DE102024110649A1 - PROCESS FOR REHABILITATION OF SHAFTS - Google Patents

Abstract

The present invention relates to a method for rehabilitating a canal or shaft, comprising the following steps, in particular in this order:
a) recording measurement values representative of the inner diameter of the shaft by means of a measuring device and generating a digital representation of the shaft by means of a data processing device;
b) Inserting a lining tube into the shaft;
c) expanding the lining tube by means of compressed air, whereby the diameter of the lining tube is measured by means of the measuring device; and
d) Curing of the lining tube after completion of the expansion.

Description

The present invention relates to a method for rehabilitating canals or shafts.

For the inspection, maintenance, and rehabilitation of manholes, pipes, sewer systems, and the like, devices are often inserted into the pipes to perform the necessary measurements and/or mechanical rehabilitation work. To measure the current condition of a pipe prior to rehabilitation, the devices usually have camera systems or 3D scanners to visualize or measure the condition of the pipe. After the hose is inserted, camera systems are used during the rehabilitation.

If a defect or damage is detected, the affected section of the piping system can be replaced with new sections. However, this is usually very complex.

Alternatively, methods are known in the art for the rehabilitation of piping systems, e.g., sewers and similar pipe systems, in which a flexible, curable layer impregnated with a curable resin, also known as a liner, is inserted into the piping system. After insertion, the liner is expanded so that it fits snugly against the inner wall of the piping system. The resin is then cured.

The resin-impregnated fiber tape is often wound spirally and overlappingly around the inner tube of a lining tube for its production. The outer tube is then also wound spirally and overlappingly around the resin-impregnated fiber tape. Unsaturated polyester resins or vinyl ester resins, which can be dissolved in styrene and/or an acrylic ester, are used as curable resins in the prior art. These unsaturated polyester or vinyl ester resins can be cured thermally (usually by peroxide catalysts) or by radiation, e.g. by UV light with photoinitiators, as for example in the EP-A 23623 described, cured.

So-called combination curing processes with a peroxide initiator used for thermal curing in combination with photoinitiators are also possible and have proven particularly advantageous for lining tubes with large wall thicknesses. One process for such a so-called combination curing process is described, for example, in EP-A 1262708 Unsaturated polyester or vinyl ester resins are subject to shrinkage during curing, which can impair the stability of the rehabilitated piping system during subsequent operation.

The inner tube itself is wound around a winding mandrel to simplify production. Alternatively, for example, WO 95/04646 A prefabricated inner film tube can be inflated and can serve as a winding mandrel. Such a prefabricated inner film tube is made from a film strip, the edges of which are joined together by welding or gluing to form the inner film tube.

A radiation-curing lining tube typically comprises an opaque outer protective film, an inner film that is transparent to at least certain wavelength ranges of electromagnetic radiation, and a resin-impregnated curable layer positioned between the inner film and the outer film. The outer film tube is designed to prevent the resin used for impregnation from leaching from the curable layer and entering the environment. This requires a good seal and bond between the outer film tube and the resin-impregnated curable layer.

The lining tubes are inserted into the pipe system to be repaired before they harden and inflated using a fluid, usually compressed air. To inflate the lining tube, one opening end of the lining tube is pressurized with compressed air according to the state of the art, and the opposite opening end of the lining tube is sealed with a closure device, a so-called packer. This closure device comprises a hollow cylinder and a cover element with which the hollow cylinder can be closed.

To cure the lining tube, a curing device is inserted into the lining tube. This device contains a radiation source and is guided through the lining tube to activate or initiate the curing of the curable layers of the lining tube using the radiation energy. Complete curing of the lining tube is of utmost importance, i.e., a specific amount of radiation energy must be introduced into each point of the lining tube. The amount of radiation energy depends on the power output of the radiation sources and the speed at which they are passed through the lining tube.

Lining tubes are used in channels or shafts. While channels are usually run with a slight incline, shafts are vertically or diagonally inclined and can end in a channel.

The main difference between channels and shafts is that in shafts the lining tubes are often lifted vertically above the shaft by means of a crane and then lowered section by section into the shaft, which may be inclined, whereas in channels and piping systems the lining tubes are essentially pulled in horizontally.

The packer, which seals the uncured lining tube on one side, is usually located at the top of the shaft. The packer can rest on the shaft entrance and thus remain in place. The curing light chain is inserted with a cover element before the packer is closed and suspended on a pull rope. It is lowered and then raised again to cure after the tube has expanded.

A disadvantage of the previous systems, especially in the rehabilitation of shafts, is that the expansion of the lining hose with compressed air takes place in an uncontrolled manner until the desired expansion state is reached.

First, a lining tube is selected whose expanded outer diameter matches the inner diameter of the shaft. To expand the lining tube, a specific pressure is generated inside the lining tube. The pressure inside the lining tube is gradually adjusted or increased in several steps based on empirical values; however, the expansion process itself is not measured. Rather, the internal pressure at which expansion occurs is known, and empirical values are available for the internal pressure at which the lining tube should be in contact with the inside of the sewer.

This state-of-the-art method has the particular disadvantage that expanding the lining tube takes longer than necessary and/or the lining tube does not fit optimally against the inside of the sewer or shaft. Furthermore, there is no documentation of the correct execution of the work.

Therefore, the object of the present invention was to make the expansion of a lining hose faster and safer and, in particular, to be able to carry out documentation.

1. a) Erfassen von Messwerten repräsentativ für den Innendurchmesser des Schachts mittels einer Messeinrichtung;
2. b) Erzeugen einer digitalen Repräsentation des Schachts mittels einer Datenverarbeitungseinrichtung;
3. c) Einbringen eines Auskleidungsschlauchs in den Schacht;
4. d) Aufweiten des Auskleidungsschlauchs mittels Druckluft, wobei der Durchmesser des Auskleidungsschlauchs mittels der Messeinrichtung erfasst wird und insbesondere der Druck und/oder die Haltezeit anhand des Dehnverhaltens des Auskleidungsschlauchs gesteuert oder geregelt wird; und
5. e) Aushärten des Auskleidungsschlauchs nach Beendigung des Aufweitens.

The solution to this problem is a method for rehabilitating a canal or shaft, comprising the following steps, in particular in this order:

1. a) Recording of measured values representative of the inner diameter of the shaft by means of a measuring device;
2. b) generating a digital representation of the shaft by means of a data processing device;
3. c) Inserting a lining tube into the shaft;
4. d) expanding the lining tube by means of compressed air, whereby the diameter of the lining tube is measured by means of the measuring device and, in particular, the pressure and/or the holding time is controlled or regulated based on the expansion behaviour of the lining tube; and
5. e) Curing of the lining tube after completion of the expansion.

In particular, it can be provided that in step d) the inner diameter of the lining tube is measured and the outer diameter of the lining tube is calculated by the data processing device.

Furthermore, it may alternatively or additionally be preferred that in step d) the overpressure generated by the compressed air is regulated by comparing the inner diameter of the shaft and the outer diameter of the lining hose.

The invention is therefore based on the surprising finding that detecting the internal geometry of the channel or shaft can not only be used to select the correct diameter of a lining tube, but that measuring the geometry is also advantageous with regard to the insertion and expansion of the lining tube itself.

Until now, the lining tubes have been inserted without any measurement calibration and expanded based on user experience. There are specific target air pressure values that users can use as a guide.

The pressure required inside the lining tube for it to expand is known. If the pressure continues to rise after a certain period of time, it can be assumed that the lining tube cannot expand any further.

The lining tube is expanded in so-called pressure stages, meaning a pressure is set and held for a specific period of time, for example, 5 minutes. The pressure is then increased and held for the same period again, and so on.

Matching the inner diameter of the shaft to the outer diameter of the lining tube during expansion ensures that the lining tube can be expanded evenly and no areas are underexpanded. This is important for the integrity and longevity of the rehabilitation.

In particular, the described holding time can be individually shortened or adjusted using the present invention. For example, it can be detected that the hose no longer expands within the selected period, and the next pressure increase can occur sooner. Furthermore, it is known when the maximum desired expansion has been achieved by adjusting the inner diameter of the shaft or channel to the outer diameter of the lining hose.

The measurement-based recording according to the present invention not only optimizes the expansion speed and thus reduces costs, but also leads to improved installation quality and documentation of the installation situation. It can be particularly advantageous for step e) to follow directly after step d). Direct connection means that the user starts this immediately afterward, with no breaks between the steps.

A measuring device within the meaning of the present invention is understood to be a device or system that measures physical quantities such as length, diameter, and/or the condition of a structure. This can be, in particular, a laser scanner, an ultrasonic measuring device, a camera system, or another type of sensor capable of capturing precise data about the internal geometry of the shaft and/or the inserted lining tube.

A distinction must be made between the inner diameter of the shaft or channel and the outer diameter of the lining tube. The inner diameter or geometry of the shaft or channel is recorded as a direct measurement.

Furthermore, the invention provides for the method according to the invention to be used for non-circular shafts. In this case, the characteristic "inner diameter" should be understood as an equivalent for non-circular shafts that defines their internal geometry or cross-section.

The outer diameter of the lining hose can also be measured directly using integrated sensors, but it can be particularly advantageous to calculate it based on the inner diameter.

In particular, it can be provided that the same measuring device is used to measure the inner diameter of the channel or shaft and the inner diameter of the lining tube in order to then calculate the outer diameter of the lining tube.

According to the present invention, a digital representation of the measured data is preferably provided in the form of 3D models or maps that can be generated and viewed on a computer. These models can range from simple two-dimensional drawings to complex three-dimensional structures containing detailed information about the condition and dimensions of the shaft.

It can also be provided that the digital representation is used exclusively for calculation purposes to compare the data from steps a) and d), without being graphically displayed to a user. A graphical representation is explicitly provided according to one embodiment of the present invention, as explained.

According to one embodiment, a symbol or pictogram indicating the correct expansion state can be displayed to the user, e.g., in "blue" during expansion, in "green" when the desired state is reached, and in "orange" or "red" when the air pressure is further increased. This can be easier and faster to grasp than an exact representation of the outer diameter, although a combination of precise diameter information and a symbol or pictogram is also advantageous. Acoustic signals can also be used.

In summary, it can thus be provided according to the invention that the expansion is controlled automatically and/or that the user is shown information representative of the outer diameter of the lining hose during expansion and optionally of the inner diameter of the shaft in order to control the expansion independently with the aid of these values.

According to one embodiment of the present invention, it can be provided that the annular gap from the outside of the lining hose to the inside diameter of the shaft is calculated by measurement over the length of the lining hose and the expansion of the lining hose is stopped at an annular gap smaller than a limit value x, with x smaller than 1% of the outside diameter of the lining hose, in particular at less than 0.5%, preferably at an annular gap smaller than 0.1%, particularly preferably at an annular gap smaller than 0.01%, or 0.

An annular gap is the space between two cylindrical structures, one of which lies within the other.

The annular gap according to the present invention refers to the cavity between the outer wall of an inserted lining tube and the inner wall of the surrounding material or structure, such as a wall or an existing pipe.

The annular gap is therefore a property that determines whether the lining hose fits sufficiently against the inner wall of the shaft. The smaller the annular gap, the better the result. The annular gap does not have to be zero; the advantageously specified values are sufficient, depending on the regulations.

According to the invention, the method can independently terminate further expansion of the lining tube when the value x is reached or exceeded. As already explained, it can also be provided that the user is notified of this by numbers, symbols, pictograms, or acoustic signals, and the user stops the expansion.

It may be particularly advantageous that the annular gap is smaller than x over at least 90% of the length of the lining hose in the shaft, in particular 95%, preferably 99%, particularly preferably over the entire length.

Depending on the structure of the shaft, its inner diameter may not be consistent along its entire length. The inserted lining tube can compensate for irregularities to a certain extent, but this is not always possible, for example, in cases of rapid diameter changes or unsealed excavations.

In addition, there may be inlets in the shaft that have to be exposed later and that have to be taken into account when calculating the fit of the lining hose to the shaft over its length.

According to one embodiment of the present invention, it is advantageous if the curing according to step e) begins when the annular gap is smaller than the limit value x.

According to the invention, it can be provided that the curing starts automatically or the user is shown the recommended start of the curing for manual starting, which can be done in a similar way to the indication of the end of the expansion.

In particular, it is intended that a radiation source, also known as a string of lights, be used for curing. Like the measuring device, the radiation source is preferably lowered by a pull rope and is activated when passing through the shaft, thus curing the lining tube.

According to one embodiment of the present invention, the measuring device can be guided through the shaft by means of a pulling device, in particular in the form of a pulling cable and/or
that the measuring device is attached to the shaft chain or to the packer that closes the lining hose.

It may be advantageous to define a reference point for the start of the measurement(s) of the measuring device, with each measurement starting at the reference point so that each measurement has the identical measuring path.

Crucial for comparing measured values using the measuring device is that the same starting point is established in each case. While it can be difficult to determine the starting point of the measurement for sewers, this is easier for shafts, as these end at the surface, allowing the ground level to be used as a reference value for the measurement.

It has proven advantageous to lower the measuring device into the shaft from above using a pulling device. The position of the measuring device relative to ground level is recorded and the respective diameter is determined along the lowering. This is advantageous both for the initial measurement before pulling in the lining tube and for the measurement during expansion.

However, it is not absolutely necessary to move the measuring device for the survey. Due to the more complex geometries, it is necessary to measure the shaft depending on of its length is helpful and enables more accurate measurements.

The lining tube itself has a smooth internal geometry and can, in many cases, also provide good measurement results for the inner diameter of the lining tube with a permanently connected measuring device, such as a camera system or laser scanner.

In this case, it has proven advantageous if the measuring device is attached to the packer.

As already explained, the measuring devices in steps a) and d), i.e. for the initial measurement of the channel and the subsequent measurement during expansion of the lining tube, can be identical, but do not have to be.

Furthermore, it may be advantageous if, after curing in step e), the lining tube is measured again with the measuring device and the inner diameter is measured along the lining tube.

This is particularly advantageous because the lining tube shrinks slightly in diameter during curing. The measurement is repeated after curing for quality control and documentation purposes.

Finally, it can be planned that the recorded measured values are stored on-site and/or in a cloud solution.

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP-A 23623 [0005]
• EP-A 1262708 [0006]
• WO 95/04646 [0007]

Claims (11)

A method for rehabilitating a sewer or shaft, comprising the following steps, particularly in this order: a) Recording measured values representative of the inner diameter of the shaft using a measuring device b) Generating a digital representation of the shaft using a data processing device; c) Inserting a lining tube into the shaft; d) Expanding the lining tube using compressed air, wherein the diameter of the lining tube is measured using the measuring device and, in particular, the pressure and/or the holding time is controlled or regulated based on the expansion behavior of the lining tube; and e) Curing the lining tube after completion of the expansion. Procedure according to Claim 1 , characterized in that in step d) the inner diameter of the lining tube is measured and the outer diameter of the lining tube is calculated by the data processing device. Procedure according to Claim 1 or Claim 2 , characterized in that in step cd) the overpressure generated by the compressed air is regulated by comparing the inner diameter of the shaft and the outer diameter of the lining hose. Method according to one of the preceding claims, characterized in that the annular gap from the outside of the lining hose to the inside diameter of the shaft is calculated by measurement over the length of the lining hose and the expansion of the lining hose is stopped at an annular gap smaller than a limit value x, with x smaller than 1% of the outside diameter of the lining hose, in particular at less than 0.5%, preferably at an annular gap smaller than 0.1%, particularly preferably at an annular gap smaller than 0.01%, or 0. Procedure according to Claim 4 , characterized in that the annular gap is smaller than x over at least 90% of the length of the lining hose in the shaft, in particular 95%, preferably 99%, particularly preferably over the entire length. Procedure according to one of the Claims 4 or 5 , characterized in that the curing according to step d) begins when the annular gap is smaller than the limit value x. Method according to one of the preceding claims, characterized in that the measuring device is designed in the form of an optical and/or an acoustic sensor. Method according to one of the preceding claims, characterized in that the measuring device is guided through the shaft by means of a pulling device, in particular in the form of a pulling cable, and/or that the measuring device is attached to the shaft chain or to the packer which closes the lining hose. Method according to one of the preceding claims, characterized in that after curing in step de), a renewed metrological detection of the lining tube takes place with the measuring device and the inner diameter is measured along the lining tube. Method according to one of the preceding claims, characterized in that the recorded measured values are stored on site and/or in a cloud solution. Method according to one of the preceding claims, characterized in that a reference point is defined for the start of the measurement(s) of the measuring device, each measurement starting at the reference point so that each measurement has the identical measuring path.