Gassing Device Convex Elevation Membrane Wrinkle Prevention

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Solution Overview

Problem

Intermittent operation of gassing devices in sewage treatment plants leads to membrane wrinkling and eventual tearing due to hydrostatic pressure and excess material, reducing the operational life of the membrane.

Innovation Solution

The design features a convex elevation with concave transitions on the introduction body, allowing the membrane to maintain contact without wrinkles, absorbing excess material and preventing buckling, with specific dimensional ranges optimizing the membrane's inner and outer circumference to extend its service life.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the membrane is oversized to facilitate assembly, then ease of assembly is improved, but the membrane forms uncontrolled folds under hydrostatic pressure which leads to material embrittlement and reduced service life

Engineering Contradiction:
Improveease of assemblyVSAvoidservice life of membrane
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention applies local quality by creating a non-uniform circumference profile on the introduction body with specific geometric parameters. The circumference varies along the longitudinal axis, with smaller circumferences in upper and lower regions and a larger intermediate circumference, causing the membrane to form controlled local folds only in the intermediate region rather than uncontrolled folds throughout. This localized fold control maintains reliability while preserving the oversized membrane design for ease of assembly.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the geometric parameters of the introduction body by defining specific circumference variations along its length. By controlling the circumference to be smaller at the ends and larger in the intermediate section, the patent transforms the membrane's interaction with the introduction body, directing excess membrane material to form folds only in the intermediate region where it causes minimal damage.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If controlled folds are forced in the non-perforated area to extend membrane life, then service life is improved, but the membrane material still becomes brittle over time and may eventually tear

Engineering Contradiction:
Improveservice life of membraneVSAvoidmaterial strength at fold points
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention refines local quality by precisely controlling where folds occur through the circumferential profile design. By concentrating folds in the intermediate region with larger circumference and preventing folds in the upper and lower regions, the patent reduces the number of stress cycles at any single location, thereby slowing down material embrittlement while maintaining extended service life.

Inventive Principle:
Principle #3Local quality

3Reliability

If the membrane is pressed against the introduction body under hydrostatic pressure, then gas leakage is prevented, but uncontrolled folds form in the perforation slot area causing material damage

Engineering Contradiction:
Improvegas sealingVSAvoidmembrane buckling and folding
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention applies local quality by creating different circumferential profiles at different locations along the introduction body. The smaller circumferences at the upper and lower regions prevent membrane buckling in those areas, while the larger intermediate circumference allows controlled folding. This spatial differentiation of geometric parameters enables the membrane to maintain gas sealing while avoiding harmful uncontrolled folds in the perforation slot areas.

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 keeps the membrane wrinkle-free, preventing material embrittlement and significantly extending the operational life of the gassing device, allowing for the use of membranes with larger tolerances and compensating for elasticity loss.

Implementation Method 1

a first concave transition 32 between the convex elevation 28 and the surface 26 of the basic contour of the introduction body 12. The inner circumference of the membrane (16) is larger than the shortest envelope of the introduction body (12) following tangents (44, 46) spanning the concave transitions (30, 32), such that excess membrane material can attach itself to the concave transitions (30, 32)

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

When the gassing device is switched off, ie when no gas is introduced into the liquid, the hydrostatic pressure of the liquid causes the membrane to be pressed against the introduction body

Methodology Applied
Scientific EffectHydrostatic pressure: Pressure Increase

Implementation Method 3

the convex elevation 28 in connection with the subsequent concave transitions 30, 32 results in the shortest envelope of the lead-in body following tangents which span the concave transitions

Methodology Applied
Scientific EffectGeometric configuration: Geometry

Data Source

PatentEP2374527B1Gassing device for intermittent feeding of a gas into a liquid
Publication Date: 2013.06.26 OTT FRIEDERIKE
  • EP2374527B1 patent drawingFigure 1~2
  • EP2374527B1 patent drawingFigure 3~4

AI summary

A gassing device (10) for the intermittent introduction of a gas into a liquid. The gassing device comprises a tubular inlet body (12) with a lower axially extending groove (14) for the longitudinal distribution of the gas to be introduced. The inlet body is surrounded by a membrane (16) made of an elastic material, which includes perforated slots (22) for introducing the gas into the liquid and an unperforated area (24, 25). In the invention, convex protrusions (28) and concave transitions (30, 32) are provided on the surface of the inlet body, thereby increasing the outer circumference of the inlet body and providing the inner circumference of the membrane with space to conform to the inlet body without wrinkling of the membrane.