Hydrocyclone Flow Deflection for Separation Selectivity

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Solution Overview

Problem

Existing hydrocyclones face challenges in minimizing the thickening factor (Tf) due to high fibre rejection and remixing of heavy particles with the light fraction, leading to operational issues and increased costs, as smooth inner surfaces facilitate fibre settlement and turbulence that disrupts separation efficiency.

Innovation Solution

The hydrocyclone incorporates a flow deflection mechanism with a rounded curve, rack, and ledge portion in the circumferential wall, creating controlled turbulence to transport heavy particles efficiently towards the heavy fraction outlet while avoiding remixing, by generating a secondary vortex that increases flow speed and breaks fibre agglomerates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a smooth inner surface is used in the hydrocyclone separation chamber, then particle migration to the wall is facilitated with moderate turbulence, but fibre settlement increases and separation selectivity deteriorates

Engineering Contradiction:
Improveparticle migration efficiencyVSAvoidseparation selectivity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The inner surface of the separation chamber is designed with spatially varying properties: smooth surfaces in regions where particle migration is desired, and localized turbulent flow generators (protrusions, ribs, or curved surfaces) in regions where fibre settlement must be prevented. This local differentiation allows simultaneous optimization of particle separation and fibre protection.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The surface structure incorporates dynamic flow control elements that adapt turbulence generation to local flow conditions. The protrusions and curved surfaces create controlled turbulence only where needed, allowing the flow regime to transition dynamically between laminar and turbulent states to optimize both particle migration and fibre suspension.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If turbulence is increased to expand fibre flocks and release particles, then particle separation is improved, but heavy particles remix with the light fraction and separation efficiency decreases

Engineering Contradiction:
Improveparticle release efficiencyVSAvoidseparation efficiency
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

Turbulence generation is localized to specific regions of the separation chamber where fibre flock expansion is needed, rather than throughout the entire chamber. The protrusions and curved surfaces create controlled turbulence zones that release particles from fibre networks without generating excessive mixing in the separation region.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The turbulence intensity is optimized to be sufficient for fibre flock expansion and particle release, but not excessive to cause heavy particle remixing. The controlled turbulence is applied partially in specific zones rather than uniformly throughout the chamber, achieving the minimum necessary action for particle release without the harmful effects of excessive turbulence.

Inventive Principle:
Principle #16Partial or excessive action

3Ease of operation

If the thickening factor is reduced to minimize fibre rejection, then operational problems are decreased, but separation selectivity must be maintained which increases complexity

Engineering Contradiction:
Improveoperational stabilityVSAvoidseparation chamber structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The separation chamber incorporates localized structural features (protrusions, ribs, curved surfaces) that create controlled turbulence in specific regions. These local modifications reduce the overall thickening factor and minimize fibre rejection without requiring complete redesign of the entire chamber structure.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Curved surfaces and rounded protrusions are used throughout the separation chamber to generate controlled turbulence through flow curvature effects. These geometric features create secondary flows and vortex structures that expand fibre flocks and reduce thickening without requiring complex mechanical components.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 enhances separation efficiency by minimizing fibre losses and preventing remixing of heavy particles with the light fraction, reducing fibre rejection and operational risks, thereby improving the hydrocyclone's selectivity and reducing energy and investment costs.

Implementation Method 1

creating controlled turbulence to transport heavy particles efficiently towards the heavy fraction outlet

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 2

by generating a secondary vortex that increases flow speed and breaks fibre agglomerates

Methodology Applied
Scientific EffectVortex: Vortex Ring

Implementation Method 3

a liquid stream is generated as a helical vortex about a centre axis in the separation chamber

Methodology Applied
Scientific EffectCentrifugal separation: Centrifugal Separation

Data Source

PatentEP2704842B1Flow deflecting member for hydrocyclone
Publication Date: 2017.07.12 OVIVO LUXEMBOURG R L
  • EP2704842B1 patent drawingFigure 1~3c
  • EP2704842B1 patent drawingFigure 4a~5
  • EP2704842B1 patent drawingFigure 6~7c

AI summary

A hydrocyclone (1) for separating a liquid mixture into a heavy fraction including heavy particles and alight fraction, comprising a housing (2) forming an elongated separation chamber (3) having a circumferential wall (4), abase end (5),an apex end (6),at least one inlet member (7) for supplying a liquid mixture into the separation chamber (3), at least one of the inlet member/s(7) positioned at the base end (5), a first outlet member (8) for discharging separated light fraction from the separation chamber (3)at the base end (5), a second outlet member (9) for discharging separated heavy fraction from the separation chamber (3) at the apex end (6),means (10) for supplying the liquid mixture to the separation chamber (3) via the at least one inlet member (7), so that during operation a liquid stream is generated as a helical vortex (11) about a centre axis (12) in the separation chamber (3), said helical vortex (11) extending from the base end (5) to the apex end (6), a first flow deflection means arranged in the circumferential wall (4) which comprises at least one member(14) in the path 13 of the liquid stream showing a decrease of the radius of the separation chamber, followed by an increase of the radius of the separation chamber,where in the at least one member comprises a rounded curve portion 14a for transporting the heavy particles.