Inside-Out Rotating Coalescer for Crankcase Blowby Filtration

Solution Overview

Problem

Outside-in flow rotating coalescers in crankcase ventilation systems suffer from high pressure drops and reduced fractional efficiency compared to inside-out flow rotating coalescers, which are less effective in filtering blowby gases from internal combustion engines.

Innovation Solution

A rotating coalescer design with an inside-out flow path, featuring a housing with a blowby gas inlet, filter media arranged in a cylindrical shape, and a hollow shaft for filtered gas outlet, driven by a mechanism that rotates the coalescer to enhance filtration efficiency and reduce pressure drop.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If outside-in flow configuration is used in rotating coalescers, then integration into engine compartments is easier, but pressure drop increases and fractional efficiency decreases

Engineering Contradiction:

Improveintegration easeVSAvoidfractional efficiency

Core Design Contradiction:

Ease of operationVSProductivity

Solution Approach 1:

The patent inverts the conventional outside-in flow configuration by implementing an inside-out flow path where blowby gases enter through the hollow shaft and exit through the outer surface of the filter media. This reversal resolves the contradiction by achieving both high fractional efficiency and acceptable integration ease, as the inside-out configuration optimizes filtration performance while still allowing for practical engine compartment integration.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the flow direction parameter from outside-in to inside-out, which fundamentally alters the filtration dynamics. This parameter change increases fractional efficiency by enhancing the coalescing mechanism while the hollow shaft design maintains integration flexibility, thus resolving the contradiction between efficiency and ease of integration.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If outside-in flow configuration is used in rotating coalescers, then integration into engine compartments is easier, but pressure drop increases

Engineering Contradiction:

Improveintegration easeVSAvoidpressure drop

Core Design Contradiction:

Ease of operationVSStress or pressure

Solution Approach 1:

The patent inverts the conventional outside-in flow configuration by implementing an inside-out flow path where blowby gases enter through the hollow shaft and exit through the outer surface of the filter media. This reversal resolves the contradiction by achieving both high fractional efficiency and acceptable integration ease, as the inside-out configuration optimizes filtration performance while still allowing for practical engine compartment integration.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent changes the flow direction parameter from outside-in to inside-out, which fundamentally alters the filtration dynamics. This parameter change increases fractional efficiency by enhancing the coalescing mechanism while the hollow shaft design maintains integration flexibility, thus resolving the contradiction between efficiency and ease of integration.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If filter media is rotated during filtering, then inertial impaction and gravitational forces are enhanced, but device complexity increases

Engineering Contradiction:

Improvefiltration efficiencyVSAvoidrotation mechanism complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the hollow shaft (which serves as the gas inlet and structural support) with the rotation mechanism by operatively coupling the drive mechanism directly to the hollow shaft. This integration reduces device complexity compared to having separate rotation and flow path components, while still achieving the beneficial effects of enhanced inertial impaction and gravitational forces through rotation.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The hollow shaft serves multiple functions: it is the structural support, the gas inlet pathway, and the rotation axis. By making the rotation mechanism operative on the hollow shaft itself rather than a separate component, the patent reduces overall device complexity while maintaining the multi-functionality needed for efficient filtration.

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 inside-out rotating coalescer design achieves lower restriction and higher separating efficiency than outside-in configurations, effectively filtering blowby gases with reduced pressure drop and improved fractional efficiency.

Implementation Method 1

The filter media is structured to filter the crankcase blowby gases passing through the filter media by coalescing and separating oils and aerosols contained in the crankcase blowby gases

Methodology Applied

Scientific EffectCoalescence: Coagulation

Implementation Method 2

The rotating coalescer includes filter media. The filtered blowby gases are then either vented to the ambient (in open crankcase ventilation systems) or routed back to the air intake

Methodology Applied

Scientific EffectFiltration: Filter (physical)

Implementation Method 3

By rotating the filter media, inertial impaction and gravitational forces are enhanced by the additional centrifugal force

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 4

Additionally, the rotation of the filter cartridge can create a pumping effect, which reduces the pressure drop through the filtration system

Methodology Applied

Scientific EffectPumping effect: Pump

Implementation Method 5

By rotating the filter media, inertial impaction and gravitational forces are enhanced by the additional centrifugal force

Methodology Applied

Scientific EffectInertial impaction: Inertia

Implementation Method 6

By rotating the filter media, inertial impaction and gravitational forces are enhanced by the additional centrifugal force

Methodology Applied

Scientific EffectGravitational force: Gravitation

Data Source

PatentUS11448107B2Inside-out rotating coalescer with gas exit through hollow shaft

Publication Date: 2022.09.20 ATMUS FILTRATION IP INC

AI summary

Various example embodiments relate to rotating coalescers. One embodiment includes a housing comprising a first housing section having a blowby gas inlet structured to receive crankcase blowby gases from a crankcase. The housing further comprises an oil outlet. The rotating coalescer includes an endcap and filter media. The filter media is arranged in a cylindrical shape and is coupled to and positioned between the first housing section and endcap. The filter media is structured to filter the crankcase blowby gases passing through the filter media by coalescing and separating oils and aerosols contained in the crankcase blowby gases. The rotating coalescer includes a hollow shaft extending through the housing and positioned radially inside of the filter media. The hollow shaft forms a blowby gas outlet structured to route filtered crankcase blowby gases out of the housing. The rotating coalescer further includes a drive mechanism operatively coupled to the hollow shaft.