WO1982003417A1

WO1982003417A1 - Improvements in and relating to the lining of sewers,pipes,or the like

Info

Publication number: WO1982003417A1
Application number: PCT/GB1982/000107
Authority: WO
Inventors: Stephen Tracey; Stanley Robert Moore
Original assignee: Stephen Tracey; Stanley Robert Moore
Priority date: 1981-04-08
Filing date: 1982-04-08
Publication date: 1982-10-14
Also published as: NZ200262A; GB2098300A; JPS58500619A; EP0076283A1; GB2098300B; EP0076283B1; ZA822424B; DE3274567D1; BR8207578A

Abstract

A method of removing obstructions from within a sewer or pipe system comprises introducing into a primary bore (20) of the system a water jetting device comprising at least one jet nozzle (7). An obstruction within the main bore (20) or at the orifice of a branch pipe (22) may be removed by directing from the jet nozzle (7) a high pressure water jet at a pressure sufficient to cut away the obstruction. When the obstruction is within the main bore (20) the jet nozzle (7) is located with its axis adjacent and approximately parallel to the internal circumference of the bore, and is pivoted about an axis coinciding with the central axis of the bore. When the obstruction is at the entry to the branch pipe (22) the axis of the nozzle (7) is located at right angles to the longitudinal axis of the bore (20) and is pivoted about the central axis of the branch pipe (22). The water jetting device is located within the sewer or pipe system by means of a sled or like guide means (1) and the movement of the jet nozzle (7) is effected by remotely controlled guide means under the supervision of a closed circuit television camera or other sensing means.

Description

"IMPROVEMENTS IN AND RELATIKG TO THE LINING OF SEWERS, PIPES. OR THE LIKE"

This invention concerns improvements in and relating to the lining of sewers, pipes, or the like, 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, con- sists in crawing into the sewer or pipeline a liner of synthetic 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 pipeline, all obstructions projecting from the wail of the original sewer or pipeline must be removed to allov: 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 lateral apertures in the main bore of the sewer or pips. The removal of such projections currently requires that they first be located, for example by draw-ing a remote television camera through the central bore of the sewer, and then gaining access to the appropriate point by 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 perma- nently at a later date. Such an operation is therefore a 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 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.

It is an object of the present invention to 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 is provided a method of removing by remote control an obstruction from within a sewer or pipe system, which comprises drawing into the system a device capable of providing a high pressure water jet, locating a jet nozzle of said device adjacent the internal circumference of the sewer or pipe which is obstructed, with the orifice of the jet nozzle closely adjacent said obstruction and the axis of said nozzle directed gene- rally axially along the bore of said sewer or pipe, and supplying pressurised water to said device whilst pivoting said nozzle about the longitudinal axis of said sewer or pipe whereby the obstruction is cut away substantially flush with the internal periphery of said sewer or pipe by the resulting water jet.

The method in accordance with the invention may be utilised for removing an obstruction either from a pri- mary sewer or pipeline through which the water jetting device is to be drawn, or from the orifice to a branch pipe which communicates with the primary sewer or pipe. In the former case, the axis of pivoting of said water jet nozzle coincides with tine longitudinal axis of the primary sever or pipe, and the radial distance of the nozzle from said pivotal axis is slightly less than the internal radius of the primary sewer or pipe, whereas in the latter case the axis of pivoting of said nozzle coincides with the longitudinal axis of the branch pipe, being substantially at right angles to the longitudinal axis of the primary sewer or pipe, and the radial distance of the nozzle from the rotary axis is correspondingly reduced,

In the method of the invention, the ease with which the projection to be removed may be cut by means of a water jet will depend to a large extent upon the pressure at which water is supplied to form the jet, and the distance by which the orifice of the jet nozzle is spaced from the obstruction to be cut. The water pressure should therefore nreferably be within a range of 70 to 750 kilograms per cm², and the jet nozzle located at a distance of between 1 and 15 cm from t he obstruction to be removed. Eor removal of the majority of obstructions encountered in practice, a water pressure of from 225 and 309 knlgrams per cm² will be suitable when the nozzle is located from 1 to 2.5 cm from the obstruction. Water pressures and distances for specific materials to be cut are set out in Table 1 below. Table 1

Water Pressure Distance from Material

(Kilograms per Material cm²)

70 - 150 1- 4 cm Heavy scale and porous brick-

150 - 225 Heavy scale, brick, porous salt glazed clay pipe.

225 - 300 1 - 2-5 cm Salt glazed clay pipe, brick, porous concrete, polyester impregnated Terylene needle felt tube, polypropylene, poly- urethane, low density polyethylene, medium density polyethylene, rubber, nylon, pitch fibre-

300 - 375 1 - 4 cm Glass fibre reinforced concrete. 375 - 4-50 1 - 2.5 cm Concrete, hard brick-

It will be appreciated that since the process of the invention can be carried out from within the sewer, subject only to the inserτion of drag lines from appropriate access points, the requirement for excavation to provide access to the sewer is minimised.

The invention further provides a device for use in the method, comprising a body portion mounted on a sled, ox the like, to be drawn through the sewer pipe, said body portion having mounted thereon a rotary head arranged to be driven by a motor located within said body portion, said rotary head having at least one, and preferably two water jet nozzles radially spaced from its rotary axis. The rotary axis of said head may be aligned along an access 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 jets 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 rotary head carrying said nozzles is arranged to be driven from a motor located within the body of the device and intended for remote control by an operative. Such a 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 feature of the invention a water jetting device adapted to provide the appropriate lateral cutting action may be 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

Figures 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,

Figure 2 is a perspective view of the device shown in Figure 1C shown in relation to the end of an associated sewer pipe,

Figure 3 is a view of the device of Figures 1A to 1C, showing the water jet produced thereby,

Figure 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

Figure 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, Figures 1A to Figure 3 illustrate one embodiment of a water jetting device, in accordance 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 the central axis of the pipe. The skid assembly is provided with front and rear towing hooks 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 cylindrical body portion 5 of the water jetting device may be clamped in place.

As shown more clearly in Figure 1C, the water jetting device comprises a rotary head 6 comprising two diametrically opposed jet nozzles 7 which extend outwardly at a 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 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 2nd 10 for the attachment of air supply and return hoses for the remote control of the internal pneumatic motor.

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

Referring to Figure 4, there is illustrated another embodiment of device in accordance with the invention, wherein the water jetting head is utilised for the cutting of transverse apertures in a lining inserted within a sewer pipe. In Figure 4 components corresponding to those of Figures 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 nozzles 7 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 nozzles 7 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 nozzles 7 and rotating the head 6 by means of the internal motor within the body 5.

Figure 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, 31. 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 sewer pipe 30. For the initial removal of obstructions from within the pipe 30, a water jet unit of the kind shown in Figures 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 34 from which the operation of the device is remotely controlled. The removal of projections 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 he selected, as already initially described, 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 Figure 4.

It will be appreciated that various modifications and changes may be, made to the device as described herein without departing from the scope of the invention. For example, in a modification of the device shown in Figure 4, not illustrated, the jet nozzle head 6 may be provided with only a single jet nozzle 7 , 2nd an extension adaptor may be provided for at-tachment to the single jet nozzle 7 in order to change the direction of the nozzle axis from being substantially radial to the sewer pipe 20 to being substantially axial thereto, in the manner of the device shown in Figures 1 to 3. Such a modification allows the device of Figure 4 to be utilised both for cutting the initial projections from the main bore of the sewer pipe 20 prior to insertion of the lining, and for the subsequent cutting of apertures to branch pipes, after the lining has been inserted. It will be appreciated that such' a modification enables the requirement for two separate water jetting devices for carrying out the respective cutting oυerations to be disnensed with.

Claims

1. A method of removing by remote control an obstruction from within a sewer or pipe system, which comprises drawing into the system a device capable of providing a high pressure water jet, locating a jet nozzle of said device adjacent the internal circumference of the sewer or pipe which is obstructed, with the orifice of the jet nozzle closely adjacent said obstruction and the axis of said nozzle directed generally axially along the bore of said sewer or pipe, and supplying pressurised water to said device whilst pivoting said nozzle about the longitudinal axis of said sewer or pipe whereby the obstruction is cut away substantially flush with the internal periphery of said sewer or pipe by the resulting water jet.

2. A method as claimed in Claim 1 , wherein said obstruction is an inwardly projecting end of a branch pipe connecting with a primary bore of said sewer or pipe system and said water jetting device is drawn into said primary bore and located therein with the pivotal axis of the jet nozzle coinciding with the longitudinal axis of the primary bore and the jet nozzle spaced from the said pivotal axis by a distance slightly less than the radius of said bore.

3. A method as claimed in Claim 1 , wherein said obstruction is a portion of a lining inserted-within a primary bore of the sewer or pipe system and obstructing the opening of a laterally extending branch pipe, and the said water jetting device is drawn into said primary bore and located therein with the pivotal axis of said jet nozzle at right angles to the longitudinal axis of the primary bore and the jet nozzle spaced from ponding to the radius of said branch pipe.

4. A method as claimed in Claim 12 or 13, wherein the said jet nozzle is located adjacent said obstruction with the aid of a closed circuit television camera provided on the said water jetting device.

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

6. A method as claimed in any one of Claims 1 - 5, wherein water is supplied to said device at a pressure of from 70 - 750 kilograms per sq. centimetre, and the orifice of said nozzle is located at a distance of from 1 - 15 cm from the obstruction.

7. A method as claimed in Claim 6, wherein water is applied to said device at a pressure of from 225 - 450 kilograms per sq. centimetre, and the orifice of said nozzle is located at a distance of from 1 - 4 cm from the obstruction.

8. A device for use in the method of any one of Claims 1 - 7, comprising a body portion including a union for receiving a water supply hose, a guide means for locating said body portion within a bore, a mounting arranged for pivotal movement relatively to said body portion about an axis arranged, in use, to coincide substantially with the central longitudinal axis of said bore and connected to said union of said body portion by conduit means permitting said pivotal movement, a jet nozzle carried by said mounting and spaced from said pivotal axis, and remotely controllable driving means for pivoting said mounting relatively to said body portion to enable a water jet from said nozzle to be directed against an obstruction to be removed.

9. A device as claimed in Claim 8, for use in the method of Claim 2, wherein the axis of said jet nozzle extends approximately parallel to the pivotal axis of said nozzle mounting.

10. A device as claimed in Claim 9, including two jet nozzles arranged symmetrically upon said pivoted mounting.

11. A device as claimed in Claim 8, for use in the method of Claim 3 , wherein said device further comprises a rotary nozzle head carrying said jet nozzle, said nozzle head being mounted for rotation relatively to said mounting about an axis perpendicular to the rotary axis of the latter, the axis of said jet nozzle being arranged substantially parallel to the rotary axis of said nozzle head, and further, remotely controllable driving means being provided for controlling the rotation of said nozzle head.

12. A device as claimed in Claim 11, adapted for additional use in the method of Claim 1, including an extension adapter for attachment to the nozzle orifice, in order to direct the water jet in a direction generally parallel to the pivotal axis of said mounting.

13. A device as claimed in any one of Claims 8 to 12, wherein said guide means comprises a sled shaped to extend longitudinally within a sewer or pipe and equipped with towing attachments.

14. A device as claimed in any one of Claims 8 - 13, 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 jet nozzle or jet nozzles.

15. A device as claimed in any one of Claims 8 - 14, including means located in predetermined relationship to said jet nozzle or nozzles, for detecting radioactive radiation.