US3160907A

US3160907A - tollow

Info

Publication number: US3160907A
Authority: US
Current assignee: Babcock and Wilcox Co
Publication date: 1964-12-15
Anticipated expiration: 1981-12-15

Description

1964 F. s. TOLLOW FLUID HEATER CLEANER 6 Sheets-Sheet 1 Filed May 31. 1962 '7 Inventor lllllllllllllllllllll 1". Q. L.

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Dec. 15, 1964 F. s. TOLLOW 3,160,907

FLUID HEATER CLEANER Filed May 51, 1962 6 Sheets-Sheet 2 Inventor z 9(- E; a, film/4) Alfor neys Dec. 15, 1964 F. s. TOLLOW 3,160,907

FLUID HEATER CLEANER Filed May 31, 1962 6 Sheets-Sheet 3 O R I I O Q I Q.

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I O Qv I E j I n a O E Q k 1 R R i l w 8 3 Inventor M 5% 5M1 Attorneys Dec. 15, 1964 F. s. TOLLOW 3,

FLUID HEATER CLEANER Filed May 51, 1962 6 Sheets-Sheet 4 Inventor I W 5% w fi zm Dec. 15, 1964 F. s. TOLLOW FLUID HEATER CLEANER 6 Sheets-Sheet 5 Filed May 31, 1962 F. S. TOLLOW FLUID HEATER CLEANER Dec. 15, 1954 6 Sheets-Sheet 6 Filed May 31, 1962 Inventor United States Patent Ofilice 3,160,907 Patented Dec. 15, 1964 3,166,907 FLUE HEATER CLEANER Frederick Sidney Tollow, London, England, assignor to Babcock & Wilcox Limited, London, England, a British company Filed May 31, 1962, Ser. No. 199,119 Claims priority, application Great Britain, June 2, 1%1, 2%,086/61 6 Claims. (Cl. 15-317) I This invention relates to fluid heater cleaners of the -kind having an elongated lance or nozzle tube axially reciprocable to advance the nozzle tube from a retracted position and to withdraw the tube to the retracted position. Different forms of this kind of cleaner are disclosed, for example, in the specifications of our British Patents Nos. 636,052 and 769,593.

The output and size of tubulous vapour generating and vapour heating units used in power stations for the supply of electricity has progressively increased but, since the heat exchange surfaces must be cleaned, the practical size of a unit is limited by the length of fluid heater cleaner nozzle tube available and difliculties arise in the provision of satisfactory fluid heater cleaners having nozzle tubes of the lengths required in projected vapour generating and heating units.

When a long nozzle tube is advanced horizontally into a gas pass carrying gas at high temperature a substantial sag of the discharge end of the nozzle tube is inevitable. The strength of the nozzle tube metal is affected by the high temperature to which it is heated and to provide intermediate support is impractical. Substantial rigidity of the nozzle tube by an increase in diameter cannot be obtained since such increase is accompanied by a larger surface exposed to heat and for a given bore the weight of the tube is increased while an increase in born leads to less effective cooling by the cleaning fluid. By way of example, the sag to be expected at the discharge end of a nozzle tube having an external diameter of 4 inches and a length of 40 feet when fully advanced is appreciably greater than 1 foot.

A fluid heater cleaner is necessarily designed to effect the desired cleaning when positioned a proper distance from the heat exchange surfaces to be cleaned. In the case of a nozzle tube arranged to operate in the space between horizontal tube banks, if the fluid heater cleaner is positioned so that the discharge end when the nozzle tube has been advanced a short distance is ideally spaced from the two tube banks for effective cleaning thereof the discharge end when the tube is fully advanced will be too far from the upper tube bank for effective cleaning of that bank. 7 Moreover, in order to avoid damage to the lower tube bank by cleaning fluid discharged at too close a range it may be necessary to increase the distance be tween the tube banks or decrease the cleaning fluid pressure at the nozzle, thereby lessening the effectiveness of the fluid heater cleaner throughout the travel of the nozzle tube.

tend to interfere with effective cleaning since the effective region of cleaning changes in height with longitudinal movements of the nozzle tube and the latter if near the bottom of the tube bank must-be so arranged that when fully advanced its discharge end is not too near the tube bends at the bottom of the bank.

In a fluid heater cleaner having an elongated lance or nozzle tube axially reciprocable to advance the nozzle tube from the retractedposition and to withdraw the tube to the retracted position according to the present invention means are arranged automatically to rock the nozzle Similarly, if a nozzle tube is arranged to penetrate between the limbs of an upright bank of U-shaped tubes, the sagging of the discharge end of the nozzle tube will.

tube during its reciprocation in a manner tending to compensate sagging of the discharge end of the nozzle tube unler the force of gravity acting laterally on the said tu e.

The invention will now be described by way of example with reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation, mostly in section on the axis of the nozzle tube, of a long travel lance soot blower, the nozzle tube being in retracted position;

FIGURE 2 is a plan of the soot blower;

FIGURE 3 is an outside elevation of the rearmost part of the soot blower; 1

FIGURE 4 is a plan of the. rearmost part of the soot blower in section on the line IVIV of FIGURE 3; I

FIGURE 5 is an end elevation of the soot blower frame, and

FIGURES 6 and 7 schematically show the sootblower with the nozzle tube in retracted and fully projected positions respectively. p

Referring to FIGURES 1 to 5 of the drawings, the soot blower illustrated is a long travel lance blower which in cludes a nozzle tube 1 of or of about 40 feet in length which may be advanced from the retracted position in which it is shown through an aperture in a wall 2 of the casing of a tubulous fluid heater with which the soot blower is associated. The forward end 3 of the nozzle tube 1 is provided with apair of nozzle apertures 4 one diametrically opposite to the other and adapted to discharge steam for tube cleaning purposes at right angles to the axis of the nozzle tube. While the nozzle tube is in the retracted position the forward end 3 thereof is situated within a wall box 5 the inner end of which is open.

The nozzle tube 1 extends immediately outside the wall 2 through a nozzle tubefront support 6 which is fixedly mounted on a frame or track member 7; the nozzle tube is also supported by a nozzle tube rear support 8 at the rear end 9 of the nozzle tube and extends through a nozzle tube intermediate support 10 between the front and rear supports 6 and 8. The rear and

intermediate supports

8 and 10 are mounted on the frame 7 with the capability of movement along said frame in the direction towards and away from the mentioned aperture in the wall 2.

The intermediate nozzle tube support 10 consists of a carriage 11 having four wheels 12, a casing 13 secured to the carriage and surrounding thenozzle tube, a spider carrying four rollers 15 of concave surfaces contacting the nozzle tube at equiangularly spaced locations therearound and an inner member 21 which carries the spider and which is positioned within the casing 13 by ball bearings 22 which permit rotary movement of the inner member around the nozzle tube axis with respect to the casing longitudinally of the frame 7 so that the support 10 may be moved towards or away from the mentioned wall aperture.

The nozzle tube front support 6 diifers from the nozzle. tube intermediate support 10 by the absence'of a wheeled carriage, but is otherwise of the same construction; the p casing 13 thereof is fixedly mounted on the frame].

The nozzle tube rear support 8 consists of a carriage.-

24 having four wheels 25 also fitting between-the flanges of the track-forming channel irons 23, a;casing'26.se-; cured to the carriage 24, a ring 27 to which the nozzle tube rear end 9 is welded and. an inner member 28 which carries the ring at its front end and which is positioned V support.

within the casing 26 by ball bearings 29 which permit rotary movement of the inner member 28 around an extension of the nozzle tube axis with respect to the casing .26. The said inner member 28 carries at its rear end a gland 30 through which there extends a steam feed tube 31. a

The steam feed tube 31 is welded at its rear end .to a' support 32 mounted on theframe -7 'at the rearend there- I to ensure that not too great a length of nozzle tube shall be unsupported outside the wall 2.

The lower end of the upright shaft 55 carries a sprocket 64 engaged by a chain 65 also engaging a sprocket 66, which is arranged for driving, through an upright shaft 67, bevel'wheel 68 in a casing 69'secured'to one side of the frame 7. Within the casing 69 the bevel spur wheel 68 meshes with a bevel wheel 70 formed integral with a nut 71 engaging a threaded part 72 of a shaft 73 which extends through the casing 69.

Collars

74 and 75 within the casing 69 maintain the bevel Wheel 79 in engagement a carriage 34having four wheels 35 also fitting between the flanges of the track-forming channel irons 23 and mounting brackets41for a pair of rollers 42 of concave surfaces, one roller contacting the feed tube 31 from above and the other from below. V

The'steam feed tube 31 is adapted to. convey to the interior of the nozzle tube 1 for tube cleaning purposes steam of which the supply may be controlled by operation of a steam valve 43 in an elbow piece 44 secured to the feed tube rear support 32. Actuating means (not shown) are provided for automatically opening and closing the valve 43 during operation of the soot blower.

The power required for advancing and withdrawing the nozzle tube is provided by a reversible electric motor 45 mounted on the frame 7 near the front end thereof; The motor 45 is arranged to drive a chain sprocket 46 at the upper end of an upright shaft 47 through speed-reducing with the bevel wheel 68, and a key 76 prevents rotation of the shaft 73.

The head 81 of the shaft 73 at the front end thereof is connected by a link 82 to theshor't arm 83 of a bell crank lever 84 secured to one end of cross shaft 85 in the frame 7. The long arm 86 of the bell crank lever is connected to the lower end of an elongated upright link 87 the upper end of which is pivotally connected to an anchor bracket '88 provided on a fixed support. The other end of the cross shaft 85 carries a lever 86 at the other side of the frame '7 similar to the long arm 86 of the bell crank lever 84 and connected to an upright link 87' which is similar to the link 87 and which ispivotally connectedat its upper end to an anchor bracket 88' provided on the fixed support at the other side of 'the frame 7 from the anchor bracket 88. v V

The frame 7 is supp orted at its front end near the wall a 2 by a pivot 89, and towards its outer end is supported gear in acasing 48, an upright shaft 49, a sprocket 50 on the shaft 49, a chain 51 and a sprocket 52 on the lower.

end of the shaft 47. The sprocket 46 engages a chain 53 the two strands of which extend parallel to the frame 7 and whichengages near the rear end of the frame 7 a sprocket 54 on the upper end of an upright shaft 55.

One of the two strands of the chain 53 is attached to the carriage 24 of the nozzle tube rear support 8 and thereby when the motor is driven in the appropriate direction the nozzle tube 1 may be advanced from retracted to fully projected position and when the motor is reversed withdrawn from fully projected to retracted position. The return strand of the chain engages teeth of a sprocket 61 on a spindle 62 journalled in the support 8 and carry ing a bevel wheel 63;.the bevel'wheel 63 meshes witha V V bevel wheel 64 secured to the inner member 28of the said When the motor is driven so that one chain strand moves the support 8 for longitudinal movement of the nozzletube, the return chain strand, passing the support 8 in the reverse direction .andengaging by its links teeth of the sprocket 61, rotates the sprocket and by consequence also the nozzle tube 1. Means (not shown) are provided for ensuring contact of the return chain strand with teeth of the sprocket 61. I

The two strands of the chain S3extend close to' the carriage 34 of the feed tube intermediate support 33 and meanstnot shown) in the'form of a'traction device on the chain are provided so that when the'chain moves the:

support 8 and the nozzle 1 fromthe retracted position .towards'the fully projected'position, then after a certain distance has been covered the traction device catches the carriage 34 and advances it to ensure that too great a length of feed tube shall not be unsupported. Similarly,

from the two

anchor brackets

88 and 88 through the said links 87; and 87? and the arm 86 and lever 86' under the control of the arm 83 :of the bell crank lever 84, link 82 and shaft 73. Thus if the bellcrank lever 84 is turned through an angle byacting upon'the short arm 83 thereof through the link 82,the arm 86 and lever 86' turn in unison through the same angle, the

upright links

87 and 87 turn in unison through anlappropriate angle and the frame 7 asumes a different angular position about the pivot 89.

In. the operation of the soot blower, assuming that the nozzle tube 1 is in the retracted position shown, the electric motor 45 is started in the appropriate direction for the projection of the nozzle tube and by driving the sprocket 46 near the front of the frame7 drives the chain 53 around the said sprocket and around the sprocket 54 ne'arthe rear of the frame 7. The nozzle tube rear support 8, attached to a strand of the chain, advances and 'theifront end 3 of the nozzle tube provided with the steam discharge apertures 4 is projected from the interior of the wall box 4 and into the space between tube banks of the tubulous fluid heater to be cleaned. The steam valve 43. iswopened when-the steam discharge apertures 4 are clear of the wall 2 and steam travels along the steam feed tube 31 to the interior of the nozzle nozzle tube. axis.

tube 1 and thence is discharged through the apertures 4 in two diametrically opposite jets at right angles to the The return strand of the chain 53 engaging the sprocketl 'on the nozzle tube rear support 3 rotates'the .said sprocket as'the nozzle tube is advanced and .through thecon'sequent rotation of, the support inner member 28 the nozzle tube 1 is rotated as it is advanced.

/ Asthe chain 53 advances the nozzle tube it rotates the shaft 55 of thesprocket 54at the rearfofthe frame 7;

during the reverse movement of the support 8' and the;

nozzle tube 1; from the fully projected to the'retracted position; the carriage 11015 the nozzletube intermediate the rotation of the said shaft effectsQ-through the sprocket 64, chain 65, sprocket 66, shaft 67 and beveliwheels 68 and 70, rotation of the'nu t '71 on'thejthreadedpant of the shaft .73. The shaft 73 moves longitudinally and through the link 82 and the arm 83'eflectsrotation' of the arm 86 support 19, which has been carried forwardlybyvthe con- 7 tact therewith of the. carriage 24 of the nozzleftube rear support 8, is, by means (not shown) in the form of afurth er traction device on the chain,-caught by the further traction device after a certain distance has been covered in, the withdrawing directionrby the support 8 and the nozzle tube, jandalso moved in the withdrawing direction and the lever 86 in the direction to rock theframe 7 in a downward direction about the pivot 89. As, the nozzle tube 1 advancesmore and more the length of the unsupported part thereof beyond the nozzle, tube front; support bends'more and. more underjits own weight; at the ysarne time, the rear end of the frame 7 is increasingly lowered with frespect to its front end so that the nozzle tube forward end 3 is more and more raised in opposition to the increasing sag of said front end, with the result that the nozzle tube front end moves only a relatively short distance from a horizontal plane representing the ideal level at which the steam should be discharged through the apertures 4 throughout the movement of the nozzle tube.

When the nozzle tube has reached its fully projected position the electric motor 45 is reversed and the described longitudinal and rotary movements of the nozzle tube and the rocking of frame 7 about the pivot 89 are repeated in the reverse senses. During the nozzle tube withdrawal, as the sag of the nozzle tube forward end becomes ever less the raising of the rear end of the frame 7 with respect to its pivot 89 effects maintenance of the nozzle tube forward end near the horizontal plane mentioned. Shortly before the apertures 4 come level with the wall 2 the steam valve 43 is closed.

The feed tube 31 is supported with respect to the frame 7 by the bracket 32 and the supports 33 and 8, as already described, and outside the wall 2 the nozzle tube 1 is supported with respect to the frame 7 by the supports 8, and 6, as already described.

The bevel wheel 63 within the nozzletube rear support 8 is preferably connected to the inner member 28 with a degree of lost motion so that the helices of steam discharge from the nozzle tube during the withdrawal of the nozzle tube do not coincide withthose during the projection of the nozzle tube.

Referring to FIGURES 6 and 7, FIGURE 6 shows schematically the nozzle tube 1 in retracted position sup- I ported on the frame 7 which is horizontal, and FIGURE 7 shows the nozzle tube in fully projected position, its unsupported length bent under its own weight, and also shows the frame 7 in downwardly rocked positioned about the pivot 89 so that the length of the nozzle tube supported by and extending from the frame 7 is rocked upwardly so as to oifset the sag of the nozzle tube forward end. The nozzle tube forward end sags a distance indicated by 101, but it is not positioned this distance below the horizontal plane 102 from which the steam discharges are ideally required but by virtue of the compensatory tilting of the frame 7 is positioned on or close to said plane. It is positioned on or close to said plane also during the advancing and withdrawing movements of the nozzle tube. As a result, the nozzle tube forward end 3 neither approaches too near to nor recedes too far from the tube bank 103 above the soot blower or the tube bank 104 below the soot blower.

In a modification, not illustrated, of the arrangement of FIGURES 1 to 7, the frame 7, pivoted at its front end, is suspended adjacent its rear end not by the arm 86 and lever 36' and the upright suspension links 87 and 87' respectively connected thereto but by a wire rope which is taken around pulleys or a stationary set and pulleys of a second set mounted on top of the frame 7. One end of the wire rope is secured to a bracket on the frame 7 in which the second pulley set is accommodated, the wire rope is then taken alternately upwardly to the stationary pulley set and downwardly to the second pulley set so that a speed-reducing hoist is formed and it is then taken around a guide pulley of horizontal axis mounted on the frame from which it runsforwardly to itsqfront end which is secured to the return strand of the chain 53; with this arrangement, as the nozzle tube 1 is advanced the frame 7 is rocked downwardly about its pivot 89 and as the nozzle tube is withdrawn the frame is rocked upwardly about the pivot; the speed ratio of the device is chosen so that the front end 3 of the nozzle tube remains near the horizontal plane 102 between the upper and lower tube banks of the heat exchanger to be cleaned.

The means for suspending the frame 7 at its rear end may be arranged so that when the nozzle tube is in the retracted position the nozzle tube is inclined downwardly towards its front end ata small angle to the horizontal.

Such inclination has the advantage that if the steam valve leaks the ensuing condensate drains away through the apertures 4.

In the initial movement of projection of the forward end of such a nozzle tube inclined downwardly when in the retracted position the said forward end, moves slightly downwardly but the maximum lowering thereof is limited by the automatic rocking of the frame 7 as the nozzle tube advances. If, as when the speed-reducing hoist mentioned is used as the suspension means, the ratio of rate of rock of the frame to rate of reciprocation or longitudinal movement of the nozzle tube is constant, it may be arranged that the forward end of a nozzle tube inclined downwardly in retracted position is, during the advance thereof, at first a short distance below, then a short dis tance above and finally a short distance below a horizontal plane, and a very close approximation to movement of the forward end in a horizontal plane may be achieved.

I claim:

1. A fluid heater cleaner having an elongated nozzle tube axially reciprocable to advance the nozzle tube, for operation in a gas passage or the like containing a fluid heater to be cleaned, from an inoperative; retracted position and to withdraw the nozzle tube to the retracted position, wherein means are arranged automatically, throughout the advance of the nozzle tube, to increasingly rock about a horizontal axis transverse to the nozzle tube the length of the nozzle tube outside the gas passage or the like in a manner tending to compensate increasing sag under gravity of the discharge end of the nozzle tube due to the increasing unsupported length of the nozzle tube within the gas passage or the like and automatically, throughout the retraction of the nozzle tube, to decreasingly rock about the said horizontal axis of the length of the nozzle tube outside the gas passage or the like in a manner tending to compensate decreasing sag under gravity of the discharge end of the nozzle tube due to the decreasing unsupported length of the nozzle tube within the gas passage or the like.

2. A fluid heater cleaner having an elongated nozzle tube axially reciprocable to advance the nozzle tube, for operation in a gas passage or the like containing a fluid heater to be cleaned, from an inoperative, retracted position and to withdraw the nozzle tube to the retracted position, comprising in combination a' carriage to which the nozzle tube is connected, a longitudinally extending track member which is arranged outside the gas passage or the like and on which the carriage is longitudinally movable and by which the carriage is guided, means mounted on the track member for supporting the nozzle tube for axial reciprocation of the nozzle tube longitudinally of the track member, driving means for effecting reciprocation of the carriage along the track member and thereby axial reciprocation of the nozzle tube, supporting pivot means for the track member enabling rocking of the track member about a horizontal axis, rocking means for rocking the track member about thepivot means through a range of angles to the horizontal and means coupling the driving means and the rocking means and effective to rock the track member during advance of the nozzle tube in a manner tending to compensate sagging of the discharge end of the nozzle tube under the force of gravity acting on the said tube. a

3. A fluid heater cleaner having an elongated nozzle tube axially reciprocable to advance the nozzle tube axially reciprocable to advance the nozzle tube, for operation in a gas passage or the like containing a fluid heater which is arranged outside the gas passage or the like and on which the carriage is longitudinally movable and by which the carriage is guided, means mounted on the track member for supporting the nozzle tube for axial reciprosupport, a lever pivotally mounted on the track member and linked to the 'fiXed support, means for turning the lever and thereby rocking the trackmember about the pivot means through a range of angles to the horizontal and means coupling the driving means and the means for turning the said lever and effective to rock the track member during advance of the nozzle tube'in a manner tending to compensate saggingof the discharge end of the nozzle tube under the force of gravity acting on the said tube.

4. A fluid heater cleaner as claimed in claim 3, in which the means for turning the said lever comprise a threaded shaft linked to the lever and a rotatable nut engaging the threaded shaft and prevented from axial'moveme'nt, the driving means for the carriage includes a chain extending longitudinally of the track member and to which the carriage is attached and the coupling means are arranged to effect turning of the nut in accordance with longitudinal movement of the chain. a

5. A fluid heater cleaner as claimed in'claim 4, in which thechain is an endless chain, a sprocket on a driving shaft engages the chain adjacent, the end of the track member nearer the gaspassage or the like, a second sprocket on a shaft engages the chain adjacent the other end of the track member and means are provided for turningthe nut in accordance with the turning shaft of the second sprocket.

6. A fluid'heater cleaner as claimed in claim 2, in which the means coupling the driving means and the rocking means are arranged to ensure an inclination of the nozzle tube downwardly towards its discharge end when it is in its retracted position.

of the References Cited by the Examiner UNETED STATES PATENTS 2,722,033 11/55 Glinn et al. 1s 317 2,897,532 8/59 (lantieri; 15-317 WALTER Al-scnaanrrimar Examiner.

' CHARLES A. WTILLMUTH, Examiner.

Claims

1. A FLUID HEATER CLEANER HAVING AN ELONGATED NOZZLE TUBE AXIALLY RECIPROCABLE TO ADVANCE THE NOZZLE TUBE, FOR OPERATION IN A GAS PASSAGE OR THE LIKE CONTAINING A FLUID HEATER TO BE CLEANED, FROM AN INOPERATIVE, RETRACTED POSITION AND TO WITHDRAW THE NOZZLE TUBE TO THE RETRACTED POSITION, WHEREIN MEANS ARE ARRANGED AUTOMATICALLY, THROUGHOUT THE ADVANCE OF THE NOZZLE TUBE, TO INCREASINGLY ROCK ABOUT A HORIZONTAL AXIS TRANSVERSE TO THE NOZZLE TUBE THE LENGTH OF THE NOZZLE TUBE OUTSIDE THE GAS PASSAGE OR THE LIKE IN A MANNER TENDING TO COMPENSATE INCREASING SAG UNDER GRAVITY OF THE DISCHARGE END OF THE NOZZLE TUBE DUE TO THE INCREASING UNSUPPORTED LENGTH OF THE NOZZLE TUBE WITHIN THE GAS PASSAGE OR THE LIKE AND AUTOMATICALLY, THROUGHOUT THE RETRACTION OF THE NOZZLE TUBE, TO DECREASINGLY ROCK ABOUT THE SAID HORIZONTAL AXIS OF THE LENGTH OF THE NOZZLE TUBE OUTSIDE THE GAS PASSAGE OR THE LIKE IN A MANNER TENDING TO COMPENSATE DECREASING SAG UNDER GRAVITY OF THE DISCHARGE END OF THE NOZZLE TUBE DUE TO THE DECREASING UNSUPPORTED LENGTH OF THE NOZZLE TUBE WITHIN THE GAS PASSAGE OR THE LIKE.