Curved Channel Separator for Crankcase Gas Droplet Removal

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Solution Overview

Problem

Existing separators for crankcase ventilation gases in internal combustion engines, particularly those with conical discs, face challenges in separation efficiency for fine droplets, axial length, and sensitivity to gas flow volume changes, leading to suboptimal performance and increased pressure loss.

Innovation Solution

A separator design featuring flat disk bodies with curved channels that allow gas to flow from the inner to the outer radial portion, utilizing centrifugal and Coriolis forces to separate liquid droplets on impact surfaces, optimizing channel geometry for increased separation capacity and flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conical discs are used in the separator, then separation efficiency for liquid droplets is improved, but axial length increases

Engineering Contradiction:
Improveseparation efficiencyVSAvoidaxial length
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent applies curvature by using curved channels instead of straight channels in the flat discs. The curved channels create centrifugal and Coriolis forces that enhance droplet separation efficiency while maintaining a compact axial structure, resolving the contradiction between separation efficiency and axial length.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent changes the geometric parameters of the channels (curvature radius, channel width, channel height) to optimize the balance between separation efficiency and axial length. By adjusting these parameters, the separator achieves high separation performance in a compact axial space.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conical discs are used in the separator, then separation efficiency for liquid droplets is improved, but device complexity increases

Engineering Contradiction:
Improveseparation efficiencyVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the separator into multiple flat discs with curved channels, where each disc acts as an independent separation stage. This segmentation allows the complex separation task to be distributed across multiple simpler stages, maintaining high efficiency while managing structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The curved channels in flat discs provide the necessary centrifugal and Coriolis forces for efficient separation without requiring the complex conical geometry, thus reducing device complexity while maintaining separation efficiency.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Length of moving object

If the number of discs is decreased to reduce axial length, then axial length is reduced, but separation efficiency deteriorates

Engineering Contradiction:
Improveaxial lengthVSAvoidseparation efficiency
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The curved channels generate stronger centrifugal and Coriolis forces compared to straight channels, enabling each disc to achieve higher separation efficiency. This allows the use of fewer discs while maintaining overall separation performance, thus reducing axial length without sacrificing efficiency.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

By optimizing channel parameters (curvature radius, width, height) and disc spacing, the patent enhances the separation capability of each individual disc, allowing fewer discs to achieve the required overall separation efficiency with reduced axial length.

Inventive Principle:
Principle #35Parameter changes

4Device complexity

If passive separators are used instead of driven separators, then device complexity is reduced, but separation efficiency for fine droplets deteriorates

Engineering Contradiction:
Improvestructural complexityVSAvoidseparation efficiency for fine droplets
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The curved channels in the passive separator create centrifugal and Coriolis forces that effectively separate fine droplets without requiring active driving mechanisms. This maintains low device complexity while achieving high separation efficiency for fine droplets.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent utilizes gas flow dynamics and fluid mechanics principles to generate the necessary forces for separation through the curved channel geometry, eliminating the need for mechanical driving components while maintaining effective fine droplet separation.

Inventive Principle:
Principle #29Pneumatics and hydraulics

5Volume of moving object

If separator size is reduced to save installation space, then installation space is reduced, but separation efficiency for fine droplets deteriorates

Engineering Contradiction:
Improveseparator sizeVSAvoidseparation efficiency for fine droplets
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The curved channel geometry maximizes the utilization of available space by creating effective separation forces through compact radial and axial dimensions, enabling high separation efficiency for fine droplets in a reduced overall separator size.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The patent transitions from axial separation (conical discs) to radial separation (curved channels in flat discs), utilizing the radial dimension more effectively to achieve high separation efficiency in a compact overall size with reduced axial and radial footprints.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 design achieves higher separation efficiency with reduced axial length, improved handling of fine droplets, and adaptability to varying gas flow conditions, while minimizing pressure loss and enhancing the use of installation space.

Implementation Method 1

liquid droplets carried by the gas to be cleaned are flung against the inner surfaces of the conical discs by centrifugal forces acting upon them

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

utilizing centrifugal and Coriolis forces to separate liquid droplets on impact surfaces

Methodology Applied
Scientific EffectCoriolis force: Coriolis Force

Implementation Method 3

the separated liquid then flows by gravity into the lower part of the housing and exits through its liquid outlet

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP2855025B1Separator and method for separating liquid droplets from an aerosol
Publication Date: 2019.09.25 ELRINGKLINGER AG
  • EP2855025B1 patent drawingFigure 1
  • EP2855025B1 patent drawingFigure 2~3
  • EP2855025B1 patent drawingFigure 4

AI summary

Separator for separating liquid droplets from an aerosol (crude gas), having a rotor (30) arranged in a housing (10), said rotor having multiple discs parallel to each other (32a-32e), having a gas flow path between a crude gas inlet (18a) of the separator, a clean gas outlet (20a) and an annular space (50) between the periphery of the rotor and the housing, wherein an intermediate space is formed between discs adjacent to each other, the radial outer region of which space opens into the annular space, and wherein with respect to the crude gas inlet and clean gas outlet passages, one communicates with the annular space and the other with radial inner regions of intermediate spaces. To improve the separation capability of such a separator of specified size, the separator is designed such that: the discs have flat disc bodies arranged vertically to the rotor axis; a plurality of adjacent channels (40), through which gas to be cleaned can flow, is provided between respective adjacent disc bodies; each channel extends at least substantially from a radial inner region to a radial outer region of the intermediate space; each channel is curved; the radially outer surface of the channel wall surfaces delimiting the width of the channel on both sides forms an impact and separation surface for the liquid droplets.