Coarse Separator Geometry to Limit Oil Droplet Re-Atomization

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Solution Overview

Problem

Existing liquid separation systems in compressor systems, such as those with oil-lubricated screw compressors, are inefficient due to high oil content in the compressed air, leading to reduced service life and efficiency of downstream separators and filters, primarily because of the formation of smaller oil droplets through secondary atomization and improper impact angles.

Innovation Solution

A liquid separation device with a coarse separator that guides the air-liquid mixture tangentially over a concavely curved separation surface, utilizing friction and deceleration to separate larger droplets by gravity and minimize secondary atomization, with adjustable and fixed connection options for the mixture feed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the air-liquid mixture strikes the separation surface at a large angle (conventional baffle plate design), then the separation process is simple, but secondary atomization occurs forming smaller droplets that reduce separator service life

Engineering Contradiction:
Improvesimplicity of separator designVSAvoidservice life of fine separator
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent changes the impact angle parameter from conventional large angles (producing secondary atomization) to a specific range of 10-45 degrees. This parameter optimization minimizes droplet breakup while maintaining effective separation, thereby extending fine separator service life without complicating the design

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces a movable mixture feed with adjustable positioning, allowing the impact angle to be dynamically optimized. This enables adaptation to different operating conditions while maintaining the optimal 10-45 degree range, preventing secondary atomization without requiring complex fixed structures

Inventive Principle:
Principle #15Dynamics

2Productivity

If the mixture feed outlet area is increased to improve flow capacity, then more mixture can be processed, but the angle of impact increases causing more secondary atomization

Engineering Contradiction:
Improveflow capacity of mixture feedVSAvoidsecondary atomization of oil droplets
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent positions the mixture feed outlet such that it approaches the separation surface tangentially rather than perpendicularly. This dimensional change in approach angle allows larger outlet areas for higher flow capacity while maintaining the optimal 10-45 degree impact angle, preventing secondary atomization even at elevated productivity levels

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

3Device complexity

If a fixed connection between mixture feed and coarse separator is used, then the structure is simple and stable, but the angle of impact cannot be optimized for different operating conditions

Engineering Contradiction:
Improvesimplicity of connection structureVSAvoidadjustability of impact angle
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements a movable mixture feed connected via a pivotable connection, allowing angular adjustment between the mixture feed and coarse separator. This dynamic connection maintains structural simplicity while enabling optimization of the impact angle for different operating conditions, balancing both simplicity and adaptability

Inventive Principle:
Principle #15Dynamics

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

Enhances the separation efficiency of the compressor system by increasing the separation of oil droplets and reducing secondary atomization, thereby prolonging the service life of downstream separators and improving system efficiency.

Implementation Method 1

a mixture flow striking the separation surface is guided substantially tangentially over at least a section of the separation surface... slowed down primarily by friction effects

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

Comparatively larger droplets are forced by gravity directly from the baffle plate or into an oil sump

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP4401857B1Liquid separation device for a compressor system, coarse separator for such a liquid separation device, and liquid separation system
Publication Date: 2026.01.14 KNORR BREMSE SYST FUR SCHIENENFAHRZEUGE GMBH
  • EP4401857B1 patent drawingFigure 1~2
  • EP4401857B1 patent drawingFigure 3a~3b
  • EP4401857B1 patent drawingFigure 4a~4b

AI summary

The present invention relates to a liquid separation device for a compressor system, comprising a coarse separator (30, 30', 30", 30'"), which has at least one separation surface and at least one mixture supply (20, 20', 20", 20"') designed to supply an air-liquid mixture (70) to the separation surface, wherein the mixture supply (20, 20', 20", 20"') has a mixture feed outlet which faces the separation surface and is arranged relative to the separation surface of the coarse separator (30, 30', 30", 30'") such that a mixture flow (70a) impinging on the separator surface is guided substantially tangentially over at least one portion of the separation surface.