JPH0453599B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a pipe cleaning method that is suitable for application to, for example, a pipe renewal method for restoring a decrease in water flow area due to long-term use of water pipes.

Normally, metal pipes used for waterworks have rust spots attached to the inner surface of the pipes due to long-term use, and these grow year by year, reducing the water flow area, resulting in poor water flow due to a decrease in water supply capacity, and a decline in the functionality of fire hydrants, etc. It also causes various harmful effects such as deterioration of water quality such as red water. The method of updating water pipes in such cases is to re-lay the pipes themselves, but since many pipes are buried under roads with frequent traffic, it may cause traffic obstruction during construction.
It has the disadvantage that it requires a large amount of construction cost and cannot be easily carried out.

For this reason, there is a method of removing rust bumps attached to the inner surface of the pipe and lining it with synthetic resin. As shown in Fig. 1, this construction method first defines a certain extension of the construction area, excavates a small hole, exposes and cuts the water pipe 1 at both ends, and inserts the nozzle scraper 3 pulled out from the cleaning vehicle 2 into the inside of the pipe 1. However, by supplying high-pressure water, as shown in FIG. 2, since the jet direction from the nozzle scraper 3 is backward, the rust bumps 4 are peeled off and removed while running on their own. This process is repeated several times, but
In reality, the surface of pipe 1 and rust bumps 4 can only be measured by water jet power.
Rust lumps attached to the boundary between the two are often not completely removed. Therefore, as a finishing process, the first
As shown in Figure B, the cutter device 6 connected to the pressure-resistant hose 5 of the cleaning car 2 is inserted to a far position in the pipe 1, and the cutter device 6 rotates at high speed to move it back toward the cleaning car 2 while cutting it into the inner surface of the pipe 1. Additional work will be required to remove the attached rust bumps and expose the skin. FIG. 3 shows the details, and the high pressure water supplied from the pressure hose 5 is converted into mechanical motion by the turbine 7, and the cutter 8 connected to the rotating shaft of the turbine 7 rotates at high speed. The polishing pieces open in the inner circumferential direction and come in contact with the inner surface of the tube 1 for polishing.

However, adding the above-mentioned finishing work actually causes high-speed friction and impact impact between the metal parts due to the rotation of the cutter 8, which damages the base of the pipe, and in some cases may cause impact cracks in the pipe base. This method also has the disadvantage that it is extremely difficult to completely polish the pitted portion inside the pipe. In addition, the cutter abrasive pieces may fall into the connecting recesses between the pipes, and as a result, the work must be interrupted and the ground at the fallen place must be excavated and cut to normalize, which significantly increases the number of work hours. However, there are some unavoidable drawbacks.

In view of this, the main purpose of the present invention is to completely and safely peel off the rust lumps attached to the inside of the pipe without damaging the inner surface of the pipe, and to help completely clean the painted surface, which is an essential requirement in the lining process. Moreover, the present invention proposes a method for cleaning this type of pipe, which does not require finishing work using the cutter device as described above, and can significantly reduce the number of work steps.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 4 is a diagram showing an example of the present invention. The pressure hose 11 is extended by the cleaning vehicle 10,
A nozzle device 12 is attached to the tip of the hose 11. As shown in FIG. 5, the nozzle device 12 is connected to the pressure hose 11 by a joint 13.
A plurality of nozzles 15 are removably provided radially on the main body 18 at an inclination angle θ so that water is ejected from the high-pressure water introduction hole 14 formed at the tip of the main body 18 in a direction opposite to the traveling direction (arrow A in the figure). ing. Therefore, when the axial centers of the plurality of nozzles 15 are connected, a tapered surface appears like a half-open umbrella.
The appropriate inclination angle θ of the nozzle 15 is around 45°.
The most efficient angle can be selected depending on the overall weight of the nozzle device 12, the water pressure, and the inner diameter of the tube 16. The nozzle 15 has a threaded structure so that several types of nozzles with different lengths can be replaced depending on the pipe diameter in order to minimize the distance l between the tip of the nozzle 15 and the inner surface of the pipe 16. There is. This is because the water pressure ejected from the nozzle 15 is inversely proportional to the square of the distance. A tapered guide 17 that is substantially parallel to a tapered surface formed by spraying high-pressure water from the nozzle 15 is fitted into the main body 18 . That is, the guide 17 has a cylindrical portion that fits into the main body 18, a tapered surface portion integrally formed from the cylindrical portion, and a reinforcing member 17a that reinforces the tapered surface portion and the cylindrical portion. In order to securely fix the guide 17, the main body 1
I try to push it to 8. In addition, in order to adjust the strength of the negative pressure, in addition to adjusting the strength of the injection pressure, the horizontal distance between the tapered surface of the guide 17 and the tapered surface exposed by the nozzle 15 may be changed. I can do it. Similarly to the nozzle 15, the guide 17 of several sizes is replaced in order to appropriately adjust the distance l' from the inner surface of the tube 16.

In FIG. 4, at the beginning of pipe cleaning, the nozzle device 12 is on the left side of the figure, but it moves to the right side of the figure when high-pressure water is supplied, as in the conventional case. However, the abrasive material 21 is supplied from the right end of the pipe 16 by an abrasive material feeding vehicle 20 . The water ejected from the nozzle 15 hits the inner surface of the pipe 16 with force and peels off the rust bumps 22, but at this time, the advancing side of the nozzle device 12 (A in FIG. 5) is on the opposite side (B in FIG. 5) The pressure will always be higher. Therefore, the abrasive material 21 supplied and distributed in the tube 16 is caused by the air near the tip of each nozzle 15 being formed by the guide 17 due to the air pressure difference coupled with the injection of pressurized water from the plurality of radially arranged nozzles 15. The abrasive material 21 is guided to a narrow periphery, and there is also a gap between each nozzle 15 near the tip of the nozzle 15.The air flow velocity is generated by the pressure difference necessary to attract the abrasive material 21, so that the air flows along the guide 17 with momentum. It is well absorbed, mixes with the jetted water near the circumferential edge of the guide 17, and collides with the inner surface of the pipe 16. As a result, most of the rust bumps 22 adhering to the surface of the pipe 16 and the rust bumps adhering to pitting areas eroded into the pipe 16 are removed by the impact pressure of the jetted water containing the granular abrasive material 21. It turns out. The abrasive material 21 moves toward the negative pressure area caused by the pressure water jet and the pressure difference.It mixes with the air flow and is automatically sucked as described above, but in the initial stage of pipe cleaning work, a pressure feed truck is used as needed. 20, it can be auxiliary conveyed to the vicinity of the nozzle device 12.

Although the above example is applied to water pipes, it can also be applied to pipes for general fluids such as powder and oil, and the pipes can be made of various materials such as cast iron pipes, steel pipes, hard synthetic resin pipes, etc. Can be applied to tubes. Furthermore, instead of supplying high-pressure water, a fluid such as high-pressure air can be used.

As described above, according to the present invention, a plurality of high-speed jets are ejected from a plurality of nozzles of a nozzle device inserted into a pipe in a direction opposite to the direction of movement of the nozzle device, and a high pressure state on the movement side of the nozzle device causes the nozzle device to A pressure difference is created with high pressure at the front and normal pressure at the rear, and the high-pressure air is squeezed by a conical guide installed parallel to the nozzle jetting direction and directed toward the negative pressure area generated near the tip of the nozzle. The granular abrasive material, which is conveyed by being mixed into the high-pressure air flow, is mixed into the jet water at the jet point, increases the impact force, and collides with the inner surface of the pipe, causing the particles to be generated inside the pipe. Since the rust bumps are removed, it is no longer necessary to perform finishing work using a cutter device after removing the rust bumps using a nozzle device, which is required in the conventional method, and the overall number of man-hours required for cleaning the pipes is significantly reduced. Therefore, it is possible to promote this work. Further, there are almost no scratches on the inner surface of the tube caused by using the conventional cutter device, and the life of the tube can be significantly extended.
Furthermore, since the inside of the pipe is operated under negative pressure, it is possible to prevent rust debris from entering the water supply pipe, which is a branch pipe, and there is an effect of suctioning the stagnant water remaining in the water supply pipe.

Further, according to the present invention, it can be applied not only to removing rust bumps attached to the inside of a pipe, but also to peeling off and removing debris from a lining material coated on the inner surface of a pipe.

Further, according to the present invention, an air flow is generated that rapidly flows in from the opening in front of the nozzle along the guide toward the negative pressure portion generated near the tip of the nozzle, and the air is mixed into the air flow and conveyed. The structure is such that the granular abrasive material that comes is mixed into the jet water at the jet location, increases the impact force, and collides with the inner surface of the tube.
In contrast to insufficient removal of rust lumps that have invaded the inner wall of the pipe, this method has the effect of completely removing rust lumps that have formed in the depressions formed on the inner wall of the pipe.

Furthermore, when the granular abrasive material is insufficiently mixed with the pressure fluid, the granular abrasive material can be distributed in the vicinity of the nozzle device by force-feeding it from the side opposite to the insertion direction of the nozzle device. . Therefore, when one section is long, even when the negative pressure state generated in the space in front of the nozzle device due to the injection of the pressure fluid is weak, it is possible to promote suction of sufficient abrasive material to the inner surface of the pipe near the nozzle device. .

[Brief explanation of the drawing]

Figures 1A and B are diagrams for explaining the conventional pipe cleaning method, Figure 2 is a diagram showing the action of the nozzle scraper, Figure 3 is a diagram showing the action of the cutter, and Figure 4 is a diagram showing the method of the present invention. FIG. 5 is a sectional view showing an example of a nozzle device. 12... Nozzle device, 15... Nozzle, 16...
...Tube, 17...Guide, 18...Main body, 21...
Granular abrasive material, 22...rust lumps.

Claims (1)

[Claims] 1 A plurality of high-speed jets are ejected from the nozzle in a direction opposite to the direction of movement of the nozzle device inserted into a plurality of nozzle devices and a high pressure state is created on the forward side of the nozzle device, so that the front of the nozzle device is under high pressure and the back is under normal pressure. A pressure difference is created, and the high-pressure air is narrowed by a conical guide installed parallel to the nozzle ejection direction, and then rapidly flows along the guide toward the negative pressure area generated near the tip of the nozzle. The granular abrasive material mixed in and conveyed by the flow is mixed into the jet water at the jet location, increases the impact force, and collides with the inner surface of the pipe, thereby removing rust bumps formed inside the pipe. A pipe cleaning method characterized by: