Rotating Crankcase Gas Separator for Oil Droplet Removal
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Solution Overview
Problem
Existing crankcase gas separation devices face challenges in maintaining a good efficiency/pressure drop compromise, especially as the engine ages and gas flow increases, due to complex construction and potential rupture risks from torsional forces.
Innovation Solution
A rotary impaction separator device with a transfer wall and deflection wall, featuring accelerated distribution openings and a frustoconical shape, which enhances gas concentration and centrifugal guidance to separate oil droplets efficiently without porous media, reducing re-entrainment and pressure drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If impaction separator systems with calibrated holes and impaction plates are used, then separation efficiency is improved, but pressure drop increases significantly at higher gas flow rates
Solution Approach 1:
The patent introduces a rotating impaction plate that dynamically changes the impaction surface orientation during operation. The plate rotates to present different angled surfaces to the incoming gas stream, which prevents oil film buildup that would otherwise increase pressure drop, while maintaining consistent separation efficiency throughout the rotation cycle.
Solution Approach 2:
The invention changes the operational parameters of the impaction plate by rotating it at controlled speeds. This rotation transforms the static impaction surface into a dynamic one, where the effective impaction angle and surface area vary continuously, optimizing the balance between separation efficiency and pressure drop across different operating conditions.
2Loss of energy
If dynamic coalescers with rotating rotor elements are used, then pressure drop is reduced, but device complexity and assembly difficulty increase
Solution Approach 1:
The impaction plate is divided into multiple segmented sections that can rotate independently or in coordination. Each segment can be optimized for specific impaction angles, and the segmentation allows for easier assembly and maintenance while reducing the overall complexity of the rotating mechanism.
Solution Approach 2:
The rotating impaction plate serves multiple functions: it provides the primary impaction surface for oil separation, acts as a centrifugal force generator to甩 off accumulated oil, and can be designed with varying angles to handle different droplet sizes. This multi-functionality reduces the need for additional separate components.
3Loss of energy
If dynamic coalescers with rotor elements are used, then pressure drop is reduced, but reliability decreases due to torsional forces and flange rupture risks
Solution Approach 1:
The impaction plate is designed with counterweights or balanced structural features that compensate for the torsional forces generated during rotation. This balancing reduces stress on the mounting flanges and connection points, preventing rupture while maintaining the dynamic operation needed for low pressure drop.
Solution Approach 2:
The design incorporates reinforced flanges and stress-distributing features that are pre-engineered to withstand the maximum expected torsional loads. This beforehand cushioning through structural reinforcement prevents failure before it occurs, ensuring reliability under all operating conditions.
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 solution significantly increases separation efficiency for droplets smaller than one micron, offers robustness and longevity, and minimizes pressure drops, even at higher gas flows, while simplifying assembly and reducing complexity.
Implementation Method 1
gas concentration effect in the accelerated distribution openings (before impact), due to the increase in gas velocity and the approach of the streamlines
Implementation Method 2
abrupt deflection effect by the first impact face of the deflection wall, so that the heaviest/largest oil droplets will leave the streamlines in the impact chamber
Implementation Method 3
with the gas circulation speed reduced, it is the centrifugal effect, rather than entrainment in the gas streamlines, that allows the liquid particles to be evacuated from the impaction chamber
Implementation Method 4
In the category of dynamic coalescers, pressure drop is reduced thanks to the centrifugal effect, which helps to expel oil from the filter media
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The device (1) purifies a stream (G) of crankcase gas by means of a unit (100) which separates droplets of oil (HG) from the gas stream. This unit (100) comprises, on a transfer wall (2), accelerated distribution openings (O1) opposite a first impaction surface defined by a deflection wall (4). The transfer wall (2) and the deflection wall (4) each extend in an annular manner about a longitudinal axis (A). The unit (100) is mounted to be rotatable about said axis (A), along which purified gas (GP) is released. Each opening (O1) defines an axial access to an impaction chamber. At least one portion of the deflection wall (4) guides the gas stream in an opposite direction to the direction of arrival of the raw gas through the openings (O1). The walls (2, 4) may be generally frustoconical.