JPS6030172B2 - Communication cable freezing method and sheet for forming liquid freezing agent container for the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for freezing a damaged portion of a communication cable due to flooding, and a sheet for forming a liquid freezing agent container for the method.

If a communication cable installed inside an underground conduit is accidentally passed through the conduit during road excavation, etc. and damaged, and moisture enters the cable, the cable insulating paper will become wet and the insulation will fail. The call will fail.

Conventionally, in such cases, the moisture that has entered the cable is frozen by freezing the conduit at the flooded part of the cable from the outside, and the insulation is restored.In the meantime, a replacement cable for the faulty cable is replaced with another cable. It is passed through the pipe and switched. Conventionally, the above freezing method is
Cut the outer periphery of the conduit at the cable failure point into a shape similar to covering the conduit with a Styrofoam box, cover the gap with putty, etc., and inject liquid nitrogen between them to freeze.
When liquid nitrogen decreases due to vaporization, replenish it further.
Or they put dry ice in it to keep it frozen. However, with a solid body such as a Styrofoam box, it is difficult to install it in a narrow space such as a narrow space between pipes, and therefore water that has entered the communication cable may freeze. It took time.

In view of the above-mentioned points, the present invention provides a freezing method and a method for quickly freezing moisture that has entered a communication cable by easily preparing a liquid freezing agent container in a pipe section to be cooled even in a narrow space. The present invention provides a sheet for forming a liquid freezing agent container for construction methods, and will be described in detail below with reference to the drawings.

Figure 1 shows an embodiment of the sheet for forming a liquid freezing agent container of the present invention, and 1 and 2 have an adhesive attached to one side, and the adhesive side has a non-adhesive layer to prevent it from sticking to other surfaces during inconvenient use. This is a flexible liquid-tight sheet made of an existing adhesive rubber sheet or the like to which cloth (not shown) is attached, and the liquid-tight sheet 2 is made slightly smaller than the liquid-tight sheet.

3 is a flexible heat insulating sheet made of an existing glass sheet made of cotton-like glass fibers covered on both sides with glass fiber cloth, and its dimensions are slightly smaller than that of the smaller flexible liquid-tight sheet 2. It is sandwiched between two large and small flexible liquid-tight sheets with their adhesive surfaces facing each other.

In this case, in order to be able to reuse the thermal insulation sheet 3, both the liquid-tight sheets and the anti-adhesive cloth of 2 should be used for the anti-adhesive cloth located at the periphery, leaving the part that will overlap with the thermal insulation sheet 3. is cut out, and the entire periphery of the small liquid-tight sheet 2 is adhesively bonded to the outer periphery of the large liquid-tight sheet to seal it so that the liquid freezing agent does not infiltrate into the heat insulating sheet 3. However, the younger brother's turtle picture shows both the large and small liquid-tight sheets, with the adhesive between them partially peeled off. Also, the adhesive surface is exposed around the entire periphery of the large liquid-tight sheet. Since both the liquid-tight sheet 2 and the heat insulating sheet 3 are flexible, the whole has flexibility. When forming a liquid freezing agent container using the sheet of the present invention formed in this way, bend it at the center as described below, adhesively adhere the exposed peripheral adhesive surface to the entire outer periphery of the pipe, and then The peripheral adhesive parts of the opposing surfaces of the container are immediately overlapped and adhesively bonded to form a container. Note that when the heat insulating sheet 3 is not reused, the anti-adhesive cloth on both liquid-tight sheets 1 and 2 may be completely removed so that both sides of the heat-insulating sheet 3 completely adhere to the liquid-tight sheets 1 and 2. .

FIG. 2 shows the implementation state of the freezing method of the present invention, in which 4 is a liquid freezing agent container formed from the sheet of the present invention, and 5 is a communication cable.
6 is a conduit made of steel pipe.

At the part of the conduit 6 on the outer periphery of the part of the communication cable 5 where the water intrusion problem occurred, the exposed adhesive pad on the outer periphery of the large twill dense sheet 2 of the sheet of the invention shown in FIG. Bend it at the center and cover it from both sides below so that the center part touches the bottom surface of the pipe 6, so that the adhesive pads on both sides around the large liquid-tight sheet 1 are sticky over the entire circumference on both sides of the cooling part of the pipe 6. At the upper part, the two bent sides of the large liquid-tight sheet are directly glued with paper, and before the adhesive parts on the upper side are glued together, the liquid freezing agent injection tube 7 is attached. The liquid freezing agent container 4 is formed by sandwiching the liquid freezing agent inside and attaching adhesive to the entire circumference thereof. The outer periphery of the container 4 is covered with the heat insulating sheet 2, and is effectively thermally insulated from the outer periphery of the container 4. After adhering the lees to the pipe line 6, a rubber tape 8 may be further wrapped around it in order to reinforce this adhesive part.After forming the liquid freezing agent container 4 in the above manner, the injection tube is A liquid freezing agent 9 such as liquid nitrogen is injected into the container 4 from 7. As a result, the water-damaged part of the internal cable is rapidly cooled, and the water that has entered the cable is frozen and the insulation is restored.Liquid freezing Since the agent 9 gradually evaporates, the seal can be applied as needed to maintain the frozen state.As described above, according to the freezing method of the present invention, the adhesive part is formed on the outer periphery. Since the sheet forms a liquid freezing agent container, it can be bent at the center and placed from below over the pipe section to be cooled, even in places where the space for forming the container is narrow, such as in places where there is a narrow gap between adjacent saddle pipes. All you have to do is glue it together, then overlap the upper facing adhesive part and glue it together, and then sandwich the liquid freezing agent injection tube and glue it together, making it extremely easy and quick to make a container. Therefore, it is possible to quickly freeze moisture that has entered the communication cable.

Furthermore, the outer periphery of the manufactured container has a great cold insulation effect due to the presence of a thermally insulating sheet. In addition, in the sheet for forming a liquid freezing agent container of the present invention, a heat insulating sheet is sandwiched between both large and small flexible liquid-tight sheets, and the green adhesive part on the outer periphery of the small liquid-tight sheet is connected to the outer adhesive part on the outer periphery of the large liquid-tight sheet. It can be easily and quickly produced just by attaching adhesive to it.

When a liquid freezing container is made in the pipe section to be cooled, it can be easily made even in a narrow space as mentioned above, and therefore moisture that has entered the communication cable can be quickly frozen. Thermal insulation sheet has a great cooling effect.

[Brief explanation of the drawing]

FIG. 1 is a partially peeled-off plan view of a sheet for forming a liquid freezing agent container for freezing communication cables according to the present invention, and FIG. 2 is a perspective view showing the implementation state of the communication cable freezing method of the present invention. 1, 2... Flexible liquid-tight sheet, 3... Flexible thermal insulation sheet, 4... Liquid freezing agent container, 5...
...Communication cable, 6... Conduit, 7...
...Liquid freezing agent injection cylinder, 9...Liquid freezing agent. Multi-diagram Figure 2

Claims (1)

[Scope of Claims] 1. From below, a pipe is placed between two flexible liquid-tight sheets of slightly different sizes, with their opposing surfaces being adhesive surfaces, on a conduit portion located on the outer periphery of a communication cable flooded area. A sheet for forming a liquid freezing agent container is formed by sandwiching a flexible heat insulating sheet that is slightly smaller than the smaller liquid-tight sheet and sealing it with adhesive on the entire outer periphery of both liquid-tight sheets. Bend the liquid-tight sheet from the center so that the adhesive part on the outer periphery is on the inside, apply the outer adhesive part to the entire circumference of the pipe, and then apply the adhesive on the outer periphery on both sides bent at the center. A liquid freezing agent injection tube is sandwiched and adhered between the outer peripheral adhesive portions on both sides at the upper part to form a liquid freezing agent container, and liquid freezing agent is injected into the container from the above injection tube. A communication cable freezing construction method characterized in that the moisture that has entered the communication cable is frozen at the flooded damaged portion of the communication cable. 2. A flexible heat insulating sheet with a size slightly smaller than the smaller liquid-tight sheet is placed between two flexible liquid-tight sheets of slightly different sizes with the opposite sides facing each other as adhesive surfaces. The heat insulating sheet was sandwiched and sealed with adhesive on the entire outer periphery of both liquid-tight sheets, so that the adhesive surface was exposed over the entire outer periphery of the larger liquid-tight sheet. A sheet for forming a liquid freezing agent container for communication cable freezing method.