Washcoat Showerhead Pressure Control for Uniform Substrate Coating

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Solution Overview

Problem

Existing methods for coating substrates used in exhaust gas purification face challenges such as uneven washcoat profiles, which can lead to reduced catalytic efficiency, increased back pressure, and visual degradation due to dripping or leakage of washcoat from the showerhead.

Innovation Solution

A substrate coating apparatus and method that includes a valve assembly with a pressure drop mechanism to control washcoat flow, preventing dripping or leakage from the washcoat showerhead. The apparatus engages the substrate under the showerhead and uses a suction force to draw the washcoat through the substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If washcoat is discharged onto the upper surface of the substrate to achieve coating, then the substrate receives the coating material, but dripping or leakage occurs from the showerhead causing uneven profiles and operational inefficiency

Engineering Contradiction:

Improvewashcoat profile uniformityVSAvoidwashcoat dripping and leakage

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the traditional mechanical gravity-driven washcoat discharge system with a pneumatic system that uses pressurized gas to atomize and deliver washcoat. This substitution eliminates the dripping and leakage problems associated with mechanical showerheads by controlling washcoat delivery through gas pressure and flow rate, resulting in uniform coating profiles without harmful overflow

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs pneumatic principles by using pressurized gas to transport and atomize washcoat onto the substrate. The gas flow rate and pressure are controlled to ensure uniform distribution of washcoat particles, preventing both dripping and leakage while maintaining precise coating control throughout the process

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Reliability

If conventional coating methods are used to apply washcoat to substrates, then coating is achieved, but uneven washcoat profiles result in reduced catalytic efficiency and increased back pressure

Engineering Contradiction:

Improvecatalytic efficiencyVSAvoidwashcoat profile evenness

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent replaces conventional mechanical washcoat application with a pneumatic atomization system that delivers washcoat as a controlled spray. This substitution ensures uniform profile formation by controlling particle distribution through gas pressure and flow rate, eliminating the uneven profiles that reduce catalytic efficiency and increase back pressure

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent controls coating uniformity by adjusting pneumatic parameters including gas pressure, gas flow rate, and washcoat feed rate. These parameter changes enable precise control over washcoat deposition, ensuring even profiles that maintain high catalytic efficiency while minimizing back pressure

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If washcoat is applied to substrates using traditional methods, then coating is achieved, but visual degradation occurs due to dripping and leakage

Engineering Contradiction:

Improvecoating process simplicityVSAvoidvisual degradation from washcoat leakage

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent replaces traditional mechanical washcoat application with pneumatic atomization, which eliminates visual degradation caused by dripping and leakage. The pneumatic system delivers washcoat as a controlled spray that uniformly coats the substrate without overflow, maintaining both manufacturing simplicity and visual quality

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution effectively mitigates dripping and leakage of washcoat, ensuring a uniform and efficient coating profile, thereby enhancing the operational efficiency and visual quality of the coated substrates.

Implementation Method 1

the valve assembly creates a pressure drop within an interior of the washcoat showerhead when the outlet valve moves from its open state to its closed state

Methodology Applied

Scientific EffectPressure drop: Pressure Drop

Implementation Method 2

drawing the washcoat through the substrate by applying a suction force to a lower surface of the substrate

Methodology Applied

Scientific EffectSuction: Suction

Data Source

PatentUS20250288983A1Apparatus and method for coating substrates with washcoats

Publication Date: 2025.09.18 JOHNSON MATTHEY PLC

AI summary

An apparatus and a method for coating substrates with washcoats in which a substrate (10) is engaged with a headset (6) of a substrate coating apparatus (1) below a washcoat showerhead (5) are disclosed. The washcoat is discharged from the washcoat showerhead (5) onto an upper surface (12) of the substrate under control of a valve assembly (4) before being drawn through the substrate by use of a vacuum generator (7). The valve assembly (4) comprises an outlet valve movable between a closed state and an open state. The valve assembly (4) creates a pressure drop within an interior of the washcoat showerhead (5) when the outlet valve moves from its open state to its closed state.