Air Inversion CIPP Liner Apparatus with Low Friction Seal
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Solution Overview
Problem
Current methods for installing cured-in-place liners in conduits using water inversion are inefficient due to high water requirements and increased friction during the inversion process, limiting the use of air inversion and steam cure, which offers reduced water usage and faster curing times.
Innovation Solution
An apparatus with a low friction seal, featuring an adjustable gland with compressible layers and a porting system, allows for air inversion and steam curing of resin-impregnated liners, reducing friction and enabling efficient installation of CIPP liners in small to medium diameter conduits without collapsing the liner before curing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If water inversion is used to install CIPP liners, then the liner can be inverted into the conduit, but high water consumption and increased friction occur during the inversion process
Solution Approach 1:
The patent applies pneumatic inversion using compressed air instead of hydraulic water inversion. The air pressure forces the liner through the gland and into the conduit, eliminating the need for large volumes of water while maintaining effective inversion force. This resolves the contradiction by substituting the inversion medium from water to air.
Solution Approach 2:
The patent changes the physical state and properties of the inversion medium from liquid (water) to gas (air). This parameter change reduces the quantity of substance required while maintaining the pressure differential needed for inversion. The air can be compressed to provide sufficient force without the volumetric constraints of water.
2Quantity of substance
If traditional water inversion is used, then the liner can be installed, but the process requires significant water and time for curing
Solution Approach 1:
The patent utilizes phase transition of water into steam for curing the resin. The steam is injected through the liner, and the phase change from liquid to gas provides intense heat transfer that rapidly cures the resin. This eliminates the need for large volumes of water used in traditional hot water curing methods while significantly reducing curing time.
Solution Approach 2:
The system uses pneumatic delivery of steam through the liner, combining the benefits of gas-phase heat transfer with pressurized delivery. This allows for efficient heat transfer and rapid curing without the water consumption associated with traditional hydraulic curing systems.
3Quantity of substance
If air inversion is attempted without a low friction seal, then water usage is reduced, but the liner may collapse before curing
Solution Approach 1:
The patent employs a flexible bladder or tube inside the liner that inflates with air pressure. This flexible element maintains the liner's structural integrity during inversion by providing internal support pressure that counteracts external collapse forces. The thin film structure conforms to the conduit shape while preventing collapse.
Solution Approach 2:
The inflated bladder provides counter-pressure to balance the external atmospheric pressure and prevent liner collapse. The internal air pressure in the bladder acts as a counterweight force that maintains the liner's structural integrity throughout the inversion process.
4Loss of time
If steam curing is used with air inversion, then curing time is reduced, but the apparatus must handle both air and steam flow
Solution Approach 1:
The patent designs the gland and delivery system to perform multiple functions: serving as both the inversion seal for air pressure and the curing delivery system for steam. The same apparatus components handle both the pneumatic inversion phase and the steam curing phase, eliminating the need for separate systems and reducing overall complexity.
Solution Approach 2:
The patent combines the inversion and curing operations into a single integrated process using the same apparatus. The gland that seals during air inversion also serves as the delivery point for steam curing, merging two distinct functions into one unified system that reduces complexity.
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
The solution enables efficient air inversion and steam curing of CIPP liners, reducing installation time and water usage while maintaining the structural integrity of the conduit, addressing the limitations of existing water-based inversion methods.
Implementation Method 1
The gland includes a compressible layer which may be comprised of a resilient material such as silicone rubber
Implementation Method 2
An apparatus for inverting a resin impregnated cured in place liner with air having a low friction seal between the moving CIPP liner and a stationary inverting gland
Implementation Method 3
The resin may be cured with continuous flow-through steam
Implementation Method 4
The resin may be cured with continuous flow-through steam
Data Source
AI summary
An air inversion and steam cure apparatus for installing a flexible resin impregnated cured in place liner in an existing conduit is provided. The apparatus has a low friction seal between a moving liner and the stationary apparatus gland. The gland is operated and adjusted by displaceable members that move substantially perpendicular to the liner being inverted to engage the moving liner as it passes through the gland. No part of the gland extends into the chamber so that once a pre-shaped gland is adjusted, the pressure on the moving liner is not increased. As the liner reaches the distal end, it enters a sample and porting pipe with an exhaust pipe gland and exhaust pipe and is pierced by a rigid porting tool. Steam is then introduced into the liner to cure the resin and is exhausted through an exhaust hose connected to the porting tool. After cure, steam is replaced with air to cool the liner and the ends are cut to restore service through the existing conduit.