Deformable Compensating Device for Exhaust Filter Housing

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Solution Overview

Problem

Existing exhaust gas aftertreatment systems, such as AdBlue systems, face risks of damage due to frost, pressure surges, and pressure pulsations, particularly affecting filter devices used in internal combustion engines, leading to potential system failure and operational instability.

Innovation Solution

A system with a deformable compensating device that is an independent component surrounding the filter housing, providing a fluid space for volume expansion and distributing pressure evenly, thus minimizing the risk of damage from freezing and pressure fluctuations, and ensuring stable operation under high pressures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid filter housing is used to maintain structural integrity, then strength is improved, but the system becomes vulnerable to damage from volume expansion during freezing and pressure surges

Engineering Contradiction:
Improvestructural integrityVSAvoidresistance to freezing damage
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies a flexible membrane as a compensating device that can elastically deform to accommodate volume changes of the freezing medium. The membrane is designed with specific material properties and geometric configuration to absorb expansion forces while maintaining the structural integrity of the filter housing, thus resolving the contradiction between rigidity and freezing resistance.

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If a deformable compensating device is added to absorb volume expansion, then reliability under freezing conditions is improved, but device complexity increases

Engineering Contradiction:
Improveresistance to freezing damageVSAvoidsystem structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the compensating device with the filter housing structure by integrating the membrane into the housing design. The membrane is positioned and configured to work within the existing housing geometry, merging the compensation function with the structural components rather than adding a completely separate system, thus reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of stationary object

If the compensating device is positioned close to the filter element to maximize space utilization, then volume efficiency is improved, but the filter element becomes vulnerable to damage from pressure surges

Engineering Contradiction:
Improvespace utilizationVSAvoidfilter element protection
Core Design Contradiction:
Volume of stationary objectVSStrength

Solution Approach 1:

The patent employs an asymmetric configuration where the membrane is positioned at a specific distance from the filter element, creating an optimized balance between space utilization and protection. The asymmetric positioning allows the membrane to absorb pressure surges before they reach the filter element while minimizing the volume occupied by the compensating device.

Inventive Principle:
Principle #4Asymmetry

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 system effectively absorbs deformation forces and pressure surges, preventing damage to the filter element and ensuring continuous, smooth fluid supply, even under freezing conditions or high pressures, thereby enhancing the robustness and reliability of the exhaust gas aftertreatment process.

Implementation Method 1

the shell part is thus elastically deformed during pressure and volume expansion of the medium when its state of aggregation changes in the direction of a freezing solid and then returns to its original shape

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

at least one filter device with a filter element accommodated in a filter housing for filtering a freezable substance

Methodology Applied
Scientific EffectPhysical filtration: Filter (physical)

Data Source

PatentEP2854987B1System for exhaust gas aftertreatment in internal combustion engines and for pulsation damping and volume flow smoothing of fluids
Publication Date: 2019.04.24 HYDAC FILTERTECHNIK GMBH
  • EP2854987B1 patent drawingFigure 1
  • EP2854987B1 patent drawingFigure 2
  • EP2854987B1 patent drawingFigure 3

AI summary

Disclosed is a system for exhaust gas aftertreatment in an internal combustion engine, having at least one filter device (9) comprising a filter element (77) which is accommodated in a filter housing (71) in order to filter a congealable substance, in particular in the form of an aqueous urea solution that can be introduced into the exhaust flow of the internal combustion engine, parts of the filter device (9) interacting with at least one fluid chamber (79) for at least temporarily accommodating the congealable substance inside the filter housing (71), a deformable compensating device (91) being provided as protection against damage to the system caused by volume expansion during freezing of the substance and being arranged inside the filter housing (71), the system being characterised in that the compensating device (91) is an independent component along with the filter housing (71), and in that the compensating device (91) is enclosed by the filter housing (71) at its outer periphery and substantially without spacing in every operating state. A comparable system can be used for pulsation damping and/or volume flow smoothing of fluids to be filtered.