GB2536022A

GB2536022A - Applicator device

Info

Publication number: GB2536022A
Application number: GB1503651.0A
Authority: GB
Inventors: Southward David
Original assignee: 3M Innovative Properties Co
Current assignee: 3M Innovative Properties Co
Priority date: 2015-03-04
Filing date: 2015-03-04
Publication date: 2016-09-07
Also published as: GB201503651D0

Abstract

The invention relates to an in-situ applicator device 7 for coating an internal surface of a pipe 1. The applicator device comprises a central body 9 and a centring system 12 which ensures the central body is centred in the pipe. The centring system comprises at least three centring arms 14 that extend radially from the central body 9, with at least one centring arm 14 having an adjustably extendable arm and a cushioning element 13 at the end of the arm 14. The arm 14 can also comprise two tapered mounting blacks 15, 16, the first fixed to the body and the other slidably mounted to the first, the blocks arranged such that their relative movement results in the adjustment of the radial extension of the arm 14. The centring system can comprise five centring arms 14, equally angularly spaced from each other. The cushioning element 13 can comprise a brush with a U shaped carrier, with the brush being made from synthetic fibres. The central body can comprise a motor, resin input tubing and/or a spray head 11.

Description

Applicator Device This disclosure relates to an in-situ applicator device for coating an internal 10 surface of a pipe. The applicator device comprises a central body and a centering system. This disclosure also relates to a method of adjusting the centering system of the applicator device.

Infrastructure pipelines, vessels or conduits that carry fluids such as potable water, gas and wastewater deteriorate over time due to their extensive use. This deterioration can lead to leaks and bursts resulting in costly damage if the pipelines are not maintained. Since these pipelines are typically located underground and provide essential utilities, maintenance and rehabilitation are preferably performed with as minimal disruption to service as possible. Several methods for performing in-situ maintenance and rehabilitation on these pipes, known as trenchless methods, have been developed. One such method involves feeding an applicator device through the pipe to spray a material along the interior surface of the pipe. The material then hardens to form a new, interior liner surface or protective coating to seal cracks and strengthen the existing pipeline.

One technique for spray coating the interior surface of a pipe involves centrifugally spraying a liquid liner, or resin composition, with a hole-patterned cone. A device for applying a coating according to this technique is for example disclosed in WO 2014/105630 Al. A method of forming a coating on the internal surface of a drinking water pipeline is disclosed in GB 2 402 634 A. In order to achieve an evenly applied thickness circumferentially the applicator device needs to be positioned in the centre of the pipe.

Existing applicator devices provide centering systems with centering arms of a specific radial extension. These centering arms may involve a pre-sized spacer block that is located between the central body of the applicator device and any kind of gliding element at the end of the centering arm. They are not adjustable in themselves. To adjust these centering arms the pre-sized spacer blocks need to be replaced with spacer blocks of another size. That requires subsequent re-fitting of each of the centering arms in turn. This process is time consuming and can be extremely difficult under site conditions. In addition, it may not be particularly accurate.

The internal surfaces of infrastructure pipelines may in addition be uneven. This may for example be the case, where pipes are joined to each other.

CN 201760374 U discloses an automatic centering system for an in-situ applicator device for coating an internal surface of a cylindrical pipe. The known centering system comprises two centering arms that are fixed to a central body such that their respective ends extend on both sides over the central body. The two centering arms are crosswise fixed to the central body and pivotally attached to it.

The centering system may be adjusted by pivoting the two centering arms relative to the central body. The ends of the centering arms provide rigid wheel-like elements.

In view of the above, there is still a need to provide an in-situ applicator device for coating an internal surface of a pipe with a centering system that allows effective and accurate adjustment of the centering system of the applicator device relative to the internal diameter of the pipe to be coated even under site conditions. There is also the need to provide an effective and accurate method of adjusting a centering system for centering a central body of an in-situ applicator device for coating an internal surface of a pipe inside of the pipe.

The present invention provides an in-situ applicator device or applicator head for coating an internal surface of a pipe or vessel or conduit, the applicator device or applicator head comprises a central body or sleeve and a centering system for centering the central body or sleeve in the pipe. The centering system according to the applicator device of the invention comprises at least three centering arms that extend radially from the central body, wherein at least one centering arm comprises an adjustably extendable arm having a cushioning element disposed on an end thereof.

The applicator device or applicator head according to the invention may be the front end of a coating system that carries all the equipment that is necessary to apply a material e.g. a coating to the internal surface of a pipe. The material or coating may be centrifugally sprayed into the pipe to coat its internal surface. The applicator device or applicator head according to the invention comprises a central body or sleeve that carries the above mentioned equipment. The central body may be connected to other parts of the coating system with for example electrical cables to establish a communication line between the applicator device and the rest of the system. It may also be connected to other parts of the coating system with for example a tubing for delivering the component from the rest of the coating system to the applicator device.

The pipe may be any kind of infrastructure pipe or vessel or conduit that is able to carry fluids, such as water or gas. It may for example be made out of iron, steel, asbestos cement or concrete and may have any kind of shape such as for example a cylindrical shape. The material used for coating may be any kind of appropriate material, such as for example a two part epoxy resin or a two part rapid setting Polyurethane material.

According to the invention the applicator device or applicator head further 30 comprises a centering system with at least three centering arms, wherein the centering arms extend radially from the central body and wherein at least one centering arm comprises an adjustably extendable arm having a cushioning element disposed on an end thereof. A centering system with a centering arm that is in itself adjustably extendable, in other words a centering arm that can be adjusted in its radial extension without exchanging any parts, has the advantage that the centering system can be adjusted without the use of additional parts that have to be carried to the site and that have to be mounted there. A centering system with an adjustably extendable centering arm therefore provides a solution that can be used with reasonable cost and allows a simple way of adapting the centering system of the applicator device to different diameters of a pipe. No additional parts are necessary, which makes the centering system reliable because the risk of losing necessary parts is minimized. The applicator device according to the invention is especially beneficial in multi pass lining operations where -in addition to an initial adaptation of the centering arms -the centering arms of the applicator device need to be adjusted after every single pass of the lining operation.

Finally, the cushioning element at the end of the centering arm provides in addition to the adjustably extendable centering arm a solution for a reliably applicator device that can easily be adapted to different diameters of a pipe and that can be used in pipes with uneven surfaces. The cushioning element is designed such to adjust the radial extension of the centering arm while the applicator device is used and thereby compensates any unevenness within the pipe.

Summarizing the above, the centering system of the applicator device according to the invention helps effectively adapt the extension of at least one centering arm to the diameter of the pipe before the device is being used. The cushioning elements at the end of the centering arms provide an adjustment for any unevenness within the pipe while the applicator device is being used. The combination of these features provide an effective and reliable solution for a centering system of an in-situ applicator device.

It is also possible that more than one centering arm is adjustably extendable, e.g. two or all three entering arms. If the applicator device comprises more than three centering arms any number of them may be adjustably extendable, inclusive one, two, three, four and so on and all of them.

The material that may be used as a protective coating may be any kind of suitable 5 material such as, for example, two part epoxy resin or two part rapid setting polyurethane materials.

According to one embodiment of the invention the at least one adjustably extendable arm of the centering system comprises a first tapered mounting block and a second tapered mounting block, the two mounting blocks being arranged such that by moving them relative to each other the radial extension of the centering arm may be shortened or extended in a certain range and is therewith adjustable. Two tapered blocks provide a robust and reliable system for an extendable centering arm, since a good guidance of one block relative to the other block may be provided. In addition, this system is a space saving system, which is an important feature in an in-situ application. By selecting the angle for the taper of the two tapered mounting blocks the accuracy of the system can be adjusted as well. The second tapered mounting block may be movable in an axial direction of the pipe relative to the first tapered mounting block. Any other moving direction, such as for example in a radial direction of the pipe is also possible.

Using two tapered components for adjusting the radial extension of the centering arms is one possible mechanical solution for providing an adjustably extendable arm. It is a very robust and reliable solution, which is important for in-situ applications. All other possibilities, such as, for example, a tube in tube system or a telescope system, may be applied to the applicator device according to the invention as well, as long as those systems provide the needed robustness. Each of those systems may also be combined with springs in order to make the system easily adjustable.

According to another embodiment of the invention, the central body comprises a motor and/or a resin input tubing and/or a spray head. These are examples of the mechanical components of the central body according to the invention. In general, all equipment that is needed for coating the internal surface of a pipe, may be placed inside the central body of the applicator device according to the invention. A static mixer may be placed next to the applicator head and may be connected with it, e.g. over a threaded connection.

According to another embodiment of the invention the centering system comprises five centering arms that radially extend from the central body. It may also comprise more than five centering arms. Generally the applicator device according to the invention gets more reliable and more robust with the addition of more centering arms. It has also to be considered, that too many arms may make the system too rigid. The number of centering arms may also depend on the diameter of the pipe to be coated and on the weight of the motor needed to turn the spray head and being integrated into the central body.

According to another embodiment of the invention the centering arms are angularly equally spaced from each other. Such an arrangement allows for accurate centering of the system and provides a reliable and robust solution.

The first tapered mounting block may be fixed at the central body by one or more mechanical fastening elements, e.g. by means of screws or welding. The second tapered mounting block may be movably mounted at the first mounting block. The second tapered mounting block may be movable in an axial direction of the pipe relative to the first tapered mounting block. Any other moving direction, such as for example in a radial direction of the pipe is possible as well. A groove or any similar mechanical feature may be provided that movably holds the second movable tapered mounting block relative to the first mounting block. Such a feature provides the advantage that on site, while adjusting the radial extension of a centering arm, the second tapered mounting block may not fall off after having opened and removed the mechanical fastening elements.

The second tapered mounting blocks may be slideably mounted at the first mounting block. The second tapered mounting block may be slideable in an axial direction of the pipe relative to the first tapered mounting block. Any other sliding direction, such as for example in a radial direction of the pipe is also possible.

The first and the second tapered mounting block may be fixed to each other by mechanical fastening means, such as for example screws. Any other suitable fastening means are possible as well, as long as they are robust enough for the in-situ environment in which they are used and as long as they can reliably hold the two tapered blocks in a fixed position relative to each other. Preferably they should be re-openable and reusable.

The second tapered mounting block may be fixed to the first tapered mounting block in a number of certain predetermined positions. If screws are used as mechanical fastening elements, the mounting blocks may comprise a series of parallel drilled holes for receiving the fastening screws that define the predetermined positions for the second mounting block relative to the first mounting block. If other mechanical fastening elements are used, it is also possible to continuously adjust the radial extension of the centering arm by fixing the second mounting block relative to the first mounting block in any possible position.

According to another embodiment, the cushioning element may comprise a brush being arranged at the outer end of the at least one centering arm. A brush as a cushioning element may also be arranged at more than one centering arm, e.g. at two centering arms or at all centering arms. A brush may adjust the radial extension of the centering arm until the applicator device is used and thereby compensates any unevenness in the pipe. Any other kind of cushioning element is possible as well, such as for example "spring skids".

The cushioning element of the centering arm may comprise a u-shaped carrier for carrying the brush. The u-shaped carrier may be positioned at the end of the centering arm and provides an easy way of removably fixing the brush at the centering arm.

The brush may comprise synthetic fibers or strips such as for example nylon 5 fibers. Synthetic fibers are robust and easy to clean. They can be selected such that they provide the stiffness needed for the cushioning effect. Any other kind of fibers or strips are possible as well.

The cushioning may also comprise any kind of means that are able to provide the needed flexibility for cushioning the centering arms inside a pipe in order to provide an adjustment for any unevenness within the pipe while the applicator device according to the invention is being used.

The invention also relates to a method of adjusting a centering system for centering a central body of an in-situ applicator device for coating an internal surface of a pipe, the method comprising the following steps: - determining the internal diameter of the pipe to be coated; - opening mechanical fastening elements of the at least one centering arm; - adjusting the radial length of the at least one centering arm that extends radially 20 from the central body according to the internal diameter of the pipe to be coated and - closing the mechanical fastening elements of the at least one centering arm.

The opening, adjusting and closing steps may also be applied to at least one 25 additional centering arm. The adjusting method may take place at the beginning of the coating process and also, if a multi pass lining process is applied, before every coating pass.

The invention will now be described in more detail with reference to the following Figures exemplifying particular embodiments of the invention: Fig. 1 schematic drawing of an underground pipe and equipment for spray coating the pipe; Fig. 2 an axial cross-sectional view of an applicator device with a centering system within a pipe; Fig. 3 an axial cross-sectional view of the applicator device of Fig. 2 with the two tapered mounting blocks detached from each other; Fig. 4 a radial cross-sectional view of an applicator device with a centering system within a pipe; Fig. 5 an axial cross-sectional view of the applicator device of Fig. 4 with the two tapered mounting blocks detached from each other; and Fig. 6a, 6b detailed views of a centering arm with a synthetic brush, wherein the brush is shown in two different radial positions.

Herein below various embodiments of the present invention are described and shown in the drawings wherein like elements are provided with the same reference numbers.

Fig. 1 is a schematic drawing of an infrastructural pipe 1 that needs to be rehabilitated. The pipe 1 is positioned underground. In order to be able to access a certain section of the pipe 1, two holes 2 are dug into the ground such that the to be rehabilitated section of the pipe 1 is positioned between the two holes 2. Parts of the system for rehabilitating the pipe 1 are placed above ground, such as, for example, an air compressor and generator 3, reservoirs 4 for the coating materials, a metering pump 5 and a hose drum or winch 6. Fig. 1 also shows an applicator device 7 being placed inside of the pipe 1 that needs to be rehabilitated. The applicator device 7 is connected via a tubing 8 with the equipment placed above ground. In the embodiment shown in Fig. 1, the applicator device 7 comprises a central body 9 with a lining head or spraying head 11 and a centering system 12. Next to the central body 9, a mixing device 13 is positioned for mixing the components of the coating material. The mixing device 13 is connected with the applicator device 7 over a robust, threaded connection 10. Any other conventional connection is possible as well.

The coating material may be applied to the internal surface of the pipe 1 for example by centrifugally spraying it towards the internal surface. The exact design of the applicator device 7 depends on many factors such as, for example, the pipe to be coated, the medium carried by the pipe and the viscosity and the setting properties of the coating material. Irrespective of the design options of the applicator device 7 that follow these conditions, every applicator device 7 provides a centering system 12 for accurate centering the applicator device 7 within the pipe.

In Fig. 2, a cross-sectional view (in the axial direction of the pipe) of an applicator device 7 with a centering system 12 within a pipe 1 is shown. The applicator device 7 comprises a central body 9 and a lining or spraying head 11. The central body 9 may carry, for example, a motor for turning the lining or spraying head 11. The central body 9 is also connected via a tubing (not shown in Fig. 2) with the rest of the system for rehabilitating a pipe.

In Fig. 2 the centering system 12 with one centering arm 14 is shown. The centering arm 14 comprises a first tapered mounting block 15 that is fixed to the central body 9. It may be fixed to the central body 9 by any kind of known fastening means, such as for example screws or welding. The centering arm 14 also comprises a second tapered mounting block 16 that is movably attached to the first tapered mounting block 15. How the two tapered mounting blocks 15 and 16 engage with each other will be described in more detail with reference to Fig. 4. The two mounting blocks 15 and 16 may be attached to each other via screws 18 (not shown in Fig. 2) as will be described in more detail with reference to Fig.6a and 6b. The screws may be inserted into parallel drilled holes 19 in the first and second tapered mounting block 15 and 16.

At the outer end of the centering arm 12, which in this embodiment is the second tapered mounting block 16, a profile 17 is attached for receiving a cushioning element, here a brush 13.

Fig. 3 shows the first 15 and second tapered mounting blocks 15 and 16 being detached from each other. From the perspective of Fig. 3 the tapered shape of the two blocks 15 and 16 can be seen as well as the series of parallel drilled holes 19.

Fig. 4 is a cross-sectional view of the applicator device 7 according to Fig. 2 with a centering system 12 within a pipe 1. The central body 9 is positioned in the middle of the pipe 1 surrounded by a centering system 12 with five centering arms 14. Each centering arm 14 comprises a first tapered mounting block 15 that is fixed at the central body 9 and a second tapered mounting block 16 that is movable relative to the first tapered mounting block 15. At the outer end of the centering arms 14 a u-shaped mounting profile 17 is provided for receiving a brush 13. The brush 13 functions as a cushioning element that is able to adjust the length of the centering arm while the applicator device 7 is being used. Thereby it enables moving the applicator device 7 through pipes with uneven surfaces such as, for example, at pipe joints or across internal gaskets or seals.

In the cross-sectional view of Fig. 4 the step-like shape of the two tapered mounting blocks 15 and 16 can be seen. They overlap in a mid-section of each centering arm. This configuration leads to a robust construction of the adjustably extendable centering arms 14. In addition, the overlapping mid-section of the mounting blocks 15 and 16 provide an area for the drilled holes 19 (see Fig. 2) for receiving fastening screws 18, that may be positioned at the dotted lines.

Fig. 5 shows the design of the tapered mounting blocks 15 and 16 when the two blocks are detached from each other.

Fig. 6A and 6B are detailed views of a centering arm 14 of a centering system according to the invention. In Fig. 6A the brush 13 with the profile 17 and the movable tapered mounting block 16 are moved to the left and fixed with two screws 18 at the tapered mounting block 15. In Fig. 6B the brush 13 with the profile 17 and the movable tapered mounting block 16 are moved further to the right and fixed with two screws 18 at the tapered mounting block 15. Due to the tapered shape of the mounting blocks 15 and 16, the distance I between the upper tip of the brush 13 and the lower end of the tapered block 15 varies by moving the movable mounting block 16 relative to the fixed mounting block 16. The distance l' of Fig. 6A is longer than the distance l" of Fig. 6B. In this manner, the configuration of Fig. 6B can be used during a lining run made after an initial coat has been applied to the inner surface of the pipe.

Claims

CLAIMS1. An in-situ applicator device (7) for coating an internal surface of a pipe (1), the applicator device comprising: a central body (9) and a centering system (12) for centering the central body in the pipe, the centering system comprising at least three centering arms (14) that extend radially from the central body, wherein at least one centering arm (14) comprises an adjustably extendable arm having a cushioning element (13) disposed on an end thereof.
2. The applicator device according to claim 1, wherein the at least one adjustably extendable arm (14) comprises a first tapered mounting block (15) and a second tapered mounting block (16), the two mounting blocks being arranged such that by moving them relative to each other the radial extension of the centering arm is adjustable.
3. The applicator device according to claim 1 or 2, wherein the central body comprises a motor and/or a resin input tubing and/or a spray head.
4. The applicator device according to any of the preceding claims, wherein the centering system (12) comprises five centering arms (14) that extend radially from the central body (9).
5. The applicator device according to any of the preceding claims, wherein the centering arms (14) are angularly equally spaced from each other.
6. The applicator device according to any of the preceding claims, wherein the first tapered mounting block (15) is fixed at the central body (9).
7. The applicator device according to any of the preceding claims, wherein the second tapered mounting block (16) is movably mounted at the first mounting block (15).
8. The applicator device according to any of the preceding claims, wherein the second tapered mounting block (16) is slideably mounted at the first mounting block (15).
9. The applicator device according to any of the preceding claims, wherein the second tapered mounting block (16) may be fixed to the first tapered mounting (15) block with one or more mechanical fastening elements (18).
10. The applicator device according to any of the preceding claims, wherein the second tapered mounting block (16) may be fixed to the first tapered mounting block (15) in a number of certain predetermined positions.
11.The applicator device according to any of the preceding claims, wherein the cushioning element (13) comprises a brush being arranged at the outer end of the at least one centering arm (14).
12. The applicator device according to any of the preceding claims, wherein cushioning element (13) of the centering arm (14) comprises a u-shaped carrier (17) for carrying the brush (13).
13. The applicator device according to any of the preceding claims, wherein the brush (13) comprises synthetic fibers.
14.A method of adjusting a centering system (12) for centering a central body (9) of an in-situ applicator device (7) according to any of the preceding claims inside of the pipe (1), comprising the following steps: -determining the internal diameter of the pipe to be coated; -opening mechanical fastening elements (18) of the at least one centering arm (14); -adjusting the radial length of the at least one centering arm (14) that extends radially from the central body according to the internal diameter of the pipe (1) to be coated and -closing the mechanical fastening elements (18) of the at least one centering arm (14).
15. The method according to claim 14, wherein the opening, adjusting and closing steps are applied to at least one additional centering arm (14).