Self-Healing Seal Assembly for AdBlue Leakage via Crystallization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Elastomer seals in systems for storing and transporting liquid reducing agents, such as AdBlue, fail to provide permanent sealing due to low dynamic viscosity and geometric changes or vibration, leading to leaks and increased consumption of the agent, with visible white crystals forming from urea as a result.
Innovation Solution
A sealing arrangement featuring a gap that allows leaked liquid to come into contact with the outside atmosphere, forming crystals which create a self-healing seal, utilizing an angled gap and air-permeable materials like fiber mesh or felt to absorb and retain the liquid, preventing further leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If elastomer seals are used to seal assemblies, then sealing is provided, but permanent sealing is not guaranteed due to low dynamic viscosity of liquid reducing agent and geometric changes or vibration
Solution Approach 1:
The patent converts the harmful leakage of liquid reducing agent into a beneficial self-healing mechanism. When liquid escapes through the seal, it enters the gap and crystallizes upon contact with the outside atmosphere. These crystals then form a solid barrier that prevents further leakage, thus converting the harmful leakage into a beneficial self-sealing effect.
Solution Approach 2:
The sealing system performs self-service through the self-healing mechanism. When leakage occurs, the system automatically responds by allowing the escaped liquid to crystallize in the gap, forming a natural barrier that stops further leakage without requiring external intervention or replacement of the elastomer seal.
2Reliability
If elastomer seals are used, then sealing is provided, but visible white crystals form from urea leakage on the outside of the seal
Solution Approach 1:
The patent extracts the crystal formation process from the visible exterior and relocates it to the hidden gap between the seal and the assembly. By providing this dedicated gap space, the system allows crystals to form in an invisible location, separating the sealing function from the aesthetic concern of visible crystals.
Solution Approach 2:
The gap acts as an intermediary space between the sealed interior and the exterior environment. It serves as a buffer zone where leaked liquid can be contained and crystallized without directly exposing crystals to the visible exterior surface, thus mediating between the sealing requirement and the aesthetic requirement.
3Reliability
If a gap is provided for liquid to contact outside atmosphere, then self-healing effect is achieved, but gap must be positioned and oriented properly
Solution Approach 1:
The patent applies local quality by providing the gap feature only at specific locations where it is most effective - between the seal and the assembly housing. The gap is strategically positioned to intercept leaked liquid while maintaining the overall simplicity of the sealing structure, applying complexity only where needed rather than throughout the entire system.
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 self-healing seal effectively prevents liquid escape by forming a solid crystal layer within the air-permeable material, ensuring the integrity of the seal and reducing visible crystal formation, thus maintaining system tightness and minimizing liquid consumption.
Implementation Method 1
Liquids that form crystals when they come into contact with the outside atmosphere are, for example, solutions of a substance that crystallizes out into the outside atmosphere when the water contained in the solutions evaporates.
Implementation Method 2
the liquid comes into contact with the outside atmosphere and forms crystals
Implementation Method 3
the liquid escaping as a leak on the outside of the seal, for example a liquid reducing agent containing urea, gets into the at least one gap, for example is drawn into the gap by capillary forces and in the gap remains
Data Source
Figure 1A~1B
Figure 2
AI summary
The arrangement (1) has a seal (3) i.e. O-ring, made of elastomer, and a gap (4) in which liquid (2) entering via the seal comes into contact with outside atmosphere (11). An air-permeable, liquid-absorbing material (6) i.e. fiber braided fabric such as felt, is provided in the gap that is arranged between two components or sealing plug (5). The seal seals a space between the sealing plug and a component wall (14) so that an inner side (10) of a component (100) is separated from the outside atmosphere. USE : Seal arrangement for sealing components e.g. tank, spacer, pipe and hose, of a system for storage and/or transport of liquid i.e. AdBlue(RTM: Aqueous urea solution), in a motor vehicle (claimed). Can also be used for sealing pump and dosage device. ADVANTAGE : The sealing arrangement avoids leakage of the liquid, thus reducing amount of consumption of the liquid. DESCRIPTION OF DRAWINGS : The drawing shows a schematic sectional view of a component with a seal arrangement. 1 : Seal arrangement 2 : Liquid 3 : Seal 4 : Gap 5 : Sealing plug 6 : Air-permeable, liquid-absorbing material 10 : Inner side of component 11 : Outside atmosphere 14 : Component wall 100 : Component.