NZ200262A - Removing obstructions from sewers or pipe-lines using high pressure water jets - Google Patents

Description

2002a Priority Date(s): Complete Specification Filed: y..k.&£ Class: £<?$£!I . &&&£&&£- • • • • V' * f *g MDV198^*.(! Publication Date; U 7.7.

P.O. Journal, No: Patents Form No. 5 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION "REMOVAL OF OBSTRUCTIONS IN SEWERS AND PIPELINES USING HIGH PRESSURE WATER JETS" i/WE STEPHEN TRACEY a British subject, of 61, Highfield Gardens, Aldershot, Hants., Great Britain, and STANLEY ROBERT MOORE a British subject, of Lavender Cottage, School Road, Grayshott, Nr. Hindhead, Surrey, Great Britain, hereby declare the invention, for which £-/we pray that a patent may be granted to ae/us, and the method by which it is to be performed, to be particularly described in and by the following statement:- (followed by page 1A) 20020. - 1A- H®R0¥EMENTSXlHX3SKBxRE2A22NSxffixXHExIsiNiNS ©FXSEWERSX0RXK2BES This invention concerns improvements in and relating to the lining of sewers or pipes, and in particular the removal of obstructions from within the sewer or pipe by remote controlled means.

# A known method of reconditioning existing sewers or pipelines that have become subject to leakage, consists in drawing into the sewer or pipeline a liner of syn-10 thetic plastics material, which liner has to be inflated or pulled through the existing sewer as a unit. Such liners may, for example, be made of rigid PVC or like material. A drawback of this lining method is that before such a liner can be inserted into the sewer or 15 pipeline, all obstructions projecting from the wall of the original sewer or pipeline must be removed to allow passage of the inserted liner. Such projections may, for example, consist of the protruding ends of soil pipes or branch pipes which have been inserted into 20 lateral apertures in the main bore of the sewer or pipe. The removal of such projections currently requires that they first be located, for example by drawing a remote television camera through the central bore of the sewer, and then gaining access to the appropriate point by 25 excavation. Once the protruding obstruction has been located by this means, it is necessary for it to be repaired, back-filled and reinstated temporarily, and then the road surface would be reinstated permanently at a later date. Such an operation is therefore a 30 timely and costly exercise involving traffic delays and environmental disturbance. After the lining has subsequently been inserted, it is necessary to complete the further operation of cutting appropriate apertures in the lining at the point where any lateral connections 17JULB85 2.002 £2 are intended to communicate with the main bore of the sewer. This operation must again be carried out from the surface at the point of excavation. r It is an object of the present invention to 5 provide means which enable simplification of the above-mentioned, lining procedure, and an elimination, or at least a reduction, in the need for access to be gained to the sewer by excavation.

In accordance with the present invention there 10 is provided a device for use in removing an obstruction within a sewer or pipe, or in a lining of such a sewer or pipe, comprising a body portion mounted upon a sled to be drawn through the sewer or pipe and including a union for receiving a water supply hose, said body 15 portion having mounted thereon a rotary head arranged to be driven by a remotely controllable motor located by the body portion, and at least one water jet nozzle provided on said rotary head and radially spaced from the rotary axis thereof, said water jet nozzle being 20 connected to said union of said body portion.

The invention also provides a method of removing an obstruction within a sewer or pipe by means of the device of the invention including the steps of introducing said device into said sewer or pipe at an appro-25 priate access point, together with a water supply hose connected to said union, drawing said sled along the axis of the sewer or pipe to bring the nozzle or nozzles of said rotary head to a point adjacent said obstruction, supplying water under pressure to said jet nozzle or " 30 nozzles and remotely controlling said motor or motoro to effect movement of said nozzle to cut the obstruction from the sewer or pipe.

The rotary axis of said head of the device may be aligned along an axis intended to be parallel to, or perpendicular to the longitudinal axis, of the sewer pipe, in accordance with whether the cutting action of the water jet is to be utilised for removing peripheral obstructions from the bore of the sewer, or for cutting lateral access apertures in a lining thereof. The remotely controllable motor may be a pneumatically operated motor arranged to be coupled to air supply and return hoses to be drawn into the sewer together with the water jetting device and its associated water supply hose. The coupling of the air supply and return hoses to an appropriate remote control unit enables an operative to control the position of the rotary water jet cutting head, as seen, for example, with the aid of a closed circuit television camera fitted to the body of the device behind the rotary cutter head. The television camera thus enables both the initial location of projections to be removed and the control of the cutting process by the operative In the case where the cutting head is to be used for cutting apertures in the wall of an inserted lining, it will be appreciated that such apertures cannot be located by visual inspection, and thus in accordance with a further 200262 r) V feature of the invention a water jetting device adapted to provide the appropriate lateral cutting action maybe provided with a.Geiger counter or similar sensor located in the region of the cutting head for detecting radiation from an isotope that may be located within the lateral branch pipe to which a communication aperture is to be cut. Location of the desired position of the cutter head can thus be achieved by remotely monitoring an output signal from the Geiger counter.

The invention is illustrated by way of example in the accompanying drawings, in which Figs. 1A to 1C are perspective views of a water jetting device in accordance with the invention for use in removing obstructions from the internal wall of a sewer pipe or the like.

Fig. 2 is a perspective view of the device shown in Fig. 1C shown in relation to the end of an associated sewer pipe, Fig. J is a view of the device of Figs. 1A to 1C, showing the water jet produced thereby, Fig. 4 is a diagrammatic view of a further embodiment of the water jetting device in accordance with the invention, shown in place within a sewer pipe, for the purpose of cutting a lateral aperture - within an inserted lining, and .

Fig. 5 is a diagrammatic view of a sewer pipe showing the method of access to and operation of a device in accordance with the invention.

Referring to the drawings, Figs. 1A to Fig. 3 illustrate one embodiment of a water jetting device in accord- 2002it ance with the invention which comprises a sled or skid assembly indicated generally at 1, said assembly being arranged to fit within a given diameter of sewer pipe and to locate the body of the water jetting device on 5 the central axis of the pipe. The skid assembly is pro vided with front and rear towing eyes 2, 3, by means of which the device may be drawn along a sewer pipe as described in more detail below. The skid assembly comprises clamping means 4 by means of which the generally 10 cylindrical body portion 5 of the water jetting device may be clamped in place.

As shown more clearly in Fig. 1C, the water jetting device comprises a rotary head 6 comprising two diametrically opposed jet nozzles 7 which extend outwardly at a 15 small angle to the central rotary access of the head 6.

The head 6 is rotatable about its central axis by means of a pneumatic motor, not shown, located within the cylindrical body 5 of the device, the water supply conduit from the body of the device 5 to the head 6 being sealed 20 by appropriate seals allowing rotation of the head 6.

At the end of the cylindrical body portion 5 opposite to the water jetting head 6, there are provided a union 8 for connection of a high pressure water supply hose and unions 9 and 10 for the attachment of air supply and 25 return hoses for the remote control of the internal pneu matic motor.

Fig. 2 illustrates the size relationship between the water jetting device and an associated sewer pipe, and as may be seen by comparison of Figs. 1B and 1C, the device 30 may be adapted to pipes of varying size by utilising jet nozzles 7 of different effective lengths.

Referring to Fig. 4, there is illustrated another embodiment of device in accordance with the invention, wherein the water jetting head is utilised for the cut ting of transverse apertures in a lining inserted within a sewer pipe. In Fig. 4 components corresponding to those of Figs. 1 to 3 have been indicated by like reference numerals, the only difference being that the axis of the water jetting device extends radially to a sewer pipe 20, rather than axially as in the previous embodiment. In this case the water jets from nozzles 7 are utilised to cut an aperture within an internal liner 21 which has been located within the sewer pipe after removal of internal projections. The location of the jet nozzles7 accurately in alignment with a branch pipe 22 is effected with the aid of a radioactive isotope pack 23 which is located within the branch pipe, and the radiation from which is picked up by a Geiger counter device indicated diagrammatically at 24. The body 5 of the water jetting device is in this case provided with an additional control motor, not shown, arranged for the rotation of the body 5 about the axis of mountings 25 connecting it to the sled 1. In use, the longitudinal position of the sled 1 and the rotary position of the body 5 are adjusted until a maximum reading is obtained on the Geiger counter 24, whereupon the rotary head 6 carrying the nozzles7 will be centred accurately in alignment with the axis of the branch pipe 22. Cutting of the aperture in the lining 21 may then be effected by turning on the high pressure water supply to the jet nozzles7 and rotating the head 6 by means of the internal motor within the body 5.

Fig. 5 shows the general arrangement of a device in accordance with the invention in use within a sewer pipe 30, to which access has been gained through manholes, or the like, y\. Initially, a system of drag lines is set up through the sewer pipe 30 utilising winches 32 and pulleys 33» in known manner, the drag lines being connected to the front and rear towing eyes of the sled 1 to enable this to be winched along the 200262 N. sewer pipe 30. For the initial removal of obstructions from within the pipe 30, a water jet unit of the kind shown in Figs. '1 to 3 is utilised, the device .carrying a closed circuit television camera, not shown, and all hoses and control connections being fed to the device through an appropriate manhole 31 from a mobile control and service unit 3^ from which the operation of the device is remotely controlled. The removal of projectic: which are located within the pipe 30 by means of the television camera,is effected by appropriate controlled rotation of the jet nozzle head 6, as already described above, in conjunction with the application of a high pressure water supply, which may be between 1 and 10,000 lbs per square inch, (0.067-667 bar), in accordance with the nature of the obstruction to be removed.

After removal of the internal obstructions, the water jetting unit is removed, the lining is inserted in known manner, and then lateral access apertures to the lining are cut in the manner already described above with reference to Fig. 4. , 20026a

Claims (16)

WHAT WE CLAIM IS:

1. A device for use in removing an obstruction within a sewer or pipe, or in a lining of such a sewer or pipe, comprising a body portion mounted upon a sled to be drawn through the sewer or pipe and including a 5 union for receiving a water supply hose, said body portion having mounted thereon a rotary head arranged to be driven by a remotely controllable motor located by the body portion, and at least one water jet nozzle provided on said rotary head and radially spaced from 10 the rotary axis thereof, said water jet nozzle being connected to said union of said body portion.

2. A device as claimed in Claim 1, wherein the axis of said jet nozzle extends approximately parallel to the rotary axis of said rotary head. 15

3. A device as claimed in Claim 2 including two jet * nozzles arranged symmetrically upon said rotary head. 20

4. A device as claimed in any one of Claims 1-3, wherein said rotary head is rotatable about an axis extending parallel to the longitudinal axis of said sled.

5. A device as claimed in any one of Claims 1 - 3» wherein said rotary head is rotatable >about an axis extending at right angles to the longitudinal axis of said sled. 25

6. A device as claimed in Claim 5, wherein said body portion is arranged to be rotated about an axis extending parallel to the longitudinal axis of said sled, by a ftir-ther remotely controllable motor. 2.00UZ - 9 -

7. A device as claimed in any one of Claims 1-6, wherein said body portion is equipped with a closed-circuit television camera, the field of view of which is arranged to include the path of movement of said 5 jet nozzle or jet nozzles.

8. A device as-claimed in any one of Claims 1-7. including means located in predetermined relationship to said jet nozzle or nozzles, for detecting radio-active radiation. 10

9. A device as claimed in Claim 1, substantially as described herein with reference to the accompanying drawings.

10. A method of removing an obstruction within a sewer or pipe by means of a device as claimed in any one 15 of Claims 1-9, including the steps of introducing said device into said sewer or pipe at an appropriate access point, together with a water supply hose connected to said union, drawing said sled along the axis of the sewer or pipe to bring the nozzle or nozzles of said 20 rotary head to a point adjacent said obstruction, supplying water under pressure to said jet nozzle or nozzles and remotely controlling said motor or motors to effect movement of said nozzle to cut the obstruction from the sewer or pipe. 25 11. A method as claimed in Claim 10, wherein the pressure of the water supply is from 1 to 10,000 lb per square inch (0.067-667 bar), in accordance with the nature of the obstruction to be removed.

Z002« \ - 10 -

12. A method as claimed in Claim 10 or 11, wherein said obstruction is an inwardly projecting end of a branch pipe connecting with said sewer or pipe.

13. A method as claimed in Claim 10 or 11, wherein said obstruction is a portion of a lining inserted within the sewer or pipe and obstructing the opening of a laterally extending branch pipe.

14. A method as claimed in Claim 12, wherein the said obstruction is located with the aid of a television camera provided on the said device.

15. A method as claimed in Claim 13. wherein the said obstruction is located by inserting a radio-active isotope within said branch pipe and detecting radiation therefrom with the aid of a radiation detecting means provided on said device. t

16. A method as claimed in Claim 10, substantially as described herein. CEY AND NLEY MOORE by Attorneys BALDWIN, SOW & CAREY L.