JP2002079205A - Method for washing internal face of pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for washing the internal face of a steel pipe by which the internal face of the steel pipe can be uniformly washed and the removed deposit can be rapidly discharged from the internal face of the steel pipe without significantly increasing the volume of a washing tank and installing complicated piping in the washing tank. SOLUTION: The flow F1 of a washing liquid 11 is generated in a direction where the liquid 11 does not flow in through the steel pipe 2, in the neighborhood of a pipe end 21 on the high position side of the steel pipe 2 soaked obliquely in the axial direction in the liquid 11. On the other hand, the liquid 11 is absorbed into the pipe 2 from the other end 22 on the low position side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The method for cleaning the inner surface of a pipe according to the present invention is a method of laminating a synthetic resin, a synthetic resin paint, a foam, a synthetic resin pipe, a metal, a metal pipe, etc. on the inner surface of the pipe to form a multi-layer pipe. The present invention also relates to a method for cleaning the inner surface of a pipe, for example, to a method for cleaning the inner surface of a pipe which can be suitably used for cleaning the inner surface of a steel pipe when lining a synthetic resin pipe on the inner surface of the steel pipe.

[0002]

2. Description of the Related Art Conventionally, when a synthetic resin pipe or the like is lined on the inner surface of a steel pipe, deposits such as oils and fats adhering to the inner surface of the steel pipe are removed, if necessary, with an alkali solution, an acid solution, a surfactant solution and / or a surfactant solution. Then, the steel pipe and the synthetic resin pipe are lined with an adhesive or the like after the inner surface of the steel pipe is cleaned by removing it with a cleaning liquid such as an organic solvent.

[0003] As a cleaning method at that time, a steel pipe is immersed substantially horizontally in a cleaning tank filled with a cleaning liquid, and the inner surface of the steel pipe is brought into contact with the cleaning liquid to remove the deposits. However, gas such as, for example, hydrogen gas, which is generated by chemical reaction and adherents that have been washed and removed from the inner surface of the steel pipe by the cleaning liquid, accumulates at the upper part of the inner surface of the steel pipe, and the cleaning liquid does not contact the inner surface of the steel pipe at that part, and the other part is The degree of cleaning and removal of deposits is different in comparison, and as a result, the degree of cleaning of the inner surface of the steel pipe is partially different, and the inner surface of the pipe is not evenly washed, and the lining can be sufficiently formed and insufficient. There is a problem in that a part that becomes is formed.

To solve this problem, a steel pipe is immersed diagonally,
Although some measures have been taken to ensure that the removed deposits are discharged from the open end of the steel pipe, the immersion angle of the steel pipe must be steep in order to quickly discharge the deposits from the inside of the steel pipe. Therefore, there is a problem that the washing tank must be deepened and the volume of the washing liquid tank becomes large, so that a large amount of washing liquid is required.

[0005] A cleaning liquid is fed into the steel pipe from one end of the steel pipe,
It has also been devised that deposits and the like discharged from the other end and removed do not remain in the steel pipe (Japanese Patent Publication No. 58-333).
No. 11). However, although this method has the effect of reducing the accumulation of deposits and the like and ensuring the cleaning, the cleaning liquid is guided to a liquid feeding device such as a pump for feeding the cleaning liquid or to one end of the immersed steel pipe. In such a case, there is a problem that a cleaning liquid pipe line or the like must be provided in the cleaning tank, which complicates the process and increases maintenance work.

In the case where steel pipes are bundled and immersed in a cleaning liquid for processing in a large amount, it is difficult to reliably pass the cleaning liquid through the inner surface of each steel pipe. However, there is a problem that it is necessary to move the nozzle for feeding the liquid to an appropriate position.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the inner surface of a steel pipe can be uniformly cleaned and removed without greatly increasing the volume of the cleaning tank and without installing complicated piping in the cleaning tank. It is an object of the present invention to provide a method for cleaning the inner surface of a tube, which can quickly remove the deposits from the inner surface of the tube.

[0008]

Means for Solving the Problems To solve the above problems, a method for cleaning the inner surface of a tube according to claim 1 of the present invention (Invention 1).
Is a method of cleaning the inner surface of a pipe, wherein a flow of the cleaning liquid is generated near one end of the pipe immersed in the cleaning liquid in a direction in which the cleaning liquid does not flow into the pipe, and the cleaning liquid is sucked into the pipe from the other end.

According to a second aspect of the present invention, there is provided a method of cleaning an inner surface of a pipe (invention 2), wherein the pipe is immersed in a cleaning liquid at an angle in an axial direction, in the vicinity of a pipe end at a high position, in a direction in which the cleaning liquid does not flow into the pipe. A method for cleaning the inner surface of a pipe, characterized by causing a flow of the cleaning liquid and sucking the cleaning liquid into the pipe from the other end on the low position side.

According to a third aspect of the present invention, there is provided a method for cleaning the inner surface of a pipe (invention 3), wherein a flow is generated near one end of a pipe immersed in a cleaning liquid in a direction away from the pipe end, and the cleaning liquid is introduced into the pipe from the other end. The method for cleaning the inner surface of a tube according to Inventions 1 to 2, characterized by inhaling water.

According to a fourth aspect of the present invention, there is provided a method of cleaning an inner surface of a pipe (invention 4), wherein a flow of the cleaning liquid is generated in an ascending or descending direction near one end of the pipe immersed in the cleaning liquid, and the flow of the cleaning liquid is started from the other end. The cleaning method for cleaning the inner surface of a pipe according to any one of Inventions 1 and 2, wherein the cleaning liquid is sucked into the pipe.

According to a fifth aspect of the present invention, there is provided a method for cleaning the inner surface of a pipe (invention 5), wherein the pipe is immersed in a cleaning liquid and rotated 180 ° or more around the pipe axis in the circumferential direction of the pipe. Is an inner surface cleaning method.

According to a sixth aspect of the present invention, there is provided a method of cleaning the inner surface of a pipe (invention 6), wherein a flow of the cleaning liquid is generated near one end of the pipe immersed in the cleaning liquid in a direction in which the cleaning liquid does not flow into the pipe.
A method for cleaning the inner surface of a pipe, wherein a cleaning liquid is sucked into the pipe from the other end, and the pipe is simultaneously rotated 180 degrees or more around the pipe axis in the pipe circumferential direction.

According to a seventh aspect of the present invention, there is provided a method for cleaning the inner surface of a pipe (invention 7), wherein the pipe is immersed obliquely in the cleaning liquid in the axial direction in the vicinity of the pipe end at a high position, in a direction in which the cleaning liquid does not flow into the pipe. The flow of the cleaning liquid is generated, the cleaning liquid is sucked into the pipe from the other end on the low position side, and the pipe is simultaneously moved in the circumferential direction around the pipe axis by 180 °.
This is a method for cleaning the inner surface of a pipe, characterized in that the pipe is rotated at a degree or more.

According to an eighth aspect of the present invention, there is provided a method for cleaning an inner surface of a pipe (invention 8), wherein a flow of the cleaning liquid is generated near one end of the pipe immersed in the cleaning liquid in a direction away from the pipe end, and the flow of the cleaning liquid is started from the other end. The cleaning method for cleaning the inner surface of a pipe according to inventions 6 to 7, characterized in that the cleaning liquid is sucked into the pipe.

According to a ninth aspect of the present invention, there is provided a method for cleaning the inner surface of a pipe (invention 9), wherein a flow of the cleaning liquid is generated in an ascending or descending direction near one end of the pipe immersed in the cleaning liquid, and the other end of the pipe is cleaned. The cleaning method for cleaning the inner surface of a pipe according to inventions 6 to 7, characterized in that the cleaning liquid is sucked into the pipe.

The pipe to be used in the present invention is a pipe whose inner surface needs to be cleaned, and its material and inner diameter are not particularly limited. That is, for example, a steel pipe for a so-called lining steel pipe in which a vinyl chloride pipe, a polyethylene pipe, or the like is laminated and lined on the inner surface thereof is used as an example. The tube may be a single tube or a bundle of a plurality of tubes.

In the present invention, the dirt adhering to the inner surface of the tube is quickly washed and removed, and the cleaning liquid is caused to flow in the tube when the inner surface of the tube is washed in order to discharge the removed deposits from the inner surface of the tube. At that time, a complicated pipe is not required in the washing tank for flowing the washing liquid, and the capacity of the washing tank is not easily increased.

That is, when a fluid flows, the pressure of a portion where the flow speed is high is smaller than that of a portion where the flow speed is low. Therefore, a pressure gradient occurs in which the pressure decreases from the side with the slower flow velocity to the faster side, and if there is an object in between, the object receives a force along the pressure gradient. A flow occurs in the fluid.

In the present invention, by causing a flow of the cleaning liquid near one end of the pipe immersed in the cleaning liquid in a direction in which the cleaning liquid does not flow into the pipe, a pressure difference is generated between the other end of the pipe and the other end. Accordingly, the cleaning liquid flows from one end where the cleaning liquid is not flowing to the one end where the cleaning liquid is flowing.

In order to generate a flow of the cleaning liquid near one end of the pipe, for example, a so-called air lift pump is provided at a location corresponding to the pipe end on the bottom of the washing tank, and a so-called air lift pump is provided to blow out air therefrom. Only the upward flow of the washing liquid can be obtained. Since the cleaning liquid flowing upward flows downward from the entire surface of the other cleaning tank, its descending speed is lower than the speed of upward flow. That is, in the vicinity of the other end of the pipe, the flow rate of the cleaning liquid is low, and the cleaning liquid in the pipe flows from the pipe end toward the pipe end on the side where the upward flow of the cleaning liquid is present.

In order to generate an upward flow, in addition to the above, an opening of a cleaning liquid circulation pipe is provided at the bottom of the cleaning tank, and the cleaning liquid is jetted upward from the bottom of the cleaning tank by a normal pump. In some cases, a method is used.

Accordingly, dirt such as oils and fats adhering to the inner surface of the pipe is constantly exposed to fresh cleaning liquid to be cleaned and removed, and since the cleaning liquid is flowing through the inner surface of the pipe, the debris washed and removed is It is quickly discharged from the inner surface of the pipe along with the flow.

When the pipe is arranged obliquely along the pipe axis direction and generates an upward flow of the cleaning liquid near the end of the pipe located above, the flow of the cleaning liquid in the pipe flows upward from below.
The washing becomes more reliable, and the adhered material that has been washed away is discharged out of the tube more quickly.

When the flow direction of the cleaning liquid is away from the pipe along the pipe axis, the pressure at the pipe end is lower than that at the other end, so that the flow velocity of the cleaning liquid flowing in the pipe is higher. As a result, the effect of washing and removing deposits on the inner surface of the tube is further improved. However, in this case, a pipe for guiding the flow of the cleaning liquid may be provided so that the flow direction of the cleaning liquid is along the pipe axis direction. However, no special pipe is required for this purpose. That is, for example, the opening of the cleaning liquid circulation pipe by the pump described above is provided laterally along the pipe axis,
It is possible only by attaching a baffle for controlling the flow direction of the air lift pump above the pipe.

Also, the pipe is immersed while being inclined in the pipe axis direction,
In addition, when the flow of the cleaning liquid is generated in the vicinity of the pipe end located above, a synergistic effect of the effect of the inclination and the flow of the liquid generated on the inner surface of the pipe further increases the effect of cleaning and removing the deposits attached to the inner surface of the pipe.

By rotating the immersed tube around the tube axis in the circumferential direction, it is possible to prevent deposits washed and removed from accumulating in the upper portion of the tube. The angle of rotation of the pipe should be such that the washed and removed deposits accumulated in the upper part of the pipe move relatively and move to another place in the pipe. It is desirable that the rotation of the tube be 180 degrees or more. By doing so, the washed and removed deposits in the tube do not remain at one location in the upper portion of the tube, so that the washing and removing effect is performed evenly.

As an example of the method of rotating the tube, for example, when immersing the tube, wrap a belt around the outer periphery of the tube or bundle of tubes, place one end of the belt above the cleaning liquid, and pull one end of the belt after immersing the tube. For example, a method such as rotating a pipe may be adopted. The material of the belt is not particularly limited as long as it is not eroded by the cleaning liquid, supports the steel pipe, has strength, and is hardly stretched. For example, an alkaline solution as a cleaning solution,
An acid solution, an organic solvent solution, a surfactant solution or the like is used. The belt is made of a material corresponding to an individual cleaning solution, such as a stretched thermoplastic synthetic resin, a fiber-reinforced thermoplastic synthetic resin, or the like. Is most preferably used.

When the pipe is immersed in the cleaning liquid obliquely in the axial direction of the pipe, and when the pipe is rotated, the adhered substance which has been washed and removed is more quickly discharged to the outside of the pipe so that the cleaning unevenness does not remain.
Further, when the flow of the cleaning liquid is generated in the vicinity of one end of the pipe, the flow of the cleaning liquid is generated in the pipe, and the effect of cleaning and removing the deposits is further increased. The flow direction of the cleaning liquid may be either a direction away from the tube along the tube axis, or an upward direction or a downward direction near the tube end. The method of causing a flow in the cleaning liquid is as described above, and will not be described again.

(Operation) As described above, a flow is generated in the cleaning liquid, and the flow rate of the cleaning liquid is changed between the vicinity of one pipe end and the vicinity of the other pipe end of the immersed pipe, whereby the cleaning liquid flows into the pipe. A flow is generated, the cleaning effect is exhibited, and the adhered material that has been cleaned and removed is quickly discharged out of the tube. Also,
By tilting or rotating the tube, the cleaning effect on the inner surface of the tube is further increased. Moreover, in order to generate the flow of the cleaning liquid, it is only necessary to provide the air jet port or the cleaning liquid jet port on the bottom of the cleaning tank, so that there is no need to provide a pipe in the cleaning tank.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Next, as an example, a case where an inner surface of a steel pipe is cleaned with a cleaning liquid will be described in detail with reference to the drawings. In FIG. 1, an air jet port 3 is provided below the vicinity of one pipe end 21 of a steel pipe bundle in which a steel pipe 2 immersed in a washing tank 1 is bound by a tying string 4, and compressed air 31 is introduced into the washing tank 1. It is gushing. The cleaning liquid 11 moves upward by the air lift effect of air, and the upward flow F1 of the cleaning liquid 11 is generated. Of course, a cleaning liquid jet port may be provided on the bottom surface of the cleaning tank 1 and the cleaning liquid 11 may be jetted upward from the jet port into the cleaning tank 1 by a pump to obtain an upward flow (not shown).

In the vicinity of the other one of the pipe ends 22, the cleaning liquid 11 hardly flows or flows slowly, and therefore, the cleaning liquid 11 flows between the pipe ends 21 and 22.
And a flow of the cleaning liquid 11 in the direction of arrow D is generated inside all the steel pipes 2. Therefore, the new cleaning liquid 11 constantly flows on the inner surfaces of all the steel pipes 2, and the deposits such as oils and fats adhering to the inner surfaces of the steel pipes 2 are well washed and removed, and are quickly taken out of the pipes along with the flow D of the cleaning liquid. Is discharged.

FIG. 2 shows a case where the steel pipe bundle is immersed obliquely in the pipe axis direction to generate an upward flow F1 of the cleaning liquid 11 near the pipe end 21 located above. As in FIG. 1,
In all the steel pipes 2, a flow D of the cleaning liquid 11 is generated from the lower pipe end 22 to the upper pipe end 21. The speed of the cleaning liquid 11 is reduced by the oblique arrangement of the pipe in FIG. Therefore, the effect of washing and removing is larger, and the adhered material that has been washed and removed is discharged out of the steel pipe 2 more quickly.

FIG. 3 shows a state in which a steel pipe bundle is immersed diagonally, a cleaning liquid jet 111 is provided on the side of the immersed steel pipe bundle, and the cleaning liquid jet 111 is provided near the pipe end 21 located above. Washing liquid 1 in the direction away from the pipe along the pipe axis direction
FIG. 4 is an explanatory diagram when a flow F2 of 1 is generated. As compared with the case in FIG. 2, the speed of the flow D of the cleaning liquid 11 in the steel pipe 2 is further increased, and the cleaning and removing effect is further increased.
The removed deposit is quickly discharged out of the steel pipe 2.

FIG. 4 shows a case where a flow F1 of the cleaning liquid 11 is generated in the vicinity of a pipe end 21 located above a steel pipe bundle in which a drawn polyethylene tape is wound around a rotating belt 5 and is immersed diagonally. is there. After immersing the steel pipe bundle, the steel pipe 2 is rotated by generating one flow F1 of the cleaning liquid 11 and generating one flow D of the cleaning liquid 11 in the steel pipe 2 while pulling one end of the rotating belt 5. Therefore, the effect of cleaning and removing the deposits on the inner surface of the steel pipe 2 is further enhanced as compared with the case in FIG. 3, and the deposits washed and removed are quickly discharged out of the steel pipe 2.

In the case of other combinations in which the bundle of steel pipes is immersed diagonally and the cleaning liquid 11 is caused to flow at one end of the steel pipe 2 or the flow of the cleaning liquid is generated while rotating the steel pipe 2, It is a combination of each case described,
And the mechanism of action for washing and removing the deposits is the same,
In particular, they are shown in the drawings and will not be described.

[0037]

As described above, according to the method for cleaning the inner surface of a pipe according to the present invention, the inner surface of a steel pipe can be reduced without greatly increasing the volume of the cleaning tank and without installing complicated piping in the cleaning tank. Can be uniformly washed, and the removed deposits can be quickly discharged from the inner surface of the pipe.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a case where a flow is generated in a cleaning liquid near one end of a immersed tube.

FIG. 2 is an explanatory diagram in a case where a flow is generated in a cleaning liquid near one end located above a tube that is immersed diagonally.

FIG. 3 is an explanatory view of a case in which a cleaning liquid near the one end located above a pipe that is immersed diagonally flows in a direction away from the pipe along the pipe axis direction.

FIG. 4 is an explanatory view showing a case where a flow is generated in a cleaning liquid near one end located above a pipe in which a rotating belt is wound and immersed diagonally.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning tank 11 Cleaning liquid 111 Cleaning liquid spout 2 Steel pipe 21 One end of steel pipe 22 The other end of steel pipe 3 Compressed air 31 Compressed air spout 4 Binding strap 5 Belt for rotation D Flow direction of cleaning liquid

Claims (9)

[Claims] 1. A method for cleaning the inner surface of a pipe, comprising: generating a flow of a cleaning liquid in a direction in which the cleaning liquid does not flow into the pipe near one end of the pipe immersed in the cleaning liquid; and sucking the cleaning liquid into the pipe from the other end. . 2. A flow of the cleaning liquid in a direction in which the cleaning liquid does not flow into the pipe near the high-end pipe end of the pipe diagonally immersed in the cleaning liquid in the axial direction, and the cleaning liquid flows into the pipe from the other end on the low position. A method for cleaning the inner surface of a tube, comprising inhaling. 3. The tube according to claim 1, wherein a flow is generated near one end of the pipe immersed in the cleaning liquid in a direction away from the pipe end, and the cleaning liquid is sucked into the pipe from the other end. Inner surface cleaning method. 4. The cleaning liquid according to claim 1, wherein a flow of the cleaning liquid is generated in an ascending or descending direction near one end of the pipe immersed in the cleaning liquid, and the cleaning liquid is sucked into the pipe from the other end. How to clean the inside of the tube. 5. A method for cleaning the inner surface of a pipe, comprising immersing the pipe in a cleaning liquid and rotating the pipe by 180 ° or more around the pipe axis in the circumferential direction of the pipe. 6. A flow of the cleaning liquid in a direction in which the cleaning liquid does not flow into the pipe near one end of the pipe immersed in the cleaning liquid,
A method for cleaning the inner surface of a tube, wherein a cleaning liquid is sucked into the tube from the other end, and at the same time, the tube is rotated 180 degrees or more around the tube axis in the circumferential direction of the tube. 7. A flow of the cleaning liquid in a direction in which the cleaning liquid does not flow into the pipe near the high-end pipe end of the pipe diagonally immersed in the cleaning liquid in the axial direction, and the cleaning liquid flows into the pipe from the other end on the low position. Inhale, and at the same time, move the pipe 180
A method for cleaning the inner surface of a pipe, characterized in that the pipe is rotated more than one degree. 8. The pipe according to claim 6, wherein a flow of the cleaning liquid is generated near one end of the pipe immersed in the cleaning liquid in a direction away from the pipe end, and the cleaning liquid is sucked into the pipe from the other end. Inner surface cleaning method. 9. The cleaning liquid according to claim 6, wherein a flow of the cleaning liquid is generated in an ascending or descending direction near one end of the pipe immersed in the cleaning liquid, and the cleaning liquid is sucked into the pipe from the other end. How to clean the inside of the tube.