Liquid Filter Air Venting via Variable Volume Closure
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Solution Overview
Problem
Liquid filters used in the motor vehicle sector to filter urea solutions often trap air during initial filling, leading to pump malfunctions due to air presence, and existing solutions either rely on temporary chemical modifications or air valves, which are not always reliable.
Innovation Solution
A liquid filter design featuring a support frame with a filter chamber and an additional chamber, where a closure element, such as a sponge element, expands to seal openings and allow air venting during filling, ensuring minimal air remains and preventing unfiltered fluid passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dry filter is first filled with liquid, then the filter medium becomes wet and functional, but air becomes trapped inside the filter causing pump malfunctions
Solution Approach 1:
The filter housing is divided into two separate chambers: a filter chamber for the filter medium and an auxiliary chamber for air venting. This segmentation allows air to be specifically managed in the auxiliary chamber while the filter chamber performs its filtration function, resolving the contradiction between maintaining filter functionality and preventing air entrapment.
Solution Approach 2:
A sealing element with variable volume acts as an intermediary between the filter chamber and auxiliary chamber. This sealing element controls the connection between chambers, allowing air to escape during initial filling while preventing unfiltered liquid from passing through, thus mediating between the need for air venting and filtration integrity.
2Object-affected harmful factors
If air venting openings are provided to allow air escape during filling, then air can be removed from the filter, but unfiltered liquid may pass through the openings
Solution Approach 1:
The sealing element is designed with variable volume that changes dynamically based on liquid level. During initial filling, the sealing element has smaller volume allowing air to pass through the opening. As liquid fills the auxiliary chamber, the sealing element expands or moves to close the opening, preventing unfiltered liquid from passing through while maintaining air venting capability during the filling process.
Solution Approach 2:
The auxiliary chamber and sealing element are configured to perform preliminary air venting action during the initial filling phase. The sealing element is positioned and sized to allow air escape before the liquid level rises to a point where unfiltered liquid could contaminate the system, thus performing the air removal function before the harmful condition could occur.
3Reliability
If a sealing element with variable volume is used to close openings, then air venting is enabled during filling and unfiltered liquid is blocked, but the device complexity increases
Solution Approach 1:
The sealing element is designed to automatically adjust its volume or position in response to liquid level changes without external control. During initial filling, the sealing element naturally allows air to pass through. As liquid enters the auxiliary chamber, the sealing element self-actuates to close the opening, eliminating the need for external actuators, sensors, or control systems, thus maintaining simplicity while achieving reliable automatic air venting and sealing.
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 design ensures safe and reliable filling of the filter with minimal air, preventing pump malfunctions and maintaining filtering efficiency by effectively venting the filter chamber and preventing unfiltered fluid from passing through.
Implementation Method 1
The sponge element has a smaller volume when wetted than when wetted. It is designed that the sponge element is configured to absorb and/or store fluid, particularly water.
Implementation Method 2
A filter medium can be arranged in or on the filter chamber. As soon as the fluid flows through the filter chamber, it is filtered, and unwanted particles are retained by the filter medium.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The invention relates to a liquid filter (1), comprising a support frame (2), which comprises a filter chamber (3) and an additional chamber (4), wherein a filter medium (6, 7) can be arranged in or on the filter chamber (3), wherein the filter chamber (3) is separated from the additional chamber (4) by a dividing wall (8), wherein the filter chamber (3) has a first passage (14) and a second passage (15), such that fluid (9) can flow through the filter chamber (3), wherein the additional chamber (4) is connected to the surroundings of the liquid filter (1) by at least one first opening (20) in the support frame (2), and is connected to the filter chamber (3) for fluid communication by at least one second opening (21) in the dividing wall (8), wherein the first opening (20) and the second opening (21) can be closed by a closure element (5) arranged within the additional chamber (4), and wherein a volume of the closure element (5) can be varied in order to close the first opening (20) and the second opening (21).