GB2200970A

GB2200970A - Pipe cleaning device

Info

Publication number: GB2200970A
Application number: GB08702921A
Authority: GB
Inventors: Frank George Groves
Original assignee: FLUID ENGINEERING PRODUCTS
Current assignee: FLUID ENGINEERING PRODUCTS
Priority date: 1987-02-10
Filing date: 1987-02-10
Publication date: 1988-08-17
Also published as: GB8702921D0

Abstract

A device for use in cleaning the inner surfaces of pipes comprises a trolley receivable within the pipe, a reversible motor (8) carried by the trolley, means (14) for periodically reversing the motor (8) to provide an oscillating drive to a shaft (9) the shaft (9) carrying at least two spaced jetting heads (12) for producing a fluid jet bearing particulate abrasive so that the points of impingement of the jets move over the inner wall of the pipe to subject every point of the inner wall to the action of at least one jet, the jetting heads (12) being connected to flexible supply tubes. The trolley is driven through the pipe either by a second motor mounted on the trolley or by an external drive such as a chain and sprocket (Fig. 2, not shown). The trolley preferably comprises two spaced apart annular collars (1, 2), each collar having two wheels (4, 5) arranged to run on the internal wall of a pipe and spaced circumferentially by 120 DEG and a spring loaded ball (6, 7) spaced circumferentially by 120 DEG from the wheels. The two collars (1, 2) are rigidly connected together and the reversible motor (8) is preferably mounted between the two collars (1, 2). <IMAGE>

Description

PIPE CLEANING DEVICE This invention relates to a device for cleaning the interior surfaces of pipes, particularly to remove mill scale and other debris produced during the manufacture of the pipe but which can also be used to remove corrosion and other fouling resulting from passage of fluids through a pipe.

According to the invention a device for use in cleaning the inner surfaces of pipes comprises a trolley receivable within the pipe and movable longitudinally of the pipe while having substantially nofreedom of movement transversely of the pipe, a reversable motor carried by the trolley, means for periodically reversing the motor to provide an oscillating drive, a shaft driven by the motor and extending axially of the pipe when the trolley is located within the pipe, the shaft carrying at least two jetting heads for producing a fluid jet bearing particulate abrasive and arranged to direct their jets at spaced portions of the inner wall of the pipe such that on oscillation of the shaft the heads are rotated so that the points of impingement of the jets move over the inner wall of the pipe so that every point of the inner wall is subjected to the action of at least one jet, the jetting heads being connected by flexible tubes to supply means located outside the pipe for supplying carrier fluid and particulate abrasive slurry to the jetting heads and drive means for driving the trolley through the pipe.

The drive means for the trolley may comprise a second motor mounted on the trolley and driving the trolley through driven wheels but preferably is separate from the trolley and is preferably located outside the pipe. The trolley may for example be mounted at one end of a rack or rigidly mounted chain which is advanced through the pipe by a pinion or sprocket drive fixed at one end of the pipe.

The jetting heads are preferably of the type described in EP-A0119203 and the means for producing the slurry of particulate abrasive and for feeding it to the jetting heads is preferably as described in GB8501091.

The motor for the trolley drive and also the motor carried by the trolley are preferably hydraulic or pneumatic motors.

The invention will now be described in greater detail by way of example with reference to the drawings in which Fig.1. is a schematic representation of one form of trolley for use in the invention and Fig.2. shows one form of drive arrangement for the trolley.

Referring to Fig.l. the trolley comprises two spaced apart annular collars 1,2 which are connected together by a means (not shown). Each collar 1,2 has a diameter smaller than the internal dimensions of a pipe 3 with which it is to be used. Each collar carries two wheels 4,5, spaced circumferentially by 1200 degrees and arranged to run on the inner wall of the pipe 3 only one wheel 4,5 for each collar 1,2 being shown. Each collar 1,2 also carries a spring loaded ball 6,7, circumferentially spaced from the wheels 4,5 by 1200 and also arranged to contact the inner wall of the pipe 3 so that between them the wheels and sprung ball 4,6 and 5,7 hold the carriage against substantial movement transverse of the pipe 3.

A pneumatic motor 8 is mounted between the two collars and drive a shaft 9, which extends from within the collar 1, axially outwards in a direction away from collar 2, via gear wheels 10, 11. Mounted on the end of the shaft 9 are two jetting heads 12 arranged with their axes substantially perpendicular such that a fluid jet bearing particulate abrasive emerging from the jetting heads 12 impinges on the inner wall of the pipe 3 at two locations spaced apart by approximately 1800.

Carried on the end of the shaft 9 that is within collar 1 are actuating means (not shown) for operating two limit switches 13 such that the limit switches 13 are operated on rotation of the shaft 9 through 1800. The limit switches are connected to a motor reverse unit 14, mounted in collar 2 so that the drive to shaft 9 is reversed each time the shaft has rotated through 1800. By this means the fluid jets emerging from jetting heads 12 are caused to impinge on the whole circumference of the inner wall of the pipe.

The trolley is attached to one end of a drive means as shown in Fig.2.

As shown in Fig.2 the drive means comprises an elongate chain 21 rigidly supported on support means 22, for example by welding. The chain 21 and support 22 pass through a sprocket drive 23 whereby the chain 21 and support 22 together with the trolley attached thereto can be advanced or withdrawn through the pipe 3. The sprocket drive is driven from a pneumatic motor 24 via shaft 25 and gear box 26. The complete drive assembly is rigidly attached to one end of a tubular drive guide 28 that can be rigidly clamped to one end of the pipe 3 such that the chain 21 and support 22 pass substantially axially through the pipe 3.

In operation of this device the trolley is introduced into the drive guide 28 and is advanced by the drive means to a position in which the fluid jets generated by jetting heads 12 will impinge on the inner wall of the pipe at the front end (the left hand end in Fig.2) of the pipe. The feed to the jetting heads is then commenced and the motor 8 is started to cause the jetting heads to oscillate through 1800 of arc. The drive to the trolley is started by starting the motor 24 and the trolley is advanced through the pipe at a rate that such every point on the inner wall of the pipe is subjected to the cleaning action of the abrasive fluid jet from one or other of the jetting heads.

Claims

1. A device for use in cleaning the inner surfaces of pipes comprising a trolley receivable within the pipe and movable longitudinally of the pipe while having substantially no freedom of movement transversely of the pipe, a reversible motor carried by the trolley, means for periodically reversing the motor to provide an oscillating drive, a shaft driven by the motor and extending axially of the pipe when the trolley is located within the pipe, the shaft carrying at least two jetting heads for producing a fluid jet bearing particulate abrasive and arranged to direct their jets at spaced portions of the inner wall of the pipe such that on oscillation of the shaft the heads are rotated so that the points of impingement of the jets move over the inner wall of the pipe so that every point of the inner wall is subjected to the action of at least one jet, the jetting heads being connected by flexible tubes to supply means located outside the pipe for supplying carrier fluid and particulate abrasive slurry to the jetting heads and drive means for driving the trolley through the pipe.

2. A device according to claim 1 wherein the drive means for the trolley comprises a second motor mounted on the trolley and driving the trolley through driven wheels.

3. A device according to claim 1 wherein the drive means for the trolley comrpises a motor located remotely from the trolley and the trolley is mounted at one end of a rack or rigidly mounted chain that can be advanced through the pipe by a pinion or sprocket drive fixed at one end of the pipe.

4. A device according to any one of claims 1 to 3 wherein the reversible motor carried by the trolley is a hydraulic or pneumatic motor.

5. A device according to any one of claims 1 to 4 wherein the drive means for the trolley comprises a hydraulic or pneumatic motor.

6.. A device according to claim 1 substantially as described herein with reference to the drawings.

7. A method for cleaning the interior surfaces of pipes wherein there is used an apparatus according to any one of claims 1 to 6.

8. A method according to claim 7 conducted substantially as described herein with reference to the drawings.