US 2089597 A
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Description (OCR text may contain errors)
A. CARTER TUBE CLEANING MACHINE Filed D96. 3, 1934 5 Sheets-Sheet l N Ema Aug. 10, 1937, A, CARTER 2,089,597
TUBE CLEANING MACHINE Filed Dec 3, 1934 5 Sheets-Sheet 2 v M 3 B mm mm mm 9+ B m N kwmwi R an R C\\ m y Berg 1 Aug. 10, 1937. .A. CARTER TUBE CLE ANING MACHINE Filed Dec; 3. 1934 5 Shee ts-Sheet 3 Aug 10, 1 7- A. CARTER TUBE CLEANING MACHINE 5 Sheets-Sheet 4 Filed Dec. 3. 1934 Fig. 10
Aug. 10, 1937. A, CARTER TUBE CLEANING MACHINE File'd Dec. 3, 1934 5 Sheets-Sheet 5 v Q Q gwm @15 7Qm @fw W Patented Aug. 10, 1937 STATES PATENT OFFIQE TUBE CLEANING MACHINE Application December 3, 1934, Serial No. 755,727
This invention relates to a method of and apparatus for cleaning the interior of tubes, and is especially concerned with a method and apparatus for removing scale from the tubes of a steam boiler or the like. Heretofore, it has been the general practice to remove scale from boiler tubes by using mechanism carrying brushing or cutting tools to brush or cut the scale from the inner surfaces of the tubes. While such methods of cleaning tubes have been more or less successful, the brushing or cutting tools, used in carrying out these methods, have required re placement at frequent intervals. Indeed, several replacements have been required during the cleaning of the tubes of one comparatively small boiler. The operation of such mechanism is therefore expensive, due to the cost of the tools, and also because of the time lost in making the replacement. The latter is often a serious disadvantage in itself, as, in many instances, the cleaning of the tubes must be accomplished while the boiler is out of operation and hence the time required for changing or replacing the tools lengthens the idle period of the boiler.
Moreover, when cutting tools are used, there is danger, in case the scale is abnormally hard on one side of the tube, for the tool to assume an eccentric position in the other direction and cut away some of the metal of the tube on the opposite side, materially weakening the wall thereof. The general object of the present invention is to provide a method and apparatus for removing scale and other foreign matter from the inner walls of boiler tubes and the like, in an economical, eflicient manner, with rapidity and without danger of injuring the tube.
I accomplish the object above mentioned, broadly speaking, by employing a blast of abrasive material which is directed against the interior of the tube. It is one of the objects of the present invention to provide an apparatus for efiiciently handling such blast for progressively cleaning the tube wall.
A further object of the invention is the provision of a mechanism which may be inserted within a boiler tube and provided with a nozzle or blast passage adapted to be wobbled or oscillated by mechanism carried within the tool.
Another object is the provision of a tube cleaning machine, which may be inserted in a tube to be cleaned and which mechanism will remove scale, and the like, from the inner walls of the tube by directing a blast of abrasive material at the walls through a nozzle, which is wobbled, by a portion of the blast stream through mechanism carried by the machine, so that the blast is directed against the walls of the tube at an acute angle thereto, and with a swirling motion.
Other objects of the invention will become more apparent from the following description, reference being had to the accompanying drawings, in which I have illustrated a preferred form of mechanism for carrying out my improved method. The essential features of the invention will be summarized in the claims.
In the drawings, Fig. 1 is an elevation of a tube partially broken away to illustrate my improved tube cleaning machine in operation; Fig. 2 is a view similar to Fig. 1, but illustrating the machine as adapted for use in a tube of a larger diameter than that shown in Fig. 1; Fig. 3 is a vertical section as indicated by the line 3--3 on Fig. 1, illustrating my machine in the elevation; Fig. 4 is an axial section on the forward portion of my improved tube cleaning machine on an enlarged scale, the plane of the section being substantially parallel to the plane of Fig. 1; Fig. 5 is an axial section on the rear portion of my machine, the section being the same as that of Fig. 4, the line aa of Fig. 5 being the same as line a a. of Fig. 4; Fig. 6 is an axial section, as indicated by the line 6-6 of Fig. 5, the plane of such section being normal to the plane of Figs. 4 and 5; Figs. 7 to 10 inclusive are radial sections as indicated by the correspondingly numbered lines on Fig. 5; Figs. 11, 12 and 13 are radial sections, as indicated by the lines H! I, l2l2 and Ill-I3, respectively, of Fig. 4. Fig. 14 is a side elevation partially in section of a modified form of my invention; Fig. 15 is a sectional detail as indicated by the lines I5l5 on Fig. 14.
My improved method comprises directing a blast of abrasive material, such as sand, through a nozzle towards the internal walls of the tube to be cleaned, and advancing the nozzle longitudinally through the tube, while causing the nozzle to direct the blast of abrasive material in a spiral path around the walls of the tube without rotating the nozzle, its supporting mechanism, or the conduits which furnish the nozzle with abrasive material and compressed air or steam which is used to provide the blast, and I prefer to utilize a portion of the compressed air or steam to move the nozzle for obtaining the swirling action of the abrasive material.
Referring again to the drawings, and especially to Fig. 1, wherein I have illustrated a preferred form of apparatus for carrying out my improved method, it will be seen that I have provided a cylindrical shaped body ID, of such diameter that it may readily be introduced into a boiler tube, such as the tube T. Flexible conduits H and I2 are connected to the rear end of the body. The conduit II supplies the body with abrasive material or grit, such as sand, which is forced into such conduit with air or steam pressure by any suitable apparatus, not illustrated, but which is generally well known and used in the sand blasting art to conduct sand to the blasting jets. The conduit l2 supplies air or steam, under pressure of about one hundred pounds to the square inch, to the body where it is introduced into the grit stream, as will be hereinafter more fully explained.
At the forward end of the body is a nozzle it which is positioned at an acute angle to both the body and the tube. The nozzle is wobbled or moved bodily in a circular path within the tube, without actually rotating the nozzle or the body. As neither the nozzle nor the body rotate within the tube, the body may be progressed longitudinally therethrough without danger of twisting the flexible conduits H and 12. This feature also permits the body to be progressed by merely pushing or shoving the conduits into the boiler tube. The conduits, while flexible, are nevertheless semi-rigid, due to the presence of grit in one and the comparatively great air pressure in the other.
The body l0 comprises a series of apertured cylindrical members joined together, by suitable bolts it, to form an integral unit. In general, each body member has four apertures 6, l, 8 and 9, which coact with similar apertures in. other body members to form four longitudinally or axially extending passageways l6, ll, I8 and Hi. The passageway I6 is in communication with the conduit l l which supplies grit to the mechanism. The passageway ll provides chambers for an air motor and suitable reduction gearing which serve to wobble the nozzle. The passageway i8 is in communication with the air conduit l2, and introduces steam or air under pressure, preferably the latter, to both the motor and the nozzle. The remaining passageway 19 serves as an exhaust passageway for the air motor.
The left hand body member 2! Figs. 5, 6 and 7, serves as a cap, and is provided with threaded openings 2i and 22, communicating with passageways lit and I8, respectively. Suitable threaded connector members Ila and I211. are inserted in the openings and have attached thereto, by any suitable clamping means (not shown) the conduits H and I2.
The air motor comprises a pair of rotors 25, secured together as a unit, as will be hereinafter more fully described, and provided with oppositely extending axial stub-shaft portions 26 which are journalled in bearings 21 and 28, carried by the body members 30 and E0, respectively.
The rotors are somewhat less in diameter than their respective cylindrical chambers 3! of the passageway E1. The axis of each chamber is parallel with but eccentric to the axis of the rotors. The arrangement is such that the upper portion of each rotor engages the upper wall of its respective chamber, as shown in Fig. 9.
Each rotor 25 is provided with a diametric slot 33, in which a pair of vanes 34 are slidably mounted end to end. Suitable springs 35 are interposed between the vanes of each pair, and retain the outer edges of each vane in engagement with the wall of its respective chamber 3| at all times. The two rotors are connected by a hub portion 36, of smaller diameter than the rotors, and arranged to be embraced by a body member which forms a valve controlling the intake and exhaust of air to and from the chambers 3|.
The body member, or valve plate 50 is best illustrated in Figs. 6 and 8. It is there shown, as provided with apertures liia, Ila, Ma and i911. which partially form the passageways, heretofore mentioned. The valve plate is provided with a lateral passageway 38, which communicates with an air pressure passageway l8, and both rotor chambers 31. A similar laterally extending passageway 39 in the valve plate 5&3 connects the discharge passageway HQ with both rotor chambers 3!. the chambers 3i and acting on one of the vanes 34 of each rotor, as indicated in Fig. 9, rotates the rotor in a counter-clockwise direction, until the opposite vane clears the passageway 38, at
which time the first vane will have moved into position to uncover the exhaust passageway 39. This is the usual operation of an air motor of this type and hence a more complete description appears unnecessary.
As heretofore mentioned, I have provided two rotors 25. The vanes of one of these rotors are positioned at right angles to the vanes of the other rotor. This prevents the stopping of the rotor unit in a dead center position and insures continuous operation Whenever air pressure is applied through the conduit [2.
The speed of the rotors is limited by the back pressure in the passageway i9. As shown in Fig. 6, the body cap member 20 closes one end of the passageway it, while the body member 80, which closes the other end of such passageway, is provided with restricted openings 4|, thereby maintaining a constant back-pressure on the vanes of the rotors.
For convenience in assembling and manufacturing, the two rotors 25 are separately made and are secured together by suitable bolts or rivets 42. The right hand rotor (Fig. 5) is provided with a reduced hub portion 43, which, when assembled, is embraced by the hollow hub portion 44 of the left-hand rotor. By so making the rotors, the slots 33 may readily be cut into the hub end of respective rotors, thereby greatly facilitating the manufacture of the unit.
The speed of the air motor, while somewhat limited by the back pressure in the exhaust passageway, is reduced by the use of compound external-internal speed reduction gearing, which is retained within the passageway ill, and also serves to increase the power available to wobble the nozzle. As shown in Figs. 5 and 10, the forwardly extending shaft portion 26 of the rotor unit has a reduced portion 45, the axis of which is eccentric to the axis of the rotor. Rotatably mounted on this eccentric portion of the rotor shaft is a pinion ll, which constantly meshes with an internal gear i8 and an internal gear 19, having the same pitch diameter but one more tooth than the gear 38.
The internal gear member 58 is secured to the body member iii, and is prevented from rotation relative thereto by a key 5!. The other internal gear member 59 is rigidly secured to a shaft 52, journalled in a bearing 53 in the body member 88. Every time the external gear 59 makes one complete revolution relative to the internal gear 58, the internal gear 69 is rotated a distance equivalent to one tooth. Hence, if the gears 88 and 49 are provided with I5 and i6 teeth respec- Air under pressure, therefore, enters tively a sixteen to one reduction is obtained between the shaft 26 and shaft 52.
The speed of the shaft 52 is further reduced by the use of another compound internal-external gear reducing member. As shown, a spur gear 55 is rotatably journalled on an eccentric portion 56 of the shaft 52 and meshes simultaneously with internal gears 51 and 58. The gear 58 is secured against rotation in the body member 85 by a suitable key such as indicated at 59. The gear 51 is drivingly secured to a shaft member BI mounted in suitable bearings 62 in the body member 90. Hence, if the gears 51 and 58 are provided with 15 and 16 teeth respectively, the result will be a 15 to 1 reduction between the shafts 52 and 5 I.
The shaft 6| serves to wobble a bearing member 68. As shown in Fig. 4, the right-hand end of the shaft 6! is secured to a curved tube 65, the outer end of which projects forwardly, at an angle to the axis of the shaft, and has secured thereto a jet member 55. The jet is rotatably mounted in suitable bearings 61, carried by the annular bearing member 68. The bearing member abuts, at one end of the tube 55, and at the other end a cap member 59 secured to and forming part of the jet 65, thereby preventing axial movement between the jet and the bearing member.
The bearing member 68 wobbles the nozzle I4, which in turn serves to prevent rotation of the bearing member. As shown in Figs. 4 and 13, the bearing member 68 is connected with a ring II by integrally formed connecting posts or bars 12. The nozzle I I comprises an apertured member 15, mounted in a retaining ring 15, which is secured to the ring H by suitable bolts 15. Threadingly secured to the right-hand body member IE5 is a collar I5I and similarly secured to the ring TI is a collar I02. The two collars are connected by a flexible conduit I05, comprising a metallic guard I58 and a flexible rubber or composition tube !51. The metallic guard is preferably a flexible metal tube and is brazed or otherwise secured to the respective collars IIlI and I52, thereby preventing rotation of the nozzle, while permitting it to wobble about the axis of the right-hand end of the Wobbler tube 65.
Sand is fed to the nozzle I4 through the passageway I5, which communicates with an opening I09 in the body member I00, through which the sand or grit enters the flexible tube I55. The compressed air or steam under pressure entering through the passageway I8, as shown in Fig. 6, is fed into a chamber IIil in the body member I00 and passes through openings III in the hollow tube 5I which is in communication with the hollow tube 55 and the jet member 66. The air therefore carries or ejects the sand through the nozzle 1A in the form of a blast.
The various bearings and shafts are lubricated with oil stored in a chamber I20 within the body member 28. As shown, this body member is provided with suitable opening adapted to be closed by a plug I2I so that oil may be supplied to the chamber I29 from time to time. A felt or fibrous washer member I22 retains the bulk of the oil within the chamber I20, but permits the filtering or seeping of the oil into the passageway I6, where it lubricates the various bearings and the rotor vanes. The oil is conducted from one of the vane slots through a tubular passageway I24 in the sub-shaft 25 0f the rotor into the chamber I25, which contains the reduction gearing 45, 48 and 49, from whence an axial opening I26 in I15- the shaft member 52 permits the oil to flow into the chamber I21, which encloses the reduction gearing 55, 51 and 58. Suitable oil passageways I28 in the shaft member GI permit the oil to lubricate the bearing member 62. A small passageway I29 between the air pressure conduit or passageway I8 and the oil chamber I28 equalizes the pressure on the oil.
The bearings 58 and 61 are lubricated by moisture and oil which is conveyed to the jet by the compressed air stream. As shown, a suitable opening I 39, communicating with the blast passageway I3I of the jet, and with a hollow groove or recess I33 in the bearing member permits moisture to enter and lubricate such bearing.
The body, as shown in Fig. 1, is slightly smaller than the internal diameter of the tube T. To adapt the body to larger diameter tubes, such is illustrated at T in Fig. 2, I prefer to provide a carriage, such as is shown in Figs. 2 and 3, and which maintains the body substantially in the center of the tube and thereby enables the grit to act against the inner wall of the tube with substantially the same force in any direction.
The carriage comprises a pair of bands I42) arranged to be clamped in position on the body. Pivoted to each band I 35 are a series of equispaced links IlII. Each link is pivoted at one end to its respective ring and at the other end carries a roller I52 adapted to engage the inner walls of the tube. The corresponding links Id! of each ring I48 are pivoted together intermediate their ends, as at I44. Hence, by adjustably positioning the clamping rings axially of the body, the carriage may readily be adjusted for different diameters of tubes.
As heretofore described, my improved tube cleaner utilizes a blast of abrasive material, such as sand or mineral grit for cleaning tubes. Materials such as these are apt to cause premature wear on the walls of the grit passageway I 5. In the form of the invention illustrated, in Figs. 1 to 13 inclusive, the grit passageway I6 is formed integral with the body members 38, 50, 50, 65, 10, 80 and 90. Hence, in event of excessive wear, due to the use of certain grits, such members might require replacement. I therefore may prefer to provide a grit passageway independent of such body members. Such an independent passageway eliminates the entrance of grit in the air motor and gear reduction mechanism in event of complete erosion of the walls of the passageway.
In Figs. 14 and 15 I illustrate a modified form of body provided with a series of body members similar to the correspondingly numbered body members heretofore described. In this instance, however, the intermediate body members each have recesses I10 formed in their outer walls. Such recesses are aligned to form a channel I'II arranged to receive a removable tubular member I12 having walls formed complementary with the walls of the channel HI and an outer wall forming substantially a continuation of the cylindrical contour of the body. The ends of the tube I12 about the openings 6 in the body members 20 and I00, suitable gaskets I15 being interposed therebetween to insure a tight joint consequent upon the clamping of the tube in position by the tightening of the body bolts I5. This, therefore, eliminates replacement requirements for the intermediate body parts and their complicated mechanisms.
From the foregoing description it will be seen that I have provided a simple yet effective method of economically cleaning the inner walls of boiler tubes, without danger of injuring them, by applying a sand blast to the walls through a mechanism which may be inserted and fed through the tube to be cleaned, and I have provided a, mechanism for causing the sand to be applied with a spiraling motion, which mechaanism may be inserted in tubes of comparatively small diameters, and which mechanism contains. a power unit and reduction gearing to wobble a sand blast nozzle, while preventing actual rotation of the machine itself, the nozzle or connecting conduits.
1. A mechanism for cleaning tubes, comprising a body adapted to be wholly inserted in the tube to be cleaned, conduit means communicating with the body, a nozzle carried by the body, means for ejecting a blast of abrasive material through the nozzle toward the wall of the tube to be cleaned, and power operated means carried by said body and reacting thereon to move the nozzle relative to the body and transversely of the tube.
2. A mechanism for cleaning tubes, comprising a body adapted to be wholly inserted in the tube to be cleaned, a conduit communicating with the body, a nozzle carried by the body, means carried by the body and commun cating with said conduit to eject an abrasive material from said body towards the wall of the tube, and a power-operated mechanism carried by said body to move the nozzle relative to the body while the body is being progressed through the tube.
3. A mechanism for cleaning tubes comprising a body adapted to be inserted wholly in the tube to be cleaned, a conduit for abrasive material connecting the body, a nozzle movably carried by the body, means to cause an abrasive material to be ejected from the nozzle toward the wall of said tube, and means operated by said last-named means to move said nozzle relative to the body.
4-. A mechanism for cleaning tubes comprising a body adapted to be inserted wholly in the tube to be cleaned, a conduit for abrasive material connecting with the body, a pressure conduit communicating with the body, a nozzle carried by the body and communicating with both of said conduits to cause an abrasive material to be ejected from the nozzle, and a motor carried by said body to continuously move the nozzle.
5. A mechanism for cleaning tubes comprising a body adapted to be inserted in the tube to be cleaned, a conduit for abrasive material connecting the body, a pressure conduit communicating with the body, a nozzle carried by the body, a jet mechanism carried by the body and communicating with both of said conduits to cause an abrasive material to be ejected from the nozzle, an air motor operated from air pressure and carried within said body to move the nozzle, and means to maintain the nozzle at an acute angle to the wall of the tube being cleaned.
6. A mechanism for cleaning tubes, comprising a body adapted to be inserted in the tube to be cleaned, a conduit communicating with the body, a nozzle carried by the body whereby material may be ejected from the body toward the Wall of the tube, reduction gearing mounted in said body, and power operated mechanism for applying power to said reduction gearing to move the nozzle continuously.
'7. A mechanism for cleaning tubes, comprising a body adapted to be inserted in the tube to be cleaned, a conduit communicating with the body, a nozzle carried by the body, whereby material feed to the body through said conduit may be ejected from the body toward the wall of the tube, and a power-operated mechanism mounted in said body to wobble the nozzle relative to the tube to be cleaned.
8. A mechanism for cleaning tubes, comprising a body'member adapted to be inserted in the tube to be cleaned, a flexible conduit communicating with the body and adapted to convey an abrasive material thereto, a second flexible conduit communicating with the body and adapted to convey air under pressure thereto, a nozzle carried by said body through which abrasive material is ejected from the body in the form of a blast by air pressure, an air motor, and means operated by a portion of the air pressure to cause a wobbling movement to be imparted to said nozzle.
9. A mechanism for cleaning tubes, comprising a body member adapted to be inserted in the tube to be cleaned, a conduit communicating with the body and adapted to convey an abrasive material thereto, a second conduit communicating with the body and adapted to convey air under pressure thereto, a nozzle, means whereby the abrasive material is ejected from the nozzle by air under pressure, an air motor, means operated thereby to impart a wobbling movement to said nozzle, said last-named means including a speed reducing gearing and. a webbler operatively connected to such gearing and to said nozzle.
10. A mechanism for cleaning boiler tubes and the like, comprising a series of apertured members secured together to form a body having a plurality of axial passageways, a flexible conduit adapted to convey an abrasive material to one of said passageways, a flexible conduit adapted to convey a blast to another of said passageways, a motor mounted in another of said passageways, a communication between said motor and said blast, whereby said blast operates said motor, reduction gearing operatively connected with said motor and carried in said lastnamed passageway, a hollow shaft operatively connected to said gearing and communicating with said blast passageway, a jet carried by said shaft, a nozzle spaced from said jet and in communicationwith the abrasive and blast passageways, bearing interposed between said shaft and said nozzle, said bear lg coacting with a portion of said shaft projecting at an angle to the main portion thereof, a flexible connection between the nozzle and the body adapted to prevent relative rotation therebetween, whereby said nozzle is caused to wobble when the blast stream is fed to the body without rotating the body or the nozzle or the conduits relative to the tube to be cleaned.
11.A mechanism for cleaning tubes, comprising a body member, a nozzle movably carried by said body and through which abrasive material may be ejected toward the walls of the tube, and a flexible metal conduit connecting the nozzle with said body and forming a passageway for abrasive material. said tube being lined with a flexible composition material.
12. A mechanism for cleaningtubes comprising an elongated body, an air motor and reduction gearing mounted in substantial ain'al alignment with each other in said body, a lubricant reservoir, a lubricant passageway through said motor and said gearing, a fibrous washer disposed between the lubricant passageway and said lubricant chamber, a pressure conduit in said body and a passageway communicating with said chamber and the pressure conduit to force a lubricant through said lubricant passageway to lubricate the motor and the gearing.
13. A mechanism for cleaning tubes comprising a substantially cylindrical body member having a longitudinal recess in its outer wall and adapted to be inserted in a tube to be cleaned, a conduit for an abrasive material connected to one end of said body, a nozzle at the other end of the body and through which abrasive material is directed toward the walls of the tube to be cleaned, nozzle operating mechanism within said body, means communicating with said nozzle and said conduit, said last-named means comprising a member removably inserted in the body recess.
14. An apparatus for cleaning tubes comprising a nozzle adapted to be inserted into the tube to direct an abrasive blast against its interior surface, a support for the nozzle and means reacting on the support to wobble the nozzle without rotating it.
15. An apparatus for cleaning tubes comprising a nozzle adapted to be introduced into such tube, means for ejecting a blast of abrasive material from the nozzle, means adapted to be advanced through the tube, arranged for supporting the nozzle with its operating axis directed at an acute angle to the tube surface, and means reacting on the support and operatively connected with the nozzle to wobble it about.
16. An apparatus for cleaning tubes comprising a nozzle adapted to be introduced into such tube, a conduit adapted to feed abrasive material through the nozzle under pressure, means to guide the nozzle for advancement along the tube, and means to impart a wobbling motion to the nozzle without rotating the conduit.
17. A tube cleaning tool having a nozzle and supporting body therefor, and means reacting on the body to cause the nozzle to wobble in a fixed conical path.
18. A mechanism for cleaning tubes, comprising a body adapted to be wholly inserted in the tube to be cleaned, conduits communicating with the body, a nozzle carried by the body, means to progressively move the nozzle so that its axis follows a substantially conical path relative to the body, and means for ejecting a blast of abrasive material through the nozzle toward the wall of the tube to be cleaned.
19. A mechanism for cleaning tubes, comprising a body adapted to be wholly inserted in the tube to be cleaned, a nozzle carried by the body, means toeject a blast of abrasive material from said nozzle towards the wall of the tube to be cleaned, means to maintain the nozzle at an acute angle relative to the axis of the tube, and power mechanism carried by said body and means connecting said mechanism to the nozzle to move the nozzle circumferentially of the tube during the ejection of said blast of abrasive material.
20. A mechanism for cleaning tubes of varying diameters comprising a body adapted to be inserted wholly in the tube to be cleaned, means for supplying air under pressure and abrasive material to the body, a nozzle carried by the body whereby the abrasive material may be ejected from the nozzle toward the wall of said tube, and adjustable centering means arranged to continuously engage the tube at three spaced points circumferentially of the tube and on the inside thereof to maintain the body axially located relative to the wall of the tube.