Compact Fuel Vapor Canister Layout for EVAP Space Constraints
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Solution Overview
Problem
Existing carbon canisters for evaporative emission control systems face space constraints due to their size and configuration, making it difficult to accommodate them in devices with limited space, such as vehicles and generators.
Innovation Solution
The design of a carbon canister with multiple bed volumes, each filled with different types of fuel vapor filtering media, and a compact configuration with the load and purge ports positioned on the side, along with a purge control insert to minimize the risk of liquid fuel conveyance, allowing for a more compact and efficient vapor filtration system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a common carbon canister with chambers filled with activated carbon and springs is used, then fuel vapor adsorption and desorption functions are achieved, but the device size becomes large making it difficult to accommodate in space-constrained applications
Solution Approach 1:
The patent places the spring inside the purge port assembly rather than having it extend into the chamber, nesting components within each other to reduce overall canister volume while maintaining the necessary functions of both the spring (for carbon bed compression) and the purge port assembly
Solution Approach 2:
The patent repositions the load port and purge port from protruding from the end of the chamber to being located on the side of the chamber, changing the spatial arrangement from a linear end-to-end configuration to a side-mounted configuration, which reduces the overall length and volume of the canister while maintaining proper vapor flow paths
2Object-affected harmful factors
If load port and purge port are positioned protruding from the end of the chamber, then condensed fuel vapor is prevented from being conveyed to the air intake manifold, but the canister size increases making space accommodation difficult
Solution Approach 1:
The patent repositions the load port and purge port from protruding from the end of the chamber to being located on the side of the chamber, changing the spatial arrangement to reduce overall canister volume while maintaining the functional separation that prevents condensed fuel vapor from reaching the air intake manifold through proper flow path design
3Stability of the object's composition
If springs are positioned to apply force along the length of the chamber, then activated carbon is kept tightly packed, but the canister requires more space accommodating the spring extension
Solution Approach 1:
The patent nests the spring within the purge port assembly housing rather than having it extend into the chamber volume, allowing the spring to maintain compression force on the activated carbon bed while occupying minimal additional space within the existing canister structure
Solution Approach 2:
The spring is designed to be contained within the purge port assembly while still being able to dynamically compress and expand with the carbon bed, maintaining packing density without requiring a larger canister volume to accommodate spring movement
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 solution enables a more compact design that accommodates space constraints while effectively adsorbing and desorbing fuel vapor, minimizing the risk of liquid fuel conveyance, and ensuring efficient fuel vapor management during engine operation.
Implementation Method 1
activated carbon in the carbon canister adsorbs the fuel vapor in the mixture
Implementation Method 2
the EVAP system directs 'clean' air through the activated carbon to purge the fuel vapor from the carbon (a.k.a. desorption)
Data Source
AI summary
An evaporative emission control system (EVAP) canister including a housing, where the housing has a first bed volume, a second bed volume, a load port, and a purge control receptacle. The first bed volume includes a first opening and a second opening opposite the first opening. The second bed volume includes a third opening and a fourth opening opposite the third opening. The load port enables fuel vapor from a fuel tank to enter the first bed volume. The purge control receptacle is on a side of the first bed volume and is configured to receive a first purge control insert. The first purge control insert is configured to ensure that unfiltered fuel vapor condensate drawn in during a purge cycle is passed through a first portion of a fuel vapor filtering medium in the first bed volume.