Dosing Conduit Flow Guides for Exhaust Mixing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Diesel engine exhaust aftertreatment systems face inefficiencies due to incomplete mixing of reactants with exhaust gases, leading to deposit buildup and potential clogging, which reduces system efficiency and prevents exhaust flow.
Innovation Solution
The introduction of flow guides within the dosing conduit of the aftertreatment device, which induce swirling of reactants and exhaust gases to enhance mixing, thereby reducing deposit formation and clogging risks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If reactant is injected into exhaust gas without flow guides, then the dosing system is simple, but mixing efficiency is poor and deposit buildup occurs
Solution Approach 1:
The dosing conduit is segmented into multiple functional regions: an injection region for reactant introduction, a swirl region with flow guides for mixing, and a perforated region for exhaust interaction. This segmentation allows each region to perform its specific function optimally, improving mixing efficiency while maintaining manufacturing simplicity through modular design
Solution Approach 2:
Flow guides act as intermediary elements between the reactant injection point and the exhaust gas flow. These guides mediate the interaction by inducing swirl motion that enhances mixing without requiring complex injection systems, thus improving productivity while keeping the overall system simple
2Duration of action of moving object
If reactant injection continues without flow guides, then dosing operation is continuous, but deposit buildup clogs the system
Solution Approach 1:
The flow guides perform preliminary mixing action immediately after reactant injection, creating swirl motion that prevents deposit formation before it can occur. This preliminary action ensures continuous operation can proceed without clogging by addressing the mixing issue at its source
Solution Approach 2:
The system converts the potential harm of continuous reactant injection (which causes deposit buildup) into a benefit by using the continuous flow itself to sustain swirl motion in the flow guides. This continuous motion prevents deposition while maintaining dosing operation, transforming what was a problem into a solution
3Productivity
If flow guides are added to induce swirling, then mixing efficiency improves, but device complexity increases
Solution Approach 1:
The flow guides are confined to a specific swirl region within the dosing conduit, segmented from the injection and perforated regions. This localized approach improves mixing efficiency only where needed without complicating the entire dosing system, maintaining manufacturing simplicity in non-swirl areas
Solution Approach 2:
The flow guides provide more mixing action than strictly necessary (excessive action) within the swirl region, ensuring thorough mixing of reactant and exhaust. This partial concentration of complexity in one region allows the rest of the system to remain simple, achieving high productivity without overall system complexity
4Productivity
If flow guides extend along entire dosing conduit, then mixing occurs throughout, but manufacturing complexity and material usage increase
Solution Approach 1:
The dosing conduit is segmented into distinct regions with flow guides present only in the swirl region, not throughout the entire conduit. This segmentation reduces material usage while maintaining effective mixing coverage by concentrating flow guides where they are most needed for reactant-exhaust interaction
Solution Approach 2:
The flow guides provide enhanced mixing quality locally in the swirl region where reactant and exhaust first interact. This local quality approach ensures adequate mixing coverage at the critical interface without requiring flow guides throughout the entire conduit length, reducing material consumption
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
Improved mixing of reactants with exhaust gases reduces deposit formation and clogging, maintaining system efficiency and ensuring proper exhaust flow through the aftertreatment device.
Implementation Method 1
The flow guides surround at least a portion of the spray zone and induce swirling to mix the reactant with the exhaust
Implementation Method 2
Exhaust entering the aftertreatment device flows towards the dosing conduit and enters the dosing conduit through a perforated region
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An aftertreatment device includes flow guides disposed within a dosing conduit. Exhaust enters through a perforated region of the dosing conduit and passes through the flow guides. The flow guides induce swirling or other turbulence to mix injected reactant with the exhaust gas. Various types of flow guides include cantilevered vanes, guide passageways, and louvered openings of a second conduit. Some types of flow guides induce localized mixing to inhibit deposit formation at the doser mounting unit. Other types of flow guides induce mixing downstream of the dosing conduit.