Rotating Coalescer Inside-Out Flow for Crankcase Oil Separation

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Solution Overview

Problem

Existing internal combustion engine crankcase ventilation systems face challenges in efficiently separating air from oil in blowby gas, leading to clogging and increased pressure drop across coalescing filters, which affects the coalescing capacity and overall engine performance.

Innovation Solution

An annular rotating coalescing filter element is used, driven by centrifugal force to create an inside-out flow, reducing oil clogging and pressure drop by pumping blowby gas radially outward, enhancing oil separation and coalescence through increased rotational speed and gravitational settling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a stationary coalescing filter is used for oil separation, then oil particles can be captured and coalesced, but the filter becomes clogged with oil over time causing increased pressure drop and reduced coalescing capacity

Engineering Contradiction:
Improvecoalescing capacityVSAvoidoil saturation
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies the dynamics principle by transforming the stationary coalescing filter into a rotating component. The filter element rotates about its axis, dynamically changing the flow patterns and preventing oil saturation on any single side of the filter. This rotation continuously refreshes the coalescing surfaces, maintaining high coalescing capacity over time and preventing the pressure drop increase that would occur in a stationary system.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotating coalescing filter implements periodic action through its continuous rotation, which periodically brings different sections of the filter through the oil-laden gas stream. This periodic movement ensures that no single area of the filter remains stationary and saturated with oil, instead cycling through all sections to distribute and process oil particles evenly throughout the filter element.

Inventive Principle:
Principle #19Periodic action

2Reliability

If the coalescing filter rotates at high speed to reduce oil saturation, then coalescing capacity improves, but energy consumption increases

Engineering Contradiction:
Improveoil separation efficiencyVSAvoidrotational energy
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system applies self-service by designing the coalescing filter to rotate using the kinetic energy already present in the blowby gas stream. The gas flow itself provides the rotational force, eliminating the need for separate external motors or energy-intensive drive mechanisms. This self-driven rotation maintains oil separation efficiency while minimizing additional energy consumption.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent utilizes pneumatic principles by employing the gas flow dynamics to drive the rotation of the coalescing filter. The pressure differential and kinetic energy of the blowby gas are converted into rotational motion of the filter element, leveraging the existing pneumatic energy in the system rather than requiring additional mechanical or electrical energy input.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Productivity

If inertial impaction is used for oil separation, then oil particles can be removed at high velocities, but the system becomes more complex with additional nozzles and impactors

Engineering Contradiction:
Improveoil removal rateVSAvoidseparator structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the functions of multiple separate oil separation mechanisms into a single integrated rotating coalescing filter element. Instead of using separate nozzles, impactors, and coalescing chambers as would be required in a complex inertial impaction system, the rotation of the filter element combines centrifugal separation, coalescence, and filtration into one unified component, simplifying the overall separator structure while maintaining high oil removal capability.

Inventive Principle:
Principle #5Merging (Combining)

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 solution effectively reduces oil saturation and pressure drop across the filter, improving the capture and coalescence of submicron oil particles, enhancing engine performance and turbocharger efficiency by variably controlling the coalescer's speed based on engine and turbocharger conditions.

Implementation Method 1

driven by centrifugal force to create an inside-out flow, reducing oil clogging and pressure drop by pumping blowby gas radially outward

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

enhancing oil separation and coalescence through increased rotational speed and gravitational settling

Methodology Applied
Scientific EffectGravitational settling: Gravitation

Data Source

PatentEP2528674B1Crankcase ventilation inside-out flow rotating coalescer
Publication Date: 2018.12.19 CUMMINS FILTRATION IP INC
  • EP2528674B1 patent drawingFigure 1
  • EP2528674B1 patent drawingFigure 2
  • EP2528674B1 patent drawingFigure 3

AI summary

An internal combustion engine crankcase ventilation rotating coalescer includes an annular rotating coalescing filter element, an inlet port supplying blowby gas from the crankcase to the hollow interior of the annular rotating coalescing filter element, and an outlet port delivering cleaned separated air from the exterior of the rotating element. The direction of blowby gas is inside-out, radially outwardly from the hollow interior to the exterior.