Electrical Coalescer Fuel Filter Water Separation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional water separators in fuel filter devices have a limited service life and require periodic replacement, leading to increased maintenance and decreased performance over time.

Innovation Solution

An electrical coalescer with two electrodes, at least one of which is mechanically and/or electrically isolated, is integrated into the fuel filter device to facilitate continuous water separation without the need for replacement, utilizing an electric field to enhance droplet coalescence and mobility, allowing for compact design and reduced maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional water separator (coalescer) is used in the fuel filter device, then water separation is achieved, but the service life is limited and performance decreases over time requiring periodic replacement

Engineering Contradiction:
Improveseparation performance consistencyVSAvoidservice life of water separator
Core Design Contradiction:
ReliabilityVSDuration of action of stationary object

Solution Approach 1:

The patent replaces the conventional mechanical coalescer with an electrical coalescer that uses electrostatic fields to separate water from fuel. The electrical coalescer comprises at least one electrode (preferably two electrodes) that generate an electrostatic field to coalesce water droplets, eliminating the mechanical filtration media that degrades over time. This substitution maintains consistent separation performance throughout the service life of the fuel filter device.

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

2Reliability

If a conventional coalescer is used, then water separation occurs, but maintenance effort increases due to periodic replacement requirements

Engineering Contradiction:
Improvewater separation efficiencyVSAvoidmaintenance effort
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The electrical coalescer eliminates the need for mechanical replacement by using an electrically isolated electrode system that does not consume or degrade. The electrode can remain in the fuel filter device for the entire service life without periodic replacement, significantly reducing maintenance efforts while maintaining reliable water separation efficiency.

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

Solution Approach 2:

The electrical coalescer is designed to be self-sustaining throughout the service life of the fuel filter device. The electrostatic field generation does not require replacement of consumable materials, and the system automatically continues to separate water from fuel without intervention until the end of the filter device's service life.

Inventive Principle:
Principle #25Self-service

3Reliability

If conventional coalescer materials are used, then water separation is achieved, but sensitivity to fuel composition and additives increases

Engineering Contradiction:
Improveseparation performanceVSAvoidsensitivity to fuel composition
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

By replacing mechanical coalescer materials with an electrical field-based separation system, the patent eliminates the sensitivity to fuel composition and additives. The electrostatic field interacts with water droplets based on their dielectric properties, which remain consistent regardless of fuel additives or composition variations, providing reliable separation across different fuel types.

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

4Duration of action of stationary object

If the water separator is designed to last the entire service life, then replacement is eliminated, but the device complexity increases

Engineering Contradiction:
Improveservice life of water separatorVSAvoidcomplexity of water separator design
Core Design Contradiction:
Duration of action of stationary objectVSDevice complexity

Solution Approach 1:

The electrical coalescer simplifies the overall device architecture by eliminating complex mechanical coalescer materials, housings, and replacement mechanisms. The electrode structure (preferably two coaxial electrodes forming an annular channel) is simpler to manufacture and install than conventional coalescers, while providing the durability needed for the entire service life.

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

Solution Approach 2:

The electrode structure serves multiple functions: it generates the electrostatic field for water coalescence, provides structural support for the annular channel, and can be designed as a single integrated component that lasts the entire service life. This multi-functionality reduces the number of separate components needed, lowering overall device complexity.

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 electrical coalescer maintains consistent separation performance throughout its service life, reduces maintenance efforts, and is less sensitive to fuel composition, enabling efficient and prolonged operation with improved water separation efficiency.

Implementation Method 1

utilizing an electric field to enhance droplet coalescence and mobility

Methodology Applied
Scientific EffectElectrostatic field: Electric Field

Implementation Method 2

accelerated by the polarizing effect of the applied electrical field. The forces occurring in the electrical field increase the mobility of the water droplets, which consequently leads to a higher collision rate, which in turn has a positive effect on droplet coalescence

Methodology Applied
Scientific EffectDroplet coalescence: Coagulation

Implementation Method 3

If the droplets are large enough, gravity will prevail and the specifically denser water phase will sink

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3064277B1Fuel filter device
Publication Date: 2019.12.18 MAHLE INT GMBH
  • EP3064277B1 patent drawingFigure 1
  • EP3064277B1 patent drawingFigure 2~3
  • EP3064277B1 patent drawingFigure 4~5

AI summary

The invention relates to a fuel filter assembly (1) for an internal combustion engine, comprising a ring filter element (2) that separates a raw side (3) from a clean side (4), and a water separator (6) designed as an electrical coalescer (5) for separating water (7) from the fuel (8). A key feature of the invention is that the water separator (6), designed as an electrical coalescer (5), is arranged on the clean side (4) within the ring filter element (2) and has two electrodes (10, 11) arranged coaxially to the filter axis (9) and preferably electrically and/or mechanically insulated from the fuel (8).