US3824738A

US3824738A - Pipe cleaning apparatus

Info

Publication number: US3824738A
Application number: US00302637A
Authority: US
Inventors: S Allen; W Hall
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-11-01
Filing date: 1972-11-01
Publication date: 1974-07-23
Anticipated expiration: 1991-07-23

Abstract

An apparatus and method for cleaning the inside of pipes by throwing abrasive material into contact with the internal surface of the pipe from a rotating wheel moving longitudinally therethrough, wherein the abrasive material and the material abraded from the pipe are expelled from an open end of the pipe during the cleaning operation by an air flow created by the rotating wheel. One embodiment of the invention includes a carriage movable into and out of the pipe, an abrading wheel rotatably mounted on a annulus tubular housing carried on the forward portion of the carriage, an auger conveyor for supplying the wheel with abrasive material, and a shroud mounted behind the wheel for reducing the effective cross-sectional area of the pipe. The rotating abrading wheel is inserted in one open end of the pipe and, as it is moved through the pipe, creates an air flow which moves the abrasive material and the material abraded from the pipe out of the opposite open end of the pipe. The abrasive material is then separated from the material abraded from the pipe for reuse on subsequent pipes. The abrading wheel is comprised of a front disc, a rear annular having an outer diameter less than the diameter of the disc and a plurality of blades interconnecting the disc and the annulus.

Description

United States Patent [191 Hall, deceased et al.

[ PIPE CLEANING APPARATUS [76] Inventors: Wayne C. Hall, deceased, late of Salt Lake City, Utah; by Scott D. Allen, executor, Oregon City, Oreg.; Wayne C. Hall, Jr., 20100 S. Beavercreek Rd., Oregon City, Oreg. 97045 221' Filed: Nov. 1, 1972 21 Appl. No.: 302,637

Primary Examiner-Othell M. Simpson Assistant Examiner-Robert C. Watson Attorney, Agent, or Firm-Roylance, Abrams, Berdo & Kaul 1 July 23, 1974 57] ABSTRACT An apparatus and method for cleaning the inside of pipes by throwing abrasive material into contact with the internal surface of the pipe from a rotating wheel moving longitudinally therethrough, wherein the abrasive material and the material abraded from the pipe are expelled from an open end of the pipe during the cleaning operation by an air flow created by the rotating wheel. One embodiment of the invention includes a carriage movable into and out of the pipe, an abrading wheel rotatably mounted on a tubular housing carried on the forward portion of the carriage, an auger conveyor for supplying the wheel with abrasive material, and a shroud mounted behind the wheel for reducing the effective cross-sectional area of the pipe. The rotating abrading wheel is inserted in one open end of the pipe and, as it is moved through the pipe, creates an air flow which moves the abrasive material and the material abraded from the pipe out of the opposite open end of the pipe. The abrasive material is then separated from the material abraded from the pipe for reuse on subsequent pipes. The abrading Wh1i$2 r s1 of a rttse r nqrts 2 ing an outer diameter less than the diameter of the disc and a plurality of blades interconnecting the disc and the annulus.

12 Claims, 7 Drawing Figures 1 PIPE CLEANING APPARATUS This invention relates to an apparatus and method for cleaning the internal surfaces of tubular goods, such as pipes, and more particulalry, it relatesto an apparatus and method for cleaning theinterior of pipes by means of an abrading wheel, wherein the abrading material used and the material abraded from the pipe are both blown from the pipe during the cleaning operation.

it is a common custom in the manufacture of metal pipes to produce pipes of various lengths and diameters and to stockpile them for future delivery. During the time the newly manufactured pipes remain stockpiled, the interior surfaces of the pipes may rust,'otherwise be corroded, or accumulate other foreign materials. Additionally, the internal surfaces of the pipes usually contain a substantial degree of mill scale. When specific pipes are ordered and immediate delivery requested, the interior surfaces of the pipes must be cleaned of the mill scale and other accumulations to minimize the frictional resistance to fluid flowing through the pipes and to enhance the adherence of a protective coating which is applied to the interior surfaces of the pipes.

Various'attempts have been made in the past to pro vide apparatus for cleaning pipes described above;

however, they have been unsatisfactory because thay have been time-consuming and expensive, and have generally necessitated complicated equipment to ac-' complish the desired result.

One manner of cleaning the interior of pipes has been by spraying abrasive materialfrom tubes directed at the interior surface of a pipe, which tubes are moved through the pipe as the pipe is rotated. The abrasive material is forced through the tubes by compressed air. However, the cleaning results have not been totally satisfactory and, additionally, this process has been slow and has demanded large amounts of horsepower to pump the abrasive material and rotate .the pipe.

Attempts have also been made to utilize what is com- 7 monly referred to as a throwing or abrasive wheel which throws abrasive material into a pipe lying horizontally to abrade the interior surface of the pipe. This has provided reasonable results in so far as cleaning is concerned; however, an additional step is necessitated to remove from the interior of the pipe the abrasive material used in the cleaning operation and the material abraded from the pipe, which materials remain in the pipe after the cleaning operation. In order to overcome this problem, prior art devices have been utilized which, after the interior of the pipe has been cleaned, move the pipe into an upright position so the abrasive material and the abraded material flow from the pipe under the forces of gravity. However, of course, this is a two-step process and necessitates the use of compli cated equipment having high horsepower requirements to invert or otherwise elevate the usually rather heavy pipes which can weigh in excess of four tons. Other attempts have been directed towards initially positioning the pipe vertically and moving the abrading or throwing wheel through the pipe to allow the abrasive material and the abraded material to fall by gravity out one end of the pipe. Likewise, this has necessitated the use of additional equipment and power to raise and lower the pipe and is a two-step process.

It is therefore an object of the present invention to overcome the limitations and drawbacks associated with the aforesaid prior art devices and to provide a new and improved apparatus and method for cleaning pipes.

Another object of the present invention is to provide an apparatus for cleaning the interior of pipes without the necessity of elevating or otherwise inverting the pipe to be cleaned, and wherein the pipe may remain in a horizontal plane during the cleaning operation.

A further object of the present invention is to provide a pipe cleaning apparatus and method which will expel the abrasive material and the material abraded from the internal surfaces of the pipe in one operation and reduce the time necessary to clean a pipe.

Another object of the present invention is to provide a pipe cleaning apparatus utilizing a throwing or abrading wheel which, in addition to cleaning the pipe, will also cause the abrasive material and the material abraded from the internal surfaces of the pipe to be expelled therefrom by an air flow or pressure created by the abrading wheel.

Another object of the present invention is to provide an apparatus and method for cleaning the interior surfaces of a pipe by use of abrasive material wherein that material can be recycled and reused.

Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention.

" In general, one embodiment of the apparatus includes a motor-driven carriage for longitudinal movement into and out of an open ended pipe lying horizontally, an abrading wheel rotatably mounted on a tubular housing mounted on the carriage for feeding abrasive material against the sides of the pipe to clean them, an auger conveyor on the carriage communicating between a hopper carrying the abrasive material and the abrading wheel to supply the wheel with abrasive material, and a shroud mounted on the carriage between the hopper and the abrading wheel for reducing the effective cross-section of the pipe. An air pressure or flow generated by the rotating abrading wheel moves in an axial direction along the pipe from one end to the other and expels the abrasive material and the material abraded from the pipe out one end of the pipe. The wheel is moved in a first direction into one open end of a pipe and along the entire length of the pipe and then is moved in a reverse direction and out of the pipe through the open end. The shroud has a rubber seal along its periphery to provide for an adjustable fit between the shroud and pipes of various diameters. Additionally, an endless conveyor and supply hopper are provided for recycling the abrasive material used in the cleaning operation back to the hopper on the carriage for reuse. A cabinet which receives the end of the pipe opposite from that initially receiving the carriage contains a vacuum pump for removing therefrom the lighter weight particles abraded from the internal surface of the pipe and an elevating conveyor for moving the heavier shot or abrasive material which enters the cabinet to the endless conveyor for return to the supply hopper. The abrading wheel has a front disc, a rear annulus and a plurality of blades interconnecting the annulus and the disc.

Referring now to the drawings which form a part of this original disclosure:

FIG. 1 is a side elevational view of the overall system in accordance with the present invention;

FIG. 2 is an elevational view in partial section showing the details of the carriage, the supply hopper, the auger conveyor, the shroud and the abrading wheel of one embodiment of the present invention;

FIG. 3 is a perspective view of the parts comprising the abrading wheel and part of the shaft which is connected to the wheel;

FIG. 4 is a sectional view of the shroud taken substantially along the lines 44 in FIG. 2;

FIGS is a sectional view of the auger conveyor and the supply hopper taken substantially along lines 55 in FIG. 2;

FIG. 6 is a top plan view showing the details of the supply hopper and the mechanism for actuating the supply hopper to feed abrasive material therefrom; and

FIG. 7 is an elevational view in partial section, similar to FIG. 2, showing a second embodiment of the present invention.

Referring now to the drawings in further detail, as seen in FIG. 2, the apparatus of the present invention in a first embodiment is generally designated 10 and comprises a carriage 12 and a material feeding assembly 14 comprising a supply hopper 48, an auger conveyor 16, a shroud l8 and an abrading wheel 20.

The carriage 12 is an elongated rectangular plate having at its front end 13 two downwardly depending supports 24 having wheels 26 at their ends for engagement with the inner surface of a pipe 30. At the rear end of the carriage is a rectangular plate 27 suitably connected perpendicular thereto for receiving one end of a support pipe 28 which is in turn mounted on a motor-driven cart as will hereinafter be described. An aperture 29 in the plate communicates with the interior of the pipe 28. Various lines used to supply electrical power and compressed air to the apparatus are contained in the support pipe 28 and pass through the aperture 29 and to their respective motors valves and nozzles as will be described hereinafter. Mounted along the forward top portion of the carriage 12 on suitable supports 31 is an open ended tubular housing 32 having a forward end 34 and a rearward end 35. The forward end has a reduced diamter 36.

As best seen in FIGS. 2, 5 and 6, evenly spaced along the top rear portion of the tubular housing 32 are a series of apertures 37 oriented in two-spaced rows extending longitudinally of the housing. The forward end 34 of the tubular housing extends past the front end 13 of the carriage l2 and has a cylindrical shroud 18 concentrically mounted thereto. As seen in FIGS. 2 and 4, the shroud, which is a right cylindrical open-ended pipe, has a radius equal to approximately three times the radius of the tubular housing and is supported on the housing by four equally spaced spokes 38 attached to the surface of the housing and the inner surface of the shroud. Suitably connected to the exterior surface of the shroud 18 is a thin collar 40 having a rubber extension ring 42 surrounding the periphery of the collar to span the space between the collar and the pipe 30. The front end of the shroud is adjacent the forward end of the housing 32.

As best seen in FIGS. 2, 5 and 6, a variable feed supply hopper 48 is mounted longitudinally on the top of the tubular housing 32 extending from adjacent the rear end of the shroud 18 to substantially the other end of the tubular housing. As seen in FIGS. 5 and 6, the hopper 48 is formed on its sides by two elongated

rectangular side plates

50 and 51 mounted along their bottom edges at an angle less than 90 to the outer surface of the tubular housing along lines parallel to the longitudinal axis of the housing and at its ends by

end plates

74 and 76 which have bottom edges conforming to and resting on the circular top of the housing 32. An inverted V-shaped member 52, formed from two elongated plates jointed at an angle, is interposed between the

plates

50, 51, 74 and 76 to form two troughs in the hopper 48 so that the hopper has a W-shaped crosssection. As seen in FIG. 5, the side edges 73 of the member 52 rest along the lines formed by the intersection of the tubular housing 32 and the

plates

50 and 51. Spaced along the edges 73 are a series of rectangular cut-outs 71 which spacing coincides with the longitudinal spacing of the apertures 37 formed in the top of the tubular housing. The length of the member 52 is less than that of the hopper 48 and therefore can be reciprocated longitudinally thereof to a position where the cut-outs 71 coincide with the apertures 37 wherein abrasive material in the hopper is allowed to flow through the apertures or to a position where the cutouts 71 do not coincide with the apertures 37 wherein abrasive material in the hopper is prevented from flowing through the apertures. The front end of the member 52 has a rod 75 mounted in the apex of that member which is slidable along an invertedV-shaped guide 77 mounted to the end plate 74. Similarly, rod 79 is mounted at the other end of the member 52 in the apex of that member for slidable movement through a pipe 81 fitted into a suitably provided bore in the end wall 76. As seen in FIG. 6, one end of the rod 79 is pivotally connected to the middle of a rod 83 which is pivotally mounted at one end to a support 85 extending from the end plate 76 and pivotally mounted to a piston shaft 60 at its other end. The shaft 60 is connected to a piston 62 enclosed by and movable through an air cylinder 64. A conventional four-way solenoid valve 66 has

conduits

63 and 65 connected to respective sides of the piston 62 in the air cylinder 64, whereby the interconnected member 52 may be moved longitudinally along the tubular housing 32 on actuation of the valve 66 to allow abrasive material in the hopper 48 to flow into the tubular housing. That valve has a connection by line 67 to a suitable air pressure line carried in the support pipe 28 and an outlet line '69 to the atmosphere.

As seen in FIG. 2, mounted for rotation within the tubular housing 32 on bearings 45 and 47, which are supported at respective ends 34 and 35 of the housing, is

a shaft 90. The shaft is connected at its rear end to a motor 92 by means of belts 93, which motor is located adjacent the rear of the housing 32 and on the carriage 12, and at its front end to the abrading wheel 20. A power line for the motor 92 is carried in the support pipe 28, and on actuation the motor causes the shaft and the abrading wheel 20 to rotate.

Mounted for rotation on the shaft 90 and within the tubular housing 32 is the auger conveyor 16 which is comprised of a pipe 44 having a length substantially equal to the length of the tubular housing and a radius equal to substantially one-half the radius of the tubular. housing. Mounted on that pipe is a helical member 46 which extends the entire length of the pipe.

Bearings

55 and 57, located on the inside of the ends of the pipe 44, support the pipe 44 on the shaft 90 and allow the auger to rotate relative to the shaft 90.

As seen in FIG. 2, a motor 78 is mounted to the rear portion of the carriage 12 adjacent the support plate 27 and has a motor shaft 80 connected thereto with a sprocket 87 at its end. A chain belt 89 connects the sprocket 87 on the shaft 80 to a sprocket 91 on the rear of a shaft 180 rotatably mounted along the top of the carriage 12. On the front of the shaft 180 is a sprocket 82 which is connected via a chain belt 84 passing through a cut-out 86 in the bottom of the tubular housing 32 to a sprocket 88 connected to the rear end of the pipe 44 carrying the helical member 46. Actuation of the motor'78 causes the auger conveyor to rotate and feed abrasive material in the tubular housing towards the wheel 20.

As seen in FIGS. 2 and 3, the abrading wheel 20 is comprised of a front, circular plate or disc 94, a rear, circular plate or annulus 96 and a series of eight equally radially spaced rectangular throwing blades 98. The diameter of the front disc 94 is approximately threequarters the inside diameter of the shroud, the inner diameter of the rear annulus 96- is substantially equal to the inner diameter of the tubular housing 32 and the outer diameter of the rear annulus 96 is slightly smaller than the diameter of the front disc 94. Concentrically mounted to one side of the front disc 94 by bolts 95 is a smaller disc 100 which is integrally formed with one end of a tubular hub 102 which passes through a suitably drilled central bore 93 in the front disc 94 and extends rearwardly substantially to the front end 34 of the tubular housing. The front of the shaft 90 passes through a cylindrical bore 104 in the hub 102 and extends into a central bore in the smaller disc 100. A small radius disc 105 is bolted to the end of the shaft 90 to keep the wheel 20 from moving off the shaft. A key 106 passes through a slot in the surface of the shaft 90 and a slot 101 in the hub 102 to connect-these two members and prevent relative rotation between them. The front disc 94 and the rear annulus 96 are oriented parallel and concentric to each other. The eight blades 98 are equally radially spaced around the hub 102 such that their outer ends are coincident with the exterior periphery of the front disc 94 and their inner ends are just slightly spaced from the exterior periphery of the hub 102. Each blade 98 is suitably attached along opposite sides to the front disc and the rear annulus and is in a plane perpendicular to the planes of the annulus and disc. If desired, slots in the disc and annulus may be provided to receive the edges of the blades. An annular inlet 95 in the wheel 20 is formed between the end of the hub 102 and the inner radius of the annulus 96 which is partially received around the reduced diameter 36 of the housing 32. I

Also included in the material feeding assembly 14 and located on the bottom side of the shroud 18 in front of the collar 40 is an arcuate, closed ended pipe 108 which communicates with an air line 110 suitably mounted to the carriage 12 and passing through a suitably formed bore 112 in the bottom of the shroud 18. As seen in FIG. 4, a plurality of arcuately spaced orifrees 114 are provided in the portion of the arcuate pipe facing forward. The free end of the air line 110 is connected to a source of compressed air capable of providing approximately 90 pounds per square inch of pressure. Line 110 is provided with air through a line carried in the support pipe 28.

As mentioned above with regard to the description of the abrading wheel 20, the rear annulus 96 has an outer diameter which is slightly less than the diameter of the front disc 94. It has been discovered that when the rear annulus has such a reduced diameter and a shroud, having a diameter equal to substantially 4/3 of the diameter of the front disc, is positioned adjacent the rear annulus and when the wheel and the shroud are moved through a pipe having a diameter substantially larger than the shroud, an air pressure or flow is created by the rotation of the abrading wheel, which flow moves along the longitudinal axis of the pipe from one open end to the other open end in a direction from the rear annulus towards the front disc. If the front and rear plates on the abrading wheel are of equal diameter no air flow directed down the pipe is created. Thus, in the operation which will be described hereinafter the rotating wheel both throws abrasive material to clean the walls of the pipe and additionally creates an air pressure or flow along the length of the pipe to blow the abrasive material and the abraded material out the rear end of the pipe. As shown in FIG. 2, the combination of the shroud 18, the collar 40 and the rubber extension 42 effectively reduces the diameter of the pipe 30 which is larger than that of the shroud to the proper 4:3 ratio. This is indicated in FIG. 2 wherein the diameter of the shroud is designated A and the diameter of the front disc is designated A.

As seen in FIG. 7, a second embodiment in accordance with the present invention is presented. It has also been discovered that when the diameter of the pipe being cleaned is substantially in a ratio of 4:3 with the diameter of the front disc of the abrading wheel being used the shroud is not necessary to aid in creating the desired air blast. This relationship is indicated in FIG. 2 wherein the diameter of the pipe is designated A and the diameter of the front disc is designated A. FIG. 7 contains all of the apparatus as that shown in FIG. 2 except the shroud, the spokes, the collar and the rubber extension ring, which are not utilized. Those same parts are given the same character numerals.

The overall operation of both embodiments is essentially the same; however, the two different embodiments are utilized, with the above mentioned differences in structure, when the relationship of the diameter of the pipe and the front disc is as set forth above. With only the addition of the shroud, an abrading wheel of one size may be used to clean pipes of various diameters.

As seen in FIG. 1, the apparatus 10 can be incorporated in an overall system for delivering a pipe to be cleaned to a position adjacent the front end of the apparatus with the pipe lying horizontally. Various conveyors and hoppers also are utilized to return used abrasive material back to the hopper for reuse.

Specifically, in FIG. 1, the apparatus 10 is shown with the support pipe 28 mounted to a cart 116 which is motor-driven and guided on rails 117. The drive for the cart is preferably of variable speed and reversible. The support pipe rides along a hydraulicallyelevated roller 118 as the cart moves the entire apparatus 10 into the front end 39 of the pipe 30 and then along its entire length. The cart is then actuated to move the apparatus in the reverse direction and out of the front end 39 of the pipe 30. That pipe and others like it are rolled into position adjacent to. the front of the apparatus along suitable supports 120 and held in place by wedges 121. Preferably, the pipes are oriented in a plane horizontal to the ground. The front end 39 of the pipe can be received ina shroud (not shown) so that if abrasive material is sprayed from the apparatus beforethe wheel enters the pipe, that material will be confined in the shroud. A rear end 33 of the pipe 30 is positioned within a suitable opening in a housing or cabinet 122 which has a sloping bottom 124 and an elevating bucket conveyor 126 at the rear of it and extending from the lowest portion of the sloping bottom 124 to a position above the cabinet. Located to receive material discharged'rom the buckets in the elevating conveyor 126 is an endless belt conveyor 128 having a delivering end 129 located above a reservoir hopper 130 which is suitably supported on supports 132 in a position to supply the hopper 48 on the carriage 12 when the apparatus is removed from the pipe 30. Additionally, the cabinet 122 has a vacuum pump 134 communicating with the interior thereof to remove lightweight particles suspended in the volume enclosed by the cabinet and to transfer them to a dust collector 123. These particles comprise the material cleaned from the pipe.

In the preferred embodiment of the present invention actually built and operated the electrical motor 92, used to run the abrading wheel, is 20 hp and capable of rotating the wheel by suitable gearing arrangements at approximately 2,600 rpm. The electrical motor 78, used to run the auger conveyor, is a hp motor and capable of rotating the auger conveyor by suitable gearing arrangements at approximately 200 rpm. Preferably, the pipe 44 incorporated in the auger conveyor has an inner diameter of 4'inches, the tubular housing 32 has an inner diameter of 8 inches and the helical member 46 has an outer diameter of 7 inches. The shaft 90 rotated by the motor 92 and supporting the abrading wheel 20 has a 2-inch diameter with the forward disc 94 having a diameter of approximately 19.5 inches and the rear annulus having an outer diameter of l 7 inches withan interior diameter of 8.5 inches. The longitudinal length of the supply hopper 48 is 7 feet, the longitudinal length of the shroud 18 is l foot and the diameter of the shroud is 26 inches. The pipes to be cleaned by an apparatus having the above-mentioned dimensions can beas small as 30 inches and can be of a length of approximately 40 feet. Pipes of larger diameters and lengths can be operatedon with a concomitant adjustment of the dimensions of the apparatus as necessary. Additionally, the rubber ring 42 surrounding the collar 40 can be provided in various thicknesses to accommodate larger diameter pipes. Utilization of the apparatus described herein has reduced the time necessary to clean one pipe from minutes using old methods to 5 minutes. And additionally horsepower requirements have been reduced from approximately 600 to approximately 50.

In operation, the pipe to be cleaned, as seen in FIG. 1, is manipulated on the supports 120 so that a front end 39 is adjacent the front of the abrading wheel, and the rear end 33 is partially received in the cabinet 122, and the pipe 30 is lying in a horizontal plane. The abrasive material, which can be steel or iron grit or other suitable shot-blasting" material, is contained in the reservoir hopper 130 located above the apparatus 10,

and is delivered to the variable feed supply hopper 48 I mounted on the carriage 12 to fill it substantially to the top of the

side walls

50 and 51.

The motorized cart 116 is actuated to move the apparatus in a first direction into the front open end 39 of the pipe and completely along the length of the pipe 30 as seenin FIG. 2 with the height of the apparatus relative to that end 37 being adjusted by the hydraulically elevated roller 118. As the apparatus moves through the pipe, the forward end of the apparatus 10 is supported on the bottom of the inside of the pipe on the wheels 26 connected to the carriage 12. Preferably, the speed at which the cart 116 moves the apparatus 10 through the pipe is approximately l3.5 feet per minute in a 40 foot pipe. However, since the motorized cart 1 16 can be moved at varying speeds, any desired speed may be utilized. Just before the front of the abrading wheel 20 enters the pipe, the motors 92 and 78 are actuated to begin rotation of the abrading wheel and the auger conveyor 16, which conveyor will feed the abrasive material which will be fed to it from the supply hopper through the apertures 37 and to the abrading wheel through the inlet 95 formed between the hub 102 and the rear annulus 96.

At this time, the solenoid valve 66 is also operated to in turn movethe member 52 to uncover the apertures 37 in the tubular housing to allow the abrasive material in the hopper 48 to pass into the tubular housing 32 through those apertures 37. The amount of abrasive material fed into the tubular housing can be as much as desired taking into consideration the speed at which the apparatus is to move through the pipe and the speed at which the abrading wheel is rotating. However, it is desired that at no time the abrasive material in the tubular housing be allowed to completely fill that housing so that a clear passageway is provided in the housing from the open rear end 365 to the open forward end 34. This allows air to move through the tubular housing and through the annular inlet 95 as will be described hereinafter.

The combination of the rapidly rotating blades 98 on the abrading wheel and the forces exerted on the abrasive material by therotating auger conveyor feed the abrasive material along the tubular housing into the center of the abrading wheel through inlet 95. From that center point the abrasive material is thrown substantially perpendicularly to the longitudinal axis of the pipe to be cleaned and impinges upon the internal surface of the pipe with great force. This impinging action removes various mill scale and corrosion and other foreign material which have accumulated on the internal surface of the pipe. Also, because of the unique configuration of the wheel as described above, an air flow is created within the pipe along which air moves into the front open end 39 of the pipe, along the pipe behind the apparatus 10, through the tubular housing 32, through the shroud 18, through and around the abrading wheel, along the pipe ahead of the apparatus 10, and finally out the rear open end 33 of the pipe.

This stream of air carries the abrading material thrown from the abrading wheel and also the material removed from the pipe by the abrading action of the abrading material towards the end of the pipe located in the cabinet 122. Due to this air flow in combination with the movement of the entire apparatus in a first direction from the front open end 39 of the pipe towards the rear open end 33, the material is moved into the cabinet 122. Most of the material is carried by the air flow completely along the length of the pipe and into the cabinet 122. However, some of the material might only move along a portion of the pipe and not directly into the cabinet, this material is transferred into the r 9 cabinet as the apparatus moves through the entire pipe.

Additionally, the air line 110, which is connected to a high pressure air compressor, can be actuated to deliver compressed air through the orifices 114 in the arcuate pipe 108 suspended below the shroud 18. If any of the material accumulates at the bottom of the pipe, it is moved along by the additional thrust added to the air stream by the high pressure air emanating from the pipe 108.

At the end of the pipe, the abrasive material and the material removed from the internal surface of the pipe enter the cabinet 122. The heavier abrasive material rolls along the sloping bottom wall 124 and is then elevated by the buckets in the conveyor 126 and deposited on the endless belt conveyor 128. From that conveyor 128 the abrasive material is returned to the reservoir hopper 130 for reuse on subsequent pipes. The material removed from the internal surface of the pipe, being lighter than the abrasive material, is suspended in the volume enclosed by the cabinet and is removed therefrom by the vacuum pump 134 and collected in a dust container 123.

After the apparatus has been moved completely through one pipe and has cleaned its entire length, the motorized cart 116 is stopped, and the motors 92 and 78 are turned off, as is the infeed of compressed air to the air line 110 and the feed of abrasive material from the supply hopper 48. Then the motorized cart 116 is energized in a reverse direction to move the apparatus in a direction opposite from the first direction along the length of the pipe and finally out of the front end 39 of the pipe 30. The hopper 48 is then refilled from the reservoir hopper 1'30 and a new pipe is maneuvered into position along the supports 120 replacing the cleaned pipe and the operation outlined above is repeated for subsequent pipes.

The operation of the second embodiment shown in FIG. 7 is the same as the first embodiment except that the pipe itself takes the place of the shroud.

While two advantageous embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. An apparatus for cleaning the interior walls of a pipe, the combination comprising:

a carriage;

means for moving said carriage through a pipe in a first direction;

material feeding means coupled with said carriage for discharging abrasive material against the interior walls of said pipe; and

said material feeding means also providing an air flow through said pipe in said first direction;

whereby said abrasive material is discharged into contact with the interior walls of said pipe to clean them and is then carried with the material cleaned from the walls in said first direction by said air flow,

wherein said material feeding means includes a plurality of blades for throwing said abrasive material.

2. An apparatus for cleaning the interior walls of a pipe, the combination comprising:

a carriage;

means for moving said carriage through a pipe in a first direction;

wherein said material feeding means includes a circular front plate;

a circular rear plate having an outer diameter less than the diameter of said front plate;

a plurality of blades interconnecting said front and rear plates; and means connected to said front plate for rotating said front plate.

'3. An apparatus for cleaning the interior walls of a pipe, the combination comprising:

a carriage;

means for moving said carriage through a pipe in a first direction;

wherein said material feeding means includes rotating blade means for throwing said abrasive material in a direction substantially perpendicular to said first direction into contact with the interior walls of said pipe and for generating said air flow; and

means coupled to said rotating blade means for directing said air flow in said first direction.

4. An apparatus according to claim 3 wherein said material feeding means includes:

conveyor means for feeding said abrasive material in said first direction to said rotating blade means.

,5. An apparatus according to claim 4 wherein said material feeding means includes:

a hopper means for feeding abrasive material to said conveyor means.

6. An apparatus according to claim 5 wherein said material feeding means includes:

a shroud means mounted adjacent said rotating blade means for reducing the cross-sectional area of the pipe.

7. An apparatus according to claim 6 and further including:

means located at one end of the pipe for separating said abrasive material and said material cleaned from the walls; and

means, coupled to said means for separating, for transferring said abrasive material back to said hopper means.

8. An apparatus according to claim 7 and further including:

support means for positioning said pipe in a substantially horizontal plane; and

to the longitudinal axis of the pipe.

11. An apparatus according to claim 3 wherein said material feeding means includes a shroud means mounted adjacent said rotating blade means for reducing the cross-sectional area of the pipe.

12. An apparatus according to claim 3 wherein said means for directing said air flow includes front and rear plates.

Claims

1. An apparatus for cleaning the interior walls of a pipe, the combination comprising: a carriage; means for moving said carriage through a pipe in a first direction; material feeding means coupled with said carriage for discharging abrasive material against the interior walls of said pipe; and said material feeding means also providing an air flow through said pipe in said first direction; whereby said abrasive material is discharged into contact with the interior walls of said pipe to clean them and is then carried with the material cleaned from the walls in said first direction by said air flow, wherein said material feeding means includes a plurality of blades for throwing said abrasive material.

2. An apparatus for cleaning the interior walls of a pipe, the combination comprising: a carriage; means for moving said carriage through a pipe in a first direction; material feeding means coupled with said carriage for discharging abrasive material against the interior walls of said pipe; and said material feeding means also providing an air flow through said pipe in said first direction; whereby said abrasive material is discharged into contact with the interior walls of said pipe to clean them and is then carried with the material cleaned from the walls in said first direction by said air flow, wherein said material feeding means includes a circular front plate; a circular rear plate having an outer diameter less than the diameter of said front plate; a plurality of blades interconnecting said front and rear plates; and means connected to said front plate for rotating said front plate.

3. An apparatus for cleaning the interior walls of a pipe, the combination comprising: a carriage; means for moving said carriage through a pipe in a first direction; material feeding means coupled with said carriage for discharging abrasive material against the interior walls of said pipe; and said material feeding means also providing an air flow through said pipe in said first direction; whereby said abrasive material is discharged into contact with the interior walls of said pipe to clean them and is then carried with the material cleaned from the walls in said first direction by said air flow, wherein said material feeding means includes rotating blade means for throwing said abrasive material in a direction substantially perpendicular to said first direction into contact with the interior walls of said pipe and for generating said air flow; and means coupled to said rotating blade means for directing said air flow in said first direction.

4. An apparatus according to claim 3 wherein said material feeding means includes: conveyor means for feeding said abrasive material in said first direction to said rotating blade means.

5. An apparatus according to claim 4 wherein said material feeding means includes: a hopper means for feeding abrasive material to said conveyor means.

6. An apparatus according to claim 5 wherein said material feeding means includes: a shroud means mounted adjacent said rotating blade means for reducing the cross-sectional area of the pipe.

7. An apparatus according to claim 6 and further including: means located at one end of the pipe for separating said abrasive material and said material cleaned from the walls; and means, coupled to said means for seParating, for transferring said abrasive material back to said hopper means.

8. An apparatus according to claim 7 and further including: support means for positioning said pipe in a substantially horizontal plane; and wherein said first direction is along the longitudinal axis of said pipe.

9. An apparatus according to claim 8 wherein said material feeding means includes: means coupled to said carriage for supplying air under pressure along the bottom of said pipe.

10. An apparatus according to claim 1 wherein said plurality of blades are coupled to a shaft rotatably coupled to said carriage, said shaft being oriented parallel to the longitudinal axis of the pipe.