Variable Section Circulation Member for Crankcase Oil Separation

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Solution Overview

Problem

Current oil settling systems for crankcase gases in internal combustion engines are ineffective in treating fine and large oil particles across varying flow rates, leading to incomplete purification and high pressure drops, and require complex maintenance.

Innovation Solution

A settling system with a separation device featuring a circulation member with a variable outlet section and an impact wall with a coalescing filter media, ensuring constant gas flow speed and effective oil separation regardless of flow rate, using a combination of circulation members and an impact device to intercept and separate oil droplets from gases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If settling systems use a settling method with larger cross-section chamber, then gas flow velocity decreases allowing oil droplets to settle, but only large oil particles are treated effectively and fine oil particles remain untreated

Engineering Contradiction:
Improveoil particle separation effectivenessVSAvoidability to treat different oil particle sizes
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The settling system is divided into multiple independent settling chambers arranged in series, each chamber handling different stages of oil particle separation. This segmentation allows each chamber to be optimized for specific particle size ranges while maintaining overall system effectiveness for both fine and large particles.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from a single large cross-section chamber to multiple smaller chambers arranged in series, adding the dimension of sequential processing. This multi-chamber arrangement provides both the velocity reduction needed for settling and increased surface area for capturing fine particles that a single chamber cannot achieve.

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

2Manufacturing precision

If settling by baffling is used to generate localized accelerations and decelerations, then medium and large particles are extracted, but significant pressure drops occur under high crankcase gas flow rates

Engineering Contradiction:
Improveoil particle extraction efficiencyVSAvoidpressure drop in gas flow
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The gas flow is divided into multiple streams passing through separate settling chambers in parallel, then recombined. This segmentation distributes the flow rate across multiple paths, preventing excessive velocity and pressure drops that would occur in a single high-flow path with baffles.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of using aggressive baffle arrangements that cause high pressure drops, the system uses gentle settling chambers with optimized dimensions that provide sufficient separation for medium and large particles while maintaining low pressure loss. The chamber sizes and configurations are carefully selected to achieve adequate settling without excessive flow resistance.

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If cyclone separator is used to create swirling effect and centrifugal force for oil droplet separation, then separation is achieved, but high pressure losses are generated

Engineering Contradiction:
Improveoil droplet separation capabilityVSAvoidpressure loss in separator
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The invention extracts and removes the cyclone separator component entirely, replacing it with gravity-based settling chambers. This eliminates the high pressure losses associated with cyclone rotation while maintaining oil droplet separation capability through natural settling processes in the multi-chamber configuration.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The active mechanical cyclone rotation system is replaced with passive gravity-based settling chambers. The kinetic energy required to create centrifugal force in a cyclone is substituted with the potential energy of gravity acting on oil droplets in the settling chambers, significantly reducing pressure losses.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Manufacturing precision

If coalescing media is used to capture and agglomerate oil droplets, then fine particles are treated, but the medium becomes contaminated with combustion residues requiring regular cleaning and maintenance

Engineering Contradiction:
Improvefine oil particle removal efficiencyVSAvoidmaintenance requirement of coalescing media
Core Design Contradiction:
Manufacturing precisionVSEase of repair

Solution Approach 1:

The system uses simple, easy-to-clean settling chamber surfaces instead of complex coalescing media. The chamber walls are designed with smooth, non-porous surfaces that prevent oil and combustion residue adhesion, allowing for easy maintenance without requiring replacement of specialized media.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention avoids using porous coalescing media that trap combustion residues. Instead, it employs smooth, non-porous chamber surfaces that allow oil droplets to coalesce and settle without adhering to the surface, eliminating the fouling and maintenance issues associated with porous materials.

Inventive Principle:
Principle #31Porous materials

5Reliability

If decantation systems are equipped to purify crankcase gases by removing oil, then emissions standards are met, but the systems are complex to implement and maintain

Engineering Contradiction:
Improvepurification effectiveness for emissions complianceVSAvoidsystem implementation and maintenance complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple settling chambers are combined into a single integrated unit that handles the complete oil separation process. This merging of functions into one compact device reduces overall system complexity while maintaining effective purification capability for emissions compliance.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The settling chambers serve multiple functions simultaneously: they provide velocity reduction for particle settling, offer large surface area for oil droplet coalescence, and act as collection points for separated oil. This multi-functionality reduces the need for separate components, simplifying the overall system design and maintenance.

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

The system effectively removes oil particles of all sizes, from 0.01 μm to 10 μm, across a wide range of flow rates with minimal pressure drop, ensuring purified gases can be recycled without oil contamination, enhancing engine efficiency and compliance with pollution standards.

Implementation Method 1

its outlet cross-section varies according to the crankcase gas flow rate passing through it so that the velocity of this gas flow exiting the separation device remains substantially constant

Methodology Applied
Scientific EffectFlow velocity regulation:

Implementation Method 2

an impact wall with a coalescing filter media, ensuring constant gas flow speed and effective oil separation

Methodology Applied
Scientific EffectCoalescence: Coagulation

Implementation Method 3

This larger cross-section results in a corresponding decrease in velocity, and this slowing of the gas flow allows oil droplets to settle at the bottom of the separator

Methodology Applied
Scientific EffectGravitational settling: Gravitation

Implementation Method 4

The specific shape of the housing creates a swirling effect, forming a cyclone. The rotation of the crankcase gases allows centrifugal force to separate the oil droplets from the gas.

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2841724B2Device for the oil separation from a blowby gas stream of an engine
Publication Date: 2019.09.04 S T E E P
  • EP2841724B2 patent drawingFigure 1~2
  • EP2841724B2 patent drawingFigure 3~4
  • EP2841724B2 patent drawingFigure 5~6

AI summary

The invention relates to a system for separating off the oil contained in the crankcase gases of a combustion engine, comprising a separation device (20) intended to be interposed in a crankcase gases circuit, characterized in that the separation device (20) comprises at least one circulation member (21) which is a duct formed in a narrowed shape from an elastic material, with an inlet cross section that is wider than the outlet cross section, said outlet cross section being of a diameter that can vary according to the crankcase gas flow rate.