Exhaust Heaters with Double-Ended Slots for Catalyst Light-Off
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Solution Overview
Problem
Existing exhaust aftertreatment systems face challenges in quickly achieving catalyst light-off temperatures, leading to prolonged emissions reduction inefficiencies during engine startup.
Innovation Solution
An electrical heater with a serpentine current-carrying path and double-ended slots that create a dead zone near electrode attachment sites, combined with slot separators, to manage current flow and enhance heat generation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If electrical heaters are used to increase catalyst temperature, then catalyst light-off temperature is achieved faster, but energy is wasted in areas where current flow is blocked
Solution Approach 1:
The patent applies local quality by creating dead zones with blocked current flow in specific areas where heat generation is unnecessary, while maintaining open slots in areas where heat is needed. This localized differentiation of current flow paths optimizes energy distribution to match thermal requirements across the catalyst substrate.
Solution Approach 2:
The patent segments the heater body into multiple zones with different slot configurations. By dividing the continuous current path into separate segments through strategic slot placement, the design controls current flow to specific regions, preventing energy waste in areas where the catalyst is already sufficiently heated.
2Productivity
If slots are added to define current path, then heat generation efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent utilizes parameter changes by varying the width, depth, and positioning of slots to control current flow characteristics. By adjusting these geometric parameters rather than changing the fundamental heater structure, the design achieves efficient heat generation while maintaining compatibility with existing manufacturing processes.
3Ease of operation
If double-ended slots are used to create dead zones, then current flow control is improved, but device complexity increases
Solution Approach 1:
The patent merges the current flow control function with the structural heater body by integrating slots directly into the substrate. The dead zones are created by combining slot geometry with the existing heater architecture rather than adding separate control components, thus managing complexity while achieving precise current directionality.
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
Facilitates rapid catalyst light-off by optimizing current flow and reducing heat wastage, ensuring consistent emissions reduction even during cold starts.
Implementation Method 1
Electrical heaters provide one manner for assisting in control of temperature during treatment of a fluid stream, such as to increase the temperature of a catalyst material
Data Source
AI summary
An electrical heater including a plurality of slots that disconnect some of the cells of the heater body from each other to define a serpentine current-carrying path. The plurality of slots includes one or more double-ended slots that each includes two of second end portions split off the from a first end portion. The serpentine current-carrying path is at least partially defined along the second end portions of the double-ended slot. The double-ended slot creates a dead zone proximate to the corresponding electrode attachment site near the outer periphery of the heater body in which electrical current is blocked from traveling past the first end portion and thereby directed along the serpentine current-carrying path.