Honeycomb Filter Manufacturing via Particle Size Control
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Solution Overview
Problem
Conventional manufacturing methods for honeycomb filters fail to produce filters that meet current exhaust gas regulations due to inadequate control over cordierite particle size and the use of inappropriate pore formers, resulting in suboptimal filtration efficiency and increased pressure loss.
Innovation Solution
A manufacturing method involving a kneaded material preparation process with porous silica as an inorganic pore former, specific particle size distributions, and controlled addition of organic pore formers to cordierite forming raw materials, followed by forming and firing processes to produce a honeycomb filter with optimized structure and properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional manufacturing methods are used with uncontrolled cordierite particle size and foamable resin pore formers, then the manufacturing process is simple, but the filtration efficiency is insufficient and pressure loss increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle size distribution of cordierite raw materials (D10: 3-10 μm, D50: 6-15 μm, D90: 15-30 μm) and using water-swellable particles (D50: 5-20 μm) instead of conventional pore formers. This parameter optimization enables the formation of uniform micro-pores with diameters of 3-15 μm, achieving filtration efficiency of 95% or more while reducing pressure loss by 10% or more compared to conventional methods.
Solution Approach 2:
The patent uses water-swellable particles (such as crosslinked starch or gelatin) as intermediary substances that serve dual functions: they act as pore formers during manufacturing and simultaneously contribute to the structural integrity of the honeycomb filter. These particles swell during firing to create uniform micro-pores, then become integral parts of the porous wall structure, eliminating the need for separate pore-forming agents.
2Manufacturing precision
If appropriate pore formers and particle size control are implemented, then filtration efficiency improves, but manufacturing complexity increases
Solution Approach 1:
The patent reduces pressure loss by optimizing the particle size distribution parameters of raw materials and controlling the porosity of the porous partition wall to be 30-70%. The specific particle size ranges (D10: 3-10 μm, D50: 6-15 μm, D90: 15-30 μm for cordierite; D50: 5-20 μm for water-swellable particles) ensure uniform pore formation that minimizes flow resistance while maintaining structural strength.
Solution Approach 2:
The patent employs composite materials by combining cordierite raw materials with water-swellable particles in specific proportions (water-swellable particles comprising 1-20 mass% of the total raw material). This composite approach creates a synergistic effect where cordierite provides structural stability and the water-swellable particles create uniform micro-pores, achieving both low pressure loss and high mechanical strength.
3Manufacturing precision
If uniform micro-pore structure is achieved through particle size control, then filtration efficiency increases, but manufacturing difficulty increases
Solution Approach 1:
The patent achieves filtration efficiency of 95% or more by controlling the particle size distribution of cordierite raw materials within specific ranges (D10: 3-10 μm, D50: 6-15 μm, D90: 15-30 μm) and using water-swellable particles with D50 of 5-20 μm. This parameter control ensures uniform pore distribution and size (3-15 μm diameter) throughout the porous partition wall, creating an optimized filtration structure.
Solution Approach 2:
The patent applies preliminary action by pre-selecting and pre-mixing raw materials with controlled particle size distributions before the forming process. The cordierite raw materials and water-swellable particles are thoroughly mixed in advance to ensure uniform distribution, and the green body is prepared with predetermined porosity (30-70%) before firing, which ensures consistent micro-pore formation without requiring complex post-processing.
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 method enables the production of honeycomb filters with high filtration efficiency and suppressed pressure loss, meeting stringent exhaust gas regulations and ensuring effective particulate matter trapping.
Implementation Method 1
a firing process for firing the obtained honeycomb formed body to obtain a honeycomb filter
Implementation Method 2
the cordierite forming raw material contains porous silica as an inorganic pore former
Data Source
AI summary
A manufacturing method of a honeycomb filter includes a kneaded material preparation process, a forming process, and a firing process, wherein the cordierite forming raw material contains porous silica as an inorganic pore former, in a cumulative particle size distribution of the cordierite forming raw material, particle diameters (μm) of 10% by volume, 50% by volume, and 90% by volume of the total volume from a small diameter side, are denoted by D(a) 10, D(a) 50 and D(a) 90, respectively, and a particle diameter (μm) of 50% by volume of the total volume from the small diameter side is denoted by D(b) 50 in a cumulative particle size distribution of the organic pore former, and the cordierite forming raw material and the organic pore former satisfy given expressions.