each vequipped vwith nozzles and Y havingits endsmountedinlsaid bearings, an ear-v on the second :named pipe ynear one/-enditherecd mounted to slide on said rod betweensaid bear= A' ings, a nut fixed to theY second named piper near; the vother endV thereof, al feed vscrev'v threaded` throughsaid nut vandfextendingfromtheother Y endA of said support along the same in axialk alignmentwith said rod, said feed screwhavlng dits inner end rotatably received in thecentrally lo'- cated bearing-V and a combined supportingand thrust bearing for the outer end of the feed screw,`

said last namedbearing fixed to awalljofthe smoke box and outside the latter. 'Y

Louis N. Winning)CK. f

y CERTIFlCATE OF CORRECTIN.

Patent No. 2,911,330. August 13, 1935.

LOUIS N. WHEELGCK.

lt is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page l, first column, beginning with line 9, strike out all to and including lines l and 2, second l column, of same page; same page, second column, line 3, for "A further" read ne; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the ease in the Patent Office.

Signed and sealed this 17th day of September, A. D. 1935.

Leslie Frazer (Seal) Acting Commissioner of Patents.

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