Cryogenic Vent Pipe Isolation Balloon With Network Reinforcement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional vent pipe isolation balloons for liquefied gas storage tanks lack sufficient physical strength and durability when used in cryogenic temperatures, as they are either not inflatable or prone to cracking due to stress on fabric substrates, and have low adhesion to the inner pipe surface.

Innovation Solution

A balloon with a network structure reinforcing substrate made of ultra-high density polyethylene fibers, sandwiched between inner and outer membranes of cold-resistant rubber, allowing for increased flexibility and pressure resistance without stress concentration at the substrate-membrane interface, enabling easy insertion and stable occlusion of the vent pipe.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a fabric substrate with silicon rubber coating is used for the balloon, then adhesion to the pipe surface is improved, but physical strength and durability in cryogenic temperatures deteriorate due to stress concentration at the substrate-membrane interface

Engineering Contradiction:
Improveadhesion to pipe surfaceVSAvoidphysical strength in cryogenic temperature
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent uses a composite structure consisting of a fabric substrate (nylon, aramid, or polyethylene) coated with silicon rubber. This composite material combines the adhesion properties of silicon rubber with the strength of the fabric substrate, resolving the contradiction between adhesion and physical strength in cryogenic conditions.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies silicon rubber coating specifically to the fabric substrate at the portions that contact the pipe surface, rather than uniformly throughout. This localized application improves adhesion where needed while minimizing stress concentration and maintaining overall structural integrity in cryogenic temperatures.

Inventive Principle:
Principle #3Local quality

2Reliability

If internal pressure during inflation is increased to increase occlusivity, then adhesion force is improved, but the balloon tends to crack due to stress on the fabric substrate and silicon rubber boundary surface

Engineering Contradiction:
Improveocclusivity of vent pipeVSAvoidresistance to cracking
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The composite structure of fabric substrate and silicon rubber coating allows the balloon to withstand higher inflation pressures. The fabric substrate provides tensile strength while the silicon rubber maintains adhesion, enabling increased occlusivity without cracking at the interface.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

By concentrating the silicon rubber coating at the contact portions with the pipe surface, the patent localizes the adhesion function to where it is most needed for occlusion, while the rest of the fabric substrate maintains its structural strength to resist cracking under pressure.

Inventive Principle:
Principle #3Local quality

3Strength

If a thick fabric is used as substrate, then physical strength is improved, but ease of insertion into the vent pipe deteriorates and inflatability is reduced

Engineering Contradiction:
Improvephysical strength of balloonVSAvoidease of insertion into vent pipe
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent uses a thin fabric substrate with localized silicon rubber coating only at the contact portions, rather than uniformly thick fabric throughout. This localized approach provides sufficient strength where needed while keeping the overall structure thin and flexible for easy insertion and inflation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The composite structure allows the use of a thin fabric substrate that would normally be too weak, because the silicon rubber coating provides localized reinforcement at critical contact points, maintaining strength while enabling ease of insertion and inflation.

Inventive Principle:
Principle #40Composite materials

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 balloon provides enhanced physical strength, inflatability, and durability, ensuring safe and stable isolation of the vent pipe even in cryogenic temperatures, with improved adhesion and resistance to cracking.

Implementation Method 1

A silicon rubber layer 207 is formed on the surface of the intermediate portion 203, and an engaging force due to the frictional resistance occludes the vent pipe.

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

an inert gas such as nitrogen gas is injected into the balloon to inflate the balloon and occlude the vent pipe

Methodology Applied
Scientific EffectGas pressure expansion: Pressure Increase

Data Source

PatentEP3696460B1Vent pipe isolation device
Publication Date: 2023.09.13 MITSUBISHI RUBBER CO LTD
  • EP3696460B1 patent drawingFigure 1~1(b)
  • EP3696460B1 patent drawingFigure 2~3
  • EP3696460B1 patent drawingFigure 4

AI summary

An object of the present invention is to provide a vent pipe isolation balloon for a liquefied gas storage tank, which has excellent physical strength, inflatability, and durability at cryogenic temperatures, and a vent pipe isolation device including the balloon. The vent pipe isolation balloon of the present invention has inner and outer membranes made of silicon rubber, and a reinforcing substrate sandwiched between the inner membrane and the outer membrane. The balloon has an outer shape of a cylindrical shape or a truncated cone shape with both ends opened, and is inflated when an inert gas is injected into the balloon with the openings sealed. The reinforcing substrate is composed of a fiber bundle and has a network structure.