US3157903A

US3157903A - matthews

Info

Publication number: US3157903A
Authority: US
Current assignee: Babcock and Wilcox Co
Publication date: 1964-11-24
Anticipated expiration: 1981-11-24

Description

Nov. 24, 1964 .1. MATTHEWS FLUID HEATER CLEANERS 3 Sheets-Sheet 1 Filed Dec. 17, 1962 Invent g; g M

Nov. 24, 1964 E. J- MATTH E W$ FLUID HEATER CLEANERS 3 Sheets-Sheet 2 Filed Dec. 17, 1962 I I %Inuenl r V A ttorney;

N v- 24, 1964 E. J. MATTHEWS FLUID HEATER CLEANERS 3 Sheets-Sheet 3 Filed Dec. 17, 1962 WM I QR M% e o o RM mm M Q 1| & \N m w mm 0 F8 Q E228 Q swam R w I lnvenl United States Patent 3,157,933 FLUID HEATER CLEANERS Eric J. Matthews, London, England, assignor to Eabcocir Wilcox Limited, London, England, a British company Filed Dec. 17, 1962, See. No. 245,119

Claims priority, application Great Eritain, Dec. 21, 1961,

2 Claims. (65. 15--3l7) This invention relates to fluid heater cleaners of the I kind having a nozzle tube which may be advanced from and withdrawn to a retracted position. In my co-pending application No. 245,263 there is described such a fluid heater cleaner in which flexible driving means extending in the direction of reciprocation of and coupled with the nozzle tube are adapted to determine the longitudinal movements of the nozzle tube.

In the operation of a fluid heater cleaner of the kind specified, the cleaning fluid, generally steam supplied at a substantial pressure, exerts a force tending to advance the nozzle tube. Consequently, rupture of the iiexible driving means or of its connection with the nozzle tube might, in some instances, lead to projection of the nozzle tube at substantial velocity into the space containing the heating surfaces to be cleaned. This invention provides means for guarding against this eventuality.

The present invention includes a fluid heater cleaner having a rotatable nozzle tube movable longitudinally to advance the nozzle tube from, and to withdraw the nozzle tube to, a retracted position, a main carriage supporting and connected with the nozzle tube movable with the nozzle tube along an essentially horizontal track and operating mechanism including a fixed driving motor connected with the main carriage through a driving chain secured to the main carriage and passing over front and rear guide wheels mounted at the ends of the track, said track being formed with a series of abutments, a springbiassed catch pivotally mounted on the carriage and movable between an operative position to which his biassed by said spring and in which the catch is engageable with the series of abutments to prevent forward movement of the carriage along the track and an inoperative position in which the catch is held clear of the series of abutments, said driving chain being secured at one end to the main carriage and at the other end, through tensioning spring means, to the catch to hold the catch in the inoperative position.

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 a side elevation of a portion of the soot blower, to an enlarged scale; and

FIGURE 4 is a plan view, looking in an upward direction, corresponding to FIGURE 3.

Referring to FIGURES 1 and 2 of the drawings, the soot blower illustrated is a long travel lance blower which includes 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 lower is associated. The forward end 3 of the nozzle tube 1 is provided with a pair 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 3,157,903 Patented Nov. 24, 1964 wall 2 through a nozzel tube front 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 it) between the front and rear supports 6 and 8. The rear and intermediate supports 8 and ll) 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 the nozzle tube, a spider carrying four rollers 15 of concave surfaces contacting the nozzle tube at equian ular'ly spaced locations therearound and an inner member 21 which carries the spider and which is positioned within the casing 13 by ball bearings ZZ'which permit rotary movement of the inner memher around the nozzle tube axis with respect to the casing 13. With this construction of support, the nozzle tube may be rotated within the support and relative longitudinal movements of the nozzle tube and the support are possible. The pairs of wheels 12 on respective sides of the carriage 11 extend between the upper and lower flanges of respective channel irons 23 forming tracks extending longitudinally of the frame 7 so that the support it may be moved towards or away from the mentioned wall aperture.

The nozzle tube front support 6 differs from the nozzle tube intermediate support 10' by the absence of a wheeled carriage, but is otherwise of the same construction; the

casing 13 thereof being mounted in fixed position on the frame 7. r

The nozzle tube rear support 7 consists of a carriage 24';- having four wheels 25 also fitting between the flanges of the track-forming channel irons 23, a casing 26 secured 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 which is positioned within the casing 26 by ball bearings 29 which permit rotary movement of the inner member 23 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 3% through which there extends a steam feed tube 31.

The steam feed tube 31 is welded at its rear end to a support 32 mounted on the frame 7 at the rear end there of. The said feed tube extends co-axially of the nozzle tube 1 and its front end (not shown) lies within the nozzle tube in all longitudinal positions of the latter. The noz-' zle tube rear support 8 acts also as a support for the feed tube 31 and the feed tube is also supported between the nozzle tube rear support 8 and the feed tube support 32 by feed tube intermediate support 3 3, which consists of a carriage 34 having four wheels 35 also fitting between the flanges of the track-forming channel irons 23 and mounting brackets 41 for a pair of rollers 42 of concave surfaces, one roller contacting the feed tube 31 from above and the other from below.

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 gear in a casing 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 which engages 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, as is hereinafter described, 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 carrying a bevel wheel 63; the bevel wheel 63 meshes with a bevel wheel 64 secured to the inner member 28 of the said support. When the motor is driven so that one chain strand moves the support 8 for longitudinal movement of the nozzle tube, the return chain strand, passing the support 8 in the reverse direction and engaging 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.

The two strands of the chain 53 extend close to the carriage 34 of the feed tube intermediate support 33 and means (not 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 tube 1 from the 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, during the reverse movement of the support 8 and the nozzle tube 1 from the fully projected to the retracted position, the carriage 11 of the nozzle tube intermediate support 10, which has been carried forwardly by the contact therewith of the carriage 24 of the nozzle tube rear support 8, is, by means (not shown) in the form of a further traction device on the chain, caught by the further traction device after a certain distance has been covered in the withdrawing direction by the support 8 and the nozzle tube, and also moved in the withdrawing direction to ensure that not too great a length of nozzle tube shall be unsupported outside the wall 2.

Referring in the main, to FIGURES 3 and 4, a catch 65 mounted upon a downwardly extending stud 66 below a bottom plate 67 of the nozzle tube carriage 24 serves, when effective, positively to lock the nozzle tube carriage against forward movement. The catch 65 is in the form of a lever having a tail 69 connected to a tensioned spiral spring 70 for biassing the catch 65 to its operative position, shown in dotted outline in FIGURE 4 and a head 71 which, when in the operative position, projects to engage one of a series of stops 72 provided at intervals of approximately three feet on the beam 7. The operative position is defined by a lug 73, projecting from the bottom plate 67, against which the head 71 of the lever abuts under the action of the biassing spring 70, an end of which is anchored to a lug 85 projecting from the bottom plate 67 of the carriage.

The duplex roller chain 53 is connected at one end 74 by a link 75 to two springs 76 mounted on a yoke 77 pivoted on the catch 65 adjacent its head 71. The other end 78 of the chain 53 is connected to means for adjusting the chain tension including a bolt 79 keyed to,

but slidable within :1 lug 80 on the bottom plate 67 and provided with a nut 81 and lock nut 82 for co-operating with the said lug.

The catch 65 is arranged to act like a pawl to permit rearward movement of the carriage 24 when the catch 65 is in the operative position. Thus, at its rear side the head 71 of the catch 65 is bevelled at 68 so that when the catch, during rearward movement of the carriage, engages a stop 72, the catch is caused to rotate against the force exerted by the biassing spring 7 0 as the catch moves past the stop.

The inoperative position of the catch is defined by a lug 83 which projects from the bottom plate 67 of the carriage and against which a part 84 of the catch 65 adjacent its head 71 is biassed by the springs 76.

In operation, should failure of the chain 53 or of a connection between the chain 53 and the carriage 24 efiect release of the tension normally exerted by the chain 53 and transmitted to the catch 65, the biassing spring moves the catch 65 to its operative position. Forward acceleration of the carriage 24 also tends to have the same result since the tail 69 of the catch 65 is short and light as compared with the head 71. When the catch 65 is in the operative position, forward movement of the carriage 24 results in engagement of the catch 65 with one of the series of stops 72, with the result that further forward movement of the carriage 24 and nozzle tube 1 is prevented.

A locking device in accordance with the invention is with advantage provided on the fluid heater cleaner disclosed in the complete specification accompanying my copending application No. 245,263.

I claim:

1. In a fluid heater cleaner having a rotatable nozzle tube movable longitudinally to advance the nozzle tube from, and to withdraw the nozzle to, a retracted position, a main carriage supporting and connected with the nozzle tube movable with the nozzle tube along an essentially horizontal track and operating mechanism including a fixed driving motor connected with the main carriage through a driving chain secured to the main carriage and passing over front and rear guide wheels mounted at the ends of'the track, said track being formed with a series of abutments, a spring-biassed catch pivotably mounted on the carriage and movable between an operative position to which it is biassed by said spring and in which the catch is engageable with the series of abutments to prevent forward movement of the carriage along the track and an inoperative position in which the catch is held clear of the series of abutments, said driving chain being secured at one end to the main carriage and at the other end, through tensioning spring means, to the catch to hold the catch in the inoperative position.

2. A fluid heater cleaner as claimed in claim 1, wherein the spring-biassed catch is shaped to act as a one way pawl to permit rearward movement of the carriage when the catch is in the operative position.

References Cited in the file of this patent UNITED STATES PATENTS 369,399 Dunstan Sept. 6, 1887 907,835 Martini Dec. 29, 1908 2,883,694 Hibner et a1 Apr. 28, 1959 FOREIGN PATENTS 486,560 Germany Nov. 19, 192.9

Claims

1. IN A FLUID HEATER CLEANER HAVING A ROTATABLE NOZZLE TUBE MOVABLE LONGITUDINALLY TO ADVANCE THE NOZZLE TUBE FROM, AND TO WITHDRAW THE NOZZLE TO, A RETRACTED POSTION, A MAIN CARRIAGE SUPPORTING AND CONNECTED WITH THE NOZZLE TUBE MOVABLE WITH THE NOZZLE TUBE ALONG AN ESSENTIALLY HORIZONTAL TRACK AND OPERATING MECHANISM INCLUDING A FIXED DRIVING MOTOR CONNECTED WITH THE MAIN CARRIAGE THROUGH A DRIVING CHAIN SECURED TO THE MAIN CARRIAGE AND PASSING OVER FRONT AND NEAR GUIDE WHEELS MOUNTED AT THE ENDS OF THE TRACK, SAID TRACK BEING FORMED WITH A SERIES OF ABUTMENTS, A SPRING-BIASSED CATCH PIVOTABLY MOUNTED ON THE CARRIAGE AND MOVABLE BETWEEN AN OPERATIVE POSITION TO WHICH IT IS BIASSED BY SAID SPRING AND IN WHICH THE CATCH IS ENGAGEABLE WITH THE SERIES OF ABUTMENTS TO PREVENT FORWARD MOVEMENT OF THE CARRIAGE ALONG THE TRACK AND AN INOPERATIVE POSITION IN WHICH THE CATCH IS HELD CLEAR OF THE SERIES OF ABUTMENTS, SAID DRIVING CHAIN BEING SECURED AT ONE END TO THE MAIN CARRIAGE AND AT THE OTHER END, THROUGH TENSIONING SPRING MEANS, TO THE CATCH TO HOLD THE CATCH IN THE INOPERATIVE POSITION.