Membrane Cartridge End Caps for Pressure-Stable Gas Separation

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Solution Overview

Problem

Conventional membrane modules for gas separation and liquid filtration are costly to replace due to their complex design, require toxic and environmentally unfriendly release agents, and suffer from pressure instability and reliability issues, leading to high maintenance costs and potential gas leakage.

Innovation Solution

The use of plastic end caps that adhere to the cartridge element, eliminating the need for release agents and O-rings, and distributing pressure evenly across the bond surface, resulting in a more reliable and cost-effective cartridge system with improved thermal stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If release agents are used to prevent epoxy resin from sticking to metal surfaces, then the tube sheet can be easily demoulded, but the epoxy resin curing is compromised and the tube sheet becomes weaker

Engineering Contradiction:
Improvedemoulding easeVSAvoidtube sheet strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The invention extracts and eliminates the release agent from the manufacturing process. By using a cartridge tube made of plastic or polymer material instead of metal, the release agent is no longer needed, thus avoiding its harmful effects on epoxy curing while still enabling easy demoulding of the tube sheet.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the material parameter of the cartridge tube from metal to plastic/polymer. This material substitution fundamentally changes the interaction between the tube surface and epoxy resin, eliminating the need for release agents and allowing the epoxy to cure properly while maintaining ease of demoulding.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If a non-stick design is used between tube wall and potting, then the tube sheet can be easily removed, but pressure stability deteriorates and gas leakage occurs

Engineering Contradiction:
Improvetube sheet removal easeVSAvoidpressure stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention changes the material parameter of the cartridge tube from metal to plastic/polymer. This creates a stick design where the potting resin adheres to the tube wall, providing excellent pressure stability and preventing gas leakage, while the plastic material still allows for easy tube sheet removal when needed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite structure where the plastic/polymer cartridge tube works in conjunction with the potting resin to create a stick design. This composite approach provides both the adhesion needed for pressure stability and the ease of removal when maintenance is required.

Inventive Principle:
Principle #40Composite materials

3Reliability

If the entire module is replaced when membranes need replacement, then the system maintains reliability, but the cost and complexity increase significantly

Engineering Contradiction:
Improvesystem reliabilityVSAvoidreplacement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention segments the membrane separation device into two replaceable parts: the cartridge element (containing membranes and cartridge tube) and the cartridge housing. This allows only the cartridge element to be replaced when membranes need maintenance, while the expensive housing remains in place, significantly reducing replacement complexity and cost while maintaining system reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention enables selective discarding of the cartridge element (which contains the consumable membranes) while recovering and reusing the expensive cartridge housing. This approach maintains system reliability by ensuring proper membrane replacement while reducing overall system complexity and maintenance costs.

Inventive Principle:
Principle #34Discarding and recovering

4Ease of manufacture

If release agents are applied to prevent sticking, then the tube sheet can be demoulded, but the production process becomes more complex and costly

Engineering Contradiction:
Improvedemoulding capabilityVSAvoidproduction process complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the release agent step from the production process. By using plastic/polymer cartridge tubes instead of metal, the demoulding process becomes simpler and more cost-effective, as no additional release agent application steps are needed while still maintaining easy tube sheet removal capability.

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

The new cartridge system achieves higher pressure stability, reduced production complexity, and lower maintenance costs, while allowing broader application under extreme conditions without gas leakage, thus enhancing the economic viability and reliability of gas separation processes.

Implementation Method 1

end caps (7a, 7b) made of a polymeric material which are fixed to the cartridge element

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

a bundle of hollow fiber type membranes aligned in a cartridge tube

Methodology Applied
Scientific EffectMembrane separation: Semipermeable Membrane

Data Source

PatentEP3936223B1Use of a cartridge element for separation of gas mixtures
Publication Date: 2026.02.11 EVONIK OPERATIONS GMBH
  • EP3936223B1 patent drawingFigure 1~2
  • EP3936223B1 patent drawingFigure 3~4a
  • EP3936223B1 patent drawingFigure 4b~5

AI summary

The present invention is related to a new membrane cartridge system comprising hollow fiber membranes, a special new end cap for the production of the new cartridge, membrane separation devices comprising the new membrane cartridges and a process for manufacture of the new cartridges.