Expressway optical cable blowing laying construction method

Abstract

The invention discloses an expressway optical cable blowing laying construction method. The method comprises the steps of S1, construction preparation; s2, the ratio of the outer diameter of the optical cable to the inner diameter of the silicon core pipe ranges from 0.35 to 0.6; the suitable working environment temperature is 6-32 DEG C; s3, slowly opening a compressed air inlet ball valve, and controlling the traction force of an air seal piston on the optical cable by changing the opening size of the valve; s4, when the feeding distance of the optical cable is short, the opening degree of the air inlet of the valve is small, and then the opening degree is gradually increased until the air inlet is completely opened; and S5, after the optical cable reaches a preset point, namely, the air seal piston comes out of the pipe (the air pressure is sharply reduced at the moment), an observer at the pipe end timely prompts an operator of the cable blowing machine to shut down immediately and stop conveying the optical cable into the pipe, so that the air-blowing laying operation of a section of optical cable is completed. And S6, cable reversing operation, namely conveying the optical cable into the'optical cable reversing device ', so as to pour out the remaining optical cable on the original cable tray and find out the other end to prepare for blowing and conveying the optical cable in the reverse direction.

Description

Technical Field

[0001] The invention relates to the technical field of cable blowing, and in particular to a construction method for laying optical cables by blowing on highways. Background Art

[0002] The cable air blowing method is widely used in the construction of highway optical cables. It uses high-pressure airflow to blow the optical cable into the pre-buried silicon core tube. The cable blowing machine blows high-pressure and high-speed compressed air into the silicon core tube. The high-pressure airflow pushes the air sealing piston, so that the air sealing piston connected to the end of the optical cable forms a settable uniform pulling force on the optical cable. At the same time, the hydraulic crawler conveying mechanism of the cable blowing machine clamps the optical cable and conveys it forward to form a conveying force. The combination of pulling force and conveying force allows the inserted optical cable to quickly travel in the pipeline in a suspended state along with the high-speed airflow.

[0003] At present, the existing optical cable laying methods are subjected to uneven tension during the laying process; the laying process is cumbersome, and the number of manholes and handholes on the pipeline line is relatively large; and the laying operation uses a lot of manpower.

[0004] It is desired to provide a highway optical cable blowing and laying construction method that can solve the above-mentioned technical problems. Summary of the invention

[0005] The first object of the present invention is to provide a method for laying optical cables by blowing on highways. Compared with other optical cable laying methods, the tension on the optical cable by blowing is more uniform and much smaller during the laying process; the laying process is simplified and the optical cable laying speed is fast; the laying distance is long at a time, and a longer optical cable can be used, which reduces the number of joints and reduces attenuation; the number of manholes and handholes on the pipeline line can be greatly reduced; and less manpower is used in the laying operation.

[0006] In order to achieve the above-mentioned purpose, a highway optical cable blowing and laying construction method of the present invention comprises the following steps:

[0007] S1. Construction preparation;

[0008] S2. The ratio of the outer diameter of the optical cable to the inner diameter of the silicon core tube is within the range of 0.35 to 0.6; the suitable working environment temperature is 6 to 32°C; the exhaust pressure of the air compressor should be no less than 1.2Mpa; the optical cable passes through the guide mechanism, the speed measuring wheel, the conveying mechanism, and the cable blowing head in sequence, and the cable head is connected to the air sealing piston through the cable mesh sleeve, and each part of the mechanism is adjusted and each control parameter is set;

[0009] S3. Slowly open the compressed air inlet ball valve and control the pulling force of the air sealing piston on the optical cable by changing the size of the valve opening;

[0010] S4. When the distance of the optical cable is short, the air inlet of the valve should be opened slightly, and then gradually increased until it is fully opened; the speed control handle on the control console is used to control the laying speed of the optical cable. In this way, when the traction force at the front end of the optical cable is too large, the feeding speed of the optical cable can be restrained, and when the air pressure is insufficient, auxiliary thrust can be provided to make the blowing force used by the optical cable smaller during travel; the transmission speed of the optical cable is controlled between 8 and 80 m / min;

[0011] S5. When the optical cable reaches the predetermined point, that is, the air-sealing piston has come out of the tube (the air pressure will decrease sharply at this time), the observer at the tube end should promptly remind the operator of the cable blowing machine to stop the machine immediately and stop conveying the optical cable into the tube, thus completing the air-blowing laying operation of a section of optical cable;

[0012] S6, cable rewinding operation, is to convey the optical cable into the "optical cable rewinding device", the purpose is to pour out the remaining optical cable on the original cable drum, find the other end, and prepare for blowing the optical cable in the reverse direction.

[0013] Specifically, in step S1, construction preparation includes pre-construction preparation, route retest, optical cable single reel inspection and optical cable reel distribution;

[0014] Preparation before construction: Before laying optical and electrical cables, the main technical indicators of each optical and electrical cable shall be checked and tested; installation process inspection, optical cable specifications, pipe hole positions, optical cable connection specifications and quality, optical cable direction and fixation, optical cable protection, optical cable entry and termination quality, distribution frame installation and wiring; cable insulation resistance test, insulation resistance of all cables and to ground.

[0015] Specifically, in step S2, the relationship between the outer diameter of the optical cable and the inner diameter of the silicon core tube is as follows:

[0016]

[0017] Specifically, in step S4, the conveying speed of the optical cable is 70 m / min.

[0018] Specifically, in step S4, when the optical cable is transported over a long distance, the output torque of the hydraulic motor is increased by adjusting the pressure regulating handle on the operating console, thereby obtaining a suitable transport force.

[0019] Specifically, in step S4, after the optical cable is blown into place, the cable conveying work of the conveying mechanism should be stopped in time and the air inlet valve should be closed.

[0020] The highway optical cable blowing and laying construction method and method provided by the present invention have the following advantages compared with the prior art:

[0021] (1) The tension of the optical cable during the laying process is more uniform and much smaller in the air-blowing laying method; the laying process is simplified and the laying speed is fast; the laying distance is long, and the optical cable with longer coils can be used, which reduces the number of joints and reduces the loss; the number of manholes and handholes on the pipeline line can be greatly reduced; less manpower is used in the laying operation;

[0022] (2) The construction methods described in this process are all carried out on the ground, which is convenient, fast and safe;

[0023] (3) The construction methods and procedures such as cable blowing process selection, cable installation, cable blowing operation, and start-up and shutdown are clear and easy to understand;

[0024] (4) This process method describes in detail the precautions for cable blowing construction, etc., ensuring the installation quality and no rework during the construction process;

[0025] (5) The process flow is clear and easy to understand, easy for operators to master, simple to operate, and highly usable, which can speed up the construction progress, shorten the project period, and improve the project quality;

[0026] (6) Characteristics of highway construction: short construction time requirement, not too large construction area, and cable blowing length of 500m-2000m (compared to 50-150m in urban and county roads). DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with specific embodiments.

[0028] Example 1

[0029] A method for laying optical cable on a highway by blowing cable, comprising the following steps:

[0030] S1. Construction preparation:

[0031] S1.1 Preparation before construction. Before laying optical and electrical cables, the main technical indicators of each optical and electrical cable shall be inspected and tested (opening inspection and testing), and the installation process shall be inspected. Optical cable specifications, pipe hole positions, optical cable connection specifications and quality, optical cable direction and fixation, optical cable protection, optical cable entry and termination quality, distribution frame installation and wiring, etc. Cable insulation resistance test. Insulation resistance of all cables and to the ground;

[0032] S1.2 Route re-survey: Check the construction drawings, the distance between manholes (handholes), the occupancy of pipe holes, the actual measured length of the pipeline, the construction status of the pipeline, such as the trial run of pipelines in key sections, etc. When local routes need to be changed, consult with the construction unit and the design unit, and go through the design change procedures as required; make good re-survey records to provide a basis for laying sub-pipes and optical cable trays.

[0033] S1.3 Inspection of single optical cable reel: Single reel inspection includes the following contents: optical cable appearance inspection, model, terminal, attenuation coefficient of 1310NM and 1550NM, optical cable wavelength, optical fiber backscattering signal curve, cable insulation, insulation between cables, insulation to ground, etc.; if there is obvious damage during the appearance inspection, records should be made, marked and reasons analyzed. If the optical and electrical cables cannot be used after testing, the specific situation shall be reported to the engineering project department, and the words "Strictly prohibited from use" shall be marked on the optical and electrical cable reels with red paint, and they shall be isolated and placed in accordance with the "Incoming Inspection and Test Control Procedure".

[0034] S1.34 Optical cable tray. The basis for optical and electrical cable trays is the pipe length measured during route retest. Optical and electrical cables are selected according to the design model. The natural bending of optical and electrical cables is considered to be 5%. 12 meters of overlap is reserved for optical cable joints. The length of optical cable laid in a straight manhole (handhole) increases by about 0.5 to 1 meter. The number of joints should be minimized.

[0035] The ratio of the outer diameter of the S2 optical cable to the inner diameter of the silicon core tube is within the range of 0.35 to 0.6; the suitable operating environment temperature is 6 to 32°C; the exhaust pressure of the air compressor should be no less than 1.2Mpa; the optical cable passes through the guide mechanism, the speed measuring wheel, the conveying mechanism, and the cable blowing head in sequence, and the cable head is connected to the air sealing piston through the cable mesh sleeve, and each part of the mechanism is adjusted and each control parameter is set.

[0036] Precautions

[0037] The optical cable laying end shall be based on the construction drawing design.

[0038] The exposed optical cables in the manholes (handholes) are fixed with plastic tie ties and marked with hanging plastic signs.

[0039] The optical and electrical cables in the office should be laid neatly and beautifully. The optical and electrical cables on ladders and wiring racks should be firmly tied with plastic ties and marked with plastic signs.

[0040] The reserved part of optical and electrical cables in the office should be tied firmly and beautifully with plastic signs. The reserved length on the equipment side is 15 to 20 meters.

[0041] The terminal and patch panel should connect a single optical fiber to a single optical fiber lead-out line and store spare optical fibers. The storage of spare optical fibers should not cause microbending losses. The "in" and "out" of the optical cable should be terminated on the same patch panel.

[0042] Selection of Cable Blowing Process Parameters

[0043] Generally, the ratio of the outer diameter of the optical cable to the inner diameter of the silicon core tube is within the range of 0.35 to 0.6. When it is greater than 0.6, a greater hydraulic thrust may be required when air blowing the optical cable, and the installation distance will be affected. When it is less than 0.35, there is a potential risk of folding of the optical cable in the silicon core tube, as shown in Table 1.

[0044] Table 1 Recommended relationship between the outer diameter of the optical cable and the inner diameter of the silicon core tube

[0045]

[0046] Compressed air pressure and hydraulic delivery force

[0047] The best compressed air pressure and hydraulic pressure depend on the different working conditions of each operation. For the hydraulic pressure, it should be lower at the beginning of the cable blowing machine. When the optical cable entering the silicon core tube is longer, the hydraulic pressure should be gradually increased. In addition, when blowing the optical cable with a smaller diameter than the pipeline, it is recommended to limit the hydraulic pressure to reduce the potential danger of the optical cable being folded in the pipeline.

[0048] Since the traction force at the front end of the optical cable is equal to the effective cross-sectional area (the cross-sectional area of ​​the pipe minus the cross-sectional area of ​​the optical cable) multiplied by the compressed air pressure, the larger the effective cross-sectional area, the greater the traction force on the optical cable. For example, when blowing a φ15mm optical cable in a pipe with an inner diameter of φ33mm, the traction force applied to the optical cable is 679N at a compressed air pressure of 1MPa, and the traction force applied to the optical cable at a compressed air pressure of 1.2MPa is 815N; when blowing a φ20mm optical cable in a pipe with an inner diameter of φ42mm, the traction force applied to the optical cable is 1071N at a compressed air pressure of 1MPa, and the traction force applied to the optical cable at a compressed air pressure of 1.2MPa is 1285N.

[0049] Suitable working environment temperature

[0050] The suitable working environment temperature is 6-32℃. When the ambient temperature is lower than 6℃, it is recommended to use an air line heater; when the ambient temperature is higher than 32℃, overheated compressed air is harmful to optical cables and plastic pipes, so consider using a compressed air cooler.

[0051] Air compressor selection

[0052] The selection of air compressor also has a great influence on the air blowing laying distance. The higher the output pressure of the air compressor, the greater the traction force applied to the front end of the optical cable. The exhaust pressure of the air compressor should be no less than 1.2MPa.

[0053] The output flow of the air compressor is also very important. When the optical cable is traveling in the plastic pipe, the flow of compressed air should be able to compensate for the air leakage in the cable blowing system. The larger the diameter of the plastic pipe, the larger the flow of the air compressor should be.

[0054] For plastic pipes with an inner diameter of φ26 to φ33 mm, the air compressor flow rate shall not be less than 9m3 / min. For plastic pipes with an inner diameter greater than φ33 mm, the air compressor flow rate shall not be less than 12m3 / min.

[0055] Check the sealing of plastic pipes: Use the supporting tool of this machine, "GDJ50 Pipe Sealing Detection Device", to conduct a sealing test on the plastic pipe. Only after confirming that the plastic pipe is leak-proof can the optical cable be blown.

[0056] Pre-lubricate plastic pipes, especially non-silicon core pipes, with pre-lubricant for optical cable blowing to achieve the best one-time cable laying length. Inject 0.2-0.4 liters / km of lubricant into the plastic pipe, install a special lubricating sponge plug, and push the lubricating sponge plug through the plastic pipe by inputting compressed air, so as to achieve the purpose of uniform pre-lubrication of the inner wall of the plastic pipe.

[0057] Installation of optical cables

[0058] The optical cable passes through the guide mechanism, speed measuring wheel, conveying mechanism, and cable blowing head in sequence, and the cable head is connected to the gas sealing piston through the cable mesh. Adjust each part of the mechanism and set each control parameter.

[0059] Operation of blowing optical cable by cable blowing machine

[0060] After all the above preparations are completed, the cable blowing operation can begin.

[0061] Because the main working parameters of the cable blowing machine are to control the air blowing laying speed of the optical cable, the traction force of the air sealing piston and the conveying force of the conveying mechanism.

[0062] Slowly open the compressed air inlet ball valve, and control the traction force of the air sealing piston on the optical cable by changing the size of the valve opening. When the optical cable is fed in a short distance, the valve inlet opening should be small, and then gradually increase until it is fully opened.

[0063] The speed control handle on the control console is used to control the laying speed of the optical cable. In this way, when the traction force at the front end of the optical cable is too large, the feeding speed of the optical cable can be restrained. When the air pressure is insufficient, it can provide auxiliary thrust, so that the blowing force used by the optical cable during travel is smaller. The transmission speed of the optical cable is generally controlled between 8 and 80m / min. 70m / min is usually appropriate.

[0064] When the optical cable is transported over a long distance, the output torque of the hydraulic motor can be increased by adjusting the pressure regulating handle on the operating console, so that the appropriate transmission force can be obtained.

[0065] When the optical cable reaches the predetermined point, that is, the air-sealing piston has come out of the tube (the air pressure will drop sharply at this time), the observer at the tube end should promptly remind the operator of the cable blowing machine to stop the machine immediately and stop feeding the optical cable into the tube, thus completing the air-blowing laying operation of a section of optical cable.

[0066] Cable rewinding operation is to convey the optical cable into the "cable rewinding device" to pour out the remaining optical cable on the original cable drum and find the other end to prepare for blowing the optical cable in the reverse direction. The "cable rewinding device" can save the labor of rewinding the reel in the shape of "8", saving time and effort and improving work efficiency. During the rewinding operation, care should be taken not to dirty the optical cable to avoid affecting the subsequent air blowing construction of the optical cable.

[0067] Startup and shutdown and precautions

[0068] Startup and shutdown sequence: When starting up, open the air blowing valve first, then start the conveying mechanism; when shutting down, stop the conveying mechanism first, then close the air blowing valve.

[0069] When the optical cable is blown into place, the cable transmission work of the transmission mechanism should be stopped in time and the air inlet valve should be closed.

[0070] Cable Blowing Precautions

[0071] Normally, a cable blowing machine can blow optical cable 1000m-2000m at a time.

[0072] In actual operation, the factors that affect the length of the blown optical cable are mainly the following:

[0073] The impact of topography and the quality of silicon core tube laying. When the route is relatively flat and the silicon core tube is laid relatively straight, the speed and length of cable blowing are relatively ideal; when there is a single arc with a large curvature radius (left or right or up and down) in the cable blowing section, it will have a slight impact on the speed and length of cable blowing; when the curvature of the silicon core tube is small, especially when a "W" shaped bend occurs, the impact is greater. Therefore, these situations should be avoided as much as possible when selecting the route. When laying the silicon core tube, the bottom of the trench should be straight, and the silicon core tube should have as few continuous left and right and up and down bends as possible.

[0074] The ratio of the outer diameter of the optical cable to the inner diameter of the plastic pipe;

[0075] The unit length weight of the optical cable and the outer sheath material (generally, the air blowing effect of the optical cable with the outer sheath of medium-density polyethylene is better);

[0076] Performance parameters of air compressor;

[0077] Report ambient temperature and humidity during construction;

[0078] When selecting the cable blowing point, try to choose a location that blows from top to bottom in uphill and downhill areas;

[0079] Operation points:

[0080] Before blowing the cable, check the tightness of the plastic pipe: use the supporting tool of this machine, "GDJ50 pipe sealing detection device", to conduct a tightness test on the plastic pipe. Only after confirming that the plastic pipe is leak-proof can the optical cable be blown.

[0081] Pre-lubricate plastic pipes, especially non-silicone core pipes. It is recommended to use a special pre-lubricant for optical cable blowing to pre-lubricate plastic pipes in order to achieve the best one-time cable blowing and laying length.

[0082] When blowing the cable, the length of the cable should be set reasonably, and the location from top to bottom should be selected as much as possible for the cable blowing operation.

[0083] The optical cable should be installed correctly according to the operating application instructions to ensure the quality and progress of the cable blowing operation.

[0084] During construction, auxiliary manpower cable transmission tools, special air-blown micro-cable trial-through heads, special micro-tube joints and micro-cable special joint box fixing devices, and reserved racks can be used for construction. If there are already optical cables in the pipeline, micro-tubes can be blown into them by air blowing. Large-core micro-cables can be blown into the micro-tubes to achieve online capacity expansion. After testing, the original optical cable and micro-cable signals can be opened normally. By utilizing existing pipelines, new pipeline resources can be provided to customers.

[0085] The specific implementation scheme described above further describes in detail the purpose, technical scheme and beneficial effects of the present invention. It should be understood that the above is only a specific implementation scheme of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes and modifications made by any technician in the field without departing from the concept and principle of the present invention should fall within the scope of protection of the present invention.

Claims

1. A method for laying optical cable on a highway, characterized in that: The following steps are included: S1. Construction preparation; S2. The ratio of the outer diameter of the optical cable to the inner diameter of the silicon core tube is within the range of 0.35 to 0.6; the suitable working environment temperature is 6 to 32°C; the exhaust pressure of the air compressor should be no less than 1.2Mpa; the optical cable passes through the guide mechanism, the speed measuring wheel, the conveying mechanism, and the cable blowing head in sequence, and the cable head is connected to the air sealing piston through the cable mesh sleeve, and each part of the mechanism is adjusted and each control parameter is set; S3. Slowly open the compressed air inlet ball valve and control the pulling force of the air sealing piston on the optical cable by changing the size of the valve opening; S4. When the distance of the optical cable is short, the air inlet of the valve should be opened slightly, and then gradually increased until it is fully opened; the speed control handle on the control console is used to control the laying speed of the optical cable. In this way, when the traction force at the front end of the optical cable is too large, the feeding speed of the optical cable can be restrained, and when the air pressure is insufficient, auxiliary thrust can be provided to make the blowing force used by the optical cable smaller during travel; the transmission speed of the optical cable is controlled between 8 and 80 m / min; S5. When the optical cable reaches the predetermined point, that is, the air-sealing piston has come out of the tube (the air pressure will decrease sharply at this time), the observer at the tube end should promptly remind the operator of the cable blowing machine to stop the machine immediately and stop conveying the optical cable into the tube, thus completing the air-blowing laying operation of a section of optical cable; S6, cable rewinding operation, that is, conveying the optical cable into the "optical cable rewinding device", the purpose is to pour out the remaining optical cable on the original cable drum, find the other end, and prepare for blowing the optical cable in the reverse direction.

2. A highway optical cable blowing and laying construction method according to claim 1, characterized in that: In step S1, construction preparation includes pre-construction preparation, route retest, optical cable single reel inspection and optical cable reel distribution; Preparation before construction: Before laying optical and electrical cables, the main technical indicators of each optical and electrical cable shall be checked and tested; installation process inspection, optical cable specifications, pipe hole positions, optical cable connection specifications and quality, optical cable direction and fixation, optical cable protection, optical cable entry and termination quality, distribution frame installation and wiring; cable insulation resistance test, insulation resistance of all cables and to ground.

3. A highway optical cable blowing and laying construction method according to claim 1, characterized in that: In step S2, the relationship between the outer diameter of the optical cable and the inner diameter of the silicon core tube is as follows:

4. A highway optical cable blowing and laying construction method according to any one of claims 1 to 3, characterized in that: In step S4, the conveying speed of the optical cable is 70 m / min.

5. The method for laying highway optical cable by blowing according to claim 1, characterized in that: In step S4, when the optical cable is transported over a long distance, the output torque of the hydraulic motor is increased by adjusting the pressure regulating handle on the operating console, thereby obtaining a suitable transport force.

6. A highway optical cable blowing and laying construction method according to claim 5, characterized in that: In step S4, after the optical cable is blown into place, the cable conveying work of the conveying mechanism should be stopped in time and the air inlet valve should be closed.

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