Crescent Mixing Plate Layout for Low-Backpressure Exhaust Mixing
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Solution Overview
Problem
Existing mixers in exhaust aftertreatment systems for internal combustion engines increase backpressure, which decreases engine power and efficiency, and are prone to deposit formation due to turbulent flow, reducing mixing efficiency.
Innovation Solution
The use of crescent-shaped mixing plates in the mixer, positioned obliquely within the tubular conduit, induces turbulent, spiraling flow to enhance mixing while minimizing deposit formation and backpressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional mixers are used to mix treatment fluid and exhaust, then mixing efficiency is improved, but backpressure increases and engine power decreases
Solution Approach 1:
The mixing plates are designed with crescent shapes featuring convex and concave edges instead of flat or straight configurations. This curvature creates more effective flow disruption and mixing while maintaining lower resistance to exhaust flow, thereby reducing backpressure while preserving mixing efficiency.
Solution Approach 2:
The mixing plates employ asymmetric crescent shapes with distinct convex and concave edges positioned at specific orientations. This asymmetric design creates optimized flow patterns that enhance mixing effectiveness while minimizing the resistance imposed on exhaust flow, addressing the backpressure issue.
2Productivity
If conventional mixers are used to mix treatment fluid and exhaust, then mixing efficiency is improved, but deposit formation increases
Solution Approach 1:
The crescent-shaped mixing plates with curved convex and concave edges create flow patterns that reduce stagnant zones where deposits typically form. The curvature promotes continuous fluid motion and prevents the accumulation of treatment fluid residues that would otherwise solidify into deposits.
Solution Approach 2:
The specific geometric parameters of the crescent-shaped plates, including the curvature radius and edge orientation, are optimized to create flow conditions that minimize deposit formation while maintaining effective mixing. The design alters flow velocity distribution and pressure patterns to prevent deposit accumulation.
3Productivity
If mixing plates are positioned to maximize mixing, then mixing efficiency is improved, but device complexity increases
Solution Approach 1:
The mixer is divided into multiple discrete crescent-shaped mixing plates positioned at different locations and orientations within the conduit. Each plate performs a specific mixing function, and the segmented design allows for optimized placement that achieves thorough mixing without requiring a single complex structure.
Solution Approach 2:
The crescent-shaped mixing plates serve multiple functions simultaneously: they disrupt flow to enhance mixing, guide exhaust flow through the conduit, and minimize backpressure through their curved geometry. This multi-functionality reduces the need for additional components, simplifying the overall device structure.
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 crescent-shaped mixing plates facilitate efficient mixing of exhaust and treatment fluid, preventing deposit formation and minimizing backpressure, thereby improving engine performance and efficiency.
Implementation Method 1
The use of crescent-shaped mixing plates in the mixer, positioned obliquely within the tubular conduit, induces turbulent, spiraling flow to enhance mixing
Data Source
AI summary
An exhaust aftertreatment assembly includes a tubular conduit and a mixer disposed in the tubular conduit. The tubular conduit includes a central axis. The mixer includes a first mixing plate and a second mixing plate. The first mixing plate is crescent shaped and includes a first plate convex edge coupled to the tubular conduit, and a first plate concave edge. The second mixing plate is crescent shaped and includes a second plate convex edge coupled to the tubular conduit, and a second plate concave edge. The first mixing plate and the second mixing plate are positioned relative to the tubular conduit such that the central axis extends between the first plate concave edge and the second plate concave edge. A first plane in which the first mixing plate extends and a second plane in which the second mixing plate extends are oblique to the central axis of the tubular conduit.


