JP2889527B2 - Polishing method for the inner surface of existing piping - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION

[0001] The present invention relates to an existing pipe which is used to supply water to each household, and the inside of which has a poor flow due to scale or rust bumps, or an old pipe whose water becomes turbid due to rust. The present invention relates to a polishing method for rehabilitation.

[0002]

2. Description of the Related Art In this kind of pipe rehabilitation, the inside of the pipe is polished and then lining with a predetermined paint. As a means for the polishing, an appropriate sandy abrasive is used. Is sent from the end of the pipe together with the swirling air flow to pass through the inside, and the abrasive collides with rust bumps and scales in the pipe, and these are crushed, removed and polished. I have.

[0003] In particular, as a technique for polishing by reciprocating an abrasive, a technique disclosed in Japanese Patent Application Laid-Open No. Sho 60-177869 is known as a conventional example. The polishing method of this conventional example is to supply a swirling air flow from one end of a pipe to be polished, throw an abrasive into the air flow and pass it to the other end to polish the outward path, Next, the air flow and the abrasive are supplied from the other end side to polish the return path.

This prior art is characterized in that a swirling air flow is used and that the polishing material is continuously supplied for a predetermined time until the polishing of one block is completed. is there.

[0005] As shown in Fig. 6A, rust bumps and the like generated in a pipe are formed by a portion formed by a hard component a and a portion formed by a soft component b. It is often formed of a so-called composite structure. Then, when a granular abrasive is caused to collide with the composite structure by an air flow, first, as shown in FIG.
The portion of the soft component b is scraped off, and the portion of the hard component a remains in a protruding state.

Since the hard component a remains in a protruding state, it is easily broken by an abrasive.
(C) As shown in FIG.
Level. Thus, the soft component b
The complex structure such as rust bumps is removed by successively and repeatedly performing the removal of the hard component a.

The use of the swirling airflow has the effect of blowing off the abrasive material toward the wall surface at the start end, so that the polishing effect at the start end is strong. Therefore,
A connecting portion such as an elbow near the starting end including the straight portion on the starting end has a problem that it is excessively polished and easily broken.

[0008] Further, since the abrasive is continuously fed, when reciprocating polishing is performed, as described above, if rust bumps or the like composed of a composite structure are to be entirely removed, it takes a relatively long time. The abrasive must continue to be supplied through the pipe, causing an overpolishing phenomenon over the entire length of the pipe, especially at the start end of the return path, where the abrasive passes many times and There is a problem in that the abrasive material is blown off, resulting in overpolishing and a non-averaged polishing as a whole.

Further, the swirling air flow can maintain the swirling flow for a predetermined length on the start end side, but after that, the swirling flow cannot be maintained and becomes turbulent, and the abrasive is continuously charged. The density of the abrasive in the air flow is high, and the abrasives collide with each other, consuming energy at the start end side, and consequently, at a joint portion such as an elbow located at the farthest part of the return path, There is a problem that the polishing power is reduced and sufficient polishing cannot be performed.

[0010]

SUMMARY OF THE INVENTION As a specific means for solving the problems of the prior art, the present invention relates to an existing pipe having a plurality of branch pipes branched from one end of each branch pipe with reference to one end. Are set as one section, and for each section
An existing pipe characterized by detecting a situation in a pipe , reciprocating an air flow having a pressure set according to the situation, and performing reciprocating polishing by intermittently supplying an abrasive to the air flow a plurality of times. The present invention provides an inner surface polishing method, in which after the forward polishing for each section is completed, the backward polishing is performed for each section; the pressure of the air flow for the backward polishing is set higher than that for the forward polishing. And polishing the abrasive by forming a collective floating flow in the abrasive.

[0011] The existing pipe is divided into a plurality of sections, and an abrasive is intermittently charged into an air stream of a set pressure to perform polishing, and reciprocating polishing is performed. Polishing can be performed well, and polishing in a substantially complete state from the start end to the end can be expected.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a first embodiment of the present invention. In Figure 1, 1 is shows the entire existing piping substantially expressly, the existing pipe via a joint such as the elbow or Chisu more branch pipes 1a, 1b, 1c,
.. Are branched and connected, and change their directions to stand up. A discharge member such as a faucet is generally attached to an end of each branch pipe. M is an end to which the meter is attached.

[0013] When reproducing the existing piping, after removal of the discharge member of each branch pipe, joint及 beauty branch pipe 1a, 1
The inside of the existing pipe 1 including b, 1c,... is removed in advance by appropriate cleaning means to remove rust and scales, and the inside is dried and cleaned, and the inside is lined with a predetermined paint. Is what you do.

In this way, in the polishing means for rehabilitating the existing pipe 1, that is, in the step of polishing the inside of the pipe, the polishing is sequentially performed from the branch pipe near the base end side (end M to which the meter is attached) of the pipe. In this case, the operation is performed in a state where the branch pipes are divided for each branch pipe.
To the meter mounting end M, the first section A, and the branch pipe 1
The section from b to the meter mounting end M is a second section B, the section from the branch pipe 1c to the meter mounting end M is a third section C, and the section from the branch pipe 1d to the meter mounting end M is a fourth section D. It is divided and polished sequentially for each divided section.

Prior to the polishing, the internal state of the existing pipe 1 is detected by a predetermined detecting means. For example,
Air of a predetermined pressure may be blown into the existing pipe, and the air resistance may be detected to grasp the state of the rust bumps formed inside. This detection detects not only the entire inside of the pipe but also the state of each section. This detection means is disclosed in Japanese Patent Application No. 7-36 filed by the same applicant.
No. 667 also includes the means described in the specification.

Therefore, the initial flow velocity and pressure of the air flow are set in accordance with the state of the inside of the pipe detected by appropriate means, for example, so that the inside of the pipe is not blocked by the supplied abrasive. In this case, the initial flow velocity in the air flow is approximately 80 m
/ Sec to a pressure of about 3.0 kg.

The granular (crushed stone) or sand-like abrasive to be supplied for polishing is intermittently performed at predetermined intervals, not continuously. That is, a predetermined amount of abrasive is intermittently supplied to the continuously supplied air flow after a predetermined time.

In this case, when the end of the pipe 1 is open, the flow rate of the air supplied to the inside of the pipe 1 is higher at the end than at the start. When a predetermined amount of the abrasive 2 is supplied to such an air flow, as shown in FIG. 2, the mass initially forms a mass floating flow, which is a mass having a high density, and the mass flows. As it flows to the terminal end, it gradually spreads and forms a low-density collective floating flow.

Therefore, at the initial stage of the supply of the abrasive 2, that is, at the start end side, the abrasive 2 has a high density, so that the abrasive 2 may collide with each other and the polishing power is low. Then, since the density of the abrasive material 2 becomes lower and the flow velocity becomes faster toward the end portion, the polishing force is improved, and the end portion side is more efficiently polished than the start end portion.

First, section A in FIG. 1 is polished. In this polishing, a small amount of abrasive was applied several times from the end to the end M to which the meter was attached (2 to 3).
Preliminary charging is performed intermittently over the same period), and the passing state of the abrasive in the section A is determined. The determination of the passing state is made based on a change in the gauge pressure.

That is, as shown in the graph of FIG. 3, first, the gauge pressure is set to 3.0 kg by adjusting the opening of the main valve for generating the air flow in accordance with the internal condition before polishing. When a predetermined amount of the first abrasive is introduced while observing the gauge pressure, the gauge pressure immediately increases. When the supply of the abrasive is stopped when the pressure reaches about 3.5 kg when this rise is observed, the gauge pressure gradually decreases and falls below the initial set value, that is, 3.0 kg. This phenomenon indicates that the inside of the pipe is polished to improve the flow of the air flow.

When the flow of the air flow is improved, the gauge pressure falls below the set value of 3.0 kg to about 2.7 to 2.8 kg. Therefore, the second polishing material is supplied. With this addition, the gauge pressure also gradually increases, and when the supply of the abrasive is stopped when the visual pressure reaches approximately 3.5 kg, as in the previous case, the gauge pressure gradually decreases so as to be lower than the previous time. Thus, it can be confirmed that polishing is further advanced.

The same procedure is followed for the third to fifth polishing materials to finish the forward polishing in the section A.
In this case, the input amount of the abrasive 2 is larger in the second time than in the first time, and is gradually increased in the third time and the fourth time.

The number of times the abrasive is supplied in the outward path of one section is set to about five times in advance, but the number of times is not limited to this and can be arbitrarily selected, such as four or six times. The point is that the primary polishing should be limited to a degree that does not cause overpolishing and that the internal state can be grasped and recorded as temporary data. In the same manner, the forward polishing in the sections B to D is sequentially performed, and the internal state is grasped by the forward polishing for each section and recorded as data.

Further, depending on the state or section of the piping, an abnormal state may occur. For example, as shown in FIG. 4, there is a case where a phenomenon occurs in which the gauge pressure is abnormally reduced after the second polishing material is charged and polishing is performed. It is determined that such a phenomenon is due to abnormal internal polishing or the condition of the pipe (pipe diameter), and the supply pressure of the air flow, that is, the main valve is adjusted to reduce the internal pressure to 3.0.
Change the setting to kg.

The reason is that the abrasive must be supplied for a relatively long time in order to increase the gauge pressure to 3.5 kg, which is a reference of the supply amount, by the third supply of the abrasive. This is because the amount of the abrasive supplied is abnormally large, and an overpolishing phenomenon occurs on the terminal end side.

When the internal pressure is reset from the initial set value, the supply amount of the air substantially increases. However, when the abrasive is injected into the air flow, the gauge pressure quickly becomes 3.5 kg, which is a standard. And normal polishing work can be performed. Even in such a case, the situation of the corresponding section is recorded as data so as to be useful for the work at the time of secondary polishing.

In particular, in the first polishing, first, FIG.
As described with reference to (C), the soft component b, which is a composite structure, is scraped off, and the hard component b remains protruding,
The hard component a is in a state where it is easily broken by an external force, and is broken and removed by the collision of the abrasive 2, and the scale and rust bumps are polished and removed by repeating this. It has been recognized that the hard component a of the composite structure cannot be removed without a relatively strong impact.

After the primary polishing of each of the sections A to D is performed as described above, the secondary polishing, that is, the finish polishing is performed from the opposite direction. In this case, the polishing is performed sequentially from the mounting end M side of the meter toward the ends of the branch pipes 1a to 1d. According to the experiment, it is possible to perform polishing of about 70% or more by the primary polishing.

Since the secondary polishing is a finish polishing,
The portion that cannot be completely polished by the primary polishing is polished. To do so, we learned in the primary polishing work,
Alternatively, the set value of the gauge pressure is determined by setting the supply amount of the air flow for each section based on the contents recorded as data. The gauge pressure in this case is 3.0 k as in the case of the primary polishing.
g may be used, but since the composite structure remains and the finish polishing is performed, it is understood that a better result can be obtained by slightly increasing the set value than the primary polishing.

That is, as shown in FIG. 5, the gauge pressure is set to 3.5 kg, and the main valve for air supply is adjusted for each section. Then, as in the case of the primary polishing,
When the abrasive is supplied for the second time, the supply of the abrasive is stopped when the gauge pressure rises to 4.0 kg.

When the supply of the abrasive is stopped, the internal resistance is reduced by the amount that the inside of the pipe is polished, the air flow is improved, and the gauge pressure falls below the set value. The degree of this reduction depends on the internal polishing state of the primary polishing. For example, in the first supply of the abrasive, it drops to about 3.1 kg, and in the second supply, it drops to about 3.0 kg, and after the third supply, it does not drop below 3.0 kg, that is, to a certain level. If it is confirmed that the polishing has been completed, it indicates that the polishing has been performed almost completely, and the finish polishing is completed. After the polishing, air blowing is performed for a predetermined time (in some cases, the intensity may be increased) in order to completely remove the internal abrasive.

In any case, in the present invention, reciprocating polishing is performed, but most of the polishing is completed by the primary polishing in the outward path, the internal polishing state is grasped, and the final polishing is performed by the secondary polishing in the return path. Is performed,
In the reciprocating polishing, the air flow into which the abrasive was injected was set to a predetermined pressure for each section, and the abrasive was intermittently injected to form a collective floating flow, and polishing was performed by the collective floating flow. Therefore, polishing is efficiently performed from the start end to the end.

[0034]

As described above, the method for polishing the inner surface of an existing pipe according to the present invention provides a method for polishing an existing pipe in which a plurality of branches are branched from one end to the end of each branch. Each section is set as one section, and
Detecting and reciprocatingly flowing an air flow having a pressure set according to the situation, and performing reciprocating polishing by intermittently supplying abrasives to the air flow a plurality of times, thereby fixing a fixed air flow.
Compared to the method of continuously supplying abrasives by airflow, overpolishing at the start end side can be prevented, collision between abrasives is reduced, energy loss is reduced, and polishing is efficiently performed with a small amount of abrasives It has an excellent effect that it can be done.

Also, the intermittently supplied abrasives form collective floating flows, and the density of each collective floating flow becomes coarser from the starting end side to the end side, and the speed increases to increase the polishing efficiency. Therefore, there is an excellent effect that the polishing can be uniformly performed from the start end to the end.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of an existing pipe to which a polishing method according to the present invention can be applied.

FIG. 2 is an explanatory diagram showing a state of a starting end side, an intermediate part, and an end side of an intermittently supplied abrasive.

FIG. 3 is a graph showing a relationship between intermittent supply of abrasive in an outward path and polishing in the polishing method according to the present invention.

FIG. 4 is a graph showing a situation in which pressure is reset when an abnormal state occurs in the polishing method, and a relationship between intermittent supply of abrasive and polishing.

FIG. 5 is a graph showing a relationship between intermittent supply of abrasive and polishing in the backward polishing in the same polishing method.

FIG. 6 is an explanatory view showing a removal state of a scale or a rust bump generated in a pipe by polishing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Existing piping 1a-1d Branch pipe 2 Abrasive material-End of branch pipe A-D Sectioned section M Mounting end of meter

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-60-177869 (JP, A) JP-A-61-33864 (JP, A) JP-A-1-317577 (JP, A) JP-A 61-338577 25774 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B24C 3/16 B24C 1/00

Claims (4)

(57) [Claims] In an existing pipe in which a plurality of branch pipes are branched, one section is set up to one end of each branch pipe as one section, and an in-pipe situation is detected for each section.
A method for polishing an inner surface of an existing pipe, wherein reciprocating polishing is performed by reciprocating an air flow having a pressure set according to the situation and intermittently supplying an abrasive to the air flow a plurality of times. . 2. The method for polishing the inner surface of an existing pipe according to claim 1, wherein after the forward polishing for each section is completed, the backward polishing for each section is performed. 3. The method for polishing the inner surface of an existing pipe according to claim 1, wherein the pressure of the airflow in the backward polishing is set higher than that in the forward polishing. 4. The method for polishing an inner surface of an existing pipe according to claim 1, wherein the polishing is performed by forming a collective floating flow in the abrasive.