BE1030968B1 - METHOD AND SPRAYING DEVICE FOR IN SITU APPLICATION OF RESIN TO AN INNER WALL OF A PIPE - Google Patents

Abstract

Method for applying resin in situ to an inner wall of a pipe, such as a sewer pipe, the method comprising the steps of introducing into the pipe a spraying device adapted to move through the pipe and having a rotatable spray arm that is equipped with a nozzle to spray resin in the radial direction of the pipe; applying a first resin layer by spraying resin onto a first surface of the inner wall, the spray arm is periodically rotated back and forth between a first and second set arm position for a period of at most 40 seconds, while the spray device moves through the pipe from a first position to a second position.

Description

METHOD AND SPRAYING DEVICE FOR IN SITU APPLICATION

RESIN ON AN INNER WALL OF A PIPE

The present invention relates to a method and a spraying device for applying a resin in situ to an inner wall of a pipe, such as a sewer pipe, in order to repair or renovate the pipe.

Pipes typically experience damage or failure over time that can cause them to leak and require replacement or repair. Some techniques have already been designed to provide repairs to a pipe.

A first technique uses “a stocking” to provide an inner lining. The disadvantage of this technique is that a stocking must be provided, impregnated and rolled up and then unrolled in the pipe, which is complex. It was also found that the sleeve does not always remain reliably in the pipe due to a lack of sufficient adhesion to the inner wall. Especially when there is dirt or moisture on the inner wall of the pipe, the wick cannot adhere strongly. Furthermore, the sleeve method is less suitable for pipes with splits or side connections.

A second technique uses “rotors and centrifugal forces” to throw resin onto an inner wall of the pipe. However, the necessary equipment for this typically requires more maintenance and this technique is not accurate and unable to perform a selective renovation on a selective part of the pipe. A third technique uses “a spray”. Fast-curing resins (flash cure) are typically used for this. These flash cure resins harden quickly (within 4-6 seconds) but the applied layer is typically less durable due to the lack of total cross-linking of the resin throughout the layer. The layer is made up of separate (thin) resin layers, to the detriment of the resistance of the final resin layer.

Furthermore, these rapid hardeners are difficult to handle and a single system error can cause the spray device to fail. It only takes a few seconds for the resin to harden and the spray equipment to become ineffective.

All in all, there is a need for a technique to apply a resistant resin layer to the inner wall of a pipe in an accurate manner.

SUMMARY OF THE INVENTION

To this end, a first aspect provides a method for applying resin in situ to an inner wall of a pipe, such as a sewer pipe, a water pipe, gas pipe, industrial pipe and the like. The method includes the steps of:

a. introducing into the pipe a spraying device that is designed to move through the pipe and has a rotatable spray arm provided with a nozzle for spraying resin in the radial direction of the pipe b. applying a first resin layer by spraying resin onto a first surface of the inner wall, characterized in that the spray arm is periodically rotated back and forth between a first and second set arm position for a period of at most 40 seconds, while the spraying device passes through the pipe moves from a first position to a second position.

The invention is based on the inventive insight that through the periodic rotational movement and the set arm positions, the resin can be applied accurately and a strong and resistant resin layer can be provided on the inner wall of the pipe. By limiting the period of the spray movement to preferably a maximum of 40 seconds, more preferably a maximum of 30 seconds, even more preferably a maximum of 20 seconds, a rapid and repeated application of resin to the inner wall is ensured, thereby applying a resin layer with a uniform and strong cross-linking. This uniform and mutual cross-linking increases the strength and resistance of the final resin layer so that the resin layer can withstand longer against damage, leakage and other forms of loss of functionality. In a certain preferred embodiment, the period is even limited to a maximum of 10 seconds, such as a period of 3 or 4 seconds in favor of cross-linking between the resin just applied and the resin just sprayed.

Preferably the spray arm is rotated back and forth at least 2 times, preferably at least 3 times, more preferably at least 4 times per meter of the nozzle traveled through the pipe. This causes the rotating arm to perform at least twice the movement in which the arm is moved from the first to the second arm position and back to the first arm position. By carrying out the movement per meter in such a way that the nozzle travels through the pipe, you ensure that the newly applied resin can better cross-link with the resin already applied to the inner wall.

Preferably, the spray arm is changed direction of rotation at least 2 times, preferably at least 3 times, more preferably at least 4 times per 10 seconds and/or per meter traveled by the spray device through the pipe. This control of the rotating arm ensures a more uniform crosslinking throughout the sprayed resin, especially between the just applied resin and the just sprayed resin.

In a certain preferred embodiment, the spraying device moves over a lower segment of the inner wall and the first and second arm positions are adjusted so that resin is sprayed over an upper segment. In this way, a section of the inner wall along which the spraying device moves remains free of resin. This is advantageous as the means of motion, e.g. wheels and/or tracks of the spraying device typically contact the lower segment of the pipe. By not spraying resin on the lower segment, the spraying device can be moved more quickly through the pipe. Furthermore, the spraying device remains clean and free of resin and it is ensured that the uniformity of the resin already applied is minimally or undesirably adjusted by contact with, for example, the moving means of the spraying device.

In one embodiment, the applied first resin layer is sprayed with resin to apply an additional resin layer thereon while the spraying device moves from the second position to the first position. In this way the protection of the inner wall can be increased. Preferably, the additional resin layer is applied within a period of 2 hours, preferably 1 hour, more preferably 0.5 hours, even more preferably 0.25 hours after the first resin layer has been applied, so that the total duration of the renovation project remains limited. In one embodiment, almost only the applied first resin layer is sprayed with resin, so that the extra resin layer is only applied to the first (already applied) resin layer.

In a certain preferred embodiment, the method further comprises the step of: c. applying a second resin layer by spraying resin over a second surface that is at least complementary to the first surface while the spraying device moves from the second position to the first position. As seen from a cross-section of the pipe, this provides a complete resin coating on the inner wall, e.g. in the case of a round pipe, the wall is coated with resin over 360°.

Preferably, the first resin layer is applied to the upper segment of the inner wall and the second resin layer is applied to the lower segment of the inner wall.

In one embodiment, the second resin layer is at least complementary to the first resin layer and can optionally partially or completely overlap with the first resin layer on the first surface of the inner wall. In this way a strong, resistant and complete resin coating is provided on the inner wall of the pipe and the risk of the spraying device being contaminated with resin is reduced, for example by splashing and/or dripping resin. Furthermore, in this way it is possible to apply a (relatively thick) complete and resistant resin layer to the inner wall in one operation with a short period of time (e.g. less than a day) since one does not have to wait until the resin has hardened sufficiently before moving the spray device back through the pipe can move to apply an extra layer. This is particularly advantageous over techniques where one day is waited before applying an additional layer. Preferably, the second resin layer is applied within a period of 2 hours, preferably 1 hour, more preferably 0.5 hours, even more preferably 0.25 hours after the first resin layer has been applied so that operating times are kept to a minimum. This is furthermore particularly advantageous when the second resin layer partly or completely overlaps with the first resin layer on the first surface of the inner wall and one wants to provide improved adhesion between the first and second resin layers.

In one embodiment, during the application of the second resin layer, a rotational movement is performed in which the rotatable spray arm is rotated back and forth between a third and fourth arm position, such that the second resin layer is applied over (only) the first resin layer and/or over at least the complementary second surface and optionally overlapped with the first applied resin layer. For example, the second resin layer can be applied in a continuous sinus-like pattern to a part of the inner wall, for example on the applied first resin layer or on a part where resin has still been applied or on both the first resin layer and the part where there is no resin yet. applied. The spray arm can also continue to rotate fully so that the second layer of resin is applied in a continuous helical pattern. For example, an even resin finish can be provided on the inner wall, which is particularly advantageous in pipes where it is desired that the flow profile remains undisturbed.

In one embodiment, the spray arm is fully rotated during movement of the spray device such that a continuous layer of resin is applied in a continuous helical pattern over the first layer of resin on the first surface and over a complementary surface to provide complete resin coverage on the inner wall of the pipe is installed.

Preferably, the movement is performed during a return movement from a final position (e.g. the second position) back to starting position (e.g. the first position). The rotating arm is preferably rotated with a first angular speed w1 during the spraying of resin over the first (already applied) resin layer and further rotated with a second angular speed m2 during the spraying of resin on the complementary surface, where there is typically no or less resin. has been applied.

The first angular velocity ©1 is greater than the second angular velocity w2 in favor of uniformity and equality in the thickness of the final applied resin, seen over the length of the pipe.

Preferably, the movement of the spraying device between the first and second position is carried out at a (movement) speed that is virtually equal to the (movement) speed of the device during the movement between the second and first position. Preferably, the speeds are virtually constant and the spraying device is moved through the pipe at a speed between 1m/0.5sec and 1m/10sec. The speed can be determined by an operator from outside the pipeline.

In one embodiment, the method further comprises heating and/or maintaining the temperature of resin through a supply hose. This temperature control benefits the handling and implementation of the resin.

In one embodiment, the method includes the step of mixing a first resin component and second resin component in a static mixer. In this way, the resin is mixed into a more homogeneous mixture before being sprayed so that the adhesion and internal cross-linking of the resin improves in favor of the strength and resistance of the final resin layer on the inner wall of the pipe. A static mixer can typically be understood as an element, for example a tube element,

containing molded parts (mixing elements), which ensure that the flow profile of the resin is disturbed, so that the two components are mixed into one homogeneous mixture, which benefits the resistance and durability of the ultimately applied resin layer.

In one embodiment, the method includes the step of flushing a resin passage in the rotatable arm with a non-hardening fluid to reduce or eliminate the risk of internal blockage.

A further aspect provides a method comprising the steps of introducing into the conduit a spraying device adapted to move through the conduit and having a rotatable spray arm provided with a nozzle for spraying resin in a radial direction of the conduit and applying a first resin layer by spraying resin onto the inner wall; wherein the method includes mixing a first resin component and a second resin component in a static mixer before the resin is sprayed.

A further aspect provides a spraying device for applying resin in situ to an inner wall of a pipe, such as one where the spraying device is adapted to move through the pipe. The spraying device is equipped with a rotatable spray arm with a nozzle to spray the resin in a radial direction of the pipe. The spraying device further has a control system to control a rotational movement of the rotatable spraying arm. The control system is designed to periodically rotate the spray arm back and forth between a first and second set arm position when the spraying device moves through the pipe and wherein the back and forth movement has a period of a maximum of 40 seconds, preferably a maximum of 30 seconds, even more. more preferably 20 seconds at most. The spraying device can thus be used to apply the resin in an accurate manner with a periodic movement between the set arm positions. Furthermore, a strong and resistant resin layer can be provided on the inner wall of the pipe. As described above, the repeated back-and-forth application of the resin to the inner wall ensures a uniform and strong mutual cross-linking, which increases the resistance of the applied resin layer. This means that the pipe is better protected against damage factors that can cause fractures or other forms of damage to the pipe.

In one embodiment, the control system has an adjustment means with a user interface for receiving a user input to adjust the first and second arm positions (P1, P2). For example, an operator can set that resin is applied to (only) a certain part of the inner wall while the spray device moves through the pipe and the spray arm is periodically rotated between the first and second arm position, so that a resin layer is applied with strong mutual cross-linking and a high resilience. A preferred interface includes a touch screen so that an operator can easily indicate where to apply the resin using the periodic back and forth movement of the spray arm to coat a specific segment of the inner wall of the pipe with resin.

In one embodiment, the control system is designed to rotate the spray arm back and forth at least 2 times, preferably at least 3 times, more preferably at least 4 times, per meter of the nozzle traveled through the pipe. The sprayer is typically moved at a speed of between 0.1 m/sec and 10 m/sec. In one embodiment, the speed is controlled remotely by an operator.

In one embodiment, the control system is designed to rotate the spray arm at least 2 times, preferably at least 3 times, per 10 seconds and/or per meter traveled by the spraying device through the pipe. times, preferably at least 4 times. In this way, an improved crosslinking can be provided through the repeated resin application, so that the resistance of the applied resin layer can be improved.

In one embodiment, the control system is designed to rotate the rotatable spray arm with a rotation speed of at most 50 RPM, more preferably at most 40 RPM, even more preferably at most 35 RPM. Limiting the rotational speed (expressed in °/sec or RPM) ensures an improved application of the resin because more volume is applied per unit of time and per surface of the inner wall, so that better mutual cross-linking can be provided, which benefits the resistance of the final applied resin layer.

In one embodiment, the spraying device has a mixing chamber, preferably provided on the rotatable spraying arm. The mixing chamber is provided with one or more mixing elements, preferably static mixing elements, to disrupt a flow profile of the resin through the spray arm, such that components in the resin are forcibly mixed. This allows components of the resin to be mixed before spraying. This benefits the resistance and durability of the ultimately applied resin layer. It is understood that the features of the mixing chamber are implementable and its benefits can be achieved independently of the control system. Thus, one aspect provides a spraying device for applying resin in situ to an inner wall of a pipe, wherein the spraying device is adapted to move through the pipe and is provided with a rotatable spray arm with a nozzle to deliver the resin in a radial direction from to spray the pipe and is also equipped with the mixing chamber.

Preferably, the mixing chamber has a longitudinal axis extending in a direction substantially parallel to an axis of rotation Ax; of the spray arm. This simultaneously provides a desired mixing and results in a compact design, preferably the mixing chamber has a length Lm of at least 5 cm, preferably at least 7 cm, more preferably at least 10 cm. The mixing chamber is preferably arranged interchangeably, for example via a screw thread connection. This allows the mixing chamber to be replaced if desired. Preferably, the one or more mixing elements in the mixing chamber are paddle-shaped, so that a desired mixing can be provided at an acceptable pressure.

In one embodiment the nozzle has a nozzle that is located at a distance d from a rotational axis Ax; of the spray arm. This is arranged so that this distance ds is smaller than 15 cm, preferably smaller than 10 cm, so that the spray opening is virtually in line with the rotational axis Ax; of the spray arm. This ensures a compact design of the spraying device so that it can be used in pipes with smaller dimensions. Furthermore, the resin is sprayed from a central point so that the spray distance can easily be controlled and/or adjusted as desired.

In one embodiment, the nozzle is adapted to spray resin in a direction between the transverse direction of the pipe and the direction of a rotational axis of the spray arm, so that resin is applied to otherwise difficult-to-reach surfaces on the inner wall of the pipe, for example in the case of irregularities or bulges on the inner wall. Preferably, the nozzle is designed to spray resin in a spray pattern with a cone or fan shape. The legs of the fan shape preferably extend in a plane parallel and through the axis of rotation of the rotating arm to reach difficult-to-reach surfaces on the inner wall of the pipe.

More specifically, the legs of the fan shape preferably form an angle of between 30 and 70 degrees, such as 50 degrees.

In one embodiment, the nozzle has a spray tip holder with a resin channel and a removable spray tip adapted to adjust a flow profile of resin in the resin channel.

The spray tip holder is designed to removably retain the spray tip in an opening with a central axis that is substantially perpendicular to the resin channel. This smart device allows the spray tip to be exchanged or replaced without tools. This has the advantage that the spray pattern can be adjusted by choosing a spray tip. For example, one can opt for a spray tip that is designed to spray resin according to a specific spray pattern, such as a cone or fan shape. You can also adjust the spray angle by choosing a spray tip, e.g. a fan shape with an angle of 30 degrees or a fan shape with an angle of 50 or 70 degrees. This allows you to adjust the spray angle depending on the dimensions of the pipe. It is understandable that features of the nozzle described herein can be implemented and their benefits can be achieved independently of how the control system is designed. Thus, one aspect provides a spraying device with one or more features of the nozzle as described herein.

In one embodiment, the spraying device is designed to receive resin at a pressure of at least 350 bar, preferably at least 380 bar, such as 400 bar. In this way the resin is applied neatly and a desired and reliable spray pattern can be provided. A preferred spray pattern is a fan shape with the legs oriented in the longitudinal direction of the pipe and/or in the direction of the rotational axis of the rotating arm. The relatively high pressure also reduces the risk of resin blockage in the spray device.

In one embodiment, the spraying device has an upper frame on which the rotating arm is mounted and a base. The top frame is adjustable in height relative to the base using an actuator. In this way, the rotatable arm can be positioned as desired in the pipe to apply the resin layer uniformly. Preferably, the upper frame and lower frame are hinged to each other via a parallelogram connection so that the upper frame can be adjusted in height relative to the lower frame using the actuator.

In one embodiment, the spraying device comprises a moving means provided with wheels and/or one or more caterpillar tracks. Preferably tracks to provide traction on the inner wall. In this way, the spraying device is movable through the pipe, even when the spraying device is connected to (relatively heavy) supply hoses. The tracks are preferably made of rubber for increased grip and to minimize or completely avoid the risk of damage to the pipe.

In one embodiment, the spraying device is further designed so that an angle between an axis of rotation of the wheels of the one or more caterpillar tracks with respect to a horizontal level line can be adjusted. For example, in various pipes (e.g. large or small), the contact surface between wheels, preferably the caterpillar track(s) and the inner wall of the pipe can be improved, thus increasing grip. This also increases the distance range of the spraying device through the pipe because the spraying device can carry the weight of longer supply hoses without losing traction on the inner wall of the pipe.

In one embodiment, the spraying device comprises a rear frame that is designed to receive and connect to one or more supply hoses. The rear frame is hingedly connected to a front frame, such as a base, of the spraying device. This method of arrangement makes it easier to adjust the direction of movement of the spraying device as desired and allows the spraying device to be introduced through an opening in the pipe in a more compact manner.

In one embodiment, the rotatable spray arm is designed as a modular arm, which comprises several exchangeable arm pieces that are detachably connected to each other, preferably several tubular arm pieces that are connected to each other via a screw thread connection.

This makes it easier to subject the arm to maintenance if necessary. Furthermore, the arm can be adjusted to the dimensions of the pipe, e.g. to adjust the distance between the nozzle and the inner wall. Furthermore, the tubular arm pieces are typically better suited to higher pressures. The threaded connection is also a simple way of coupling.

In one embodiment, the spraying device is further provided with a camera module and/or a light module. In this way, the operator receives feedback about the condition of the spray arm, the condition of the pipe, whether or not the resin layer has been applied and feedback about the spraying and rotation behavior of the rotating spray arm. Further aspects further provide a spray device with one or more of the features described above, such as the nozzle, the mixing chamber, the pressure, the top and/or bottom and/or rear carriage, the moving means, the modular arm, regardless of how the control system has been furnished.

A further aspect of the invention provides a system comprising the spraying device described herein and furthermore one or more additional, interchangeable arm pieces of different sizes for positioning the spraying piece at a predetermined distance relative to a rotational axis of the rotatable spraying arm. Using the additional exchangeable arm pieces, the distance between the nozzle and the inner wall of the pipe can be adjusted as desired. This makes the spraying device widely applicable in pipes of different sizes and/or shapes. It is understandable that applicability in various pipes is possible with different sizes and/or shapes, examples of which are cylindrical pipes, rectangular pipes, ovoid pipes (egg-shaped). The movement of the spray arm and/or the spraying behavior can be adjusted based on the type of pipe and/or the shape and type of surface of the inner wall of the pipe.

BRIEF DESCRIPTION OF THE FIGURES

With reference to the figures, it is emphasized that the embodiments shown serve only by way of example. They are presented to illustrate some principles and conceptual aspects of the invention and are not to be interpreted in any way limitingly.

Figure 1 schematically shows a spraying device according to an embodiment.

Figure 2 schematically shows, seen from a cross-sectional view, a pipe with an inner wall to which resin has been applied according to an embodiment.

Figures 3A-3C further show schematic representations of an inner wall to which resin has been applied according to some embodiments.

Figures 4A-4B show, seen from a cross-sectional side view, a spraying device according to an embodiment in a pipe to illustrate some principles of the method.

Figure 5 schematically shows a system with a spraying device according to an embodiment in a pipe.

Figure 6 shows a perspective side view of a spraying device according to an embodiment.

Figures 7A-7B show the spraying device shown in Figure 6 from a front and rear view.

Figure 8 shows the spraying device shown in Figure 6 from a side view.

Figure 9 shows the rotatable spray arm of the spray device shown in Figure 6 in more detail and seen from a cross-sectional view.

Figures 10A-10D show the spraying device shown in Figure 6 in various states, seen from a side view.

Figures 11A-11B show embodiments of the spraying device in various states, seen from a front view.

Figures 12A-12C show a principle of the spraying device according to an embodiment, in more detail.

The same reference number is assigned to the same or corresponding elements.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows spraying device 100 inserted into the line L. It is understood that the line

L is not limited to a particular geometry or material and that applicability of aspects of the invention are possible in various pipes such as gas pipes, water pipes, sewerage networks, including industrial pipes of different sizes. The spraying device 100 is provided with a rotatable spray arm 10 that comprises nozzle 11. Resin is sprayed in the radial direction of the pipe L, here according to spray pattern 19, in which the resin is sprayed at angle y to apply resin layer RL to a first surface A; of the inner wall of the pipe.

During the application of the resin R, the spray device is moved through the line L from first position A to second position B, as shown via vector arrow Bar.

To apply the resin, the rotating arm 10 is periodically rotated back and forth between a first arm position H; and second arm position H> as shown in figure 2, where a first back and forth rotational movement of the rotating arm 10 is indicated by vector arrow 52. The periodic rotating ensures that the resin R is applied in short succession to a predetermined part of the inner wall . This provides a better interconnection between the resin just applied to the inner wall and the resin just sprayed. For this purpose, the spray arm 10 is rotated back and forth at least 2 times, preferably at least 3 times, more preferably at least 4 times, per meter traveled by the nozzle 11 through the pipe L. It has also been found that it is preferable to rotate the spray arm at least 2 times. , preferably at least 3 times, more preferably at least 4 times, changes the direction of rotation, for example clockwise or counterclockwise (“clockwise or counter clockwise” in English), every 10 seconds and/or per meter traveled by the nozzle through the pipe to apply a resin layer RL with increased resistance. The distance traveled by the nozzle 11 is typically equivalent to the distance traveled by the spray device 100 through the conduit.

L.

Figure 1 shows a movement of the spray device 100 from the first position A to the second position B with vector arrow Ban. The typical (movement) speed of the spraying device is between 0.1 m/sec and 7 m/sec, such as 0.2, 0.3, 0.4, 0.5 m/sec.

During the movement through the pipe L, the spraying device 100 is moved over a lower segment L2 of the inner wall and the first and second arm positions H1, H2 are set so that resin is sprayed over an upper segment L3 of the pipe L. This allows a first resin layer to be applied.

RL can be applied with a thickness of tl. It is best to prevent dripping of the resin, for example to avoid damaging the integrity of the finally applied layer, or to prevent resin from dripping onto the spray device 100. Therefore, the first resin layer RLia is applied with a limited thickness tl and, if necessary, later oversprayed with an additional resin layer RL of thickness (2) so that a final (relatively thick) resin layer can be applied that can provide a high degree of protection to the pipe L. lower segment L2 of the inner wall typically contains the part where the spray device 100 contacts the pipe L.

Any intermediate steps can be performed after the first resin layer has been applied to apply additional resin layers to a predetermined surface of the inner wall of the pipe. The movement of the spraying device during the intermediate steps is represented by vector arrow B', the additional resin layers can be applied, for example, to perform a selective spot repair or to increase a thickness t of the final resin coating for more protection.

Preferably, a second resin layer RL2 is applied by spraying resin R over a second surface A2 that is at least complementary to the first surface A2 while the spraying device moves from the second position B to the first position A. This provides, as viewed from a cross-section of the pipe, a substantially complete resin coating on the inner wall of the pipe L (as shown in Figure 2 and Figures 3B and 3C).

Moreover, the first resin layer, RL, is preferably applied to the upper segment

L3 of the pipe L and the second resin layer RL: applied to the lower segment L3 of the pipe during a movement of the spray device 100 from the second position B. The movement is preferably a returning movement, in which case the second position B can be be seen as a final position and the first position A as a starting position. By applying the resin in two steps, a complete resin coating can be provided in a short period of time. You should not have to take any breaks to allow the resin to harden. The upper segment L3 can be coated in a first step during a forward movement of the nozzle 11 (vector arrow Ba) and the lower segment where the device 100 contacts the pipe can be coated in a return movement of the nozzle 11 (vector arrow Bra). During the return movement, the rotational movement 53 of the spray arm 10 can be controlled to periodically rotate back and forth or rotate completely to apply the second resin layer RL2. The second resin layer RL2 is preferably applied within a period of 2 hours, preferably 1 hour, more preferably 0.5 hours, even more preferably 0.25 hours after the first resin layer RL; is applied, in this way a short operating time and a strong bond between the first and second resin layers are provided, if the second resin layer is applied in an overlapping manner (see fig. 2 and 3C). The final resin layer can also be sprayed over during one or more additional spraying steps, for example based on the roughness of the inner wall.

Figure 2 shows a schematic representation of a cross-section of a pipe L with an inner wall to which a resin layer RL has been applied according to an embodiment of the method.

The back and forth rotational movement of the spray arm 10 between the first and second arm positions

H1, H2 are shown with vector arrow 52. The arm is preferably moved at a constant rotational speed in favor of the uniformity of the resin layer.

The spray arm 10 is moved from the first arm position H1 to the second arm position H2 and back to the first arm position H1 during a period of time that can be understood as the previously described "period" which lasts a maximum of 40 seconds. By limiting the period, a resin layer can be applied with high resistance due to a strong mutual cross-linking of the resin between the newly applied resin and the just sprayed resin. In the first arm position H1, the spray pattern 19 is directed towards 9 o'clock as seen on an analog clock. However, the first arm position H1 can be adjusted as desired so that resin is sprayed in any direction, for example 7,8,9, 10, 11 o'clock.

In the second arm position H2, the spray pattern is oriented 19° (shown in dotted line) towards 3 o'clock as seen on an analog clock. However, the second arm position H2 can be adjusted as desired so that resin is sprayed in any direction, for example 1, 2, 3, 4, 5 hours. In this way the resin can be applied accurately to a predetermined part of the inner wall of the pipe. The arm positions H1, H2 can be adjusted to periodically apply resin with a back and forth movement to a predetermined part of the inner wall of the pipe L.

For example, to apply a layer of resin between 9 and 11 or between 2 and 5 o'clock as seen on an analog clock. The rotating arm can be controlled, allowing an operator to adjust one of the rotation speed ©, rotational direction, alternating frequency and the spray direction of the rotating spray arm as desired.

In Figure 3A, in a first rotational step S1, the rotatable arm 10 is moved back and forth between the first arm position H1 and the second arm position H2, which, as described herein, are adjustable as desired to apply resin to a predetermined segment of the inner wall. of the pipe L. The periodic back-and-forth movement is represented by vector arrow 52. During the first rotational movement S1, the first resin layer RL1 is applied to a first surface A1 of the inner wall. The spray arm 10 is typically rotated back and forth by at least 10° during the periodic rotational movement, preferably at least 15°, more preferably at least 20°.

The spray arm 10 can furthermore be rotated back and forth through at least 90°, preferably at least 100° and more preferably at least 180°, in order to spray more surface area of the inner wall.

For example, a back and forth rotation through approximately 220° as shown in Figure 3A with rotational movement S1 of spray arm 10 represented by vector arrow 52. The period is the time span between the rotational movement of the arm from the first arm position H1 to the second arm position H2 and back to the first arm position H1. An upper segment of the pipe can be coated, as shown in Figure 3A during a movement from an initial position to an end position. The spraying device can then be returned (from end position to start position) and the inner wall can be sprayed, rotating the rotating arm in the manner shown in Figure 3B to apply the second resin layer.

RL2 or rotating the rotating arm in the manner shown in Figure 3C to apply the second resin layer RL» and RL:. By the way, the spraying device can be allowed to return and the rotating arm is rotated so that almost only the (already applied) first resin layer RL1 is oversprayed with resin.

In Figure 3B, the complementary surface A2 is sprayed during the periodic reciprocating rotational movement S2 of the spray arm 10 between the third and fourth arm positions H3, H4 so that the second resin layer RL2 is applied to the complementary surface A2.

Moreover, some overlap of the second resin layer RL2 over the first resin layer RL1 can be provided.

In Figure 3C, the second resin layer RL», RL, is applied with a continuous rotational movement

S2'. The spray arm 10 is fully rotated during a movement of the nozzle 11 through the pipe, preferably a returning movement of the spray device. For example, a second resin layer is applied in a continuous helical pattern, to improve the integrity of the final applied total resin layer. The thickness of the applied resin layer can be adjusted (among other things) by controlling the rotational speed © of the spray arm 10. In one embodiment, as shown in Figure 3C, the spray arm 10 is fully rotated during a movement of the spray device 100, preferably a return movement of the spray device, to ensure contact between the spray device and the just-sprayed, not yet (fully) cured resin. to avoid. The complete rotational movement of the spray arm 10 is shown with vector arrow S'2, the direction of rotation can be either clockwise or counterclockwise. This allows a continuous resin layer to be applied in a continuous helical pattern over the (already applied) first resin layer RL, on the first surface A1 and further over a complementary surface A» such that a complete coverage of resin (Ax,

A') is attached to the inner wall of the pipe L.

Preferably, the rotating arm 10 is rotated with a first angular speed 1 during the spraying of resin over the applied first resin layer RL,. As shown, the rotating arm is further rotated at a second angular velocity ©2 while spraying resin onto the complementary surface A». The angular velocity w, also described herein as rotational speed or rotational speed, is preferably set so that the first angular velocity ©; is greater than the second angular velocity ©.

It is particularly advantageous that in a short period of time, a complete resin coating with a relatively thick thickness can be provided over the entire surface of the inner wall of the pipe (as seen from a cross-section), so that the (thick) resin layer provides high protection and the pipe remains protected for a long time.

Due to dripping of resin due to gravity, the applicable thickness of a resin layer on an upper segment may be limited, meaning that a second layer must be applied to increase the protective capacity of the resin layer.

In a preferred embodiment, as shown in Figures 1 and 2, an upper segment L3 of the pipe L is therefore first sprayed with resin, to apply a first resin layer RL1a to the upper segment L3, while the nozzle 11 moves through the pipe, preferably from a starting position to a finishing position. For example, first resin layer RL 2 with a first thickness t1 is applied to upper segment L3, during the first periodic back-and-forth rotation movement represented S1. Subsequently, in a second movement of the nozzle 11, for example an intermediate movement B' or a returning movement B, preferably the returning movement Bra, an additional resin layer RL is applied to the upper segment L3 with a second thickness t2. Here, rotary arm 10 is rotated according to a second continuous rotational movement S2' (as shown in Figure 3C) or the rotary arm is rotated according to a periodic back-and-forth movement, wherein resin is applied only to the upper resin layer RL1a (not shown), for example to only to carry out a repair on an upper part. The finally applied resin layer on the upper segment has a (thick) total thickness, seen as the sum of thickness t1 + thickness t2.

The additional resin layer RL on the upper segment L3 is optionally applied to the lower segment during one movement of the nozzle 11 together with resin layer RL». The rotational speed © of the spraying arm 10 can be adjusted so that during spraying on the upper segment, the rotating arm 10 is rotated at a first rotational speed @; and so that during the spraying on the lower segment L2, the rotating arm is rotated at a second rotational speed » which is smaller than the first rotational speed w1. In this way, a final and complete resin coating is applied, the thickness of which is more uniform.

Figures 4A-4B schematically show a side view of a cut pipe to illustrate some example principles of the method. It is understandable that many variations are possible. Thus, any part or segment, for example an upper segment, a side segment or a lower segment of the inner wall of the pipe L can be provided with a protective resin layer by spraying resin with the periodic back and forth rotational movement of the rotatable spray arm 10 as herein provided. In this way, a resin layer can be selectively applied with high resistance and long-term protection.

Figure 4A shows a (forward) movement of the spraying device 100 in which the rotating arm 10 is periodically moved back and forth between a first and second arm position that are set in such a way that an upper segment L3 of the pipe L is sprayed with resin R, so that a resin layer

RL is applied with an initial thickness t. For example, resin R can be applied in a sinusoidal pattern to the top of the pipe L, during movement from the first position A to the second position B.

Figure 4B shows a (backward) movement of the spraying device 100. During this (backward) movement the rotating arm can be controlled in various ways. Some ways will be discussed below.

According to a first manner (not shown), the rotating arm 10 is controlled to spray resin onto only the upper segment L3 of the pipe, so that the upper part of the inner wall is repaired with an economical resin consumption and so that a (thick) final resin layer can be applied in a relatively short period of time.

In a second manner, the rotating arm 10 is controlled to periodically move back and forth to spray resin onto a second surface A2 of the inner wall that is at least complementary to the first surface A1 to which the first resin layer RL1 has been applied, as shown for example in Figure 3B. By applying the resin at least complementary in a subsequent spraying step, complete resin coverage is provided. Optionally, there is some overlap between the previously applied resin layer RL1 (e.g. the resin layer applied during the forward movement of the nozzle 11) and the second resin layer RL2 applied afterwards (e.g. during the backward movement of the nozzle 11).

In a third way, the rotating arm 10 is controlled to continuously rotate while the nozzle 11 is moved through the line L, so that resin is sprayed in a continuous helical pattern. The rotation speed © is preferably set as previously described above in connection with figure 3C.

Figures 4A and 4B further show a speed of movement of the spraying device 100 and/or the nozzle 11 via vector v1 and v2. The speed of movement can be controlled remotely by an operator. The speed of movement v1 during the movement from position A to position B is preferably constant and is typically in the order of 0.1 m/sec - 6 m/sec, more specifically in the order of 0.2 m/sec - 4 m/sec, as shown a speed selected from 0.5 m/sec, 0.7 m/sec, 1 m/sec, 1.2 m/sec. The speed of movement v2 during the movement from position B to A is preferably equal to or smaller than speed of movement v1 and can be controlled in a similar manner.

The thickness of the applied resin layer can be adjusted by adjusting the movement speed. In another embodiment, the speed of movement is controlled on the basis of a preset protocol and/or on the basis of sensor data collected by one or more sensors (not shown).

Figures 4A-4B further show resin being sprayed in a radial direction of the pipe L.

The (exact) radial direction is typically perpendicular to the direction of movement of the spray device 100 and/or the longitudinal direction of movement of the spray head 11 through the conduit L. The resin can be sprayed with any suitable spray pattern 19.

Preferably, the resin is sprayed with spray pattern 19, wherein resin R is sprayed in a transverse direction of the pipe L (here corresponding to the radial direction) and a direction of a rotational axis Ax; of the spray arm. The rotational axis Ax1 of the spray arm is preferably parallel to the longitudinal axis of the pipe L. By also spraying the resin in a direction different from the (exactly) radial direction, an improved application of resin to the inner wall is ensured, with in particular because difficult-to-reach surfaces on the inner wall of the pipe L can be sprayed better. This is advantageous in case of unevenness or bulges Lp on the inner wall of the pipe L as shown in figure 1. Figure 1 also shows the spray angle y of the resin (represented by the Greek letter gamma). The spray angle can be adjusted by choosing an appropriate spray tip. The spray angle y is representative of the angle between the extreme spray directions of the spray pattern 19, in particular the (theoretical) spray angle between the extreme forward and extreme rearward spray directions. The spray pattern is preferably conical or fan-shaped, preferably fan-shaped.

The spray angle y is preferably between 30 and 70 degrees, more preferably between 35 and 65 degrees, even more preferably between 40 and 60 degrees, such as 50 degrees. Adjusting the angle in this way ensures sufficient application volume of resin per inner wall surface and/or per rotational movement of the rotatable spray arm. As shown in the figures, the resin is injected into a fan shape 19, with the legs extending in a plane parallel and through the axis of rotation of the rotating arm 10, preferably at an angle of 50 degrees.

Figure 5 schematically shows a system 1000 with a spraying device 100 according to an embodiment in a pipe. The system comprises a supply module 200 with one or more supply tanks 210 for storing resin and for supplying the resin therefrom to spraying device 100 via supply hose 200. Preferably, the supply module 200 is equipped with a heating system (not shown) that is adapted to to heat the resin. The resin can be heated to a temperature of 90°C, but is typically delivered at a temperature between 60 - 80°C, more specifically 65 - 75°C. Preferably, the supply hose 230 is thermally insulated and/or provided with a heating means to maintain the temperature and/or actively heat the resin in the supply hose 230.

The system 1000 further includes a pump 220 (e.g. included in the supply module 200) to supply the resin to the spraying device 100 at an increased pressure, preferably a pressure of at least 350 bar, preferably at least 380 bar, such as e.g. 400 bar. So that a reliable spray pattern can be provided and the risk of resin blockage in the spray device is minimized or avoided.

Figure 6 shows an embodiment of a spraying device 100 from a perspective view, other views are shown in Figures 7A, 7B and Figure 8. The spraying device is adapted to spray resin with the rotatable spraying arm 10 that is provided with nozzle 11. The spraying device 100 further includes control system 20 to control the rotational movement rb of the rotatable spray arm. The control system is designed to periodically rotate the spray arm 10 back and forth between a first and second set arm position H, H; when the spray device moves through the pipe. Possible directions of rotation (e.g. counterclockwise or clockwise) of the rotatable spray arm 10 are shown with arrow td. The control system is set so that the back and forth movement has a period of no more than 40 seconds in favor of the advantages described earlier. The control system 20 further has an adjustment means 23 that includes a user interface for receiving a user input to adjust the first and second arm positions (H,, Hs). The user input can be processed by an on-board computer 22 that is designed to control drive means 21. The drive means may be based on a pneumatic system and/or electrical system. In a preferred embodiment, the drive means 21 is an electric stepping motor, so that the rotatable spray arm 10 can be accurately controlled and rotates between a first and second set arm position.

The user interface 23 is preferably located remotely and connected to the on-board computer 22 via cable or wirelessly. This makes it possible to control the rotatable arm 12 from outside the line L.

The control system 20 is further designed to rotate the spray arm back and forth at least 2 times, preferably at least 3 times, more preferably at least 4 times per meter of the nozzle traveled through the pipe and/or designed to rotate every 10 seconds and/or per meter traveled by the spraying device through the pipe, change the direction of rotation td of the spray arm 20 at least 2 times, preferably at least 3 times, more preferably at least 4 times. The spraying device 100 can be moved axially through the pipe using moving means. Examples of this include a fishing line or winch (not shown) that are attached to the device and used to pull the device through the pipe. More preferably, the spraying device is motorized and provided with an internal motor to move the spraying device through the pipe. The motor can be powered by an internal battery or supplied with power via one or more supply hoses 230. The internal motor is preferably controlled based on operator input remotely, or based on sensor data collected by sensor module 80. The movement of the rotatable arm 10 and the movement of the spraying device 100 through the line L can preferably be controlled separately.

In one embodiment, this is arranged so that the (maximum) rotational speed of the rotatable spray arm 10 is limited to 50 revolutions per minute, abbreviated "RPM". More preferably limited to a maximum of 40 RPM, even more preferably a maximum of 35 RPM. In this way, the resin is applied with improved adhesion and cross-linking to the surface of the inner wall of the pipe. This benefits the resistance of the applied resin layer.

Faster rotating parts also require more maintenance. The spraying device 100 is further provided with a mixing chamber 30 that is provided with one or more mixing elements 31 to disrupt a flow profile of the resin through the spray arm in such a way that components in the resin are forcibly mixed. It should be noted that resin is typically supplied from a supply tank, e.g. via a supply hose 230. The supply is arranged such that a first and second resin component come together near the spout opening 12, for example in a meeting chamber (not shown), after meeting the first and second resin components are pushed together through a resin passage up to the spray opening 12 from where they are sprayed against the inner wall of the pipe L. The mixing chamber can in principle be implemented at any position between the spray opening 12 and the meeting chamber 58. meeting chamber 58 is, for example, provided on the rear frame 50 and in fluid communication with the mixing chamber 30 via intermediate hose 56.

The beginning of the meeting chamber is preferably located some distance from the nozzle 12, preferably at least 10 cm, more preferably at least 15 cm, such that the first and second resin components are brought together and can interact somewhat before being sprayed through the nozzle. 12. This ensures better adhesion of the sprayed resin.

The chambers are typically sealed and resistant to high pressure. Characteristics of the mixing chamber will be discussed (in more detail) further herein on the basis of figure 9, in which the rotatable arm can be seen in more detail.

Figure 6 further shows that the spray device 100 is adapted to provide a continuous flow connection between the resin receiving module 57 and the spray opening 12, so that resin can flow in a continuous manner via the resin passage through the spray device. Preferably, some controllable control valves are provided to control the supply of resin. Preferably at least two control valves, wherein a first control valve is designed to control the supply of a first resin component and a second control valve is designed to control the supply of the second resin component. The control valves can be controlled to flush the resin passage that forms the continuous flow connection with only one type of resin component. In this way, hardening of resin in the spraying device is prevented after use.

The resin passage through the spray device can be flushed with any suitable non-curing fluid such as water or air. Thus, one embodiment provides for flushing a resin passage in the rotatable arm with a non-hardening fluid, such as one type of resin component or air.

Figures 7A, 7B further show that the spraying device 100 can be provided with a light module 81 and a sensor module 80 such as a camera module. Any type of module that can collect information from the management can be implemented, examples are IR modules (infrared) or CMOS modules. The modules are preferably in communication with an operating module that is arranged to provide the information sensed by the sensor module to an operator. In other embodiments, the sensor modules are (also) in communication with an on-board computer that controls the spraying device 100 and/or the rotating arm 10 on the basis of a protocol, taking into account the information observed by the sensor module(s).

Figure 8 is a side view and shows that the spraying device has an upper frame 30 to which the rotating arm 10 is rotatably attached. The spraying device further has a base 40. The top frame 30 is height adjustable using an actuator 41, so that the nozzle 11 can be positioned in the pipe. The height of the upper frame 30 relative to the lower frame 40 can be adjusted using various techniques, examples of which are movable arms, scissor table system, hydraulic adjustable systems, turntable systems, pneumatic systems.

An operator can adjust the height of the upper frame from outside the pipe L, for example based on information collected by the camera module. Some states of the spraying device in which the nozzle 11 has been brought to a certain height are shown in figures 10A-10C.

In a special embodiment, the upper frame 30 is hingedly connected to the lower frame 40 via a parallelogram connection 42. This means that the upper frame can be adjusted in height relative to the lower frame 40 using the actuator 41 and at the same time the position of the nozzle 11 in the Adjust the length of the pipe. In this way, certain surfaces of the pipe can still be sprayed if the freedom of movement of the spraying device would be restricted. Some principles of a parallelogram connection 32 are shown in Figures 12A-12C, these will be discussed further herein.

Figure 8 further shows that the spraying device 100 comprises a moving means 60. The moving means preferably contains wheels with sufficient grip. The moving means 60 as shown is provided with one or more caterpillar tracks 61. Rubber caterpillar tracks are preferred because of better grip on the inner wall so that the weight of any supply hoses 230 can be pulled (forward) while moving the spraying device 100.

Figure 8 further shows that the spraying device comprises rear frame 50. The rear frame is designed to receive supply hose 230 and to be connected thereto, for example via connection piece 230a.

The rear frame is hinged to the front frame, here the frame 40. Any type of hinge connection can in principle be used, as long as it allows movement between the front frame and the rear frame, e.g. a ball joint. The hinge connection 55 allows rotations about at least one axis, preferably two or three axes. In this way, a reliable connection with the supply hose 230 can be provided and the insertion of the spray device into the pipe 230 can be facilitated. As can be seen in Figure 5, using the hinge connection between the front set 40 and the rear set, the bring the spraying device into a more compact state, which facilitates insertion through the opening O of the line L.

In one embodiment, the hinge connection 55 is designed to enable rotation on one or two axes. In the embodiment shown, hinge connection 55 is designed to enable movement around a first axis of rotation that is virtually horizontal and transverse to the axis of rotation of the spray arm 10. Hinge connection 55 is further arranged to allow movement about a second axis of rotation that is substantially vertical and transverse to the axis of rotation of the spray arm 10. The hinge connection 55 comprises first connecting element 55a and second connecting element 55b, which are hinged to each other via intermediate piece 55c (as seen in figure 6). The first connecting element 55a is connected to the intermediate piece 55c, whereby rotation around a first axis is possible (here a horizontal transverse axis). The intermediate piece 55c is further connected to the second connecting element 55b, allowing rotation around a second axis (here a vertical axis). Preferably, a blocking system (not shown) is provided, which limits the freedom of rotation of the hinge connection, such that the rear frame does not drag over the pipe during movement of spraying device 100 through pipe L. The hinge system is located between the rear frame 50 that receives supply hose 230 and the Front chassis 40 further has the advantage that the spraying device can move more easily through a pipe, e.g. in cases of a 90° side connection, the spraying device can be rotated more easily to make the 90° turn.

Figure 9 shows an example in which the rotatable spray arm 10 comprises the mixing chamber. Or in other words, the mixing chamber 30 is implemented in the rotatable spray arm 10. During use of the spraying device, a first and second resin component (whether or not separated from each other) are delivered together to the mixing chamber. The first and second resin components are then mixed using the one or more mixing elements 31. These mixing elements 31 are designed to disrupt a flow profile of the resin through the resin passage 16, such that the first and second resin components are mixed in a forced manner.

As shown, the mixing chamber 30 has a longitudinal axis extending in a direction parallel to the rotational axis Ax of the spray arm. In this way, the nozzle opening 12 can be placed in a suitable position and at the same time retain its compactness. The mixing chamber 30 preferably has a length Lm of at least 5 cm, to provide sufficient forced mixing and to preferably create a distance between the spray opening and parts of the spray device 100, for example a housing, a motion module, a sensor module such as a camera module and of such. This means these parts are better protected against accidental splashes of the resin.

More preferably the length Ln is at least 7 cm, more preferably at least 10 cm. The one or more mixing elements 31 in the mixing chamber are preferably blade-shaped, so that forced mixing can be provided with a limited degree of pressure resistance. It is understood that mixing chamber features are implementable and their benefits can be achieved independently of the control system.

The spraying device further has a nozzle 11, preferably the nozzle is detachably connected to the rotating arm in such a way that the nozzle can be replaced, for example to adjust a spray pattern 19 with which the resin R is sprayed or for maintenance. The nozzle can, for example, be attached to a part of the rotating arm 10 with a screw thread connection, preferably an end part 10°.

As shown in figure 9, nozzle 11 has a nozzle opening 12 from which to spray resin. The nozzle is at a distance ds from a rotational axis Ax; of the spray arm 10. The spray arm can have different shapes, this can be arranged so that this distance ds (as shown in Fig. 9) is less than 15 cm, preferably less than 10 cm. In other words, the nozzle is located in almost an extension of the rotational axis Ax; of the spray arm. This method of arrangement has the advantage of compactness and increases the applicability of the spraying device 100 in narrower pipes. It is understood that the rotatable arm can have 10 different shapes. In the embodiment shown, the rotatable arm 10 ends in an end part 10° with a screw thread connection 10a to which the nozzle 11 can be detachably attached.

The end part 10° of the spray arm can itself be arranged to be detachable relative to other parts of the rotatable spray arm 10, such as other arm pieces. Figure 9 further shows that the nozzle 11 is arranged to spray resin R according to spray pattern 19. The nozzle is arranged so that resin R flows in a direction between a transverse direction of the pipe and a direction of a rotational axis Ax; of the — spray arm or in other words a direction between the (exact) radial direction of the pipe L (the transverse direction) and the direction of rotation axis Ax, which is typically corresponding to the longitudinal direction of the pipe L. By applying the resin in this way to spray, hard-to-reach surfaces of the inner wall can be better sprayed. Preferably, the nozzle 11 is designed to spray resin R according to a spray pattern 19 with a cone or fan shape as shown. The legs of the fan shape are located in a plane parallel to and through the axis of rotation Ax; of the spray arm 10.

Figure 9 further shows that the nozzle 11 comprises a spray tip holder 12 with a resin channel 13 and an opening 15 designed to hold spray tip 14. The spray tip 14 is removable and adapted to adjust a flow profile of resin in the resin channel 13, so that the resin R is sprayed from the spray opening 11a according to a certain spray pattern 19. The opening 15 has a central axis (not shown) that is almost perpendicular to the resin channel 13. In this way the spray tip does not come loose under increased pressure and the spray tip can be changed without tools to adjust the spray pattern 19 as desired. The spray opening 114 is further protected with protective elements 124, 12b. It is understood that features of the nozzle 11 are implementable and its benefits can be achieved independently of the control system.

The spraying device is designed to withstand the pressure in the resin passage 16, this pressure is preferably at least 350 bar, preferably at least 380 bar, more preferably at least 390 bar, such as 400 bar to increase the reliability of the spray pattern 19 and/ or to provide sufficient forced mixing in the mixing chamber 30. Spray patterns that are sprayed at less pressure, for example 170 bar (around 2500 psi) are less reliable.

Furthermore, a higher pressure, preferably between 200 bar and 700 bar, more preferably between 350 bar and 600 bar, typically ensures better adhesion between the just applied resin and the just sprayed resin, so that the final applied resin has increased resistance. and can provide longer-term protection.

Figure 9 further shows that the rotatable spray arm 10 can be designed as a modular arm with multiple arm pieces. The arm pieces are interchangeable and extend independently of each other over a certain distance in the radial and/or axial direction so that by choosing the arm pieces one can position the nozzle as desired relative to the central body of the spraying device and/or the inner wall of the sprayer. pipe. A first arm piece 17b (here the mixing chamber) is connected to a starting arm piece 17a which is rotatably connected to the central body of the spray device 100, e.g. to the upper frame 30 as shown. The first arm piece extends (at least) a certain distance (shown with length Lm) in a direction of the rotation axis Ax, this direction corresponds to the axial direction. Furthermore, a second arm piece 17c is present which extends over a distance in a direction transverse to the rotational axis Ax;, this direction corresponds to the radial direction. One or more interchangeable arm pieces 17d may be present. Due to the modular nature of the spray arm, the parts can easily be subjected to maintenance and/or the spray piece can be placed at a desired position relative to the rotation axis Ax. By choosing the arm pieces, the distance between the nozzle 11 and the inner wall can be adjusted. In large pipes the distance can be reduced by providing the interchangeable 10° arm piece as shown in figure 10C. In addition, it is possible to increase the distance from the nozzle 11 to the inner wall by providing an additional arm piece as shown in figure 10D. The arm pieces can be additionally present or supplied in a set. Figure 10C shows spraying device 100, wherein the spraying arm 10 has a starting arm piece 17a that is rotatably connected to the central body of the spraying device 100, more specifically to the upper frame 30. The spraying arm comprises a U-shaped arm piece 18 that is removably connected to the starting arm piece. 17a and/or the nozzle 11. The set may contain additional arm pieces 10°' which can be placed between the U-shaped arm piece 18 and nozzle 11 and/or the starting arm piece 17a in order to position the nozzle 11 at a desired position relative to the rotation axis Ax; to place. The additional arm pieces 10°' typically have different lengths. The U-shaped arm piece 18 is optionally modular.

The arm pieces are preferably tubular arm pieces because they can withstand higher pressures, such as pressures above 170 or above 200 bar and even pressures of above 400 bar. Furthermore, the tubular arm pieces can easily be attached to each other, preferably via a screw thread connection.

Figure 10A shows a condition of the spraying device in which the upper frame 30 is in a low position relative to the lower frame 40. The low position can be used for application of the spraying device in smaller pipes.

Figure 10B shows a condition of the spraying device in which the upper frame 30 is in a higher position compared to the lower frame 40. In this way the spraying device is better equipped for use in larger pipes.

Figure 10C shows the height of the nozzle 11 is further adjusted using an additional exchangeable arm piece 107'. In this way the spraying device is better equipped for use in even larger pipes.

As shown in figure 10C, the interchangeable arm piece 10” is connected to an end part 10° of the rotatable spray arm 10. The additional interchangeable arm piece 107 can be used to adjust the distance between the nozzle 11 and the rotation axis of the spray arm, for example when the spraying device (as shown in Figure 10C) is applied in pipes with larger dimensions or when the spraying device (as shown in Figure 10D) is applied in pipes with smaller dimensions.

Figures 11A-11C show examples of the spray device in different states. In the embodiment as shown, everything is arranged so that the angle ß between the axis of rotation ra, of wheels of the one or more caterpillar tracks with respect to the horizontal level line hwl, can be adjusted. The caterpillar tracks 61 are located in wheel housing 62, the wheel housing is hinged to the central body 63 of the spraying device 100 (as seen in Figures 7A and 7B). In the embodiment shown, the wheel arch 62 is hingedly connected via connecting arms 62a, 62b to the central body 63 of the spraying device 100. The spraying device further contains a wheel arch manipulating actuator that is adapted to adjust the position of the wheel arch 62. The connecting arms 624, 62b are connected via hinge points 614, 61b, 62c, 61d. The wheel arch manipulating actuator can basically manipulate each link arm to adjust the position of the wheel arch. In the embodiment shown, the actuator is designed to move hinge point 61d as shown with vector arrow 64.

Because the rotation axis of the wheels of the moving means 60 is adjustable, a high degree of traction and grip can be provided in different types of pipes, such as pipes with different sizes and/or different cross-sectional shapes, such as rectangle, ovoid (egg-shaped), circle. The grip can be further increased by using the rubber tracks.

Figures 12A-12C show (as already described above) some principles of an embodiment of the parallelogram connection 32. The rotatable arm (not shown) is typically rotatably connected to the upper frame 30. The lower frame 40 is typically provided with moving means (not shown) to to move the spraying device through the pipe.

The upper frame 30 of the spraying device is hingedly connected to the lower frame 40 via support arms 32a, 32b. The actuator 41 comprises a movable screw shaft 41a that is connected to hinge element 41c. The hinge element 41c is slidably connected in a slot 41b of the upper frame 30. The slot 41b shown has a moon-like shape. For example, by controlling the movable screw shaft 41a of the actuator 41, the height of the upper frame 30 relative to the lower frame 40 can be adjusted, and at the same time the nozzle can be moved in the longitudinal direction of the pipe without disturbing the entire spraying device 100. to move. This can be advantageous for (additionally) spraying hard-to-reach surfaces with resin.

The application of the resin as described herein can be applied to various types of pipes which may have different shapes and sizes, examples of which are rectangular ducts, ovoid or round-shaped pipes, such as pipes with a diameter of 400 mm or more. The resin can be applied to different types of materials, e.g. pipes made of PVC, cast iron, steel, vitrified clay, concrete or asbestos.

Claims (37)

CONCLUSIONS 1. Method for applying resin in situ to an inner wall of a pipe, such as a sewer pipe, wherein the method comprises the steps of: a. introducing into the pipe a spraying device (100) which is adapted to move through the pipe and has a rotatable spray arm (10) provided with a nozzle (11) for spraying resin in the radial direction of the pipe; b. applying a first resin layer (RL) by spraying resin on a first surface (A1) of the inner wall, characterized in that the spray arm is periodically rotated back and forth between a first and second set arm position (H, Hz); with a period of maximum 40 seconds, while the spray device moves through the pipe from a first position (A) to a second position (B). 2. The method according to any of the preceding method claims, wherein the spray arm is rotated back and forth at least 2 times, preferably at least 3 times, more preferably at least 4 times per meter of the nozzle traveled through the pipe. 3. The method according to any of the preceding method claims, wherein the spray arm changes direction of rotation at least 2 times, preferably at least 3 times, more preferably at least 4 times per 10 seconds and/or per meter traveled by the nozzle through the pipe. The method according to any one of the preceding method claims, wherein the spraying device moves over a lower segment (L2) of the inner wall, and wherein the first and second arm positions are adjusted so that resin is sprayed over an upper segment (L3). The method according to any of the preceding method claims, wherein the applied first resin layer (RL1a) is sprayed with resin to apply an additional resin layer (RL) thereon while the spraying device moves from the second position (B) to the first position (A), whereby the additional resin layer (RL) is preferably applied within a period of 2 hours after the first resin layer (RL) has been applied. 6. The method according to any of the preceding method claims, further comprising: c. applying a second resin layer (RL) by spraying resin (S2) over a second surface (A2) that is at least complementary to the first surface (A1) while the spraying device moves from the second position (B) to the first position (A). The method according to the previous two claims, wherein the first resin layer is applied (RL:) to the upper segment and the second resin layer (RL:) is applied to the lower segment. 8. The method according to the previous method claim, wherein the second resin layer (RL) is applied within a period of 2 hours, preferably 1 hour, more preferably 0.5 hours, even more preferably 0.25 hours after the first resin layer (RL ) is applied. 9. The method according to one of the preceding two method claims, wherein during the application of the second resin layer (RL) a rotational movement is performed in which: - the rotatable spray arm (10) is rotated back and forth between a third and fourth arm position (H3, H4) such that the second resin layer (RL:) is applied over at least the complementary second surface (As) and optionally overlaps with the first applied resin layer (RL); or - the spray arm (10) is fully rotated such that the second resin layer (RL) is applied in a continuous helical pattern. The method according to any one of the preceding claims, wherein the spray arm (10) is fully rotated during a movement of the spray device such that a continuous resin layer (RL) is applied in a continuous helical pattern over the first resin layer (RL1) on the first surface (A1) and over a complementary surface (Az) such that a complete coverage of resin (A2,A'2) is applied to the inner wall; wherein the rotating arm is rotated with a first angular velocity ©; during spraying of resin over the first resin layer (RL) and where the rotating arm is further rotated with a second angular speed ©: during spraying of resin on the complementary surface (Az), where the first angular speed o; is greater than the second angular velocity wa. The method according to any one of the preceding claims, wherein the method further comprises: - mixing a first resin component and a second resin component in a static mixer. The method according to any one of the preceding claims, further comprising heating and/or maintaining the temperature of resin through a supply hose (230). 13. The method according to any of the preceding method claims, further comprising: - flushing a resin passage in the rotatable arm with a non-hardening fluid. 14. A spray device (100) for applying resin in situ to an inner wall of a pipe, such as a sewer pipe, wherein the spray device is adapted to move through the pipe and comprises: - a rotatable spray arm (10) provided with a nozzle (11) to spray the resin in a radial direction of the pipe; - a control system (20) to control a rotational movement (rb) of the rotatable spray arm, characterized in that the control system is designed to periodically rotate the spray arm back and forth between a first and second set arm position (H, Hz) when the spraying device moves through the pipe and the back and forth movement has a period of at most 40 seconds, preferably at most 30 seconds, even more preferably at most 20 seconds. The spraying device according to the previous claim, wherein the control system comprises an adjustment means and a user interface for receiving a user input to adjust the first and second arm positions (H;, Hs). 16. The spraying device according to any of the preceding spraying device claims, wherein the control system is designed to rotate the spray arm back and forth at least 2 times, preferably at least 3 times, more preferably at least 4 times per meter of the nozzle traveled through the pipe. 17. The spraying device according to any one of the preceding spraying device claims, wherein the control system is designed to change the direction of rotation (Td) of the spray arm at least 2 times, preferably at least 3 times, per 10 seconds and/or per meter traveled by the spraying device through the line. , preferably at least 4 times. The spraying device according to any one of the preceding spraying device claims, wherein the control system (20) is designed to rotate the rotatable spraying arm at a rotational speed of at most 50 RPM, more preferably at most 40 RPM, even more preferably at most 35 RPM. The spraying device according to any one of the preceding spraying device claims, wherein the spraying device, preferably the rotatable spraying arm, comprises a mixing chamber (30) that is provided with one or more mixing elements (31) to disrupt a flow profile of the resin in such a way that components in the resin is forcibly mixed. The spraying device according to the previous claim, wherein the mixing chamber (30) has a longitudinal axis extending in a direction substantially parallel to an axis of rotation (Ax1) of the spraying arm. The spraying device according to any one of the previous two claims, wherein the mixing chamber (30) has a length (Lm) of at least 5 cm, preferably at least 7 cm, more preferably at least 10 cm. The spraying device according to any one of the previous three claims, wherein the one or more mixing elements (31) in the mixing chamber (30) are paddle-shaped. The spraying device according to any one of the preceding spraying device claims, wherein the nozzle (20) is connected interchangeably to the rotatable spraying arm (10). The spraying device according to any one of the preceding spraying device claims, wherein the nozzle (11) has a spray opening (112) that is located at a distance ds from a rotational axis (Ax) of the spraying arm and wherein all this is arranged so that this distance ds is smaller than 15 cm, preferably smaller than 10 cm, so that the spray opening is virtually an extension of the rotation axis (Ax;) of the spray arm. The spraying device according to any one of the preceding spraying device claims, wherein the nozzle (11) is adapted to spray resin (R) in a direction between a transverse direction of the line (L) and a direction of a rotational axis (Ax) of the spray arm . The spraying device according to any one of the preceding spraying device claims, wherein the nozzle (11) is designed to spray resin (R) according to a spray pattern (19) with a cone or fan shape. The spray device according to the previous claim, wherein the legs of the impeller are located in a plane parallel to and through an axis of rotation of the spray arm. The spray device according to any one of the preceding spray device claims, wherein the nozzle (11) includes a spray tip holder (12) with a resin channel (13) and a removable spray tip (14) adapted to adjust a flow profile of resin in the resin channel and wherein the spray tip holder removably holds the spray tip in an opening (15) with a central axis substantially perpendicular to the resin channel. 29. The spraying device according to any one of the preceding spraying device claims, wherein the spraying device is designed to receive resin at a pressure of at least 350 bar, preferably at least 380 bar. 30. The spraying device according to any one of the preceding spraying device claims, wherein the spraying device comprises an upper frame (30) on which the rotating arm (10) is mounted and a base frame (40), wherein the upper frame is adjustable in height relative to the base frame using an actuator (41). The spraying device according to the previous claim, wherein the upper frame (30) and lower frame (40) are hingedly connected to each other via a parallelogram connection (42), so that the upper frame is adjustable in height relative to the lower frame (40) using the actuator (41). The spraying device according to any one of the preceding spraying device claims, wherein the spraying device further comprises a moving means (60) that is provided with one or more caterpillar tracks (61), preferably one or more rubber caterpillar tracks. The spraying device according to any one of the preceding spraying device claims, wherein the spraying device is arranged such that an angle (B) between an axis of rotation of wheels of a moving means (60), preferably wheels of the one or more caterpillar tracks (61), relative to a horizontal spirit level line is adjustable. The spraying device according to any one of the preceding spraying device claims, wherein the spraying device comprises a rear frame (50) that is adapted to receive one or more supply hoses (230) and is hingedly connected to a front set, such as a chassis (40), of the spraying device. The spraying device according to any one of the preceding spraying device claims, wherein the spraying device is further provided with a sensor module such as a camera module (80) and/or a light module (81). 36. The spraying device according to any one of the preceding spraying device claims, wherein the rotatable spraying arm (10) is designed as a modular arm that comprises several exchangeable arm pieces (17) that are removably connected to each other, preferably several tubular arm pieces that are connected to each other via a screw thread connection. are connected. 37. Set comprising the spray device (100) according to the previous claim and one or more additional interchangeable arm pieces with different dimensions for positioning the spray piece at a predetermined distance relative to a rotational axis of the rotatable spray arm.