WO2020157757A1

WO2020157757A1 - Machine that carries out repair- restoration of concrete shedding within metal pipes coated with concrete on the inside walls of the pipes for the prevention of corrosion

Info

Publication number: WO2020157757A1
Application number: PCT/IL2020/050112
Authority: WO
Inventors: Meir YAHAV
Original assignee: Yahav Meir
Priority date: 2019-01-31
Filing date: 2020-01-26
Publication date: 2020-08-06
Also published as: IL264573A

Abstract

The invention presented here deals with a machine that carries out repair- restoration of concrete shedding within metal pipes coated with concrete on the inside walls of the pipes for the prevention of corrosion. The pipes are designed for conveying / flow of potable water or any other liquid. The machine performs also repairs of concrete shedding in pipes made solely of concrete, as for example, rain water drainage or any other thing or suitable liquid. Concrete shedding from the inner coating of metal pipes is caused by manufacture defects, hits, vibrations, deformations, etc., starting from the moment of their exiting the plant, unloading the pipes at the worksite where the pipes are connected to a continuous water line, laying them into the ditch, and covering them with soil. Each step is executed with tractors, which, in their turn, can cause damage to the pipes. The machine fills and covers any exposed metal with fresh concrete for the prevention of corrosion / rust which cause water leaks, which prolongs the water pipes lifespan. As long as the metal pipes are protected with concrete, the pipes lifespan is infinite. The machine moves within the pipeline to a distance of about 250 meters/820 feet (depending on the pipe diameter). The machine performs the repairs from the inside of pipe itself and does not cause disruption to the surroundings, prevents disruption to the lives of the residents by the tractors used otherwise in the repair and other heavy machines, prevents dust, dirt, noise, and roads closure.

Description

Machine that carries out repair- restoration of concrete shedding within metal pipes coated with concrete on the inside walls of the pipes for the prevention of corrosion. Invention Field

The invention presented here deals with a machine that carries out repair- restoration of concrete shedding within metal pipes coated with concrete on the inside walls of the pipes for the prevention of corrosion.

The pipes are designed for conveying / flow of potable water or any other liquid. The machine performs also repairs of concrete shedding in pipes made solely of concrete, as for example, rain water drainage or any other thing or suitable liquid.

Invention Background

The metal pipes in water lines are coated with concrete attached to the pipes inner walls. The concrete coating is intended to prevent corrosion in the metal pipe. Without the concrete coating, the metal is exposed to corrosion, which leads to holes through which water leaks, further leading to pipes / waterlines replacement. As long as the concrete coating is attached to the metal, the lifespan of the pipe is infinite. The standard thickness of the concrete coating on the inner walls of the pipe is as follows:

Pipe diameter 6” - thickness of the concrete coating 4 - 6 mm.

Pipe diameter 8” - thickness of the concrete coating 6 mm.

Pipe diameter 20” - thickness of the concrete coating 8 mm. The thickness size continuous even up to 10 mm. for larger diameters.

The standard length of pipe is 12 meters, the length of the concrete coating is exactly the same as the length of the pipe.

Concrete shedding from the inner coating of metal pipes is caused by manufacture defects, hits, vibrations, deformations, etc., starting from the moment of their exiting the plant, unloading the pipes at the worksite where the pipes are connected to a continuous water line, laying them into the ditch, and covering them with soil.

Each step is executed with tractors, which, in their turn, cause damage to the pipes.

The most sensitive places regarding concrete shedding in pipes, are the lips - the pipe ends.

During connection of pipes by welding, the welder cannot observe if damage was caused to the concrete on the inner side of the pipe lips. Exposed metal can also be caused because of open space created due to lack of overlapping of the lips of one pipe to the other, where the lips on one end are attached to each other and at the other end they are not attached and the place is open. This open space is created due to the movement of the pipe which has to be connected to the line. The open space created is filled with welding to supplement the absent metal. The welding is, of course, metal left exposed to corrosion. After welding, the open space must be of zero (0) dimension. At an open space of more than a zero dimension, the metal / welding will be exposed to rust, created by corrosion. Water leakage is certain to occur in exposed metal of water pipes unprotected by concrete. The holes start to appear (according to experts in corrosion, among them, Eng. Nachum Naveh, expert in materials and pipes corrosion) after about 3 to 4 years.

Let us take, for example, a water line laying contractor. The contractor lays the water line made of metal pipes protected with concrete on the inside. The length of each pipe is 12 meters.

After joining the pipes to a length of 200 - 250 meters (200 meters is the average length which a mobile video camera can reach), the contractor must scan the inside part of the pipes by video filming to the entire length of 200 meters to reveal defects - exposed metal unprotected with concrete. Let us assume that the video camera has shown that at the 100^th meter there is a spot of exposed metal with the dimensions of about 5 cm. x 7 cm.

Because it is not possible to repair the defect from the inside, the

contractor must dig the earth around the pipe in order to expose the exact place of the defect. The workers will cut a piece of the pipe of a length of between 1 to 10 meters, in which the defect is found - the exposed metal, and will lay a new pipe instead.

The joined pipe ends (lips) must have zero (0) space between them.

It is very difficult to adjust the ends / lips of the new pipe to the ends of the existing pipe in the line because the end cutting of both pipes do not fit (the cut is of an irregular shape).

The ends incompatibility leads many times to open spaces of about 6 mm. on each end. Because of the open spaces of the pipes joining, the welder must fill the empty space with welding. It means that the metal created by the welding is exposed without concrete protection.

Another damage is created by the fact that during the filling of the open spaces with welding at a temperature of 1520°C, the metal is expanding much faster than the concrete, which leads to the separation /

disconnection of the concrete from the metal.

The disconnection of metal from the concrete causes direct contact of water with the metal, leading to corrosion. Another fact is the change in the chemical structure of the concrete caused by temperature. This change leads to an inability of the concrete to neutralize the creation of corrosion.

Those two manifestations (both or separately) lead to corrosion, which causes certain water leakage in 3 to 4 years (according to experts in corrosion, among them, Eng. Nachum Naveh, expert in materials and pipes corrosion).

In the repair mentioned above, the old pipe segment with the concrete shedding was replaced with a new pipe segment. Many times, a second filming with a video camera shows that it is necessary to repeat the repair because of a large open space or because of concrete shedding at pipe ends caused during the process of pushing the pipes to reduce the open space between them.

The welder must repeat the work again and again until creating a

reasonable overlapping (of 1 to 4 mm.) between the existing joints.

Therefore, it is clear to the designers and to the supervisors that in the not too distant future, the exposed metal will be corroded, and after 3 to 4 years, there will be water leakage from that spot.

During the years, the leaking holes in the pipes expand, leading to more water leakage. After the soil around becomes saturated with water, it cannot absorb more water flowing from the pipe leaks. The water rises slowly and leads to the sinking of roads and pavements, and when the flow becomes a puddle, the place turns to a mosquito brooding spot.

Another issue created by this problem, is the repeated closure of the road and / or the pavement for the repair of every leakage hole, which in turn, increases the maintenance expenditures and causes much suffering to the residents.

It must be mentioned that there are soil types in which the water penetrates to the depth of the area, and so the leakages cannot be found.

In these cases, the water leakage is revealed after many years, due to the unexplained difference between the water consumption and the quantity of water supplied to the consumers, which necessitates the replacement of the waterline / pipes because of the difficulty to find the leakage spots.

The Drawings List The drawings attached to the application are not intended to limit the scope of the invention and the manner of execution of the invention. The

drawings are intended only to illustrate the invention and they present one option among many for its implementation.

Drawing, Fig 1/3. shows the machine with all assemblies. Drawing, Fig 2/3. shows the tractor (1) and the motors mounted on it used for panning and rotation.

Drawing, Fig 3/3. shows the concrete dispersion assembly.

Description of Invention

Machine (drawing Fig 1/3) with 2 mobile video cameras within empty water pipeline, without water. The pipes are made of metal. On the inner walls of the pipe, there is a layer of concrete of 4 mm thickness for protection against corrosion. The machine is fitted for moving within pipes of 145 mm diameter and up. The machine operation is performed from a vehicle on which the control system of the machine is installed. The machine is equipped with a container filled with fresh concrete. The machine is equipped with 2 video cameras. Upon arriving to the exposed / defect spot, the machine spreads and smears the fresh concrete on the exposed metal. The size of the exposed spot is about 10 sq. cm.. The time period of the repair execution is about 10 minutes on the average (without the time of travelling back and forth to the place of the repair). After the repair execution, the water line is ready for use after 3 to 6 hours, depending on the weather. The machine moves within the pipeline to a distance of about 250 meters (depending on the pipe diameter).

The invention - machine has solved all the problems described in section Invention Background, namely repair of concrete within a water pipeline without the need for digging. All the repairs are made from within / within the pipes themselves by remote operation. An example of executing repair / covering / filling fresh concrete on exposed metal. Before inserting the machine into the water or another type of liquid pipeline, it is necessary to adjust the height and the width of the machine to the inner diameter of the pipeline. Lifting or lowering the assemblies (drawings 2 and 3) is accomplished by 4 screws (2.2) which are connected to the tractor body (1). After adjusting the machine to the pipe diameter, the assemblies of drawings 2 and 3 are connected with screws (6) to the holes

(7.1) and attached and fastened with nuts (6.1). After the assemblies in drawings 2 and 3 were connected, fresh concrete is poured to the container (10) and the container is closed with a cover (12). This is the preparation stage before inserting the machine into the pipeline.

An electrical cable is connected to the machine and is towed by it. The cable supplies the power required for the machine operation.

The control of the machine is accomplished with a control system installed in the vehicle. The control system is equipped with a TV / computer screen which shows in real time the video pictures produced by camera (4). The pictures show the pipe walls. A front camera (15) shows the entire pipe inner space. The machine travels within the water pipeline which does not contain water in it.

While the machine was travelling, exposed metal was revealed at the 100^th meter, on the pipe upper part, of a size of about 10 cm. x 10 cm. camera (15) is shut down and camera (4) is operated. Camera 4 is connected to the body (3). An taut spring (4.1) is connected The camera (4) for stabilizing the camera (4). Within the body (3) there is an engine connected to a cogwheel

(3.1). The cogwheel (3.1) leads / conveys the panning rod (serrated rod) (5) to the right or to the left towards the pipe walls. Two arms (5.3) are

mounted on the panning rod (5) which direct / shift / move the camera (4) in the direction of the rod (5) movement, to the right or to the left towards the pipe walls.

Continuation of work execution: Camera (4) is turned to the right by means of (5) by engine (3). Engine (2) rotates the cogwheel (2.1). (2.1) can rotate 360 degrees within the pipe with parts (3), (4), (5) and (6) and the whole assembly shown together in drawing 3. A rotation of 360 degrees around the inside part of the pipe, facilitates view / scan focused on the exposed metal or any other defect. After focusing with camera (4), it was found that the size of the exposed metal area is estimated at about 10 cm. x 10 cm.. Container (10) is filled with fresh cement- concrete. Engine (14) rotates the cogwheel (11.2). (11.2) rotates like a nut around the threaded rod (11.1) (the threaded rod does not in rotate). The threaded rod (11.1) advances and thrusts the piston (11). The piston (11) shoves the cement- concrete into the spoons (ladles) housing (9). The ladles (9.1) are connected to engine (8). The turning ladles (9.1) throw / spread the concrete with centrifugal force on the exposed metal and covers it fully. The ladles (9.1) speed varies according to need and according to the pipe diameter. An engine (3) conveys / advances to the sides the panning rod (5) towards the fresh concrete attached to the exposed metal on the pipe wall until (5.2) touches the pipe wall. (5.2) is flat, rectangular, flexible, made of rubber or plastic or flexible metal, and its function is to spread / to level / to smoothen the fresh concrete. (5.2) connected to rod (5) touches the pipe wall. Engine (2) rotates (5.2) (together with engine (3) with all its components connected to it, including the entire assembly shown in drawing 3) to the left or to the right, which smoothens the fresh concrete spread on the exposed metal.

Repair - covering the metal with concrete is accomplished and the metal is protected now against corrosion. After 3 to 6 hours of waiting for concrete curing, the water pipeline is ready for use

Claims

Claim Before inserting the machine of repairing concrete shedding within metal pipeline protected with concrete on the inside, it is necessary to adjust the height and the width of the machine to the inner diameter of the pipeline. Lifting or lowering the assemblies (drawings Fig 2/3 Fig 3/3 and Fig 1/3) is accomplished by 4 screws (2.2) which are connected to the tractor body (1)· After adjusting the machine to the pipe diameter, the assemblies of drawings Fig 2/3 and Fig 3/3 are connected with screws (6) to the holes (7.1) of carrier (7), and attached and fastened with nuts (6.1). After the assemblies in drawings Fig 2/3 and Fig 3/3 were connected, fresh concrete is poured into container (10) and the container is closed with a cover (12). This is the preparation stage before inserting the machine into the pipeline. An electrical cable is connected to the machine and is towed by it. The cable supplies the power required for the machine operation. The machine is controlled by a control system installed in the vehicle. The control system is equipped with a TV screen which shows in real time the video pictures produced by camera (4) showing the pipe walls. A front camera (15) shows the entire pipe inner space. The machine travels within the water pipeline which does not contain water in it. The machine has arrived at the 100th meter. At the 100th meter, on the pipe upper part was revealed exposed metal of a size of about 10 cm. x 10 cm.. Camera (15) is shut down and camera (4) is operated. Camera (4) is connected to the body (engine house)(3). To camera (4) is connected an extended spring (4.1) for stabilizing the camera (4). Within the body (3) there is an engine connected to a cogwheel (3.1). (3.1) leads / conveys the panning rod (serrated rod) (5) to the right or to the left towards the pipe walls. Two arms (5.3) are mounted on the panning rod (5) which direct / shift / move the camera (4) in the direction of the rod (5) movement, to the right or to the left towards the pipe walls. Continuation of work execution: Camera (4) is turned to the right by means of (5) by engine (3). Engine (2) rotates the cogwheel (2.1). (2.1) can rotate 360 degrees within the pipe with parts (3), (4), (5) and (6) and the whole assembly shown in drawing Fig 3/3. A rotation of 360 degrees around the inside part of the pipe, facilitates view / scan focused on the exposed metal or any other defect. After focusing with camera (4), it was found that the dimension of the exposed metal area is estimated at about 10 cm. x 10 cm.. Container (10) is filled with fresh concrete. Engine (14) rotates the cogwheel (11.2). (11.2) rotates like a nut around the threaded rod (11.1) (the threaded rod does not rotate). The threaded rod (11.1) advances and thrusts the piston (11). The piston (11) shoves the concrete into the spoons house (9). The spoons (9.1) are connected to engine (8). The rotating spoons (9.1) throw / spread the concrete with centrifugal force on the exposed metal and covers it fully. The spoons (9.1) speed varies according to need and according to the pipe diameter. An engine (3) conveys / advances the panning rod (5) to the sides towards the fresh concrete attached to the exposed metal on the pipe wall until (5.2) touches the pipe wall. (5.2) is flat, rectangular, flexible, made of rubber or plastic or flexible metal, and its function is to spread / to level / to smoothen the fresh concrete. (5.2) connected to rod (5) touches the pipe wall. Engine (2) rotates (5.2) together with engine (3) with all its components connected to it, including the entire assembly shown in drawing Fig 3/3 to the left or to the right, which smoothens the fresh concrete spread on the once exposed metal. Repair - covering the metal with concrete is accomplished and the metal is protected now against corrosion. After 3 to 6 hours of waiting for concrete curing, the water pipeline is ready for use. Other uses: On the panning rod (5) it is possible to connect a steel brushes, knives for scraping the concrete and rust, a grindstone, a drilling machine, a paint brushes for painting.

1. The claim is for all the parts, the assemblies and the design shown in drawings Fig 1/3 Fig 2/3 and Fig 3/3.

2. The description of the invention presents and explains in detail the invention and it constitutes an integral part of the patent application.

3. The background of the invention clarifies the need for a machine to repair concrete shedding in the inside part of metal pipes for the flow of water and sewage.

4. The concrete serves as a protecting coating / covering of metal pipes from within against rust / corrosion. By means of the machine it is possible to repair / reconstruct all the concrete shedding defects found in metal pipes from the inside, from within / within the pipe itself.

5. The machine can cover / spread / fill concrete or paint on exposed

metal within pipes of any diameter and especially in diameters of 145mm (-6 inches).,, to 50cm (20 intchs) because in those diameters it is not possible to introduce a manpower to execute the repair / cover / spread / fill with concrete on exposed metal caused bv concrete shedding.

6. The machine fills and covers any exposed metal with fresh concrete for the prevention of corrosion / rust which cause water leaks, which prolongs the water pipes lifespan. As Iona as the metal pipes are protected with concrete, the pipes lifespan is infinite.

7. The machine prevents the need for maintenance and manpower, which saves money.

8. The machine saves the contractors who lay the water / liquid pipelines the costs of dismantling and installing anew the pipes in which were found defects - exposed metal spots without concrete protection.

8.1 The machine prevents water leaks, water contamination during the repair of water leaks, water flooding which leads to the destruction of roads and pavements, mosquito brooding spots, and prevents repeat suffering from the street residents for years to come in which it will be necessary to close the water line for the repair of water leaks.

9. The machine prevents environment pollution caused by leaks from sewage pipelines.

The advantages of the machine for repair / covering with fresh concrete exposed metal in steel pipes coated with concrete on the inside.

1. Improvement, time, efficiency, and costs: Bv means of the machine, it is possible to carry out covering / spread of fresh concrete on exposed metal in about 5 to 30 minutes on the average, depending on the pipe diameter and the size of the exposed metal spot. To this, it is necessary to add 5 to 20 minutes of travel from the beginning of the pipeline to the defect spot, compared to 3-7 hours, (depending on the pipe diameter) by digging. The repair necessitates digging with a tractor, a team of workers comprised of a welder accompanied by 2 other workers, checking integrity of repair with the video filming machine, covering the dig, filling and compacting, laying new asphalt. Many times, checking the repair spot again, reveals that the repair is not good, and it is necessary to repeat it.

2. Money saving: The cost of a repair from the inside of the pipe made with the machine, is very low compared with a repair made by digging and dismantling pipes.

3. Disruption to the surroundings: The machine performs the repairs from the inside of pipe itself and does not cause disruption to the surroundings, prevents disruption to the lives of the residents by the tractors used otherwise in the repair and other heavy machines, prevents dust, dirt, noise, and roads closure.

4. Repair bv means of the machine, eliminates the need for maintenance work, something that prevents disruption to the surroundings, water stoppage, and leads to substantial money savings to the water utility providers.

In spite of the elaborated description, it does not present all possible applications of the invention, and that other applications derived from the description but not mentioned explicitly in it, shall be protected by the patent.