JPH0729085B2 - How to detect the end of resin lining on a branch pipe - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention is directed to an existing pipeline in a form in which a supply pipeline (branch pipeline) leading to a demand destination is branched from a pipeline pipeline laid under a road such as a gas pipeline or a water pipeline. The present invention relates to a method of detecting the lining completion time point for the entire length of a branch pipe when repairing the lining from the end side to the conduit path side.

[Prior art]

In general, existing pipes laid underground such as gas pipes and water pipes may leak due to corrosion holes and loosening of joints over the years. After laying, at the required time, the existing pipe is repaired by applying resin lining to the inner surface of the pipe in the installed condition. As this repairing method, as described in JP-A-63-65983, liquid resin is introduced into the pipe from one end side of the existing pipe to fill the pipe, and a pressure difference is generated in the pipe. A method has been proposed in which a resin plug is caused to flow by lining the inner surface of the pipe with a required thickness of film. In this prior art, a launcher is connected to one end of an existing open pipe, a resin for lining is filled from a resin tank connected to the launcher to form a resin plug in the launcher, and this is connected to the free end side of the launcher. It is supplied into the existing pipe by low-pressure gas supplied from. When the resin plug flows through the existing pipe, the inner surface of the pipe is lined, and when the resin is consumed due to the progress of the lining and blowout occurs, the resin is again filled from the resin tank into the launcher. The resin plug thus prepared is again supplied into the existing pipe by the low pressure body. By repeating such an injection work, the lining repair by the resin is performed on the entire inner surface of the existing pipe over a predetermined length.

[Problems to be Solved by the Invention]

In the case of the above-mentioned repair, for the supply pipe (branch pipe) branched from the conduit line laid under the road, when repairing the lining from the end side of the branch pipe to the conduit line side,
The problem here is that the length of the branch pipe communicating with the conduit may be unknown, and it is not possible to confirm at which point the lining repair for the entire length of the branch pipe has been completed. The present invention addresses the above-mentioned problem, focusing on the point that the internal pressure in the pipe sharply drops when the resin plug that advances in the pipe is consumed by the progress of the lining and causes blow-through, and An object of the present invention is to provide a method for detecting the end of resin lining of a branch pipe, which can detect whether or not the repair is completed based on the time to blow through and the pressure predicted by calculation in advance.

[Means for Solving the Problems]

The present invention, on the premise of achieving the above object, injects liquid resin in a plug shape so as to fill the inside of the pipe from the end opening of the branch pipe branched from the conduit line, and causes a pressure difference in the pipe before and after the resin plug. In the lining repair method for the inner surface of the pipe, which is constructed so that the resin plug progresses a certain distance and the resin plug progresses the required distance and blows through to accumulate the number of injections and sequentially extend the lining formation section. At the end opening side of the pipe, there is a control unit for controlling the opening of the flow rate adjusting valve etc. to calculate and maintain the resin flow rate so that the required lining can be achieved based on the predetermined lining conditions. Then, the control unit predicts the point in time when the resin plug blows through each time the injection is performed, and detects the pressure gauge of the control unit. When the drop in pipe pressure occurs What is, when shorter than the prediction time, is characterized in determining that the resin lining against the branch pipe to the construction has been completed.

[Action]

According to such a detection method, when the pressure in the pipe drops in a time shorter than the time of the blow-through expected by the control unit, the resin plug is opened from the branch pipe to the opening (branch port) of the pipe at that time. Since it can be determined that the length of the branch pipe is unknown, it is possible to accurately detect the lining completion time for the entire length of the branch pipe. As a result, it is not necessary to provide an excavation opening or the like for detecting the arrival of the lining at the connection between the branch pipe and the conduit (under the road), which can improve workability and at the same time generate unlined parts in the branch pipe. In addition, it also becomes possible to eliminate inconveniences such as the resin flowing into the conduit.

【Example】

An embodiment of the present invention will be specifically described below with reference to the drawings. In the figure, reference numeral 1 is a resin supply device used in the repairing method of the present invention, and 2 is a low-pressure gas used when flowing the lining resin supplied from the resin supply device 1 to the repaired portion of the existing pipe with a low-gas gas. It is a supply device. The resin supply device 1 includes a resin injector 3, a supply pipe 4 that communicates with the bottom of the resin injector 3, and a launcher 6 that communicates with the supply pipe 4 via an electromagnetic opening valve 5. When the electromagnetic release valve 5 is opened, the lining resin in the resin injector 3 is supplied to and filled in the launcher 6 to form the resin plug E. The resin injector 3 is provided with a plunger 3a, and pressurized gas such as pressurized air is supplied to the top by means such as described later so that the resin can be extruded. There is. The lining resin with which the launcher 6 is filled is, for example, a room temperature two-liquid curing type resin prepared by mixing a main agent and a curing agent, and of these, the main agent is an unsaturated polyester resin, vinyl ester resin, epoxy resin, urethane resin, or the like. Is a composition mainly composed of a pigment, a thixotropic agent or the like is added to improve the thixotropy (for example, 250,000 to 30).
TI value is 6) at 0,000 cps. On the other hand, the low-pressure gas supply device 2 has a compressor 7, an air tank 8, flow rate adjusting valves 9 and 10, and a gas supply pipe 11 connected to the end of the launcher 6 to which an electromagnetic release valve 12 is attached. Flowmeters 13 and 14 and pressure gauges 15 and 16 are provided corresponding to the valves 9 and 10. If necessary, the three-way switching valve 1
7 is provided on the outlet side of the compressor 7 so that the pressurized gas can be branched to the pipe line 18, and is connected to the top of the resin injector 3 through the pipe line 18 and the flow rate adjusting valve 19. There is. The low pressure gas supply device 2 is provided with a control unit 20 which receives output information from the flowmeters 13 and 14 and pressure gauges 15 and 16 and performs calculation according to a required program to adjust and control the flow rate adjusting valves 9 and 10. It is provided. In the control unit 20, the amount of resin filled in the launcher 6 is calculated from the opening degree of the flow rate adjusting valve 19 and the opening time of the electromagnetic opening / closing valve 5 and stored in the memory, and the opening time of the electromagnetic opening / closing valve 5 is calculated. From the output information of the flowmeters 13 and 14 and the pressure gauges 15 and 16 of each moment, the resin flow velocity V for achieving the resin lining with the predetermined film thickness is calculated, and this velocity is maintained. It functions to control the opening of the flow control valves 9 and 10. On the other hand, the existing pipe to be repaired by the lining according to the present invention is a service pipe (branch B) that is branched from a conduit line A called a true sound or branch pipe buried underground under the road and drawn into a customer. Pipe), and the end of the service pipe B is projected to the ground and connected to the meters. And the lining repair is performed first on the service pipe B and then on the conduit line A. Prior to this, preparations for the following repairs will be made. That is, the conduit A is divided into repair sections of a predetermined length and both ends thereof are opened, so that pits C and D as shown in FIG. Open by cutting. Further, for the service pipe B communicating with the conduit A, the meters are removed and the ground end is opened. Then, pressurized air is passed through the conduit A and the supply pipe B to remove dust inside. Then, first, the launcher 6 is connected to the open end of the supply pipe B, the electromagnetic opening / closing valve 5 is opened, and the lining resin is supplied and filled into the launcher 6 by the pressurized gas from the resin injector 3, and the resin plug is inserted. To form. Then, the electromagnetic on-off valve 5 is closed, and the low-pressure gas whose pressure is adjusted by opening the electromagnetic on-off valve 12 is supplied to the resin plug through the launcher 6, is made to flow, and is sent to the service pipe B. A lining film having a predetermined thickness is formed on the inner surface of the pipe. At this time, in the control unit 20, the opening degree of the resin flow adjusting valves 9 and 10 is adjusted. In this case, the calculation basis of the control unit 20 depends on the following formula. First, assuming that the quantity Q _{1 of} low-pressure gas flowing into the service pipe B and the pressure P ₁ (for example, 0.6 kg / cm ² ) are π / 4 · D ² · l ₁ · P ₁ = Q ₁ · P _O … Because of the relationship of (1), if Q ₁ , P _O , and P ₁ are measured at the time T _{1 when the} resin plug is started to be fed by the low-pressure gas, then l ₁ can be known from the equation (1). The quantity Q _{1 of} gas flowing into the service pipe B is the measured values F ₁ and F _{2 of the} flowmeters 13 and 14, respectively.
It is obtained by the difference of. In this case, if a mass flowmeter is used for the flowmeters 13 and 14, there is no influence of the temperature of the gas, and therefore calculation is easy. Here, l ₁ is the position of the resin plug at time T ₁ , P _O and P ₁ are the measured values of the pressure gauges 15 and 16, and D is the inner diameter of the lining of the service pipe B. Similarly, if the position of the resin plug obtained by measuring and calculating the pressure P ₂ and the inflow amount Q ₂ at time T ₂ is l ₂ , the flow velocity V of the resin plug is V = Δl / Δt Become. However, Δl = l ₂ −l ₁ Δt = T ₂ −T ₁ . Therefore, the predetermined time interval Δt is set to the control unit 20.
Set with the clock of the internal oscillator, and each time, the flowmeter 13,1
The flow control valves 9 and 10 are controlled so that the amount of inflowing gas flowing into the pipe from 4 and the respective pressures from the pressure gauges 15 and 16 are measured, and the instantaneous resin flow velocity V is maintained at a constant predetermined value. To do. In the inner pipe B, the length of the resin plug is consumed by the lining on the inner surface of the pipe, but decreases, but since the flow velocity is constant, the pressure of the pressing gas drops substantially linearly (fourth).
See figure). If the resin of the resin plug is consumed before the resin lining on the inner surface of the inner pipe B is completed over the entire length of the pipe, the length of the resin plug gradually becomes shorter, and at the same time, a pressing force for keeping the resin flow velocity constant. The pressure of the gas also decreases substantially linearly, and when the resin plug length becomes 0, the gas blows through and the pressure becomes atmospheric pressure. The inflow amount Q of the pressurized gas up to this time, the length l to the position where the resin lining is finished, the elapsed time t _O, etc. are stored in the memory, and the electromagnetic opening / closing valve 12 is closed. Meanwhile control unit
At 20, when it is detected that the pressure has dropped to atmospheric pressure, the electromagnetic on-off valves 5 and 12 are opened, and the next lining resin is supplied from the resin injector 3 into the launcher 6 and filled to form a predetermined amount of resin plug. To do. Then, the electromagnetic on-off valves 5 and 19 are closed, the electromagnetic on-off valve 12 is opened, and the inner pipe B is lined again while controlling the speed V of the resin plug as before. At this time, the film thickness of the lining in the pipe does not change while the lining resin plug moves at a predetermined speed V in the previously lined pipe, therefore the length of the resin plug does not decrease and the pressure of the pressing gas does not change. It is maintained at a substantially constant value. However, after the resin plug reaches the position of the pipe B which is not yet lined, the lining is extended from here and the resin is consumed, the length of the resin plug is reduced, and the pressure of the pressing gas is gradually reduced. The progress of lining is the same as described above. In this case, the length of the resin plug becomes approximately 0, and the pressure of the pressing gas again becomes atmospheric pressure, but the elapsed time up to this point is approximately 2t _O , and the length to the end position of the lining is approximately 2l. In this manner, the lining length is sequentially extended while repeating the lining by filling and advancing the resin. When the lining of the supply pipe B is completed and the resin plug reaches the connecting portion (branch port) with the conduit A while the length of the resin plug still remains, the resin plug flows into the conduit A and the flow resistance is sharply increased. Therefore, the pressing force controlled by the control unit 20 also sharply decreases to atmospheric pressure. Also, the elapsed time until the pressing force drops to atmospheric pressure is scheduled (n ×
(n-1) t + t '(where t'<t), which is shorter than t) (see FIG. 4). That is, it is determined that the resin plug has reached the inside of the conduit from the sudden decrease in the pressing force and the difference between the elapsed time and the predicted elapsed time, and the lining repair for the entire length of the service pipe B is completed. In this way, it can be determined that the repair lining of the service pipe B has been completed, but if the resin injection and the lining with the pressure gas are performed again, the time required to reach the conduit is the same as the previous time ( n-1) t + t '. Thus, the arrival of the resin plug in the conduit path can be determined by the fact that the repair lining time is the same for each time. In this way, the resin lining for the service pipes B is sequentially performed, and then an appropriate resin invasion preventive measure is taken for each service pipe B, and then, as shown in FIG. By connecting the launchers 6 having the same diameter, the resin lining on the inner surface of the pipe is realized as in the case of the service pipe B. In the figure, reference numeral 21 is a receiver connected to the opposite end of the conduit A, and 22 is a receiver tank for the residual resin discharged to the receiver 21 at the resin lining end stage.

EFFECTS OF THE INVENTION The present invention has been described in detail above, and if a pressure drop in the pipe occurs in a time shorter than the time of blow-through expected by the control unit, at that time, the resin plug is transferred from the branch pipe to the conduit pipe. Since it can be determined that the opening (branch opening) of the road has been reached, even when the length of the branch pipe is unknown, it is possible to accurately detect the lining completion time for the entire length of the branch pipe. As a result, it is not necessary to provide an excavation opening or the like for detecting the arrival of the lining at the connection between the branch pipe and the conduit (under the road), which can improve workability and at the same time generate unlined parts in the branch pipe. In addition, it also becomes possible to eliminate inconveniences such as the resin flowing into the conduit.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram showing a condition of an existing pipe to be repaired, FIG. 3 is an explanatory diagram showing a resin lining condition of a service pipe, and FIG. FIG. 5 is a time chart showing the repeated state of the resin lining, and FIG. 5 is an explanatory diagram showing the resin lining state of the conduit. 1 ... Resin supply device, 2 ... Low-pressure gas supply device, 5 ... Electromagnetic on-off valve, 6 ... Launcher, 7 ... Compressor, 8 ... Air tank, 9,10 ... Flow control valve, 12 ... Electromagnetic on-off valve, 13, 14 ... Flow rate Total, 15, 16 ... Pressure gauge, 20 ... Control unit.

Claims (1)

[Claims] 1. A liquid resin is injected in a plug shape from an end opening of a branch pipe branched from a conduit line so as to fill the pipe, and a pressure difference is generated in the pipe before and after the resin plug to advance the resin plug. Then, when the resin plug progresses a required distance and causes blow-through, in the lining repairing method of the inner surface of the pipe, which is constructed so as to accumulate the number of injections and sequentially extend the lining formation section, in advance on the end opening side of the branch pipe, It has a control unit for controlling the opening of the flow rate adjusting valve, etc. to calculate and maintain the resin flow rate so that the required lining can be achieved based on the defined lining conditions. When the time when the resin plug blows through is predicted by calculation, and when the pressure in the pipe decreases due to the detection of the pressure gauge provided in the control unit When shorter than the prediction time, plastic lined end detection method of the branch pipe, characterized in that to determine that the resin lining has been completed with respect to the branch pipe for construction.