Ribbed Cylindrical Adsorbent Structure for Canister Purge Flow
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Solution Overview
Problem
Existing adsorbents for treating evaporated fuel in canisters face challenges in maintaining optimal temperature conditions for adsorption and desorption, leading to reduced performance due to heat generation and absorption during these processes.
Innovation Solution
The development of an adsorbent with a cylindrical outer wall and a plurality of ribs that partition the inner space into cells, where the thickness of the outer wall and ribs is less than 0.6 mm, enhancing purge air and evaporated fuel flow, and incorporating a metal oxide to improve thermal control and rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the thickness of the outer wall and ribs is reduced to less than 0.6 mm, then purge performance and air flow are improved, but the rigidity and structural strength of the adsorbent deteriorate
Solution Approach 1:
The patent employs composite materials by incorporating metal oxide particles (such as aluminum oxide, silicon oxide, or titanium oxide) into the adsorbent matrix. This composite structure provides both the desired thin wall thickness for improved purge performance and the necessary rigidity through the reinforcing effect of the metal oxide particles distributed within the adsorbent structure.
Solution Approach 2:
The patent applies local quality by creating a non-uniform distribution of properties within the adsorbent structure. The outer wall and ribs are designed with specific thickness ranges (0.3-0.6 mm) to optimize flow characteristics, while metal oxide particles are strategically distributed to provide localized reinforcement where structural integrity is most needed, allowing different regions to have optimized properties for their specific functions.
2Productivity
If the thickness of the outer wall and ribs is reduced to less than 0.6 mm, then Diurnal Breathing Loss (DBL) performance is improved, but the structural stability of the adsorbent deteriorates
Solution Approach 1:
The composite structure with metal oxide particles provides enhanced structural stability despite the reduced wall thickness. The metal oxide framework creates a rigid skeleton that maintains the adsorbent's shape and prevents collapse during operation, while the thin walls (0.3-0.6 mm) allow for improved vapor flow and DBL performance.
Solution Approach 2:
The patent utilizes porous materials with controlled pore structures that maintain structural integrity through their three-dimensional networks. The porous framework, combined with metal oxide reinforcement, provides both the flow pathways needed for improved DBL performance and the structural stability required to maintain composition integrity during repeated adsorption-desorption cycles.
3Quantity of substance
If the outer diameter of the outer wall is increased to 3.5-40 mm, then adsorption capacity is improved, but the flow characteristics and purge efficiency deteriorate
Solution Approach 1:
The patent segments the adsorbent structure by dividing it into an outer wall, ribs, and internal cells. This segmentation allows the adsorbent to achieve a large effective outer diameter (3.5-40 mm) for increased adsorption capacity while maintaining thin wall sections (0.3-0.6 mm) that facilitate efficient vapor flow and purge characteristics. The rib structure further divides the internal space to optimize flow pathways.
Solution Approach 2:
The patent utilizes the three-dimensional structure by creating a hollow cylindrical form with internal ribbing that divides the space into multiple cells. This dimensional approach allows the adsorbent to maximize surface area and adsorption capacity in the radial direction while maintaining optimized flow paths through the axial direction, effectively decoupling adsorption capacity from purge efficiency constraints.
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
This configuration improves purge performance and Diurnal Breathing Loss (DBL) performance by facilitating better air and fuel flow, while the metal oxide enhances the adsorbent's thermal stability and rigidity, maintaining high adsorption and desorption efficiency.
Implementation Method 1
the metal oxide enhances the adsorbent's thermal stability and rigidity, maintaining high adsorption and desorption efficiency
Implementation Method 2
capture evaporated fuel, generated from volatilization of gasoline fuel stored in a fuel tank while a vehicle is stopped, by adsorption with an adsorbent made of activated carbon or the like
Implementation Method 3
adsorption of evaporated fuel to an adsorbent is an exothermic reaction
Implementation Method 4
desorption from the adsorbent is an endothermic reaction
Data Source
AI summary
An object of the present invention is to provide an adsorbent and a canister which can improve adsorption performance and purge performance. An adsorbent 10 to be packed in a canister includes:a cylindrical outer wall 10A, anda plurality of ribs 10B for partitioning along an axis of the outer wall 10A into a plurality of cells, whereinthe thickness dα of the outer wall 10A and the thickness dβ of the ribs 10B is less than 0.6 mm,the thickness of at least either of the outer wall 10A and the ribs 10B exceeds 0.4 mm,the outer diameter D of the outer wall 10A is 3.5 mm or more and 40 mm or less,a BWC exceeds 3.0 g/dL, andpurge efficiency((amount of butane adsorbed−amount of butane retained)/amount of butane adsorbed) is more than 0.86 or more.