JPS60257708A - Method of clamping oil-immersed cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a method for freezing an oil-immersed cable.

1 Conventional technology-1 411 Modification of humanoid cables, e.g. P OF cables I
', When it is necessary to cut the cable or dismantle a part of it in small buildings, etc., in order to prevent the insulating oil from leaking, - a method of cooling a part of the cable and freezing the internal insulation AI+, freezing. construction method may be adopted. As a conventional technology related to such a freezing method, for example,
Publication No. 31603 has been proposed.

By the way, the freezing temperature of insulating oil is generally around -100℃, so even if liquefied gas such as liquid nitrogen is used as a coolant, long periods of freezing work and freezing work can be carried out efficiently. The problem remains that the area is required. For this reason, the freezing space associated with freezing work became large, and a freezing box was installed at the manpole at the cable connection point to cool the cable. Do not excavate (J) or other problems may occur.

Additionally, a frozen space was constructed adjacent to the repair work due to road conditions, etc., as land could not be secured. −When it comes to the cause of the increase,
This may lead to problems such as excessive insulating oil being removed from areas where the cable does not need to be inserted into the pole.

[Problems to be Solved by the Invention] The present invention improves the efficiency of freezing by quickly freezing a limited portion of the cable, and also reduces the space required for freezing and places the work hole in place. It is an object of the present invention to solve the problems of the prior art by reducing the number of limitations.

1 Means for Solving Problems 1 The present invention cools the steel pipe with the metal wire inserted into the /111 passage through the hole in the oil-immersed cable, and improves the heat transfer of the metal wire. It is characterized by the fact that it utilizes the heat exchange function to promote the heat exchange action and leads to freezing of the insulating oil.

[One Embodiment] Hereinafter, one embodiment of the present invention will be explained based on the drawings.
When repairing an oil-immersed cable, such as a POF cable, the necessary parts of the cable W are frozen by -4°, but at this time, the copper pipe l that houses the cable W is
Attach the connector 4 having the hole 3 so as to communicate with the oil passage 2. From the hole 3 of the connector 4, insert a wire with good heat conduction such as iron wire, copper wire, stainless steel wire, etc., while making sure that the insulation NL+ does not leak. The metal wire 5 is fed out and filled so as to fill the oil passage 2 between the steel pipe 1 and the cable W, and a freezing box 6 is attached to the outer surface of the steel pipe 1 near the place where the metal wire 5 is packed. A refrigerant such as liquefied nitrogen gas, liquefied carbon dioxide, or chlorofluorocarbon gas is fed into the freezing box 6 for cooling.

At this time, between the copper tube 1 and the cable W, that is, the part where the metal wire 5 is packed in the oil passage 2, the insulating oil 7 near the metal wire 5 with good heat conduction spreads over a wide area. Due to the synergistic effect between the metal wire 5 occupying the oil passage 2 and the reduced amount of insulation 4117, which has poor thermal conductivity, The exchange action is promoted and the insulating oil 7 can be brought to a frozen state in a short period of time 2j.

In this way, since the cooling of the limited area where the metal wires 5 are packed is promoted, freezing in this area can be carried out quickly, and ura-stopping can be carried out effectively, and the time required for freezing is also reduced. Energy consumption can be reduced.

In addition, in the conventional method (J, the space (length) required for cooling was approximately 5 m, but in the illustrated embodiment according to the present invention (J)
By intensively freezing a limited area, the space required for cooling could be reduced to about 2 m.

1-Effects of the Invention] As described in 1-1 above, the present invention has the following advantages: by packing metal wires, the area to be cooled is limited to a narrow range, and heat conduction in that area is improved. By promoting the heat exchange effect of the 411 passage, the efficiency during freezing can be increased, and by performing cooling intensively, the space required for freezing is reduced, making it less likely that the work area will be restricted. , the existing manpole housing the cable connection part can be used as a freezing space, and furthermore, when installing a temporary work hole, it has the effect of limiting or reducing the number of installation locations. I can do it.

[Brief explanation of drawings]

The drawings do not show one embodiment of the present invention but are explanatory views. W・ Cable, 1 Steel pipe, 2 ・M+ communication path 3・ Hole, 4 ・Connector, 5 ・・Metal wire, 6 ・Freezing box, 7
・Insulation AI+.

Claims (1)

[Claims] The metal wire (5) is inserted into the oil passage (2) through the hole (3) made in the steel pipe (1) that houses the oil-immersed cable (W), and the outer surface of the steel pipe (1) is cooled. Af characterized by cooling the insulating oil (7) near the metal wire (5) inserted in the oil passage (7) and freezing the insulating oil (7) in the oil passage (2).
+ Humanoid type cable tying method.