JP2598294B2 - Control method of resin pushing dynamic pressure in lining repair method of pipe inner surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to existing pipes such as glass pipes and water pipes laid underground, and particularly to existing pipes having a small diameter, which are called supply pipes and branch pipes, which are uniformly laid on the inner surface of the pipes. The present invention relates to a method of controlling a resin pressing force in a pipe inner surface lining repair method for repairing a lining coating film.

[Prior art]

Generally, existing pipes laid underground, such as gas pipes and water pipes, have erosion holes and loosened threads due to aging, which may cause leakage. Alternatively, repairs have been made to form a lining coating film of resin on the inner surface of the pipe in a laid state for preventive maintenance. Conventionally, as a repair method, existing pipes of small diameter
The "pig moving method" or the "gas phase method" is known, but in the above "pig moving method", the pig is caught in a change in the diameter of the pipe or a curved pipe, and cannot be distributed or repaired. In general, lining repair by the above-mentioned "gas phase method" has become mainstream because of the inconvenience of falling into the above situation.

[Problems to be solved by the invention]

However, in the case of the conventional lining method by the “gas phase method”, (1) the thickness of the coating film is almost 0.5 mm or less due to the restriction that a resin having a low viscosity (for example, 15,000 cps or less) must be used. In addition, the lining coating has a non-uniform film thickness, such as the lower surface side of the inner wall of the tube being thinner and the upper surface side being thinner. In addition to the problem that the phenomenon of extremely thinning cannot be avoided, a high-viscosity resin is conveyed into a pipe in a repair section having a predetermined length in order to increase the film thickness and make the thickness as uniform as possible. In
Generally, a large amount of air and a high-speed airflow are required.
Since the pressure air of ² kg / cm ² or more is required, the equipment (such as a compressor) becomes large, which increases the equipment cost. In addition, the equipment cannot be carried in some work places and repair work cannot be performed. However, there were also problems such as the occurrence of noise and loud noise, which significantly deteriorated the working environment in residential areas. (2) Also, due to the pressure air of ² kg / cm ² or more added to the inside of the pipe, for example, when a pinhole-shaped corrosion hole is formed in the pipe, a blow-through phenomenon occurs outside the pipe from the corrosion hole. , Not only is it impossible to reliably fill the corrosive holes,
There was also a problem that the corrosion hole was further enlarged and the pipe was damaged. (3) On the other hand, as in the lining repair method proposed by the present inventors, a launcher having a control device is connected to the filling end of the filling resin, and the filling is connected to the other exit side. A receiver equipped with a pressure gauge and a flow meter for detecting the discharge side pipe pressure and the amount of discharged air that changes as the resin flows in the pipe is connected, and the signal that detects the discharge pipe pressure and the discharged air amount is used to detect the lining resin in the pipe. There is a lining repair method for the inner surface of the pipe that keeps the flow speed of the lining resin constant, but in this way, the flow speed of the resin can be increased to maintain the flow speed of the lining resin at a certain speed. Therefore, there has been a problem that the working efficiency cannot be improved.

[Means for Solving the Problems]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for controlling a resin pressing dynamic pressure in a new pipe lining repairing method proposed to solve the above-mentioned problems. The repair method is as follows: (a) Fill the resin in a liquid state into the pipe on one end side of the existing pipe from the opening to fill and close the inside of the pipe line for a required length, and allow the filled resin to flow,
In the lining repair method for the inner surface of the tube, which forms the required film thickness on the inner surface of the tube based on the relevant conditions such as the tube diameter, resin viscosity, and the length of the filled resin, (b) Connecting a launcher having a control device for controlling the gas flow rate and pressure of the pumping gas; (c) controlling the flow rate and pressure of the pushing gas introduced into the pipe in at least two stages; Control the moving speed of the resin group in the pipe in two stages, high speed and low speed. (D) To apply resin lining to the inner surface of the pipe, first move the resin group at high speed to perform primary lining, and then in the pipe after primary lining. The resin lining is moved at a low speed for secondary lining.

[Action]

In such a repair method, the moving speed of the filling resin is divided into two stages of high speed and low speed to perform primary and secondary lining, so that the film thickness of the lining resin is thick and constant, and moreover, efficient and uniform resin lining is performed. be able to.

【Example】

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, FIG. 1 schematically shows an embodiment of a repair method according to the present invention, and reference numeral 1 denotes an existing pipe to be repaired. The existing pipe 1 is an existing pipe such as a gas pipe or a water pipe laid underground or inside a building. In particular, the existing pipe 1 to be repaired by the present invention is used.
In general, gas pipes are intended for supply pipes having a diameter of about 15 to 32 mm, and existing pipes having a relatively small diameter, which are called branch pipes having a diameter of about 40 to 100 mm. The existing pipe 1 is divided into a repair section of a predetermined length during repair, and a launcher 2 having a predetermined length is connected to an opening of one end thereof via a flange 3. A resin injector 4 is connected to the launcher 2 via an electromagnetic opening / closing valve 5 serving as a resin supply means, and a liquid lining resin A is supplied from the resin injector 4 so as to fill and close the inside of the pipeline over a required length. Is introduced into the launcher 2. Here, as the lining resin A, a resin having a thixotropic property, which is a room-temperature two-component curable resin prepared by mixing a main agent and a curing agent, is used. The above resin injector 4
The resin in which the main agent and the curing agent are mixed in advance may be supplied under pressure by an air pressurized injector.Also, while the main agent and the curing agent are supplied by separate pumps (not shown), both are supplied by a static mixer in the process. You may make it provide mixed. The launcher 2 is provided with an electromagnetic opening / closing valve 7 which operates in the opposite direction in conjunction with the electromagnetic opening / closing valve 5 of the resin injector 4, and a flow regulating valve 11 and a flow control valve 11 which are arithmetically controlled by an arithmetic unit 6 ′. A small compressor 12 is connected via a control device 6 including a flow meter 9 for measuring the gas flow rate thereof, and pressure gauges 8 and 10 for measuring the gas supply pressure. The compressed air is flow-controlled by the control device 6, introduced into the launcher 2, and sent into the existing pipe 1. In this embodiment, the flow rate and the flow rate of the compressed air fed into the existing pipe 1 are controlled at least in two stages. Move to primary lining, then put resin A in the primary lined tube
Is moved at low speed for secondary lining. Further, the compressed air from the compressor 12 is introduced into the launcher 2 through a three-way switching valve 13 controlled by the control device 6, and is also introduced into the resin injector 4 through a flow control valve 14, The lining resin A is liquefied at a constant pressure from a solenoid on-off valve 5 that is opened via a pressure sliding plate 15 provided in the resin injector 4 in conjunction with an electromagnetic on-off valve 7 controlled by a control device 6. A predetermined amount of material is extruded and filled into the launcher 2 as it is. Next, the work process of the repair work by the above-described device will be described. First, the electromagnetic on-off valve 7 is closed, and the electromagnetic on-off valve 5 is opened to inject resin into the launcher 2 connected to the opening on the starting end side of the existing pipe 1. A predetermined amount of the lining resin A is poured from the vessel 4 while keeping the liquid state. The injection of the resin A is based on the fact that the lining resin A
Is filled over a predetermined length so as to fill and close the inside of the pipeline. Next, when the filling of the resin A is completed, the electromagnetic on-off valve 5 is closed, and the electromagnetic on-off valve 7 on the side of the air blowing system is opened to supply the compressed air from the compressor 12 to the three-way switching valve 13 to switch the flow regulating valve 11 and It is controlled so that it is fed into the pipe from the end of the launcher 2 through the flow meter 9. As a result, the compressed air acts to press the rear end face of the filling resin A from behind, the fluidity is given to the lining resin A by the pressing force of the static pressure, and the lining resin A is launched in a columnar state. From the inside 2, it flows as an aggregate in the existing pipe 1. At this time, the compression pressing force applied to the resin A is approximately 1.5 kg / cm ^{2 with} respect to the atmospheric pressure.
The flow speed of the resin A is considerably increased, and the resin A is moved at a high speed. Due to the progress of the flow of the resin A, the resin A proceeds while remaining on the inner surface of the tube due to the adhesive force to the wall surface when flowing and in contact with the inner surface of the tube. Lining coating of required thickness on pipe inner surface
18 are formed uniformly. Here, when the traveling speed V of the resin A is kept constant and the resin viscosity is changed, the end surface shape of the resin becomes a shell shape as shown in FIG. In addition, the higher the viscosity, the thinner the vertical end face shape as shown in FIG. When the resin pressing force a is increased and the traveling speed of the resin A is increased when the resin viscosity is kept constant, the end face of the resin has a shell shape as shown in FIG. When the traveling speed is reduced by lowering the pressing force a, the end face shape of the resin becomes the vertical end face shape shown in FIG. 3, and the film thickness becomes thin. In other words, in the relationship between the resin viscosity and the traveling speed V, the resin A has a shape such that the end face of the resin has a shell shape as shown in FIG.
Is caused to flow into a thick film, and the third
Resin A so as to have a near vertical end face shape as shown in the figure
It has been experimentally and theoretically confirmed that the film is formed into a thin film when flowing through. Therefore, in the repair method according to the present invention, first, the thickness of the lining coating film to be formed on the inner surface of the existing existing pipe 1 is selected to be formed, and the thickness is selected. Based on the repair-related conditions such as the pipe diameter of the pipe to be repaired, the viscosity of the resin used, and the length of the filled resin, the high and low flow rates of the resin A required to form a desired film thickness are set. Among the set flow speeds, the compressed air supplied from the compressor 12 is controlled by the control device 6 so that the lining resin A flows first in the pipe at a high speed and then the resin A flows in the primary-lined pipe at a low speed.
To apply the required static pressure to the rear end face of the filling resin A. In this case, the resin A used is a thixotropic resin as described above. When an external force is applied to this kind of resin, its paint structure is destroyed and causes a softening phenomenon.
When the external force is removed, the resin A has the property of recovering to its original state over time. Therefore, the pressing force of the resin A is approximately 1.5 kg / cm ² in the primary lining, and approximately 0.6 kg / cm ^{2 in the} secondary lining.
Set the pressure to about the following and move sufficiently. In the case of such a pressure setting, in the primary lining, since the resin A moves at a high speed, there may be a portion where the film thickness of the lining coating film 18 is slightly inconsistent. Even if a blow-through phenomenon occurs from a corrosion hole of the deteriorated existing pipe 1 in the primary lining due to a thick film, this can be surely repaired. In addition, the resin A flows in the pipe due to the above pressing force, and the formation of the lining coating film progresses. When the flow amount of the resin A decreases due to the formation of the coating film, the pressing force is attenuated according to the decrease in the resin amount. Then, the controller 6 and the flow control valves 11 and 16 control the amount of air flowing into the pipe so that the flow speed of the lining resin A is constant. That is, when the resin group moves in the pipe and the amount of resin decreases, the flow rate of the resin A tends to increase accordingly. This flow rate is controlled by the flow rate of the pushing gas introduced into the existing pipe 1. The pressure changes in relation to the pressure, and the pressure in the pipe is determined by the amount of the pushing gas flowing into the pipe and the position of the resin group, that is, the volume on the rear side of the resin group. Measure the amount of pushing gas
, And by measuring the pressure in the pipe at each point in time when the amount of gas in the pipe is measured, the arithmetic unit 6 'calculates the velocity of the resin group from the change in the volume of the gas in the pipe, that is, the change in the position of the resin. be able to. As a result, the flow control valve 11 (R ₁ ) and the flow control valve 16 ( R ₂₎
Is controlled so that the pressing force of the resin A is automatically attenuated so that the flow speed of the resin group becomes constant as the amount of resin decreases. Hereinafter, a control device 6 for keeping the flow rate of the resin A constant
The operation of will be described in detail. First, the amount Q _{1 of the} pushing gas flowing into the pipe, the pressure P ₁ inside the pipe
If, because of the relationship of ^{π / 4 · d 2 · l} 1 · P 1 = Q 1 · P 0 ...... (1), by measuring the Q _1, P _0, P ₁ at a certain time T ₁ , (1), l ₁ can be known. The push gas Q ₁ that has flowed into the tube, which is the difference between the measured value F ₂ by the measurement value F ₁ and the flow meter 17 by the flow meter 9. It is convenient to use a mass flow meter for the flow meters 9 and 17, since there is no influence of the gas temperature. Here, l ₁ is the resin position at time T ₁ , P ₀ is the measured value of the pressure gauge 10, P ₁ is the measured value of the pressure gauge 8, and d is the inner diameter of the lining in the existing pipe 1. Next, to detect the resin flow velocity, a certain time (t
The air supply is stopped for only 2 seconds, and the pressure change P ₁ → P ₂ in the pipe is measured by the pressure gauge 8. If the resin position at this time is l ₂ , then l ₁ · P ₁ = l ₂ · P ₂ , it is possible to know the resin position l ₂ of a time t seconds after knowing P _2. Therefore, the resin flow velocity V is V = l ₂ −l ₁ / t. Further, without stopping the supply of air, if continued constant inflow of the state, inflow of the pressing gas in a certain time T _2,
Q _2, to measure the pressure P ₂ in the ^{tube, π / 4 · d 2 ·} l 2 · P 2 = from _{Q 2 · P 0 l 2 =} Q 2 · P 0 / π / 4 · d 2 · P 2 becomes , And the resin flow velocity V is V = l ₂ −l ₁ / T ₂ −T ₁ . In this way, the flow rate adjusting valve 11 (R ₁ ) is controlled by the arithmetic unit 6 ′ and the control unit 6 so that the resin flow velocity V becomes constant.
The flow control valve 16 (R ₂ ) is controlled. Thus, the lining resin A is filled from the predetermined length of the launcher 2 connected to the injection-side pipe end of the existing pipe 1 so as to fill and close the predetermined length of the pipe in a liquid state. The pushing gas pressure to be applied is measured every predetermined time, and the resin position obtained by measuring the mass flow rate of the pushing gas and the pressure inside the pipe such that the flow velocity in the pipe is fast during the primary lining and slow during the secondary lining. The amount of the pushing gas in the pipe is controlled so that the resin velocity calculated from the difference in the resin position is constant, and the lining coating film 18 having a required thickness uniform over the entire length of the existing pipe 1 is provided on the inner surface of the existing pipe 1. Is formed. On the other hand, in the repair work according to the present invention, there is also a restriction on the amount of resin A filled (introduced) in the pipe, which can obtain a predetermined resin flow velocity by the pressing force, and the length of the coating film formed by the amount of the filled resin for one time. However, when the length of the existing pipe 1 to be repaired is long, the filling of the resin A according to the length,
The number of times of the flow is repeated a plurality of times to perform the divisional construction, whereby the length of the repair section can be increased or extended as desired. Also, by restricting the filling amount of the resin in the pipe to a predetermined amount, the pushing gas pressure of the resin can be suppressed to a low pressure, thereby causing blow-through even when the repair pipe has a corrosion hole or the like. Good lining can be achieved without any problem. In the repair work according to the present invention, if there is a large corrosion hole in the existing pipe 1 or a branch pipe whose valve is not closed is connected, immediately after the resin group passes, the pushing gas May blow out therefrom, causing a rapid decrease in the pressing force, and the flow of the resin A may not further proceed. In this case, since the flow rate of the blow-by gas per hour is detected and detected by the pressure gauge 8 and the flow meter 9 in the control device 6, the flow rate is added to maintain the pushing speed of the resin group. It has become. That is, when the pushing gas blow-through occurs, the corrected flow rate calculated from the flow rate of the pushing gas before blow-through and the flow rate of the blow-through gas per time immediately mapped is applied to the pushing gas after blow-through. In addition to returning to the original pushing speed, the flow of the resin is started again and the pressing force of the static pressure is maintained so as to keep the flow speed of the lining resin constant in response to the decrease in the amount of resin moving in the pipe. It can be controlled.

【The invention's effect】

As described above, in the lining repair method according to the present invention, the resin group is moved at a constant speed by connecting the launcher provided with the control device for controlling the gas flow rate of the pumping gas to the injection-side pipe end of the existing pipe. The primary lining that allows the resin A introduced into the pipe to flow at a high speed and the secondary lining that moves at a low speed can be performed at the resin injection end side of the existing pipe. Correspondingly, the flow rate of the lining resin is kept constant, and the lining is formed so that a coating film on the inner surface of the pipe is formed by the residual resin when the resin flows, so that the following effects are obtained. (1) First, the primary lining is performed by controlling the inflow amount and pressure of the pushing gas introduced into the pipe so that the flow velocity of the lining resin flowing in the pipe is high, and then the flow velocity of the resin is low. By secondary lining,
Even if there is some unevenness in the lining film thickness due to the primary lining, it can be surely made uniform by the secondary lining. In addition, the film thickness increases with two linings,
Since the primary lining is performed at high speed, the working time can be reduced. (2) Next, when the resin is caused to flow by the pressing force of the static pressure,
Since the flow rate of the resin and the viscosity of the resin can be freely controlled, after the resin is given fluidity by the thixotropy of the resin, the resin undergoes a softening phenomenon and a small pressing force (low pressure). In addition, since the gas flows with a small amount of air, it is possible to prevent the phenomenon of blow-through from the corrosive holes as seen in the conventional gas phase method. The blower used may be a baby compressor or a small cylinder, and the equipment can be reduced in size. (3) In addition, since a high-viscosity resin having thixotropic properties can be used as the resin to be used, the sagging phenomenon of the lining coating film can be reduced, and the pressing force for flowing the resin is evenly applied to the entire rear end face. Because of the distribution, variations in film thickness such as a thinner upper surface side and a thicker lower surface side can be eliminated, and a coating film having a uniform thickness in the circumferential direction of the tube can be formed.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing an embodiment of the repairing method according to the present invention, and FIGS. 2 and 3 show the relationship between the resin pressing force, the film thickness, and the traveling speed when the resin flows according to the present invention. It is explanatory drawing of a resin end surface shape. 1 ... existing piping, 2 ... launcher, 4 ... resin injector, 5 ... electromagnetic on-off valve, 6 ... control device, 6 '... arithmetic unit, 7 ... electromagnetic on-off valve, 8 ... pressure gauge , 9 ... Flow meter, 10 ... Pressure gauge, 11 ... Flow control valve, 12 ... Compressor, 13 ... Three-way switching valve, 14 ... Flow control valve, 15 ... Pressure sliding plate, 16 ... … Flow control valve, 17… Flow meter, 18… Lining coating.

Claims (1)

(57) [Claims] 1. A pipe at one end of an existing pipe is filled with a resin in a liquid state so as to fill and close the inside of a pipe from an opening thereof for a required length, and the filled resin is caused to flow to thereby reduce a pipe diameter. In the lining repair method for the inner surface of the tube, which forms the required film thickness on the inner surface of the tube from the relevant conditions such as the resin viscosity, the length of the filled resin, etc., the gas flow rate of the pressurized gas introduced into the tube at the tube end on the injection side of the filled resin And a launcher having a control device for controlling the pressure. The control device controls the flow rate and the pressure of the pushing gas introduced into the pipe in at least two stages to control the moving speed of the resin group in the pipe. High speed and low speed are controlled in two stages. When performing resin lining on the inner surface of the tube, the resin group is first moved at high speed to perform primary lining, and then the resin group is moved at low speed into the tube after the primary lining to perform secondary La The method of the resin pressing pressure in the tube surface lining repair method being characterized in that so as to training