Cross Flow Inversion Baffle for Static Mixer Streaking

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Solution Overview

Problem

Static mixers face the issue of streaking phenomenon where unmixed fluid forms along the interior surfaces, leading to inefficient mixing and increased mixer length, which results in higher retained volume and material waste, especially in handheld applications.

Innovation Solution

The cross flow inversion baffle design, featuring a divider wall and flow diverters, redirects fluid from the center to the perimeter and vice versa, creating four flow chambers that divide and recombine fluid flows in opposite lateral directions to prevent streaks from combining, thereby enhancing mixing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If baffles of greater twist are used to force fluid from periphery into center, then streaking phenomenon is reduced, but mixer length increases and mixing efficiency decreases

Engineering Contradiction:
Improvestreaking phenomenonVSAvoidmixing efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The baffle is segmented into multiple functional zones: a first baffle section for initial flow redirection, a second baffle section for further mixing, and a third baffle section for final flow inversion. This segmentation allows each section to perform a specific mixing function, effectively addressing streaking while maintaining compact overall length and high mixing efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements flow inversion by designing the baffle geometry to reverse the flow direction multiple times along the flow path. The third baffle section specifically inverts the flow direction to counteract streaking, applying the inversion principle to eliminate harmful flow patterns without requiring excessive mixer length.

Inventive Principle:
Principle #13The other way round (Inversion)

2Object-affected harmful factors

If mixer length is increased to address streaking, then mixing thoroughness improves, but retained volume increases and material waste increases

Engineering Contradiction:
Improvestreaking phenomenonVSAvoidmaterial waste
Core Design Contradiction:
Object-affected harmful factorsVSLoss of substance

Solution Approach 1:

By segmenting the mixing process into distinct baffle sections with specific functions, the patent achieves thorough mixing in a compact configuration. This eliminates the need for excessive mixer length, thereby reducing retained volume and material waste while still effectively addressing streaking.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes geometric parameters of the baffles (twist angles, section lengths, relative positions) to optimize mixing performance within a compact length. This allows thorough mixing to be achieved without increasing overall mixer length, thus reducing retained volume and material waste.

Inventive Principle:
Principle #35Parameter changes

3Length of stationary object

If combination of varying twist baffles is used, then mixer length is reduced, but number of baffles increases and mixing efficiency decreases

Engineering Contradiction:
Improvemixer lengthVSAvoidnumber of baffles
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent merges multiple mixing functions into a single integrated baffle structure with three distinct sections. Instead of using multiple separate baffles of varying twists, the functions are combined within one baffle, reducing the total number of components while maintaining compact mixer length and high mixing efficiency.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The multi-section baffle performs multiple mixing functions simultaneously: flow redirection, intermediate mixing, and flow inversion. This multi-functionality allows the single baffle to replace what would otherwise require multiple separate baffles, reducing device complexity while maintaining effective mixing performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 design improves mixing efficiency by preventing streaks from forming and reduces the overall length of the mixer, minimizing material waste and maintaining effective fluid mixing with fewer baffles.

Implementation Method 1

fluid flowing in the center of the fluid flow moves to the perimeter of the fluid flow through the first and third flow chambers, and fluid flowing in the perimeter of the fluid flow moves to the center of the fluid flow through the second and fourth flow chambers

Methodology Applied
Scientific EffectFluid flow redirection:

Implementation Method 2

The fluid flow is divided by the divider wall

Methodology Applied
Scientific EffectFlow division:

Data Source

PatentEP2301656B1Cross Flow Inversion Baffle For Static Mixer
Publication Date: 2015.11.04 NORDSON CORP
  • EP2301656B1 patent drawingFigure 1
  • EP2301656B1 patent drawingFigure 2~4
  • EP2301656B1 patent drawingFigure 5A~5C

AI summary

A cross flow inversion mixing baffle (24) that mixes a fluid flow and addresses the streaking phenomenon of the fluid flow in a motionless mixer, the cross flow inversion baffle including a divider wall (44) having first and second sides (50,52). On each side of the divider wall, the cross flow inversion baffle includes a perimeter flow diverter (54), a center-to-perimeter flow portion (55), and a perimeter-to-center flow portion (57). The cross flow inversion baffle acts to split the fluid flow so that the fluid in opposing halves of the perimeter of the fluid flow are directed towards opposing halves of the center of the fluid flow, while the center of the fluid flow is split and directed towards opposing halves of the perimeter of the fluid flow.