Honeycomb Substrate Coating with Liquid Surface Levelling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for coating catalyst slurry on honeycomb channels in a monolith substrate result in non-uniform coating due to high viscosity issues, leading to excess slurry usage and wastage, as the slurry flows unevenly into channels, causing longer coating lengths in central channels and shorter lengths in peripheral channels.
Innovation Solution
A substrate coating device that includes a slurry supplying device and a liquid surface levelling mechanism, where the slurry is supplied to a storing part with both ends open, and air pressure control is used to ensure equal slurry distribution across channels by rotating or vibrating the substrate to level the slurry surface before spreading, ensuring uniform coating without excess.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a slurry with high viscosity is supplied from the supply nozzle to the storing part, then the slurry is stored in a state raised at a portion just beneath the supply nozzle, but the slurry flows unevenly into the honeycomb channels causing non-uniform coating length
Solution Approach 1:
The patent introduces a liquid surface levelling mechanism that operates before the slurry is supplied to the honeycomb channels. This mechanism pre-levels the slurry surface in the storing part, ensuring that when the slurry flows into the channels, it does so uniformly across all channels. This preliminary action eliminates the non-uniform flow pattern that would otherwise occur due to the raised slurry state beneath the supply nozzle.
Solution Approach 2:
The liquid surface levelling mechanism acts as an intermediary between the slurry supply system and the honeycomb channels. It mediates the slurry flow by leveling the liquid surface, thereby controlling the uniform distribution of slurry into each channel without requiring direct modification of the supply nozzle or the channels themselves.
2Manufacturing precision
If a sufficient amount of slurry is supplied to coat the monolith, then excess slurry flows out from the central channels while peripheral channels are not coated as far as the lower end
Solution Approach 1:
By leveling the slurry surface before supply, the system ensures that each channel receives the precise amount of slurry needed for uniform coating. This preliminary leveling action prevents both the shortage of slurry in peripheral channels and the excess in central channels, eliminating the need to supply much more slurry than necessary and thereby preventing wastage.
Solution Approach 2:
The patent changes the physical state of the slurry surface from non-uniform (raised at the center) to uniform (levelled) before the slurry enters the channels. This parameter change in the liquid surface configuration ensures equal distribution of slurry volume to each channel, achieving uniform coating length without excess or deficiency.
3Manufacturing precision
If a much more amount of slurry is supplied to fill all honeycomb channels and then clean off surplus slurry, then uniform coating can be achieved, but the process becomes complex and wasteful
Solution Approach 1:
The liquid surface levelling mechanism performs the uniformity adjustment in advance, before the slurry is supplied to the channels. This eliminates the need for subsequent cleaning operations to remove surplus slurry, simplifying the overall process while maintaining uniform coating quality.
Solution Approach 2:
The patent extracts and eliminates the unnecessary step of supplying excess slurry and subsequently cleaning it off. By leveling the liquid surface beforehand, the system achieves uniform coating directly without the need for the complex fill-and-clean process, thereby removing the harmful complexity from the coating operation.
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 device achieves uniform coating of the entire length of channels with the necessary amount of slurry, preventing wastage and ensuring consistent coverage by leveling the slurry surface and controlling air pressure to distribute it evenly across all channels.
Implementation Method 1
rotating or vibrating the substrate to level the slurry surface before spreading
Implementation Method 2
rotating or vibrating the substrate to level the slurry surface before spreading
Implementation Method 3
air pressure control is used to ensure equal slurry distribution across channels
Data Source
AI summary
A device and a method which is capable of uniformly coating, without waste, any flow passages formed in a raw material with a slurry even if a slurry having high viscosity is fed thereto by an amount required for the use of coating without excess and shortage. When the slurry (S) fed to one end of the base material (M) in which a large number of flow passages (2 . . . ) are formed parallel with each other is forced into the flow passages (2 . . . ) by an air pressure to coat the inner walls (2w) of the flow passages, the slurry (S) is fed from a slurry feeding device (6) by a required amount to a slurry storage part (5) formed at the upper surface part of the base material (M) disposed so that both ends of the flow passages (2 . . . ) can be opened in the upper and bottom surfaces thereof. Then, before the slurry (S) is forced into the flow passages (2 . . . ), a centrifugal force and vibration are allowed to act on the slurry (S) by a liquid level uniformalizing mechanism (7) to uniformalize the level of the slurry.