JPS5849756B2 - Freezing method for liquid transport pipes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for freezing a liquid transport pipe, in which, when repairing a liquid transport pipe, it is possible to completely freeze the flowing liquid inside both sides of the repaired part up to the center of the pipe. It is related to.

Conventionally, in order to repair or replace two parts of the liquid transport pipe 11 with the pipe filled with liquid, for example, as shown in the schematic diagram of the liquid transport pipe in FIG. Cut points 2 and 3 are set, and the outer surface of the transport pipe 1 portion on both sides of the removed portion 1a between these cut points 2 and 3 is surrounded with a freezing box 4, and a refrigerant such as dry ice and liquid nitrogen is filled. By cooling and freezing the internal liquid of the transport pipe 1 portion on both sides of the removed portion 1a from its outer surface using
After blocking the flow of fluid in the transport pipe 1, the transport pipe 1 is cut at the cut points 2 and 3, removed, and then a new pipe is connected to the removed part. It is taken.

However, when using this conventional freezing method, when the temperature of the liquid to be transported is high or the diameter of the transport pipe is large, cooling only from the outside of the pipe using a freezing box is not sufficient to cool the center of the pipe ( It is not easy to freeze the liquid (indicated by a in Figure 1), and there is a problem that it takes a long time to completely freeze the liquid in the center part 1 of the tube, and in some cases, it is not possible to completely freeze the liquid. There is a problem.

Therefore, this invention has been made to solve the above-mentioned problems and provide a method for freezing a liquid transport pipe that can completely freeze the pipe at its center 1. This invention is aimed at solving the above-mentioned problems and providing a freezing method for a liquid transport pipe that can completely freeze the pipe at its center 1. A method for freezing liquid transport pipes, in which the flow of the liquid inside the sandwiched sides is frozen with a refrigerant to prevent the flow of the liquid within the transport pipe, and then the area to be repaired is repaired. and a double cooling pipe is located inside both sides of the liquid transport pipe sandwiching the portion to be repaired, and the liquid transport pipe including the double cooling pipe penetrating portion is located inside the parts on both sides of the liquid transport pipe, sandwiching the part to be repaired. The outer surface is surrounded by a freezing box, and the refrigerant is circulated through the double cooling pipe, and the refrigerant is supplied to the freezing box. The present invention is characterized in that the flowing liquid inside the both side portions is cooled and frozen.

The present invention will be described below based on embodiments and with reference to the drawings.

FIG. 2 is a schematic diagram of a liquid transport pipe to which the present invention is applied, and as shown in the figure, cut points 6 and 7 are set in the transport pipe 5, and a removed portion 8 between these cut points 6 and 7 is shown. A saddle with a cock 9 is attached to the outer surface of the transport pipe 5 on both sides.

Incidentally, an uninterrupted drilling machine 1o having a drilling awl 10a is attached to the upper part of the cocked saddle 9 in advance, or it is attached to the cocked saddle 9 after being attached to the transport pipe 5.

Then, open the spherical cock of the cocked saddle 9 (by rotating the cock by a predetermined angle, the position of the through hole drilled in it can be changed and the upper and lower parts of the saddle body can be opened and closed). , After drilling the hole 11 in the transport pipe 5 by lowering the drilling drill 10a of the continuous drilling machine 10,
The boring drill 10a is pulled up, the cock is closed, and the continuous drilling machine 10 is removed from the cocked saddle 9.

Next, FIG. 3 shows the cocked saddle 9 attached to the transport pipe 5.
As shown in the cross-sectional view, after the packing gland 12 is attached to the upper part of the cocked saddle 9, a metal double cooling pipe 13 with high thermal conductivity is connected to the packing gland 1.
2 from above and insert the packing 12a inside it.
penetrate.

After opening the cock 14 of the cocked saddle 9, the metal double cooling pipe 13 is further passed through the cock 14, inserted into the transport pipe 5 through the hole 11, and its tip is transported. It is located further below the center of the pipe 5 (in the figure, 15 is a seal packing for the cocked saddle 9, and this seal packing 15 surrounds the hole 11 and connects the transport pipe 5 and the cocked saddle 9). (The sealing of the hole 11 is performed by placing it in between.)
, On the other hand, as shown in the schematic diagram of the liquid transport pipe in FIG. The outer surface of the transport pipe 5 is surrounded by a freezing box 16.

After completing such work, the liquid in the transport pipe 5 is
Liquid nitrogen is supplied from the outside to the inner pipe 13 of the metal double cooling pipe 13.
By taking out the liquid nitrogen to the outside through the outer pipe 13b and circulating it, the liquid nitrogen is cooled from the metal double cooling pipe 13 in the transport pipe 5, and the liquid nitrogen is removed from the outside of the freezing box 16. The transport pipe 5 is cooled from its outer surface by being fed into the interior through the inlet 16a and taken out to the outside through the outlet 16b for circulation.

Therefore, the liquid in the transport pipe 5 is not only cooled from the outer surface of the pipe 5, but also is cooled by the metal double cooling pipe 13.
Since it is also cooled (especially the liquid in the center tube), it freezes completely and in a short time.

1.If two metal double cooling pipes are placed close to each other, crossed, and placed with the removed part 8 in between,
It is clear that the cooling efficiency can be further improved.

In this way, after it is confirmed that the liquid in the transport pipe 5 has frozen, the removed part 8 is replaced with a new one, and after this is completed, the metal double cooling pipe 13 is replaced, leaving the cocked saddle 9.
Remove the freezing box 16, button and packing gland 12.

Note that the liquid frozen portion can be melted in a short time by circulating hot water or the like through the metal double cooling pipe 13 and the freezing box 16.

As a method for detecting the frozen state of the liquid in the transport pipe 5, there are, for example, the following methods.

That is, as shown in the cross-sectional view of the liquid transport pipe in FIG.
If the button and the ultrasonic receiver 18 are respectively positioned and moved simultaneously along the axial direction of the tube 5, the receiving condition (ultrasonic attenuation rate) will differ depending on the frozen state of the frozen portion 19. , you can see the frozen state.

As explained above, according to the present invention, even pipes with large diameters and liquids with high liquid temperatures can be completely frozen.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of a conventional liquid transport pipe, Figure 2 shows the button and
The figure is a schematic diagram of a liquid transport pipe to which the present invention is applied, FIG. 3 is a cross-sectional view of a saddle with a cock attached to the transport pipe, and FIG. 5 is a cross-sectional view of the liquid transport pipe. 1, 5... Transport pipe, 2, 3, 6, 7... Cutting location,
1a, 8...Removed part, 4, 16... Freezing box, 9...
・Saddle with cock, 10...Continuous drilling machine, 1oa・
... Perforation drill, 11 ... Hole, 12 ... Packing gland, 13 ... Metal double cooling pipe, 13a ... Inner pipe, 13b ... Outer pipe, 14 ... Cock, 15 Seal packing, 16a Inlet, 16b Outlet, 17 Ultrasonic transmitter, 18 Ultrasonic receiver, 19 Frozen part.

Claims (1)

[Scope of Claims] 1. After freezing the flowing liquid inside the portions on both sides of the liquid transport pipe that sandwich the part to be repaired with a refrigerant to prevent the flowing liquid within the transport pipe, the above-mentioned repair is performed. In the method of freezing liquid transport pipes, which repairs the parts to be repaired, dual cooling pipes are penetrated from the outside and positioned inside both sides of the liquid transport pipes sandwiching the parts to be repaired;
Further, the outer surface of the liquid transport pipe including the penetrating portion of the double type cooling pipe is surrounded by a freezing box, a refrigerant is circulated through the double type cooling pipe, and the refrigerant is supplied to the freezing box. A method for freezing a liquid transport pipe, characterized in that the flowing liquid inside the both sides of the transport pipe is cooled and frozen by the inside and outside of the both sides of the transport pipe that sandwich the part to be repaired.