Honeycomb Filter Cement Shrinkage Control

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Solution Overview

Problem

Fiber cements with silica sols face issues of high shrinkage during drying and curing, leading to voids and cracks in honeycomb filter segments, which can reduce filter functionality and cause telescoping effects under high temperatures, especially during thermo shock regeneration.

Innovation Solution

A cement composition comprising a non-oxide inorganic silicon containing component, a water soluble phosphate component, a metal oxide ceramic component, and a polysaccharide component, which is dried at 100°C and hardened at a sufficient temperature to transform phosphate components into metaphosphates, providing a stable and crack-free assembly layer with thermal conductivity and expansion coefficients matching the filter material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If fiber cements with silica sol are used as the binder for assembling honeycomb filter segments, then the segments can be bonded together, but high shrinkage occurs during drying and curing, leading to voids and cracks in the assembly layer

Engineering Contradiction:

Improvebonding strengthVSAvoiddimensional stability

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent changes the chemical composition parameters of the binder system by replacing silica sol with a combination of water-soluble phosphate binder and colloidal silica, adjusting the molecular structure and bonding mechanism to eliminate excessive shrinkage while maintaining bonding strength

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite binder system combining water-soluble phosphate binder with colloidal silica and ceramic fibers, where each component contributes specific properties: the phosphate binder provides dimensional stability, colloidal silica enhances adhesion, and ceramic fibers provide structural reinforcement, together achieving both strong bonding and minimal shrinkage

Inventive Principle:

Principle #40Composite materials

2Productivity

If the honeycomb filter segments have high porosity and thin cell walls to reduce thermal mass, then the filter efficiency is improved, but the segments become more susceptible to damage during thermo shock regeneration

Engineering Contradiction:

Improvefilter efficiencyVSAvoidresistance to thermal shock

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent employs an elastic assembling layer with flexible binding mechanisms that can accommodate thermal expansion and contraction of the thin-walled honeycomb segments during thermo shock regeneration, preventing crack propagation while maintaining segment integrity

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The elastic assembling layer acts as a cushioning element that absorbs and distributes thermal stress before it can reach the fragile thin cell walls of the honeycomb segments, protecting them from thermal shock damage during regeneration cycles

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Quantity of substance

If multiple honeycomb filter segments are assembled into a large diameter filter, then the filtration capacity is increased, but the assembly layer becomes more prone to cracking and telescoping under high temperature

Engineering Contradiction:

Improvefiltration capacityVSAvoidstructural integrity

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent divides the large diameter filter into multiple smaller honeycomb segments that are assembled together, allowing each segment to maintain structural integrity while collectively providing high filtration capacity, with the elastic binding layer accommodating differential thermal movements between segments

Inventive Principle:

Principle #1Segmentation

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 new cement achieves high thermal conductivity and specific heat capacity, maintains mechanical strength and adhesion under thermal stress, and prevents shrinkage and cracking, ensuring the integrity of honeycomb filters even under extreme conditions.

Implementation Method 1

dried at 100°C

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 2

hardening at a sufficient temperature to transform phosphate components into metaphosphates

Methodology Applied

Scientific EffectPhase transformation: Phase Change

Implementation Method 3

achieves high thermal conductivity and specific heat capacity, maintains mechanical strength and adhesion under thermal stress

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

expansion coefficients matching the filter material

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS10443461B2Honey comb assembly

Publication Date: 2019.10.15 DINEX AS

AI summary

The present invention relates to a composition comprising a non-oxide silicon containing component, a water soluble phosphate component, a metal oxide ceramic component, a polysaccharide component and water to 100% w/w. This composition can be transformed into a cement that holds individual honey comb filter segments of a honey comb filter together.