US2248947A - Soot blower - Google Patents

Description

July 15, 1941.

F. BOWERS SOOT BLOWER Filed March 25. 1938 2 Sheets-Sheet l Trank @amers ATTORNEY.

July-15,1941.

F. BOWERS SOOT BLOWER Filed March 25, 1938 INVENTOR. Fran k Bowers ATTORNEY.

2 lSheets--Sheet 2 Patented July 15, 1941 UNITED v*STATES PArENT gOFFICE soo'r BLOWER Frank Bowers, Detroit, Mich., assigner to DiamondV Power Specialty CorporatiomjDetroit, Mich., a corporation of Michigan j Application March 25, 1938, serial No.'.19',099l 1 claim. (o1. 12a-,392)

This invention relates to a boiler cleaning apparatus of the uid blast type and particularly to the class having a blower nozzle that moves into the boiler to project a stream of cleaning fluid against that portion of the boiler to be cleaned and is withdrawn from the path of the boiler gases when not in operation.

Many lboiler cleaning devices of this general character have proved unsatisfactory in operation because cleaning fluid is supplied to the nozzle at the time the nozzle starts its movement into the boiler. This results in an expensive waste of cleaning fluid and frequently severe damage to parts of the boiler contacted by the cleaning iiuid as the nozzle moves into vthe proper blowing position. It is an object of the present invention to avoid these shortcomings by providing a boiler cleaning apparatus wherein the nozzle is placed in the proper blowing position before cleaning uid is admitted to it.

A second feature of the invention is the prof vision of means to prevent movement of the blower nozzle into the boiler unless thevalve admitting cleaning fluid to the apparatus is in the open position.

The linvention further discloses new and improved means forprojecting the blower nozzle to the desired blowing position and then rotating it about its longitudinal axis.

Other objects and features ofthe invention will become apparent as the descriptionproceeds particularly when reference is made to the accompanying drawings wherein like reference characters indicate` like parts in the several views and wherein:

Figure 1 is a semi-diagrammatic vertical sectional view of my invention, Y Y

Figure 2 is an upper plan view partially broken away on the line 2-2 of Figure 1, Y

Figure 3 is a rear elevation,

Figure 4 is a front elevation, Y

Figure 5 is a vertical sectional view ofthe tube structure taken on the line 5-5 of Figure 1, and

Figure 6 is a view in perspective of the guide tube. l

Referring rst to Fig. 1 of the drawings, II denotes a rack tube fitted at one end with a blower nozzle I2 of any desired construction. The tube II is mounted in a head I3 which is intimately secured to wall box I4 as by screws I5 passing through the flanged end I6 of the head I3. It will beunderstood that the wall box I4 is set in the furnace wall II in the usual manner. Threadably inserted in the head I3 is tube casing I8 which is further secured to the head I3 by studs I9. Packing 20 and the associated packing nut 2l are employed tomake a fluidtight connection. A guide tube 22 which carries keyway 23 is immovably connected to the tube casing I8 preferably byv welding. `The end of the rack tube `II opposite the nozzle I2 is closed by an end plug 24 welded therein. Attached to the end plug 24 as by screws 25 is end plate 26. A pin or key 2'I carried Iby the end platef26 is fitted to the ,keyway 23 insuch a manner that it may travel longitudinally therein.

vA sheavelwheel Z8 is provided for projecting the blower into the lboiler and for subsequently withdrawing it to v its'idle position. Associated with the sheave wheel 28 is chain 29 and chain guide 30. The sheave wheel 28 is xedly engaged to one end vof a pinion shaft 3| which is journaled in suitable bushings 32 and 33, -as shown in Figs. 2 and 3, in the head I3. Bushing 32 carries packing 32a to prevent the escape of cleaning fluid from the head I3. Also rigidly mounted on pinion 'shaft `3| is pinion 34 which is arranged to engage the gear teeth 35 of rackV tube I I. The teeth on the pinion'34 and the'gear teeth 35 are cut on a 45 spiral, and at the end of the'rack tube I I opposite the nozzle I2 the teeth continue completely around the. periphery. Y

Thus, with the blower in its idle position, as viewed in Fig. 1, counter-clockwise rotationof 'the sheave'wheel-2`8 by actuation of the right hand chainfall, results in rotation of pinion 34 by the connecting pinion shaft 3l. At the start of its travel key 21 riding in keyway 23 prevents 4the blowertube II from rotating about its longitudinal axis so that the action of the pinion 34 on the gear teeth of the tube II results in the rack tube II travelling linearly outward vfrom the head I3 until the key 21 reaches the circumferential portion 36 of the keyway 23 whereupon the rack'tube I Iv is permitted to revolve about its longitudinalaxisin an arc which is determined by the length o-f the circumferential portion 36 of the keyway 23. Since the slot 36 is inclined the tube II and hence the nozzle I2 will be projected further as the tube IIYrevolves about its longitudinal axis and when the key 2l reaches the end of the keyway 23, 36 the deviceis positively stopped against further movement inthe ,outward or projecting direction.y To retract the blower to its idle position, movement ofY the sheave .wheel 28 is reversed by'pulling on the left hand chainfall and the above described process is reversed.

While the invention is described, for convenience sake, as being manually operated, it Will be apparent that the device could be readily adapted to .power driven means without alteration of any essential parts.

The head I3 is provided with a branch 31 through which cleaning fluid is supplied. Adjacent to the branch 31 is disposed a cylinder 38 in which valve piston 39 is loosely fitted and arranged to seat on the fitting `4I). A spring 4I tends to hold piston 39 to its seat. Supporting the spring 4I and closing the end of the cylinder 38 is the anged plate 42. Studs 43 hold the plate 42 to the head I3 in a relation that is made fluid-tight by the gasket 44. Projecting upwardly from the valve piston 39 and forming a part thereof is rod 45 which when the valve piston 39 is seated extends into a slot 46 cutout of the wall of the rack tube II. The arrangement is such that the rack tube II cannot be extended into the boiler unless the rod 45 has been Withdrawn trom the recess 46, and thisris true only if the valve 39 is open. y c `Opening into the cylinder 38 bel-ow the piston 39 is -a line 41 through which the pressure built up by the uid permitted to leak past .the valve piston 39 .is discharged. The line 41 terminates in a valve chamber 48 (see Fig. 2) in which a pilot valve 49 is located. This pilot valve 49 comprises a valve member 50 which is held to its seat 5| by a vspring 52 under compression. Fitting 53 and gasket 54 close and seal the end of .the valve chamber, the tting 53 further providing support for the spring 52. Valve stem 55 xed to the valve member 56 normally projects into a recess 56 in the blower tube II.V The free end of the valve stem 55 and the cam-shaped edge 58 of the recess 56 are -shaped so that projection of the blower tube I I will actuate valve stem 55 thus opening `the valve 49 and exhausting the pressure in valve chamber 48 into the wall box I4 through the passage 51.

rIn operation with the parts position as in Fig. 1 shaft 3I is rotated by pulling the chain 29 as previously described. This causes the pinion 34 to casing I8 and the end plate 26. The opposite end of the by-pass tube 62 opens through the wall of th-e rack tube I I at any convenient point intermediate the ports 63 and the nozzle I'2/but preferably near the ports 63. The arrangement is such that the iiuid leakage around the rack tube II is carried back of the end plate 26 thus tending to equalize the pressure on the end plate. Further, when the blower is retracted from its fully extended position the by-pass I62 serves to exhaust any pressure that may be built up in the tube casing I8. As the rack tube II and nozzle .I2 are projected the end of the by-pass tube 62 is act on the teethV of the rack tube II and start it on its outward travel. As the tube I I moves, the cam edge 58 depresses valve stem 55 and opens pilot Valve 49 exhausting the pressure in chamber 49, line 41, and below the piston 39. It will be apparent that as the tube II moves outward from the head I3 it will hold the pilot valve 49 open until the tube II is returned to .the position where the valve stem 55 is opposite the recess 56. The parts are so proportioned that the spring 4I alone is not able to resist the force of the fluid on the shoulder 59 of the valve piston 39 which is thus moved to its open position permitting the cleaning uid to ow from branch 31 to the annular chamber 6U. The presence of fluid under pressure in the annular chamber 6II actuates the whistle 6I and gives the operator an audible indicationV of when the valveV 3'9 is open. Should the valve 39 fail to open, the tub-e I I can only move outward until the end of slot 46 abuts against the rod whereupon the device is held against further movement in the outward direction.

In order to maintain a balanced pressure on both sides of the end plate 26 a by-pass tube 62 is provided in the rack tube II. It is so designed that it passes through the end plate 26 and opens into the space formed by the closed end of tube exposed to Athe full uid pressure in annular chamber 60 and carried back of the end plate 26, upon further movement the ports 63 enter the chamber 60 and fluid under pressure is supplied to the nozzle I2. At the same time that the ports 63 are moving into the annular chamber 60 key 21 is entering the circumferential portion 36 of the keyway 23 so that the full force of the fluid under pressure reaches the nozzle I2 as it commences to rotate and the cleaning fluid is emitted in-an arc of a size dependent upon the size of the circumferential portion 36 of the keyway. When the key 21 reaches the end of the keyway 23 the device is locked against further outward movement. f

To restore the blower to its idle position the operator merely reverses the movement of the sheave wheel 28 by pulling on the opposite chainfall. This backs the key 21 through the circumferential portion 36 of the keyway which rotates the rack tube II and nozzle I2 through the same blowing arc it has just completed but in a reverse direction. As the key. 21 enters the longitudinal portion of the keyway 23 the ports 63 leave the annular chamber 60 and the blowing operation is complete but the valve 39 remains open. Continued retraction of the rack tube II brings the recess 56 opposite the valve 49, the valve stem 55 is forced into the recess by the spring 52 and the valve 49 i-s closed. This closing of the pilot valve 49 shutting off the exhaust of the fluid leaking past the valve pist-on 39 as it does results in a building up of pressure below the valve piston 39 until the pr-essure is so nearly equal on both sides of the piston that the force of the spring 4I forces it to its seat 46. The blow-er is then in its idle position and ready for another cleaning operation.

It is obvious that many minor changes may be made in the form, and construction of 'th-is invention without departing lfrom the material principles thereof. It is not, therefore, desired to confine the. invention to the exact form herein shown and described, but to include all forms coming within the purview of the attached claim.

What I claim as my invention is:

'In a fluid heater cleaning apparatus, a blower tube having a nozzle at one end thereof, manual means for traversing said tube axially for projection into and from a iiui-d heater, and a source of pressure cleaning uid supply, a valve guarding said source of supply, means for opening said Vvalve to render available said source of supply to said nozzle, and means obstructing the projecti-on of said tube by said manually operable means ,when the pressure on said source of supply falls `below a predetermined value.

- FRANK BOWERS.

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