JPH0246271B2 - PURASUCHITSUKUFUNTAINYORUKINZOKUSEIKANNONAIMENRAININGUHOHO - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for lining the inner surface of metal tubes with plastic powder. Generally, as a method for lining the inner surface of a metal pipe with plastic powder, a method is known in which plastic powder is sprinkled on the inner surface of the heated metal pipe and the powder is fused to the inner surface to form a protective film. It is being On the other hand, metal irregular-shaped pipes include bent pipes, U-shaped pipes, Y-shaped pipes,
Many types of pipes are known, such as pipes, Y-tubes with different diameters, T-tubes, 2-way J-tubes, and 2-flange J-tubes. [Conventional technology and its problems] When lining the inner surface of a metal deformed pipe by welding plastic powder, the main points to check during construction are (1) ensuring the target film thickness; )
It is said that attention should be paid to maintaining a uniform film thickness and (3) eliminating wavy marks and sag. Various experiments have shown that the filling method is the most suitable lining method that satisfies these check points. That is, the filling method refers to a method in which the tube is filled with plastic powder and then discharged. In this filling method, the applicant has found through trial and error that plastic powder with a larger MFR (melt flow rate, an index of plastic melt flow) has better melt flow and fewer defects such as pinholes. Although it is advantageous to use plastic powder with a large MFR value (5 to 9), it has the disadvantage of poor workability, and on the other hand, even when using powder with a small MFR value (≒3), welding We discovered a problem that caused the paint film to sag easily. Therefore, no matter what MFR value plastic powder is used, a simple filling method will cause sagging and will not satisfy the above-mentioned check points. On the other hand, as one of the above-mentioned filling methods, a method of rotating or rocking the metal tube upside down in a vertical plane including the tube axis can be used in combination.
This was proposed in Japanese Patent Publication No. 54-44019. That is, according to the proposal, the longitudinal axis of the heated metal tube is first positioned in the vertical direction, and the lower opening communicates with the inside of the tube.
By connecting the tanks containing the plastic powder, attaching a blind cover to the other opening, and inverting these vertical positions, the powder is filled into the pipe, and then the pipe is opened, including the pipe shaft. The plastic powder is welded to the inner surface of the tube while rotating (or rocking) upside down in a vertical plane, then the vertical positions of the tube and tank are restored, and the plastic powder inside the tube is removed from the tank. The paper proposes a lining method that collects wastewater inside the plant. However, according to this proposal, since the metal tube is rotated or swung in a vertical plane that includes the tube axis, in other words, the metal tube is simply overturned and restored, so the metal tube is In the case of irregularly shaped pipes, even if the tank capacity is increased and a large amount of plastic powder is sufficiently filled into the pipe, the powder will still reach the end of the branch pipe or blind spot of the irregularly shaped pipe. If there are areas where the powder is not distributed or where the powder accumulates, please check the check point (1) above.
There was a risk that points (2) and (3) would not be satisfied. In addition, in this proposal, the metal irregularly shaped tube is first positioned vertically and installed in a vertical plane including the tube axis, so the heated large diameter irregularly shaped tube is attached to the rotating device. When doing so, there is a risk of it falling over, and furthermore, when the irregularly shaped metal tube is connected to a tank located below containing plastic powder, the position of the center of gravity in the longitudinal direction is not known, so the irregularly shaped metal tube is connected to the tank located below. When installing the irregularly shaped tube on the top, there is a risk that the center of gravity in the longitudinal direction of the irregularly shaped tube is far away from the center of rotation in the vertical plane.
In such a case, rotational movement within the vertical plane is not performed smoothly. [Means for Solving the Problems] Therefore, the present invention was created in an attempt to solve the disadvantages of the conventional example, and the longitudinal axis of the heated metal deformed pipe to be lined is
Position it horizontally, connect one flange of the odd-shaped tube to a tank that stores plastic powder and opens laterally, cover the other flange with a lid, and then The powder is filled into the tube by placing the tank upward while rotating, and then the powder is shaped into an odd shape while swinging (or rotating) and rotating within a vertical plane including the tube axis for a predetermined period of time. After welding it to the inner surface of the tube, the tank is positioned downward and the remaining powder inside the irregularly shaped tube is discharged into the tank, and then the irregularly shaped tube is restored to a horizontal position and after cooling (air cooling or water cooling) is completed, the tube is removed. Provided is a method for lining the inner surface of a metal deformed pipe with plastic powder, which is characterized by taking out. Hereinafter, the configuration of the present invention will be explained in detail using examples. Fig. 1 is an overall side view of an apparatus using an embodiment of the present invention, Fig. 2 is a side view taken from arrows A to A in Fig. 1, and Fig. 3 is a view of essential parts taken from arrows C to C in Fig. 1. , FIG. 4 is a view of the main parts in the direction of arrows B to B in FIG. 1,
FIG. 5 is a sectional view of the main part, and FIG. 6 is a diagram illustrating the operating principle. Reference numeral 1 denotes a tank containing powder 33, which is configured in a cylindrical shape, one end of which is closed with a plate, and a shaft 2 protruding from and fixed to the center thereof. A short pipe 3 with a flange and a slightly larger diameter is protruded from the center of the other end face and fixed thereto, and the remaining part is covered with a plate. A bearing 4, a large chain wheel 5, a slip ring 6, and a rotary joint (for air) 7 are respectively attached to the shaft 2 in this order. A gate 9 operated by a pair of air cylinders 8, 8 is provided in the short pipe 3, as shown in the third figure.
It is attached so that it can be opened and closed freely. On the end surface of the tank 1 on the short pipe 3 side, there is a bed 1 on which a deformed metal pipe 10, which is a pipe to be lined, is placed.
1 is extended, and the bed 11 has a hook-like configuration when viewed from the side, and has a shaft 12 protruding from its end.
The shaft 12 is supported by a bearing 4' of a fishing basket-shaped frame 34, which will be described later. Furthermore, as shown in FIG. 4, tube attachment devices 13, 13 are placed and fixed at two locations approximately in the center of the bed 11 in a slidable manner. Each of the tube attachment devices 13 is provided with a strip 14, which is used to fasten and fix various shaped tubes 10 depending on the tube diameter. At the opening of the short pipe 3, there is a flanged flexible pipe 1 which can be used interchangeably depending on the pipe diameter of the irregularly shaped pipe 10.
5 is installed. The flange of the flexible tube 15 and the flange of the irregularly shaped tube 10 are connected to a connecting fitting 16.
It is concluded by. The longitudinal tube section of the deformed tube 10 is installed horizontally on the tube attachment device 13, and one opening thereof is fastened to the flange of the flexible tube 15 as described above, and the other opening is fastened to the flange of the flexible tube 15. is the flange 17 (first
(Two pieces in the figure) are fitted with cover lids 18 according to their respective sizes. A chain 19 is engaged with the large chain wheel 5, and the chain 19 is engaged with a small chain wheel 21 of a reduction drive device 20 installed below the frame 34. Therefore, due to the rotation of the chain 19, the large chain wheel 5
As a result, the tank 1 and the irregularly shaped tube 10 rotate about their longitudinal tube axis. The frame 34 is configured in the shape of a fishing basket, and the shafts 2 and 12 are rotatably inserted through the frame 34 in the front-rear direction (left-right direction in FIG. 1) as described above.
Further, in the left-right direction (left-right direction in FIG. 2), arms 22 and 23 are provided upwardly on both sides of the center, and a shaft 2 is attached to the upper ends of these arms 22 and 23.
4 and 25 are provided to protrude outward. These axes 2
4 and 25 are pillars 27 and 27 protruding from the floor 26.
It is supported by bearings 28 and 29 at the upper end of the . A slip ring 30 and a rotary joint (for air) 31 are respectively attached to the outer end of the shaft 24, and a large chain wheel 32 is attached to the outer end of the other shaft 25. From the above configuration, bearing 4
and 4' overlaps the center line in the longitudinal direction of the tank 1 and the irregularly shaped pipe 10, and the center line a connecting the bearings 28 and 2
A center line b connecting the points 9 is perpendicular to the center line a in a horizontal plane. Next, to explain the operation of this embodiment, the tank 1
With the opening of the short tube 3 facing upward, powder 33 was introduced through the short tube, as shown in FIG.
The tank 1 is made almost full and the gate 9 is closed. Next, with the center line a horizontal, approximately 250
Pipe attachment devices 13 and 1 fix the deformed tube 10 heated to ℃ (the fixing position can be adjusted as appropriate).
3 and secure it horizontally. Next, the longitudinal flange of the irregularly shaped tube 10 and the flange of the flexible tube 15 are fastened together using a chuck fitting 16. Deformed pipe 1
A cover 18 is attached to the flange 17 of the other opening of 0 (FIG. 6). Next, the large chain wheel 32 is rotated to bring it into the state shown in FIG. 6, and just before this state is reached, the deceleration drive device 20 is activated to rotate the irregularly shaped pipe 10 around its longitudinal pipe axis. Start the rotation. In this state, the gate 9 is opened and the powder 33 is filled into the tube at once. Note that, if necessary, it may be preferable to apply an appropriate pressure to the powder. During the time required to weld the powder 33 to the inner surface of the tube, the irregularly shaped tube 10 is rotated about the centerline a while swinging (or rotating) about the centerline b. This operation is 360
It can be rotated by degrees, partially repeatedly oscillated between certain angles, fixed at a certain angle, etc., and such operations are electrically controlled by a limit switch (not shown).
After a predetermined time required for welding, the gate 9 is closed. Next, the large chain wheel 32 is rotated to the position shown in FIG. 6 (for a straight pipe, etc.) or the position shown in the figure (for a J-shaped pipe, etc.), the gate 9 is opened, and the powder 33 is discharged into the tank 1. . again,
After setting it to the position shown in FIG. 6, cooling water is sprayed onto the irregularly shaped tube 10 to cool it (or air cool it). When the cooling is completed, the deceleration drive device 20 is stopped, the deformed tube 10 is stopped and removed, and the lining is completed. Although this embodiment has been described with respect to the illustrated irregularly shaped pipe 10, the present invention is not limited to this, and can also line a straight pipe, and is particularly advantageous for large diameter (300 mmφ or more) metal pipes. . The table below shows experimental examples in which the inner surface of various shaped pipes was lined using this device.

【table】

【table】

【table】

[Table] Since the present invention employs the above configuration, the following effects are achieved. [Effects of the Invention] Since the pipe to be lined is rotated around its longitudinal pipe axis and also swung (or rotated) in a vertical plane that includes the pipe axis, the filled powder can spread to every corner of the pipe. MFR
Regardless of the magnitude of the value, each of the check points in the construction of the inner lining can be satisfied. In other words, there is no problem even with powder having an MFR value of 5 to 9, which is considered difficult to apply. When directly connecting the tank and lined pipe,
Since the tubes are connected with their longitudinal axes positioned horizontally, the center of gravity in the longitudinal direction can be confirmed, and rocking (or rotation) and rotational movement in a vertical plane that includes the tube axes is smooth. It will be held in Although irregularly shaped pipes are difficult to install, since the irregularly shaped pipe to be lined is installed horizontally, it is easier to connect it to the tank even if there is an installation error in the installation position, compared to when it is installed vertically. be done. Since the tube heated to a high temperature is installed horizontally in the device, the installation can be done safely.

[Brief explanation of the drawing]

Fig. 1 is an overall side view of an apparatus using an embodiment of the present invention, Fig. 2 is a side view taken from arrows A to A in Fig. 1, and Fig. 3 is a view of essential parts taken from arrows C to C in Fig. 1. ,
Figure 4 is a main part view from arrow B to B in Figure 1;
The figure shows a cross-sectional view of the main part, and FIG. 6 shows a diagram explaining the operating principle. 1...tank, 10...metal irregularly shaped pipe, 18...
...Cover lid, 33...Powder.

Claims (1)

[Claims] 1. Positioning the longitudinal tube axis of the heated metal tube to be lined horizontally, connecting to one opening of the tube a transversely open tank containing plastic powder; After attaching a cover to the other opening of the tube, the tank is positioned upward while rotating around the tube axis to fill the powder into the tube, and then the tube axis is held for a predetermined period of time. After the powder is welded to the inner surface of the tube by rotating or swinging the tube in a vertical plane including the vertical plane and rotating, the tank is positioned downward and the remaining powder in the tube is discharged into the tank. 1. A method for lining the inner surface of a metal tube with plastic powder, the method comprising: removing the tube after the tube has been completely cooled.