Angled Catalyst Bank for Exhaust Distribution
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Solution Overview
Problem
Existing aftertreatment modules with multiple SCR catalysts face challenges in efficient exhaust and reductant distribution, leading to increased backpressure and packaging size issues, and often include unnecessary components that complicate the exhaust system.
Innovation Solution
An aftertreatment module with a catalyst bank positioned at an oblique angle to the exhaust flow direction, creating a decreasing cross-sectional area inlet passage and an increasing cross-sectional area outlet passage, which ensures even distribution of exhaust and reduces backpressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple SCR catalysts are used to meet emissions control requirements, then NOX reduction efficiency is improved, but exhaust backpressure increases and packaging space requirements increase
Solution Approach 1:
The catalyst bank is segmented into multiple catalyst elements arranged in parallel, allowing exhaust flow to be distributed across multiple pathways. This segmentation maintains NOX reduction efficiency while reducing backpressure compared to a single large catalyst block.
Solution Approach 2:
The catalyst bank is positioned at an oblique angle (e.g., 45 degrees) relative to the exhaust flow direction, transitioning from a conventional axial arrangement. This angular orientation creates tapered passages that improve flow distribution and reduce backpressure while maintaining effective catalyst contact.
2Reliability
If multiple SCR catalysts are used to meet emissions control requirements, then NOX reduction efficiency is improved, but packaging size increases
Solution Approach 1:
Multiple catalyst elements are merged into a single integrated catalyst bank assembly that functions as one unit. This consolidation achieves the required NOX reduction through multiple catalysts while optimizing the overall packaging footprint compared to separate catalyst installations.
Solution Approach 2:
By orienting the catalyst bank at an oblique angle rather than axially, the design utilizes three-dimensional space more efficiently. The angular configuration allows the catalyst bank to fit within constrained packaging volumes while maintaining effective catalyst surface area for NOX reduction.
3Device complexity
If conventional axial catalyst positioning is used, then packaging is simplified, but exhaust distribution across catalysts is uneven
Solution Approach 1:
The catalyst bank is positioned asymmetrically at an oblique angle relative to the exhaust flow, breaking the conventional symmetric axial arrangement. This asymmetric positioning creates tapered inlet and outlet passages that naturally promote uniform exhaust distribution across all catalyst elements without requiring complex flow control mechanisms.
4Reliability
If unnecessary aftertreatment devices are included to ensure complete treatment, then emissions control reliability is improved, but packaging size increases
Solution Approach 1:
The catalyst bank is designed to perform multiple functions simultaneously: NOX reduction through SCR catalysis, exhaust flow distribution, and backpressure management. This multi-functionality eliminates the need for separate dedicated components, achieving complete emissions control within a compact packaging volume.
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 oblique angle configuration enhances even exhaust distribution across catalysts, minimizes backpressure, and optimizes packaging by efficiently using space, resulting in a more compact and effective exhaust treatment system.
Implementation Method 1
The injected urea solution decomposes into ammonia (NH3), which reacts with NOX in the exhaust gas to form water (H2O) and diatomic nitrogen (N2)
Data Source
AI summary
An aftertreatment module for use with an engine is disclosed. The aftertreatment module may include a housing having an inlet configured to direct exhaust in a first flow direction into the aftertreatment module, and an outlet configured to direct exhaust in the first flow direction out of the aftertreatment module. The aftertreatment module may also include a catalyst bank separating the inlet from the outlet. The catalyst bank may have a face disposed at an oblique angle with respect to the first flow direction. The oblique angle may create an inlet passage extending from the inlet to the catalyst bank and having a decreasing cross-sectional area, and an outlet passage extending from the catalyst bank to the outlet and having an increasing cross-sectional area.