Mixing Device with Flow Guide Tube for Wastewater Flocculation

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Solution Overview

Problem

Existing methods for treating industrial and urban wastewater, particularly those involving flocculation and precipitation, face challenges with residual shear effects that disrupt the growth of solid species, leading to inefficient energy use and particle dislocation.

Innovation Solution

A device featuring a paddle stirrer with a flow-guide tube and a static obstacle designed to minimize shear effects by guiding fluid flows into U-shaped trajectories, reducing radial components and promoting harmonious growth of solid species without collision with tank walls.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a paddle stirrer with significant radial component is used to agitate the fluid, then mixing efficiency is improved, but aggregates collide with side walls causing disruption and energy loss

Engineering Contradiction:
Improvemixing efficiencyVSAvoidaggregate collision with walls
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

A flow guide tube is introduced as an intermediary component between the paddle stirrer and the tank walls. This tube redirects the radially outward flow from the stirrer into a downward axial flow, preventing aggregates from colliding with the tank walls while maintaining effective mixing. The flow guide tube acts as a mediator that transforms the harmful radial flow pattern into a beneficial axial flow pattern.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If stirring speed is increased to improve homogenization, then mixing quality is improved, but shear effects increase causing floc dislocation and energy dissipation

Engineering Contradiction:
Improvehomogenization qualityVSAvoidshear effects and vortex formation
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The invention changes the flow pattern parameters by introducing the flow guide tube, which transforms the radial flow component into an axial flow component. This parameter change in flow direction allows for effective homogenization at lower stirring speeds, reducing shear effects and vortex formation while maintaining mixing quality. The flow guide tube effectively changes the velocity distribution and flow direction parameters in the mixing zone.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If a flow guide tube is used to reduce radial flow, then aggregate growth is improved, but device complexity increases

Engineering Contradiction:
Improveaggregate growth harmonyVSAvoidstructure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The mixing system is segmented into distinct functional zones: the paddle stirrer creates axial flow, the flow guide tube redirects flow downward, and the static obstacle at the bottom redirects flow radially outward along the tank walls. This segmentation of flow patterns into distinct zones allows for controlled aggregate growth in each zone while maintaining overall system simplicity through the use of basic geometric components.

Inventive Principle:
Principle #1Segmentation

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 solution achieves efficient mixing and homogenization at low energy consumption, allowing for rapid growth of solid particles and reduced stirring speed, while minimizing shear effects and vortex formation.

Implementation Method 1

a paddle stirrer suitable for providing thrust that is more longitudinal than radial

Methodology Applied
Scientific EffectAxial thrust:

Implementation Method 2

The flow-guide tube ensures the compartmentation of the tank between the interior of the flow-guide tube where the current is descending, and the exterior of the flow-guide tube where the current is ascending

Methodology Applied
Scientific EffectFlow guidance:

Implementation Method 3

The water is agitated by a paddle stirrer to create adhesion

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 4

a crosspiece opposing the rotation of the flow leaving the flow-guide tube, which allows a reduction in the size of installations

Methodology Applied
Scientific EffectFlow opposition:

Data Source

PatentEP2673076B1Expanding device for combining a liquid species and a particulate solid species
Publication Date: 2015.04.08 VEOLIA WATER SOLUTIONS & TECHNOLOGIES SUPPORT SAS
  • EP2673076B1 patent drawingFigure 1~3
  • EP2673076B1 patent drawingFigure 4
  • EP2673076B1 patent drawingFigure 5~8

AI summary

The invention relates to an expanding device for combining a liquid species and a particulate solid species, which includes a vessel 200 in which a stirrer 800 having paddles that rotate about a shaft 810 is arranged, the stirrer being optionally provided with a flow guide tube 210, wherein the vessel 200 also includes a static obstacle 830 that is generally centred around said shaft and aligned with the stirrer, characterised in that the static obstacle 830 has, in a plane passing through the shaft, an outer transverse dimension that increases as it moves away from the stirrer 800 parallel to said shaft 810, having a constant or increasing slope relative to said shaft.