Urea Filter Heater with Float for Freezing Protection
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Solution Overview
Problem
Existing filter devices for urea water in SCR systems are prone to breakage due to freezing and expansion of urea water, which cannot be effectively prevented by existing technologies.
Innovation Solution
A filter device design incorporating a rod-shaped heater within the filter case, a cylindrical inner cylinder with a partition plate and floats to manage volume expansion, and a gourd-like shape for the filter case to reduce stored liquid volume, along with an air vent system to prevent unfiltered liquid flow and air accumulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a heater is added to prevent freezing of urea water, then the reliability of the filter device is improved, but the device complexity increases
Solution Approach 1:
The heater is integrated into the filter device structure, merging the heating function with the existing filter housing and elements. This combination approach adds freezing protection capability while minimizing the increase in overall device complexity by utilizing the existing structural space and components.
Solution Approach 2:
The filter device housing serves multiple functions: it contains the filtration elements, provides structural support, and acts as a housing for the heater element. This multi-functionality approach allows the same structure to fulfill both filtration and temperature maintenance roles, improving reliability without proportionally increasing complexity.
2Object-affected harmful factors
If the filter case is designed with a gourd-like shape to reduce stored liquid volume, then the harmful effects of freezing are reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The filter case is divided into distinct sections with varying cross-sectional areas, creating a gourd-like shape that tapers at certain regions. This segmentation of the housing volume reduces the amount of urea water stored in extreme positions, thereby reducing freezing damage risk while using standard manufacturing techniques to achieve the desired geometry.
Solution Approach 2:
The filter case exhibits local quality variations in its cross-sectional area along its length, with narrower sections at the ends and a broader middle section. This localized geometric modification reduces liquid volume in freezing-prone areas without requiring high-precision manufacturing throughout the entire component, as the shape transitions can be achieved through conventional forming methods.
3Reliability
If an air vent system is added to prevent unfiltered liquid flow and air accumulation, then the reliability is improved, but the device complexity increases
Solution Approach 1:
The air vent system extracts and separates the air removal function from the main filtration path. By providing a dedicated air vent passage that is distinct from the liquid filtration elements, the system prevents air accumulation and unfiltered liquid flow while maintaining the core filtration function, improving reliability with a relatively simple additive component.
Solution Approach 2:
The air vent system acts as an intermediary mechanism that manages gas-liquid separation within the filter device. This intermediate system handles air accumulation and pressure regulation without interfering with the primary liquid filtration process, thereby improving operational integrity while adding minimal complexity through a dedicated venting pathway.
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
Prevents freezing and breakage of the filter device by maintaining contact between the heater and urea water, managing volume expansion through floats and reducing air accumulation, thus ensuring operational integrity during freezing events.
Implementation Method 1
the heater being substantially rod-shaped extends in the vertical direction inside the filter case. Thus, the liquid and the heater come into contact with each other, and the freezing of the liquid can be prevented
Implementation Method 2
In a process in which the liquid freezes and the volume increases, the first float is pushed up while compressing air enclosed in a space surrounded by the side surface of the inner cylinder, the partition plate and the first float
Implementation Method 3
the first float is pushed up while compressing air enclosed in a space surrounded by the side surface of the inner cylinder, the partition plate and the first float. Thus, even when the liquid freezes, the breakage of the device can be prevented
Data Source
AI summary
An inner case being substantially cylindrical and being covered at an upper end is provided to cover a heater being substantially rod-shaped. A float being substantially plate-shaped and having substantially the same inner diameter as an inner diameter of the inner case is provided movably in the vertical direction in the inner case, and in the float, a hole through which the heater is inserted is formed. Gas is enclosed in a space surrounded by the inner case and the float. The length in the vertical direction of the inner case is smaller than the length in the vertical direction of the heater. In addition, when the float is positioned at a lower end of the inner case, a gap exists between the float and a bottom surface of a filter case.