Strip Diffuser Co-extrusion for Alignment and Sealing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing strip diffusers face challenges in achieving consistent body alignment, maintaining dependable membrane end and edge sealing, and securely positioning in liquid treatment vessels, leading to inefficiencies in wastewater treatment processes.

Innovation Solution

A strip diffuser assembly with a pipe having a longitudinally extending central axis and a membrane support member co-extruded with the pipe, featuring a connecting portion with thickened regions and lateral portions, which are integral with the pipe and support the membrane diffusion element, providing a sealing engagement mechanism without bracing, and a gas supply conduit integral with the diffuser body for enhanced stability and ease of installation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If bracing is added to connect the pipe to the lateral portion, then structural strength is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvestructural strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent integrates the bracing structure directly into the lateral portion by co-extruding them as a single unit. The lateral portion and bracing are formed simultaneously from the same material in one manufacturing process, eliminating the need for separate bracing components and their associated assembly steps. This merging of functions reduces manufacturing complexity while maintaining the required structural strength.

Inventive Principle:
Principle #5Merging (Combining)

2Manufacturing precision

If membrane support member is co-extruded with the pipe, then manufacturing precision and alignment are improved, but device complexity increases

Engineering Contradiction:
Improvebody alignmentVSAvoiddevice complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The membrane support member is co-extruded with the pipe as an integrated structure. This simultaneous formation process ensures precise alignment between the support member and pipe while eliminating the need for separate assembly operations. The single-step manufacturing process achieves high manufacturing precision without significantly increasing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The membrane support member is designed with distinct functional segments including the lateral portion, connecting portion, and thickened region. This segmentation allows each part to perform its specific function while being manufactured as an integrated unit with the pipe, achieving both precision and functional optimization.

Inventive Principle:
Principle #1Segmentation

3Reliability

If thickened regions are added to the connecting portion, then sealing reliability is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvesealing reliabilityVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The thickened regions are incorporated directly into the connecting portion during the co-extrusion process. The varying thickness profile is built into the single manufacturing operation, creating the sealing structure without requiring additional machining or assembly steps. This integration maintains sealing reliability while avoiding increased manufacturing complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The connecting portion features localized thickened regions at specific locations where sealing is required. This local quality enhancement provides improved sealing reliability only where needed, rather than uniformly increasing the complexity of the entire structure. The thickened regions are precisely positioned during co-extrusion to match the sealing requirements.

Inventive Principle:
Principle #3Local quality

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 configuration ensures consistent alignment, improved sealing, and secure positioning of the diffuser, reducing manufacturing and installation costs while enhancing oxygen transfer efficiency and ease of installation in wastewater treatment plants.

Implementation Method 1

a membrane diffusion element which is elongated in the direction of the central axis, has ends and longitudinally extending marginal portions

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

a membrane support member co-extruded with the pipe, featuring a connecting portion with thickened regions and lateral portions, which are integral with the pipe

Methodology Applied
Scientific EffectCo-extrusion: Extrusion

Data Source

PatentEP2260932B1Strip diffuser
Publication Date: 2019.02.27 XYLEM IP HOLDINGS LLC
  • EP2260932B1 patent drawingFigure 1~2
  • EP2260932B1 patent drawingFigure 3
  • EP2260932B1 patent drawingFigure 4

AI summary

A strip diffuser has an elongate diffuser membrane support defining an upper surface for location of the membrane. An elongate groove is formed in a lateral portion on either side of the support for receiving a marginal edge portion of the membrane. The marginal edge is secured in the groove by means of an elongate securing member. The sidewalls of the groove are formed with at least one elongate projection, and the securing member has a cross-section large enough to clamp the marginal portion of the membrane against that projection upon insertion of the securing member into the groove over the membrane. Normally, the sidewalls of the groove are formed with at least one opposed pair of elongate projections. In an assembly of the invention the height of the projection or projections is normally a substantial portion of the thickness of the membrane. A typical height is in the range 0.2 to 0.4 mm, and based on measurements from the groove sidewalls, inclined at an angle of about 45 degrees.