Vacuum Lock Liner Impregnation Degassing

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Solution Overview

Problem

Existing methods for impregnating liners in pipelines often result in voids within the liner, which can lead to premature degradation and leakage due to trapped air bubbles, as they fail to effectively degas the fibre material before resin infusion.

Innovation Solution

The impregnation station employs a vacuum lock system to compress and degas the liner, followed by a resin bath with a resin jet to ensure complete resin penetration, utilizing a low-pressure chamber and a continuous vacuum pump to remove residual air and a system for monitoring resin levels to maintain optimal impregnation conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the liner is impregnated by submerging it in a resin bath without degassing, then the impregnation process is simple and quick, but air bubbles become trapped inside the fibre material creating voids that lead to premature degradation and leakage

Engineering Contradiction:
Improveliner stabilityVSAvoidimpregnation process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The liner is compressed in the vacuum lock before resin impregnation to remove air from the fibre material. This preliminary degassing action prevents air bubbles from being trapped during subsequent resin infusion, eliminating voids that would cause premature degradation and leakage while maintaining process efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A vacuum lock serves as an intermediary chamber between the resin bath and the exit. This intermediate space allows controlled compression and degassing of the liner using vacuum pressure, facilitating complete air removal before the liner enters the resin bath, thereby ensuring void-free impregnation without complicating the overall process

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the liner is compressed strongly to remove air, then degassing is more effective, but the fibre material may be damaged or crushed

Engineering Contradiction:
Improvedegassing effectivenessVSAvoidfibre material integrity
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The vacuum lock controls compression through parameter changes - using vacuum pressure (negative pressure) instead of direct mechanical compression. This allows air to be removed from the fibre material without applying crushing forces, maintaining fibre integrity while achieving effective degassing. The pressure is gradually adjusted rather than applied abruptly

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Pneumatic pressure control via vacuum pump creates a controlled low-pressure environment in the vacuum lock. This pneumatic approach removes air from the liner through pressure differential without mechanical contact that could damage fibres, achieving effective degassing while preserving fibre material strength and structure

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Manufacturing precision

If a vacuum lock system is introduced to degas the liner, then void formation is reduced, but the device complexity and process time increase

Engineering Contradiction:
Improvevoid-free impregnationVSAvoidimpregnation speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The vacuum lock and resin bath are integrated into a single continuous impregnation line. The liner moves sequentially through the vacuum lock for degassing and then directly into the resin bath for impregnation without interruption. This merging of operations maintains high productivity while ensuring void-free results through proper degassing

Inventive Principle:
Principle #5Merging (Combining)

4Productivity

If the liner is not thoroughly degassed before resin infusion, then the process is faster and simpler, but trapped air bubbles create weak spots leading to cracking and leakage

Engineering Contradiction:
Improveimpregnation speedVSAvoidliner defect-free quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The vacuum lock performs preliminary air removal from the liner before resin infusion. By removing air in advance through vacuum compression, the subsequent resin impregnation proceeds quickly without interruption for defect correction, maintaining high productivity while ensuring defect-free quality

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The vacuum lock extracts air from the fibre material before resin infusion. This extraction of harmful air bubbles prevents their entrapment during impregnation, eliminating the source of future defects such as cracking and leakage while maintaining efficient process speed

Inventive Principle:
Principle #2Taking out (Extraction)

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 significantly reduces the occurrence of voids within the liner, enhancing its stability and preventing premature degradation and leakage by ensuring thorough resin infusion and degassing.

Implementation Method 1

a low pressure environment is created by a vacuum pump

Methodology Applied
Scientific EffectVacuum: Vacuum

Implementation Method 2

the material is compressed in the vacuum lock and subsequently allowed to expand inside the low pressure space

Methodology Applied
Scientific EffectDecompression: Depressurisation

Implementation Method 3

The fibre material may be e.g. a glass fibre material or felt material, which is flexible and at the same time may hold a large quantity of resin. The material should exhibit affinity to the resin to allow the resin to soak the liner completely.

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Data Source

PatentEP2331310B1Impregnation plant and method
Publication Date: 2019.08.21 PER AARSELFF AS
  • EP2331310B1 patent drawingFigure 1
  • EP2331310B1 patent drawingFigure 2
  • EP2331310B1 patent drawingFigure 3A~3B

AI summary

The object of the invention is to provide a method and system for impregnating a liner, simultaneously reducing the risk of a void inside the liner after curing. This object is achieved by an impregnation plant (10) comprising a vacuum lock (16) comprising a housing having an inlet (14) and an outlet and defining an ambient pressure space (15) near the inlet and a low pressure space (24) near the outlet. The pressure spaces are separated by a seal (20) comprising a first and a second sealing element (22, 23), allowing the fibrous liner (12) to be conveyed there between from the inlet (14) towards the outlet. The liner is degassed by compressing it between the first and second sealing elements (22, 23) and is subsequently relaxed in an uncompressed state inside the low pressure space (24). The plant further comprises a vacuum pump communicating with the low pressure space, and an impregnation station in gas-tight communication with the outlet or the vacuum lock (16) and comprising a resin bath (28) for accommodating the liner, a resin reservoir, a nozzle (32), a pipe system (38) and a resin pump (36) for propelling the resin from the resin reservoir via the pipe system (38) and the nozzle (32) into the resin bath (28) in a direction towards the liner.