Leaking Plug Cable Installation for Pressure-Limited Duct Laying
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Solution Overview
Problem
Existing methods for installing cables into ducts, such as those buried or underwater, face challenges with high liquid flow requirements and risks of damaging the duct or cable due to excessive pressure, especially in large power cable installations.
Innovation Solution
A method involving a leaking plug attached to the cable, where the pressure is controlled to start a leaking mode only when necessary, allowing for reduced liquid supply and minimizing stress on the duct and cable, with phases of minimal and increased liquid flow to propel the cable safely through the duct.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a pressurized liquid is introduced at high flow to propel the cable into the duct using floating technique, then the cable can be laid through long ducts, but very high volumes of liquid are required and high flow pumps are needed
Solution Approach 1:
The cable installation process is divided into two distinct phases: a pulling phase where the leaking plug maintains pressure to pull the cable, and a floating phase where the plug leaks to allow high flow propulsion. This segmentation allows each phase to use the appropriate liquid flow level for its specific function.
Solution Approach 2:
The leaking plug dynamically transitions between two states: a non-leaking state during the pulling phase and a leaking state during the floating phase. This dynamic behavior allows the system to adapt liquid flow requirements to the current installation phase, reducing overall liquid volume needs.
2Productivity
If high flow pumps are used to supply pressurized liquid at high volumes, then the cable can be propelled into the duct, but the system complexity and equipment requirements increase
Solution Approach 1:
The liquid supply system is segmented into two operational modes corresponding to two phases: a pulling phase requiring only minimal liquid flow to maintain pressure, and a floating phase requiring high flow. This eliminates the need for continuously high-capacity pumping equipment.
Solution Approach 2:
Instead of continuously supplying excessive liquid flow, the system applies partial action (minimal flow) during the pulling phase and excessive action (high flow) only during the floating phase. This reduces overall system complexity and equipment requirements.
3Speed
If excessive pressure is applied to pull the cable into the duct, then the cable can be propelled faster, but the duct may burst or the cable may rupture
Solution Approach 1:
The leaking plug is pre-configured with a specific leaking pressure threshold before installation. During the pulling phase, it maintains pressure below this threshold to ensure safety. When the threshold is exceeded, it automatically transitions to leaking mode, preventing excessive pressure buildup that could damage the duct or cable.
Solution Approach 2:
The leaking plug provides automatic feedback control by monitoring the pressure differential across it. When the pressure exceeds the leaking pressure threshold, the plug automatically leaks, reducing the pressure. This feedback mechanism ensures pressure remains within safe limits while enabling cable propulsion.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method reduces the risk of duct or cable damage and minimizes liquid supply needs while effectively laying cables through long ducts by controlling pressure and flow, ensuring the duct is filled and the cable is propelled efficiently.
Implementation Method 1
supplying a pressurized liquid into the duct at a supply port arranged between the foremost end equipped with the leaking plug and the first extremity, and at a supply pressure equal to or higher than a predetermined pressure, so that the cable is pulled by the leaking plug
Implementation Method 2
the cable is introduced into the duct, and a pressurized liquid is simultaneously introduced, so as to create drag forces along the cable, to propel it into the duct
Implementation Method 3
setting a leaking mode of a leaking plug to start at a leaking pressure drop across the leaking plug determined to be equal to or lower than the maximum pressure
Data Source
AI summary
Method for installing a cable into a duct, comprising the steps of:determining a maximum pressure,setting a leaking mode of a leaking plug to start at a leaking pressure drop equal to or lower than the maximum pressure,attaching the leaking plug to a foremost end of the cable,introducing the foremost end of the cable into the duct,supplying a pressurized liquid into the duct:at a supply port, andat a supply pressure,so that the cable is pulled by the leaking plug,before the foremost end has reached the second extremity, exceeding the leaking pressure drop at a location close to the leaking plug.