Ash Mobilization in Exhaust-Gas Particle Filters
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Solution Overview
Problem
Existing methods for ash detachment and transport in exhaust particulate filters are inefficient, leading to increased flow resistance over time, as they often expose ash prior to detachment, which can be disadvantageous.
Innovation Solution
A method involving a regeneration phase where a soot load is purposely accumulated on the ash deposited on the filter wall, followed by active regeneration to mobilize and detach the ash, ensuring efficient ash mobilization and maintaining low flow resistance by forming a dense ash packing at the end of each filter channel.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If ash is exposed prior to detachment in existing methods, then ash detachment can be initiated, but flow resistance increases and ash mobilization efficiency decreases
Solution Approach 1:
The invention applies a layer of soot onto the deposited ash before initiating detachment. This preliminary action prepares the ash for more effective mobilization during subsequent regeneration, preventing direct exposure of ash to gas flow which causes harmful effects. The soot layer acts as an intermediary that facilitates cleaner detachment.
Solution Approach 2:
Soot serves as an intermediary substance between the ash and the exhaust gas flow. By applying soot onto the ash first, the system creates a mediator layer that enables detachment without direct harmful interaction between ash and gas flow, thereby reducing flow resistance while maintaining detachment efficiency.
2Ease of operation
If exhaust gas flow rate is increased to detach and transport ash, then ash transport is enhanced, but energy consumption increases
Solution Approach 1:
By applying soot onto the ash before detachment in advance, the system prepares the ash for more efficient transport. This preliminary preparation reduces the energy required during the actual detachment and transport phase, as the soot-coated ash detaches more easily and requires less exhaust gas flow rate enhancement for effective transport.
3Productivity
If soot load is increased to form a layer on ash, then ash mobilization improves, but filter pressure loss increases temporarily
Solution Approach 1:
The system periodically applies soot to the filter wall during operation, creating temporary increased soot load that results in elevated pressure loss. However, this is followed by regeneration phases where the soot-ash composite is burned off, restoring pressure characteristics. The periodic cycle of soot application and regeneration manages the trade-off between mobilization efficiency and pressure loss.
Solution Approach 2:
The invention temporarily changes the soot load parameter on the filter wall by applying additional soot onto deposited ash. This parameter change facilitates improved ash mobilization during the soot application phase, with the understanding that the parameter will be reversed during subsequent regeneration when the soot-ash layer is combusted.
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 approach improves ash mobilization and reduces flow resistance by ensuring the ash is effectively detached and transported, maintaining low pressure loss and optimizing filter efficiency.
Implementation Method 1
the deposited ash is mobilized by burning off the soot layer formed in the course of an active regeneration
Data Source
AI summary
A method for execution with an exhaust-gas particle filter which is operated with an exhaust-gas aftertreatment system, wherein the exhaust-gas particle filter has a filter wall along which exhaust gas is conducted for filtering purposes; wherein the method includes a regeneration phase with the steps: a) setting a soot load on the exhaust-gas particle filter, wherein the set soot load effects the formation of a soot layer on ash deposited on the filter wall; and b) subsequently mobilising the deposited ash by burning off the formed soot layer during the course of an active regeneration of the exhaust-gas particle filter.