Membrane Separator Wall Member Curvature for Pressure Resistance

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Solution Overview

Problem

The existing membrane separators face issues with structural strength due to thin wall members in water collecting cases, which can lead to deformation and breakage under pressure variations, and also experience channel resistance that affects permeate flow rates, especially when stacked in multiple stages.

Innovation Solution

The membrane separator design includes wall members with projecting and recessed portions forming a continuous curved surface, and ribs on the outer sides to enhance structural strength and reduce channel resistance, allowing for equalized permeate flow without increasing the external dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If thin wall members are used to form the water collecting case, then the device complexity is reduced and ease of manufacture is improved, but the strength and reliability deteriorate due to deformation and breakage under pressure variations

Engineering Contradiction:
Improveease of manufactureVSAvoidstrength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The wall member is designed with projecting portions and recessed portions that form a continuous curved surface. This curved structure increases the buckling load and structural strength of the thin wall member, allowing it to withstand pressure variations during filtration and chemical cleaning without deformation or breakage, while maintaining the simplicity and ease of manufacture of thin-walled construction.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Productivity

If multiple membrane modules are vertically stacked to increase productivity, then the productivity is improved, but the stress and pressure on the lower water collecting cases increase, worsening the strength requirement

Engineering Contradiction:
ImproveproductivityVSAvoidstress
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The curved surface structure with projecting and recessed portions distributes the vertical load from stacked modules more effectively across the wall member. This curvature provides structural reinforcement that enables the water collecting cases to withstand the cumulative stress from multiple vertically-stacked membrane modules, allowing increased productivity without compromising strength.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Device complexity

If the water collecting case structure is simplified to only membrane elements and water collecting cases, then the device complexity is reduced, but the reliability deteriorates due to insufficient load-bearing capacity

Engineering Contradiction:
Improvedevice complexityVSAvoidreliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The continuous curved surface formed by projecting and recessed portions in the wall member provides inherent structural reinforcement without adding complex external support structures. This maintains the simplified two-component design (membrane elements and water collecting cases) while significantly improving the load-bearing capacity and reliability of the water collecting case to withstand operational pressures and stacked module loads.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Data Source

PatentEP2260928B1Membrane separator and membrane cassette
Publication Date: 2016.09.21 KUBOTA CORP
  • EP2260928B1 patent drawingFigure 1~2
  • EP2260928B1 patent drawingFigure 3~4
  • EP2260928B1 patent drawingFigure 5~6

AI summary

The wall member of a water collecting case forms a projecting portion projecting to the outer side and recessed portions recessed to the inner side.