JP2832316B2 - Lining method of pipe inner surface - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for lining an inner surface of a buried pipe with a resin, and particularly to a buried pipe in which a relatively large corrosion hole is formed in a pipe wall. And effective lining methods.

[Conventional technology]

As a method of regenerating and repairing buried piping, a method of lining a pipe inner surface with a resin is known. As this prior art,
The present applicant has proposed various methods. One of the methods is to fill a resin having fluidity so as to close the inside of the tube in a liquid state, as described in JP-A-63-65983. In the process of flowing the filled resin at a constant speed in the form of a flow due to the pressure difference between the pressurized fluid and the suction fluid generated before and after the filling resin, the lining coating film having a required thickness according to the flow speed is formed in the tube. A lining method that is formed on the surface was proposed.

[Problems to be solved by the invention]

When the lining of the buried pipe is performed by the lining method described above, the buried pipe in which a relatively large corrosion hole is formed in the pipe wall has the following problems.

That is, in the above-mentioned prior art, the buried piping to be repaired is formed from the relationship that the resin filled in the pipe flows in the pipe at a constant speed in a confluent manner due to the pressure difference between the pressurized fluid and the suction fluid generated before and after the resin. When a relatively large corrosion hole is formed, pressure leaks from the corrosion hole will occur, so the pressure difference will change and the flow velocity of the resin aggregate flow will change inadvertently. If the thickness of the applied lining coating becomes uneven or the pressure leak from the corrosion hole is large, the flow stops when the resin aggregate passes the position of the corrosion hole, and the lining itself cannot be performed. In some cases.

An object of the present invention is to provide a lining method that solves the above-mentioned problems.

[Means for solving the problem]

In order to achieve this object, according to the present invention, when the above-mentioned lining method is used, the flow rate of the resin aggregate flowing through the pipe is low, and when the flow rate is low, the adhesion layer of the resin film thickness adhered to the pipe inner surface is relatively formed. Paying attention to the tendency that the film thickness tends to be relatively thick at the time of thin and high speed, the lining work is divided into two stages, a first process and a second process. The lining resin is mixed with a large number of flake-like flakes at a predetermined ratio as a special resin, and is caused to flow at a low speed into the pipe, so that the corrosive holes are closed with the flake-like flakes in the resin mainly adhered thinly to the pipe wall. The step is characterized in that a normal lining resin is caused to flow at a higher speed than in the first step to form a lining coating film having a required thickness on the inner surface of the tube.

[Action]

In such a lining method, in the lining in the first step, the adhesion layer of the resin film thickness attached to the inner surface of the pipe is relatively thin, and the scale-like flakes mixed in the resin are laminated almost parallel to the pipe wall surface. For example, when a corrosive hole is opened in the pipe wall surface and the pressurized fluid leaks from the corrosive hole to the outside, the flakes in the resin flowing along the tube wall surface The flakes are filled together with the resin by the leaking air flow of the pressurized fluid so as to close the corrosion holes, and the lining is performed so as to close the corrosion holes.

As a result, when performing the lining construction in the second step,
Since the airtightness inside the construction pipe is ensured and the phenomenon that the pressure difference of the pressurized fluid that flows the resin flow does not change carelessly, the flow speed is maintained at a constant speed over the entire length of the repair target pipe, The lining work can be smoothly performed so that the lining coating film having a required film thickness according to the speed is uniformly formed on the inner surface of the pipe.

In addition, as a result of the lining coating of the required film thickness of the second step being overcoated on the thin lining coating of the first step, the thin lining coating of the first step becomes the primary coating during the lining in the second step. The effect of (1) is that the formation of the lining coating film can be smoothed, and that the coating film can be formed into a thick film.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of equipment used for the installation of the pipe inner surface lining method according to the present invention. To explain this, reference numeral 1 denotes a buried pipe to be repaired. The buried pipe 1 is divided into a repair section of a predetermined length at the time of repair. A launcher 2 having a predetermined length is connected to one end of the buried pipe 1, and the inside of the other end is open through the inside. A receiver 3 is connected.

A resin injector 4 is connected to the launcher 2 via an opening / closing solenoid valve 5, and a special resin A used for lining work in a first step described later and a second resin
Lining resin B used for lining construction in the process
Are introduced according to the process order. A small compressor 6 is connected to the end of the launcher 2 via a flow control device 7, and compressed air from the compressor 6 is flow-regulated by the flow control device 7 and introduced into the launcher 2. , Into the buried pipe 1. The above compressor 6
Is introduced into the resin injector 4 via a switching solenoid valve 8 and a governor 9 which are interlocked with a flow rate control device 7, and passes through a pressure sliding plate 10 provided in the resin injector 4. The special resin A in the first step and the lining resin B in the second step
A predetermined amount is extruded and filled into the launcher 2 in a liquid state at a constant pressure from an opening / closing electromagnetic valve 5 which is opened in conjunction with the flow control device 7.

The flow control device 7 includes a filter 11 for purifying the compressed air from the compressor 6, a flow control unit 13 having a throttle valve 12 for controlling the flow of the compressed air, and a supply and cutoff of the compressed air. And a pressure controller 15 for controlling the above-mentioned on-off valve 14, relief valve 18, throttle valve 12, and the like.
The flow controller 16 receives signals such as the flow rate in the pipe of the special resin A flowing in the pipe in the first step and the lining resin B flowing in the pipe in the second step by the antenna 17, Throttle valve 12, relief valve 18, open / close valve based on air pressure detection by a total of 15.
14 is controlled.

On the other hand, a shutoff valve 28, a pressure gauge 20, a flow meter 21 and the like are connected to the receiver 3 connected to the other opening of the buried piping 1, and the pressure gauge 20, the flow meter 21 The pressure inside the pipe on the discharge side and the air discharged from inside the pipe, which change with the flow of the special resin A in the step or the lining resin B in the second step, are detected, and the detection of the special resin A or the lining resin B in the pipe is performed by these detections. The flow velocity is detected, and this detection signal is transmitted to the antenna 17 on the start end side via the oscillator 22 and the antenna 25, so that the control by the flow rate control device 7 is performed. A cyclone-type resin separation hopper 26 having an air discharge valve 27 is connected to an end of the receiver 3.
When the special resin A in the step or the lining resin B in the second step reaches the receiver 3 that can see through the inside, the air discharge valve 27 that has been closed in advance is opened, and the shutoff valve 28 is closed, so that the remaining This resin can be collected in the resin separation hopper 26.

Next, a working process of lining construction using the above-described equipment will be described.

In the present invention, the lining work is performed in the first step and the second step.
The work is divided into two stages, namely the process.

(First Step) In the lining construction of the first step, the lining resin to be used is a room temperature two-part curable resin prepared by mixing a main agent and a curing agent, and the main agent composition (unsaturated polyester resin, vinyl ester resin) , Epoxy resin, urethane resin, etc.), for example, flaky flakes S made of aluminum, mica, talc, glass, graphite, etc. as raw materials are mixed and added at a predetermined ratio, and the special resin A is produced by kneading the flakes. Use

The special resin A is accommodated in the resin injector 4, and the opening / closing solenoid valve 5 is opened. A predetermined amount of the special resin A is kept in a liquid state from the inside of the launcher 2 into the pipe on the starting end side of the buried pipe 1 for a predetermined length. Is filled so as to be closed.

When the filling of the resin A is completed, the opening / closing solenoid valve 5 is closed, the opening / closing valve 14 on the side of the air blowing system is opened, and the pressure of the compressed air (pressurized fluid) from the compressor 6 is controlled by the throttle valve 12 while the end of the launcher 2 is controlled. More into the pipe.

Thereby, the pressurized fluid acts to press the rear end face of the special resin A closed and filled in the tube from behind, and the resin A is given fluidity by a pressure difference generated in the tube,
The resin A flows in a collective flow in the buried pipe 1 toward the other end.

The flow rate of the resin A in the first step is set so as to flow and advance while maintaining a constant speed at a relatively low speed in the pipe under the control of the flow rate control device 7.

At this time, the fluid pressure acting on the resin A is set to an initial pressure for imparting fluidity to the resin A by about 1.5 kg / cm ^{2 with} respect to the atmospheric pressure.
In addition, when the fluidity is imparted and the resin A flows in the pipe, the fluid pressure is regulated by the relief valve 18 and reduced to a low pressure of about 0.6 kg / cm ² or less with respect to the atmospheric pressure. The average flow velocity at this time is 5c for a buried pipe with a pipe diameter of 25mm.
m / sec, 15 cm / sec is desirable for buried piping with a pipe diameter of 50 mm.

When the fluid flows at a low speed in this manner, the shape of the rear end surface of the resin A on which the pressurized fluid acts becomes an almost vertical end surface shape as shown in FIG. Experiments have confirmed that the film thickness of the resin A becomes a thin film. When the resin A flows in the pipe, the scale-like flakes S mixed in the resin A are caused by the propulsive force of the air flow. As shown in (1), there is a tendency to flow in a state of being stacked substantially parallel to the pipe wall surface.

As a result, the buried pipe 1 is deteriorated, and for example, a pinhole-shaped corrosion hole H as shown in FIG. 2 is opened in the pipe wall surface, and the pressurized fluid leaks from the corrosion hole H to the outside. In this case, the scale-like flakes S in the resin A flowing along the pipe wall surface are filled together with the resin A through the leaked air flow of the pressurized fluid from the corrosion holes H so as to fill the holes, and the corrosion is prevented. Lining is performed so as to close the hole H.

When the length of the pipe to be repaired is long, the flow of resin A in the pipe due to the pressurized fluid is restricted,
Divide the work so that the number of times of flow is divided into multiple times and repeated. This makes it possible to increase and extend the length of the repair section as desired.

(Second step) After the lining construction in the first step described above is completed,
Next, the process proceeds to the lining construction in the second step.

In the lining work in the second step, the above-mentioned scaly flakes S are not mixed in the resin used, and a lining resin B having ordinary room temperature two-part curing type fluidity prepared by mixing a usual main agent and a curing agent is used. .

The lining resin B is replaced with the resin injector 4 and filled in the same manner as in the first step from the inside of the launcher 2 on the start end side so as to close the buried pipe 1, and the inside of the pipe is filled with the lining resin B. It is set to flow and flow.

The average flow speed of the lining resin B in the second step is set under the control of the flow rate control device 7 so as to flow in the pipe while maintaining a constant speed at a higher speed than the flow speed in the first step. The average flow velocity is preferably 7 to 15 cm / sec for a pipe with a diameter of 25 mm, and 20 to 40 cm / sec for a pipe with a diameter of 50 mm.

When the fluid flows at a high speed in this manner, the rear end surface of the lining resin B on which the pressurized fluid acts has a shell-shaped end surface shape as shown in FIG. 5, and adheres to and remains on the inner surface of the pipe due to the flow. The film thickness of the lining resin B is thick.

In this case, the pipe wall surface of the buried pipe 1 has a pinhole-shaped corrosion hole H generated on the pipe wall surface by the lining work in the first process. Since airtightness is secured and the phenomenon that the pressure difference of the pressurized fluid does not change carelessly does not occur,
The flow velocity can be kept constant over the entire length of the pipe to be repaired.

As a result, on the inner surface of the pipe, a lining coating b having a required film thickness in accordance with the flow rate is further formed on the lining coating a in the first step as shown in FIG. Since the speed is maintained at a constant speed, the film thickness of the lining coating film b formed on the inner surface of the pipe is uniform, and the flow of the lining resin B stops flowing due to pressure leakage from the corrosion holes H. Because there is no lining, the lining can be performed smoothly.

〔The invention's effect〕

As described above, in the pipe lining method according to the present invention, even if the buried pipe to be repaired is deteriorated and the corrosive holes are generated on the pipe wall to the extent that pressure leaks, the first pipe lining method can be used. By the lining construction in the process, the corrosive holes are closed by clogging with scale-like flakes, and after the closing processing, it is a method in which the normal lining construction in the second step is performed. The leakage of the pressure fluid from the corrosive holes generated in the pipe line disappears, and the pressure difference of the pressurized fluid that causes the resin condensate flow in the pipe changes inadvertently, and the flow of the resin condensate flow due to the pressure leak from the corrosive holes Since the phenomenon such as the stop of the progress does not occur,
The effect that the flow velocity of the resin mass flow is maintained at a constant speed over the entire length of the pipe to be repaired, the lining coating of the required thickness according to the flow velocity can be formed uniformly on the inner surface of the pipe, and the lining work can be performed smoothly. Is obtained.

In addition, as a result of the lining coating of the required film thickness of the second step being overcoated on the thin lining coating of the first step, the thin lining coating of the first step becomes the primary coating during the lining in the second step. The effect of (1) is that the formation of the lining coating film can be smoothed, and that the coating film can be formed into a thick film.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing an example of equipment used for applying a pipe inner surface lining method according to the present invention, FIG. 2 is a partial cross-sectional view of a coating film obtained by lining in a first step,
FIG. 3 is a partial cross-sectional view of a coating film obtained by lining in the second step, and FIGS. 4 and 5 are explanatory diagrams showing a change in the coating film thickness in relation to the flow velocity of the resin. DESCRIPTION OF SYMBOLS 1 ... Buried piping, 2 ... Launcher, 3 ... Receiver 4 ... Resin injector, 5 ... Open / close control valve, 6 ... Compressor, 7 ... Flow control device, 8 ... Switching electromagnetic valve 11 ... Filter, 12 ... Throttle valve, 13 ... Flow control unit 14 ... On / off valve, 15 ... Pressure gauge, 16 ... Flow controller 17 ...... Antenna, 18 ... Relief valve, 20 ... Pressure gauge 21 ... Flow meter, 23 …… Transmitter, 25 …… Antenna, 26 ……
Resin separation hopper, 28 ... shut-off valve, A ... resin (special resin) used in the first step, B ... lining resin used in the second step, a ... coating film formed by the first step, b: coating film formed by the second step, S: scale-like flake, H: corrosion hole.

Continued on the front page (72) Inventor Masaki Natori 4-20-34-203, Honcho, Koganei-shi, Tokyo (72) Inventor Nobukatsu Ike 3--18, Daikan, Yamato-shi, Kanagawa 4 72) Inventor Masahito Shinozaki 3-18 Daikan, Yamato-shi, Kanagawa Prefecture 4 Within HAKKO Development Technology Laboratory Co., Ltd. (56) References JP-A-63-218284 (JP, A) JP-A-1-236973 (JP, A ) JP-A-58-207972 (JP, A)

Claims (1)

(57) [Claims] 1. A resin having fluidity is filled in a liquid state so as to close the inside of a tube, and the filled resin forms a collective flow due to a pressure difference between pressurized fluids generated before and after the resin, and the inside of the tube is maintained at a constant speed. In the lining method of forming a lining coating film of a required thickness by a resin layer adhered to the inner surface of the pipe by the flow, the lining is divided into two steps, a first step and a second step. In one step, a special resin in which flake-like flakes are mixed at a predetermined ratio into a liquid lining resin is caused to flow at a low speed in the pipe as a special resin, and in the second step, a normal lining resin is flowed into the pipe at a higher speed than the first step. A lining method for an inner surface of a pipe, characterized in that: