JP2007245473A - Method for reclaiming existing pipe and gas supply apparatus used in reclamation of existing pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for reclaiming an existing pipe which is good in energy efficiency when heating and pressurization are carried out and prevents a reclaimed pipe from being broken in a process for enlarging the diameter of the reclaimed pipe and a gas supply apparatus. <P>SOLUTION: The gas supply apparatus 1 for enlarging the diameter of the reclaimed pipe 40 by supplying gas into the reclaimed pipe 40 inserted into the existing pipe when the inner surface of the existing pipe embedded in the ground is equipped with a hot gas generator 11, an air compressor 21, a gas mixing part 31 for mixing the hot gas produced by the hot gas generator 11 with the compressed air produced by the air compressor 21, a hot gas path 12, an air path 23, a gas discharge path 32, a hot gas supply valve 13, a hot gas path check valve 14, an air supply valve 24, and an air path check valve 25. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for rehabilitating an existing pipe buried in the ground with a rehabilitation pipe, and a gas supply device used for expanding the diameter of the rehabilitation pipe.

  Existing pipes such as sewage pipes buried in the ground are reinforced and restored by various methods when they are aged.

  As a method for rehabilitating the existing pipe, Patent Document 1 proposes a method of providing a rehabilitation pipe made of a thermoplastic resin on the inner surface of the existing pipe. The rehabilitation pipe used here is in a state of being folded so that the cross-sectional area is smaller than the inner diameter of the existing pipe, and can be restored to a cylindrical shape when heated to a predetermined temperature from that state. Has an effect.

In this rehabilitation method, first, the rehabilitation pipe in a folded state is inserted into an existing pipe, and the rehabilitation pipe is heated and pressurized to expand the diameter of the rehabilitation pipe into a cylindrical shape (hereinafter referred to as a diameter expansion process). The rehabilitation pipe is installed in close contact with the inner surface of the existing pipe. The diameter expansion process of the rehabilitation pipe is as follows. First, heated gas is supplied into the rehabilitation pipe, the rehabilitation pipe is softened while being restored to a cylindrical shape, the supply of heated gas is stopped, and then pressurized air is supplied into the rehabilitation pipe. It is done by doing.
Japanese Patent Laid-Open No. 11-230212

  However, since the pressurized air used in the above-mentioned diameter expansion process is normal temperature, if this pressurized air is supplied into the rehabilitated pipe which is in a high temperature state and is softened, the rehabilitated pipe is cooled, It gradually hardens. Therefore, in order to install the rehabilitating pipe in a state of being hardened in close contact with the existing pipe, methods such as increasing the supply time of the pressurized air or increasing the pressure of the pressurized air have been taken. . When the diameter expansion work is performed by these methods, extra energy is required to generate pressurized air, which not only increases the construction cost but also forcibly expands the rehabilitated pipe that is being hardened. Therefore, the rehabilitation pipe may be damaged.

  In consideration of the fact that the rehabilitation pipe is cooled by the supply of pressurized air, a method of preheating the rehabilitation pipe to a shape memory temperature or higher in advance with a heated gas is also performed. In this method, since the temperature of the heating gas needs to be higher than usual, extra energy is required to generate the heating gas, which increases the construction cost.

  In addition, since the steam gas generally used as the heating gas increases the pressure greatly when the temperature is raised, as described above, when the steam gas having a temperature higher than usual is supplied into the rehabilitation pipe, before being softened. There was a possibility that the rehabilitation pipe was pressurized by the high-pressure steam gas and the rehabilitation pipe was damaged.

  The present invention has been made in view of the actual circumstances, and the object thereof is to rehabilitate existing pipes that are energy efficient in heating and pressurizing in the diameter expansion process of the rehabilitation pipes and that do not cause damage to the rehabilitation pipes. It is in providing a construction method and a gas supply apparatus.

  In order to solve the above-described problem, a rehabilitation method for an existing pipe according to the present invention includes inserting a rehabilitation pipe made of a thermoplastic resin having a cross-sectional area smaller than that of the existing pipe into the existing pipe buried in the ground. By heating and pressurizing the inside to expand the diameter of the rehabilitated pipe, in the rehabilitation method for the existing pipe, the rehabilitated pipe is installed in close contact with the inner surface of the existing pipe. A mixed gas with compressed air is used.

  According to the present invention, when the diameter of the rehabilitation pipe is expanded, a mixed gas of heated gas and pressurized air is used. Therefore, the temperature of the rehabilitation pipe brought to a high temperature by the heating gas is reduced. A small amount of high-pressure mixed gas can be supplied.

  Therefore, since the rehabilitating pipe in a high temperature state is not excessively cooled, it is not necessary to perform operations such as excessive supply of pressurized gas or high temperature preheating with a heating gas, unlike the conventional case.

  As a result, the possibility of damaging the rehabilitated pipe can be eliminated, and the energy efficiency is also improved, so that the construction cost in the rehabilitation work of the existing pipe can be suppressed.

  The gas supply device of the present invention is a gas supply device that expands the diameter of the rehabilitation pipe by supplying gas into the rehabilitation pipe inserted into the existing pipe when rehabilitating the inner surface of the existing pipe buried in the ground. The heated gas generator for generating heated gas, the air compressor for generating pressurized air, the heated gas generated by the heated gas generator and the compressed air generated by the air compressor are mixed. A gas mixing section, a heating gas path provided between the gas mixing section and the heated gas generator, an air path provided between the gas mixing section and the air compressor, and the gas A gas discharge path that is provided between the mixing unit and the rehabilitation pipe and is attachable to and detachable from the rehabilitation pipe; a heating gas supply valve that is provided in the heating gas path and controls a flow rate of the heating gas; Provided in the heated gas path, and in the gas mixing section A heated gas path check valve that prevents the gas from flowing back to the heated gas generator side, an air supply valve that is provided in the air path and controls the flow rate of the pressurized air, and is provided in the air path; And an air path check valve for preventing the gas in the gas mixing part from flowing back to the air compressor side.

  According to the present invention as described above, the gas supply device can produce a mixed gas of heated gas and pressurized air at an arbitrary mixing ratio. Therefore, any one of heated gas, pressurized air, and mixed gas can be used. Can be selected and fed into the rehabilitation tube.

  Therefore, for example, after heating gas is supplied and the rehabilitation pipe is heated to a high temperature, the compressed air is gradually mixed to expand the diameter, and the heating gas, pressurized air, or mixed gas is supplied in various supply patterns. It can be easily supplied into the rehabilitation pipe.

  Accordingly, a gas supply method that does not damage the rehabilitation pipe, an energy efficient gas supply method, and the like can be performed.

  Further, since the heated gas path check valve is provided, the high-pressure gas in the gas mixing section does not flow into the heated gas generator and damage the heated gas generator.

  Further, since the air path check valve is provided, the high-pressure gas in the gas mixing section does not flow into the air compressor and damage the air compressor.

  In addition, between the air compressor and the air supply valve in the air path, the pressure between the air compressor and the air supply valve is a pressure between the heating gas generator and the heating gas supply valve in the heating gas path. A pressure adjustment valve that is automatically set to the same pressure may be provided.

  In this case, since the heated gas and pressurized air supplied to the gas mixing unit can be set to the same pressure, the gas having the lower pressure is not supplied into the gas mixing unit, and the gas mixing unit has a good gas distribution. Supply can be performed.

  Further, the gas mixing section may be provided with a safety valve that is automatically depressurized when the internal pressure becomes a predetermined pressure or higher.

  In this case, the inside of the gas mixing unit is not excessively pressurized, and there is no risk of the gas mixing unit bursting.

  Further, the gas mixing section may be provided with a relief valve capable of discharging the liquid accumulated therein.

  In this case, even if the liquid is accumulated in the gas mixing part, the liquid can be discharged, so that the gas mixing part is not cooled by the accumulated liquid, and the liquid flows into the rehabilitation pipe. Thus, the rehabilitation pipe is not cooled rapidly.

  The existing pipe rehabilitation method and gas supply apparatus of the present invention are effective in energy efficiency when heating and pressurizing in the diameter expansion process of the rehabilitation pipe, and there is no possibility of damaging the rehabilitation pipe.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view showing a gas supply device used in the rehabilitation method in the present embodiment.

  The gas supply apparatus 1 according to the present embodiment includes a heated gas generator 11, an air compressor 21, a gas mixing unit 31, a heated gas path 12, an air path 23, a gas discharge path 32, and a heated gas supply. A valve 13, a heated gas path check valve 14, an air supply valve 24, and an air path check valve 25 are provided.

  The heated gas generator 11 is for generating heated gas. The heated gas generator 11 is not particularly limited, and examples thereof include a boiler that generates steam.

  The air compressor 21 is for generating compressed air by compressing air. The air compressor 21 is not particularly limited, and examples thereof include a compressor.

  The gas mixing unit 31 is a tank for mixing the heated gas generated by the heated gas generator 11 and the pressurized air generated by the air compressor 21. Since the gas mixing unit 31 is formed in a tank shape, a liquid generated by cooling the heated gas can be accumulated in the lower part of the tank, so that the liquid does not flow into the rehabilitation pipe 40. Therefore, the liquid does not flow into the rehabilitation pipe 40 and the rehabilitation pipe 40 is not easily heated.

  The gas mixing unit 31 may be provided with a safety valve 33 that automatically reduces the internal pressure when the internal pressure exceeds a certain pressure, and a relief valve 34 that can discharge the liquid accumulated inside. By providing the safety valve 33 in the gas mixing unit 31 as described above, the gas mixing unit 31 can be depressurized even if the internal pressure rises excessively, thereby eliminating the possibility of the gas mixing unit 31 being damaged. it can. Further, excessively high pressure gas is not supplied into the rehabilitation pipe 40, and the rehabilitation pipe 40 can be prevented from being damaged. Further, by providing the escape valve 34 in the gas mixing unit 31 as described above, the liquid accumulated in the gas mixing unit 31 can be discharged to the outside, so that the liquid flows into the rehabilitation pipe 40. The rehabilitation tube 40 is not easily heated.

  The heated gas path 12 is provided between the heated gas generator 11 and the gas mixing unit 31 and is a path for supplying the heated gas generated by the heated gas generator 11 to the gas mixing unit 31.

  The air path 23 is provided between the air compressor 21 and the gas mixing unit 31 and is a path for supplying the compressed air generated by the air compressor 21 to the gas mixing unit 31.

  The gas discharge path 32 is provided between the gas mixing unit 31 and the rehabilitation pipe 40 and is attachable to and detachable from the rehabilitation pipe 40. The gas in the gas mixing part 31 is introduced into the rehabilitation pipe 40. It is a route for supplying.

  The gas discharge path 32 may be provided with a gas supply pressure measuring device 35 for measuring the pressure of the gas supplied from the gas mixing unit 31 into the rehabilitation pipe 40, and thereby the approximate pressure in the rehabilitation pipe 40. Therefore, it is possible to easily control the pressure of the gas supplied into the rehabilitation pipe 40.

  The heated gas supply valve 13 is provided in the heated gas path 12 and controls the flow rate of the heated gas. The heating gas supply valve 13 is not particularly limited. For example, a manual valve that can manually adjust the flow rate of the heating gas, an adjustment valve that can adjust the flow rate of the heating gas by remote operation, or a heating gas supply valve that automatically adjusts the heating gas according to the program. Examples include valves that can adjust the flow rate.

  The heated gas path check valve 14 is provided in the heated gas path 12 between the gas mixing section 31 and the heated gas supply valve 13 so that the gas in the gas mixing section 31 flows back to the heated gas generator 11 side. It is for preventing.

  The air supply valve 24 is provided in the air path 23 and controls the flow rate of pressurized air. The air supply valve 24 is not particularly limited. For example, a manual valve that can manually adjust the flow rate of pressurized air, an adjustment valve that can adjust the flow rate of pressurized air by remote operation, and automatic pressurization according to a program. One example is a valve that can adjust the air flow rate.

  The air path check valve 25 is provided in the air path 23 between the gas mixing section 31 and the air supply valve 24 to prevent the gas in the gas mixing section 31 from flowing back to the air compressor 21 side. belongs to.

  In the air path 23, between the air compressor 21 and the air supply valve 24, the pressurized air supplied to the gas mixing unit 31 has the same pressure as the heated gas supplied to the gas mixing unit 31. It is preferable to provide a pressure adjustment valve 22 that is adjusted as described above. When the pressures of the heated gas and the pressurized air supplied to the gas mixing unit 31 are different, the lower pressure gas is not supplied into the gas mixing unit 31, so the pressure adjustment valve 22 is provided as described above. The heated gas and the pressurized air can be set to the same pressure, so that the gas can be satisfactorily supplied into the gas mixing unit 31.

  Next, an existing pipe rehabilitation method using the gas supply device 1 of the present embodiment will be described with reference to FIG.

  First, the rehabilitation pipe 40 made of a thermoplastic resin having a cross-sectional area smaller than that of the existing pipe is inserted into the existing pipe buried in the ground.

  A plug (not shown) provided with a gas vent hole is attached to one end of the rehabilitation pipe 40, and the gas discharge path 32 of the gas supply device 1 is connected to the other end. Here, a temperature measuring instrument (not shown) is installed at a predetermined position of the rehabilitation pipe 40.

  Next, the heated gas supply valve 13 is opened to supply the heated gas generated by the heated gas generator 11 into the rehabilitation pipe 40. At that time, the temperature of the rehabilitation pipe 40 and the gas supply pressure in the gas discharge path 32 are measured to confirm whether the rehabilitation pipe 40 is heated at an appropriate temperature and pressure. When the heated rehabilitation pipe 40 reaches the shape memory temperature, the rehabilitation pipe 40 is restored to a cylindrical shape.

  Next, the heated gas supply valve 13 is gradually closed, and at the same time, the air supply valve 24 is gradually opened. Thereby, since heated gas and pressurized air can be mixed in the gas mixing part 31, the high pressure mixed gas with little temperature fall can be supplied in the renovation pipe 40. FIG.

  Thereafter, the heated gas supply valve 13 and the air supply valve 24 are adjusted so that the mixed gas is mixed in the rehabilitation pipe 40 while maintaining the mixing ratio of the heated gas and pressurized air so that the mixed gas has a constant pressure at a constant temperature. Gas is supplied for a certain time. Thereby, since it can pressurize, maintaining the renovated pipe | tube 40 in a high temperature state, the regenerated pipe | tube 40 is diameter-expanded favorably and is installed in the state of contact | adherence to the existing pipe | tube.

  Finally, in order to cool the rehabilitation pipe 40, the supply of the heated gas is stopped and the supply amount of the pressurized air is increased while maintaining the high pressure state.

  In addition, when the temperature in the rehabilitation pipe 40 does not rise to a predetermined temperature, the gas in the gas mixing unit 31 may be cooled by the liquid accumulated in the gas mixing unit 31, so the gas mixing unit It is advisable to set 31 to a positive pressure state and open the relief valve 34 to discharge the liquid accumulated in the gas mixing section 31 to the outside.

  In addition, when the pressure in the gas mixing unit 31 becomes higher than a predetermined pressure, the gas in the gas mixing unit 31 may be released to the outside by the safety valve 33 to reduce the pressure in the gas mixing unit 31.

It is the schematic which shows the gas supply apparatus in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas supply apparatus 11 Heating gas production | generation machine 12 Heating gas path 13 Heating gas supply valve 14 Heating gas path check valve 21 Air compressor 22 Pressure adjustment valve 23 Air path 24 Air supply valve 25 Air path check valve 31 Gas mixing part 32 Gas discharge path 33 Safety valve 34 Relief valve 40 Rehabilitation pipe

Claims (5)

By inserting a rehabilitation pipe made of a thermoplastic resin having a cross-sectional area smaller than that of the existing pipe into the existing pipe buried in the ground, and heating and pressurizing the inside of the rehabilitation pipe, In the rehabilitation method for existing pipes, the rehabilitation pipes are installed in close contact with the inner surface of the existing pipes.
A method for rehabilitating an existing pipe, wherein a mixed gas of heated gas and pressurized air is used to expand the diameter of the rehabilitation pipe. When rehabilitating the inner surface of an existing pipe buried in the ground, a gas supply device that expands the diameter of the rehabilitation pipe by supplying gas into the rehabilitation pipe inserted into the existing pipe,
A heated gas generator for generating heated gas;
An air compressor for generating pressurized air;
A gas mixing section for mixing the heated gas generated by the heated gas generator and the pressurized air generated by the air compressor;
A heated gas path provided between the gas mixing section and the heated gas generator;
An air path provided between the gas mixing section and the air compressor;
A gas discharge path provided between the gas mixing section and the rehabilitation pipe and made removable with respect to the rehabilitation pipe;
A heating gas supply valve provided in the heating gas path for controlling a flow rate of the heating gas;
A heating gas path check valve that is provided in the heating gas path and prevents the gas in the gas mixing unit from flowing back to the heating gas generator;
An air supply valve provided in the air path for controlling the flow rate of the pressurized air;
An air path check valve that is provided in the air path and prevents the gas in the gas mixing unit from flowing back to the air compressor;
A gas supply device comprising:   The pressure between the air compressor and the air supply valve in the air path is the same as the pressure between the heating gas generator and the heating gas supply valve in the heating gas path. 3. A gas supply device according to claim 2, further comprising a pressure adjusting valve which is automatically set to the above.   The gas supply device according to claim 2 or 3, wherein the gas mixing unit is provided with a safety valve that is automatically depressurized when the internal pressure becomes a predetermined pressure or more.   The gas supply device according to any one of claims 2 to 4, wherein the gas mixing unit is provided with a relief valve capable of discharging the liquid accumulated therein.

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