JP2700328B2 - Repair method for lining of pipe inner surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to existing pipes such as gas pipes and water pipes laid underground, and in particular, to existing pipes referred to as main pipes or branch pipes, on the inner surface of the pipes, uniform resin lining as laid. It relates to a lining repair method for the inner surface of a pipe to be applied.

[Prior art]

Generally, existing pipes laid underground, such as gas pipes and water pipes, are likely to leak due to corrosion holes and loosened joints due to aging. Therefore, at a required time after the construction, the existing pipe is repaired by resin lining on the inner surface of the pipe in the laid state. Therefore, as described in JP-A-63-65983, a liquid resin is filled into a pipe at one end of an existing pipe in a plug shape, and the resin group is moved by a required pressurized gas, and the inner surface of the pipe is moved. A lining repair method for the inner surface of the pipe to provide the required lining thickness was proposed. Here, a launcher is connected to one end of an existing pipe that has been opened, and a resin tank is filled with a resin for lining from a resin tank connected to the launcher to form a resin group in the launcher. The supplied pressurized air is supplied into the existing piping. Then, the resin group flows under the pressure of the pressurized air in the existing pipe, and when the lining resin on the inner surface of the pipe is consumed, the resin is again filled into the launcher from the resin tank, and the resin group is formed in the launcher. Then, the air is supplied again into the existing piping with pressurized air. By repeating such operations, the inner surface of the existing pipe is repaired for a predetermined length.

[Problems to be solved by the invention]

The problem here is that compressed air is generated using a compressor or the like, and this is used to flow the resin group in the existing piping. This may remain in the pipe and become mixed in the gas when the gas supply is restarted, causing a danger such as an explosion. For this reason, before the gas supply after the lining, it may be necessary to perform a scavenging operation such as replacing air in an existing pipe including the branch pipe with an inert gas. However, even if such measures are taken, if there is an unknown pipe etc. in the branch pipe, air will remain there, and after the gas supply is resumed, the gas mixed with air will be May be supplied, which is inconvenient. The present invention has been made based on the above circumstances.When repairing the lining, the supply gas in the existing pipes and the branch pipes in the repair section thereof is all inert gas such as nitrogen, and even if there are unknown pipes or the like. Another object of the present invention is to provide a method for repairing a lining of a pipe inner surface, which can avoid inconveniences due to air mixing such as explosion when restarting gas supply.

[Means for Solving the Problems]

For this reason, in the present invention, both ends of the existing pipe in the repair section are opened, a plug-like liquid resin group is filled in the pipe, and a required pressurized gas is supplied from one side of the resin group to remove the resin group. In the lining repair method for the inner surface of the pipe, in which the inner surface of the pipe is lined to the required thickness in the process of moving, an inert gas of a required pressure is supplied from the open end of the branch pipe to the branch pipe from the existing pipe to be lined. Further, an inert gas is used as a pressurized gas for flowing the resin group in the existing pipe.

[Action]

Therefore, there is no air from the existing pipe into the branch pipe during the lining repair, and therefore, even if gas is supplied without a procedure such as scavenging after the lining is completed, danger such as explosion can be completely avoided. Further, when a cylinder is used, the size and weight can be reduced as compared with the case where a compressor is used, so that the lining work can be realized without any trouble even in a small work space, and there is no noise as in the case of using a compressor. Furthermore, since the inert gas is used as the pressurized gas, the measured value of the flow meter in the control system is not affected by the humidity as in the case of the compressed air, so that the control accuracy in the lining can be maintained high.

【Example】

Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings. In the drawing, reference numeral 1 denotes a resin supply device used in the repairing method of the present invention, and 2 denotes a lining resin supplied by the resin supply device 1 to a repairing portion of an existing pipe by a pressurized gas (for example, a gas such as nitrogen gas). (Active gas). The resin supply device 1 includes a resin injector 3, a supply pipe 4 communicating with the bottom of the resin injector 3, and a launcher 6 communicating with the supply pipe 4 via an electromagnetic on-off valve 5. When the electromagnetic on-off valve 5 is open, the lining resin in the resin injector 3 is supplied to and charged into the launcher 6 to form a resin group E in the launcher 6. The resin injector 3 is provided with a plunger 3a,
A pressurized gas (nitrogen gas) is supplied to the top by means described later so that the resin can be extruded. The lining resin to be filled in the launcher 6 is, for example, a room-temperature two-component curing resin prepared by mixing a main component and a curing agent, and the main component is an unsaturated polyester resin, vinyl ester resin, epoxy resin, urethane resin, or the like. And a thixotropy (eg, 250,000 to 3
The TI value is 6) at 00,000 cps. On the other hand, the pressurized gas supply device 2 includes a nitrogen gas cylinder 7,
A cock 8, a three-way switching valve 9, a flow control valve 10, and a gas supply pipe 11 connected to the end of the launcher 6 having an electromagnetic on-off valve 12 attached thereto. It has 14,15 in total. If necessary, a pipe 16 communicating with the outlet side of the nitrogen gas cylinder 7 through the three-way switching valve 9 is provided so that a pressurized gas (nitrogen gas) can be branched to the pipe 16. The resin can be supplied to the top of the resin injector 3 via the flow control valve 17. In response to the output information from the flow meter 13, pressure gauges 14, 15,
A control unit 18 that performs calculations according to a required program and controls the flow rate control valve 10 is provided in the pressurized gas supply device 2. The control unit 18 calculates the amount of resin charged into the launcher 6 from the opening adjustment of the flow control valve 17 and the opening time of the electromagnetic on-off valve 5 and stores the calculated amount in the memory. From the output information of the flow meter 13 and the pressure gauges 14 and 15 from time to time, a resin flow velocity V for achieving a resin lining with a predetermined film thickness is calculated, and the flow rate adjusting valve 10 is maintained so as to be maintained. It functions to control the opening of the motor. On the other hand, the existing piping to be repaired in the lining in the present invention is a branch pipe A (or main pipe) buried underground and a pipe B having one end protruding above the ground and connected to meters and the like. It branches off from the branch pipe A. The lining repair is first performed on the inner pipe B and then on the branch pipe A. Prior to this, the following preparations are made for repair. That is, the branch pipe A is divided into repair sections of a predetermined length,
In order to open both ends, shafts C and D as shown in FIG. 2 are formed at corresponding locations, and the ends of the branch pipe A are opened by cutting. Further, the service pipe B communicating with the branch pipe A
For, remove the meters and open the ground end. Then, pressurized air is passed through the branch pipe A and the service pipe B to remove dust inside. Then, first, the launcher 6 is connected to the open end of the service pipe B, the electromagnetic on-off valve 5 is opened, and the pressurized gas is branched to the pipe 16 via the three-way switching valve 9, and the flow control valve is opened. A pressing force is applied at a flow rate controlled by 17 to supply and fill the lining resin into the launcher 6 from the resin injector 3 to form a resin group. Then, when the electromagnetic on-off valve 6 is closed and the electromagnetic on-off valve 12 is opened, the pressurized gas (nitrogen gas) regulated by the flow control valve 10 is supplied to the resin group through the launcher 6 and flows therethrough. Then, the lining film is sent to the service pipe B, and a lining film having a predetermined thickness is formed on the inner surface of the pipe. At this time, the control unit 18 first supplies a pressurized gas (nitrogen gas) into the launcher 6 to give a required resin transport speed v by the thixotropic property of the resin group.
In order to realize the lining of the specified thickness,
The pressure Po is set based on the pipe inner diameter, lining film thickness, and the initial viscous resistance (resin length lo) of the resin group. Then, the flow rate until the inside of the launcher 6 is filled with the pressurized gas (nitrogen gas) and the resin group is introduced into the internal pipe B is measured by the flow meter 13, and the integrated value Qo is calculated. Then, the value of the pressure gauge 15 is measured so that the pressure at that time becomes Po, and the flow rate control valve 10 is feedback-controlled. From the time when the integrated value of the pressurized gas becomes Qo (the pressure of the pressurized gas in the launcher 6 is Po), the control unit 18 starts lining with the internal pipe B to maintain the resin at a constant speed V. In consideration of the amount of consumption per unit time (expressed in resin length) dl, from the pressure Po, the pressure is decreased by ΔP over time, and the amount of change ΔQ is added to the flow rate Qo by calculation. Then, the flow meter 13 and the pressure gauge 15 are checked so as to match the values, and thereby the flow control valve 10 is feedback-controlled. In this case, the elapsed time t and the pressure P (= Po−ΔP · t)
Is as shown in FIG. If the resin of the resin group is consumed before the resin lining on the inner surface of the service tube B is completed over the entire length of the tube, the pressurized gas that has pressed the resin group at that time blows through the service tube B. Then, the pressure drops to the atmospheric pressure of the branch pipe A.
Since such a change in pressure occurs rapidly, the control unit 18 checks the pressure and determines that the current resin lining has been completed, and determines the flow rate of the gas supplied to the service pipe B up to this time. Q, the length l to the position where the resin lining is completed, the elapsed time to, and the like are stored in the memory, and the electromagnetic on-off valve 12 is closed. Next, the control unit 18
Then, open the solenoid on-off valve 5 and the flow control valve 17 and set the resin injector 3
Then, a lining resin is supplied and filled into the launcher 6 to form a predetermined amount of resin group in the launcher 6. Then, the electromagnetic on-off valve 5 and the flow control valve 17 are closed, the electromagnetic on-off valve 12 is opened, and the internal pipe B is lined while controlling the resin group E to the speed V again as described above. At this time, while the lining resin group E passes through the previously lined area, the length of the resin group, in other words, the amount of resin does not change as long as the speed V is maintained. The pressure of the controlled pressurized gas is also maintained at a substantially constant value. Then, Resin Team E
After reaching the position where the inner pipe B has not yet been lined, the resin is consumed by the lining in the same manner as described above, and the length of the resin group E decreases. Therefore, the pressure of the pressurized gas gradually decreases. The lining is advanced. And the elapsed time until the resin group length becomes approximately 0, the pressurized gas blows through and drops to atmospheric pressure is approximately 2 to, and
The length up to the lining end position is also approximately 2 l. In this way, the filling of the resin and the pressing of the resin group by the pressurized gas successively extend the lining length while repeating the lining. When the lining of the service pipe B is completed and the resin group reaches the connection portion (branch point) with the branch pipe A while the length of the resin group still remains, the resin group E flows into the branch pipe A, and the resin group E is removed. The pressurized gas that has been pressed blows into the branch pipe A. For this reason,
The measured value of the pressure gauge 15 drops rapidly, and becomes substantially the atmospheric pressure.
This is determined by the control unit 18. This is (n-1) t + t '(where t is shorter than the expected elapsed time (n × t) (where n is the number of times of filling of the resin, and t is the length of time required to complete the lining of one resin group). '<T), it is determined whether or not the above-mentioned rapid pressure drop has occurred. That is, it is determined that the resin group has reached the inside of the branch pipe A from the sudden decrease in the pressing force and the difference between the actual elapsed time and the predicted elapsed time, and the lining repair for the corresponding internal pipe B is completed. is there. In the case of t '≒ t, there is a problem of a measurement error. Therefore, it is preferable to further fill the resin for one time and measure the time until the resin reaches the branch pipe A. This error range may be set in the control unit 18 in advance. That is, the control unit 18 issues a command for refilling the resin if it is within the error range, and outputs an end command if it is not within the error range. When lining the branch pipe A later, if the amount of resin remaining in the branch pipe A is unknown, the resin group length in the lining process of the branch pipe A changes. Before the lining of the branch pipe A, the resin group is removed at the branching point (connection point with the service pipe B in the branch pipe A). May be calculated by the control unit 18 so as to correct the length of the resin group to which the residual resin amount has been added when. After the resin lining of the service pipe B is sequentially performed in this manner, a receiver 21 composed of a transparent tube or the like is connected to the open end of the service pipe B as shown in FIG. A cylinder 23 of an inert gas such as nitrogen gas is connected to the receiver 21 via a flow control valve 22, a throttle valve 24 is connected to a branch 21a of the receiver 21, and a pressure gauge 25 and a flow meter 26 will be provided. In this state, as shown in FIG. 6, the launcher 6 of the same size is connected to the branch pipe A, and the resin lining of the inner surface of the pipe is realized in the same manner as in the case of the service pipe B. At this time, the pressurized gas (nitrogen gas) is supplied from the cylinder 23 to the inside pipe B via the flow control valve 22, and the throttle valve 24 is closed. For example, if the pressure of the pressurized gas (nitrogen gas) for pressing the resin group E in the branch pipe A is 1.5 kg / cm ² , a slightly lower pressure, for example, 1.3 kg / cm ² is held in the internal pipe B. I do. In this case, as described above, the pressure of the pressurized gas pressing the resin group E in the branch pipe A gradually decreases when the resin is consumed for the lining and the resin group length is shortened.
Based on this information, the flow control valve 22 may be adjusted by the control unit 18 so as to control the pressure difference to be maintained at, for example, 0.2 kg / cm ² . As a result, when the resin group E reaches the connection point between the branch pipe A and the internal pipe B in the lining process of the branch pipe A as shown in FIG. Penetrates tube B. At this time, the pressurized gas (nitrogen gas) in the serving pipe B is compressed by the intruding resin E ', and the pressure increases (equivalent to the pressure of the pressurized gas (nitrogen gas) for pressing the branch pipe A side). This is detected by the pressure gauge 25 and the control unit
Analysis is performed at 18, a command is issued, and the flow control valve 22 is closed. For this reason, the resin is consumed for the lining in the branch pipe A, and the penetrating resin is held in the service pipe B until the resin group disappears and the pressurized gas blows through (No. 8).
When the blow-through, the pressure in the branch pipe A drops to the atmospheric pressure when the blow-through, the intruding resin enters the branch pipe A into the service pipe B.
It is discharged at the pressure of the gas (nitrogen gas) on the side and is left (see FIG. 9). The control unit 18 calculates the amount of resin that has entered the serving pipe B from the gas pressure difference at that time, the inner diameter of the serving pipe B, and the like, and after that, after passing through a connection point (branch portion) with the serving pipe B. And the speed V of the resin group is kept constant. When the penetrating resin is discharged from the service pipe B into the branch pipe A, the control unit 18 detects the decrease in the support pressure of the pressure gauge 25, opens the flow control valve 22 again, and pressurizes the cylinder 23. The gas is supplied into the service pipe B at a required pressure. For this reason, the branch pipe A is filled with the next resin group, and the corresponding service pipe B is filled.
When passing through the connection point with the
The length of the resin group in the branch pipe A does not change in the process of sending the resin group to the unlined area by the pressurized gas (nitrogen gas). In this way, the filling of the resin into the branch pipe A and the press lining by the pressurized gas (nitrogen gas) are repeatedly executed,
The lining operation is continued until the lining resin group is finally discharged to the receiver 27 provided at the other end of the branch pipe A. Then, when the lining resin group reaches the receiver 27, the resin is received in the receiver tank 28, and the pressurized gas blows out and drops to the atmospheric pressure. Is detected. Finally, a required amount of resin group is supplied and filled into the branch pipe A, and when the resin group is pressed with a pressurized gas, the resin finally enters the serving pipe B in a fixed amount as described above. At this time, the control unit 18 detects the resin intrusion into the service pipe B by the pressure gauge 25 and closes the flow control valve 22, and when a predetermined time has elapsed, that is, in the branch pipe A, the resin group E After passing through the connection point with the corresponding service pipe B, the throttle valve 24 is controlled to be opened at a predetermined opening. As a result, the pressurized gas (nitrogen gas) on the open end side of the serving pipe B is gradually released into the atmosphere through the throttle valve 24, and the intruding resin is pushed by the pressurized gas in the branch pipe A. In this process, the gas passes through the service pipe B and is consumed as a lining layer in this process or is pressed as it reaches the receiver 21. In this process, the flow meter 26 measures the discharge amount of the pressurized gas, and the control unit 18 determines the inflow amount of the pressurized gas (nitrogen gas) supplied to the branch pipe A side in consideration of the discharge amount. to correct. The throttle valve 24 is closed when the intruding resin reaches the receiver 21 or when the pressurized gas (nitrogen gas) on the side of the branch pipe A blows into the receiver 21 (when the intruding resin is consumed as a lining layer). . In this way, after the penetrating resin in the service pipe B which is successively connected to the branch pipe A is disposed, the resin group which has passed through the branch pipe A is discharged to the receiver 27, thereby completing the finishing lining. (See Figure 10). In the above embodiment, at the time of the finish lining of the branch pipe A, a relief valve 29 is provided at the open end of the service pipe B as shown in FIG. The resin that has invaded at this time may be moved inside the service pipe B at a required speed by the pressurized gas supplied to the branch pipe A and the degree of restriction of the relief valve 29 and sent to the receiver 21. Further, the receiver 21 may be formed of a tubular body instead of the relief valve 29, and a small hole for squeezing may be formed in the terminal so that the function substantially equivalent to that of the relief valve 29 may be provided. As is clear from such work process, the inside pipe and branch pipe are finally filled with nitrogen gas. Therefore, the next time the gas is supplied and the gas supply is restored, the explosion occurs. There is no danger at all.

【The invention's effect】

As described in detail above of the present invention, since an inert gas such as nitrogen gas is used as a pressurized gas for resin pressing used at the time of resin lining in an existing pipe, air remains in the existing pipe in a work process. Since the gas is completely replaced by an inert gas such as nitrogen gas, it is possible to start the gas restoration work without performing the pre-treatment with the inert gas after the work is completed. Even when the pipe is in the repair section, disasters such as an explosion due to air mixing can be prevented before restarting gas supply. Also,
In this way, when using an inert gas, unlike the case where compressed air is used as a pressurized gas, the cylinder is not brought into the work site, and the cylinder is brought into a narrow work site unlike the case where compressed air is used as the pressurized gas. Is easy. Further, since the compressor is not used, there is no noise, there is no influence of humidity on the flow meter, the quality is constant, and high accuracy can be secured in controlling the pressurized gas by computer control.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, FIG. 2 is an explanatory diagram showing the condition of an existing pipe to be repaired, and FIG. 3 is a resin lining situation of a service pipe. FIG. 4 is a time chart showing the repetition state of the resin lining, FIG. 5 is an explanatory view showing a means for preventing intrusion resin at the open end of the service pipe,
FIG. 6 is an explanatory view showing the situation of resin lining of a branch pipe, and FIG.
FIG. 8 is an explanatory view showing a situation when the resin group reaches the branch to the service pipe in the branch pipe, FIG. 8 is an explanatory view showing a situation after the resin group has passed through the branch, FIG. Is an explanatory view showing the situation when the pressurized gas blows through the branch pipe, FIG. 10 is an explanatory view showing the situation at the time of the finish lining, and FIG. 11 is a countermeasure for the resin entering the internal pipe at the stage of the finish lining It is explanatory drawing which shows another example of a means. 1 ... resin supply device, 2 ... pressurized gas supply device, 5 ...
Solenoid on-off valve, 6 ... launcher, 7 ... nitrogen gas cylinder,
8 ... cock, 9 ... 3-way switching valve, 10 ... flow control valve,
12: solenoid on-off valve, 13: flow meter, 14, 15, pressure gauge, 1
7 ... Flow control valve, 18 ... Control unit, 21 ...
... Receiver, 22 ... Flow control valve, 23 ... Cylinder, 24 ...
Throttle valve, 25 ... Pressure gauge, 26 ... Flow meter, 29 ... Relief valve.

Claims (1)

(57) [Claims] 1. Open both ends of an existing pipe in a repair section, fill a pipe with a liquid resin group in a plug shape, and supply a required pressurized gas from one side of the resin group to move the resin group. In the lining repair method for the inner surface of the pipe, in which the required inner thickness is applied to the inner surface of the pipe in the process, an inert gas at a required pressure is supplied from the open end of the branched pipe to the branch pipe from the existing pipe to be lined. A method for repairing a lining of a pipe inner surface, wherein an inert gas is used as a pressurized gas for flowing the resin group in the existing pipe.