Slurry Coating Inner Diameter Conduit Uniformity

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Solution Overview

Problem

Current methods for applying slurries or powders to heat exchanger surfaces result in inconsistent and inefficient porous coatings, leading to high heat transfer resistance and increased power consumption due to variations in coating thickness and defects such as blow holes, slumping, and delamination.

Innovation Solution

A method involving a rolling apparatus that feeds a slurry formulation into a conduit through an injection nozzle, rotating the conduit to distribute the slurry uniformly, and retracting the nozzle to ensure consistent coating thickness, combined with convective heating to evaporate solvents and solidify the coating, thereby achieving uniform and reproducible porous coatings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional spray methods are used to apply slurry or powder compositions to heat exchanger surfaces, then the coating process can be completed, but the resultant porous coating exhibits significant variation in thickness and contains defects such as blow holes, slumping, and delamination

Engineering Contradiction:

Improvecoating thickness uniformityVSAvoidcoating consistency

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent inverts the conventional coating approach by rotating the conduit containing the coating composition rather than moving the spray apparatus along a stationary conduit. This inversion allows the coating material to be distributed uniformly by centrifugal force and rotational motion, eliminating defects like blow holes and slumping while achieving consistent thickness throughout the heat exchanger surface.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies preliminary action by first introducing the slurry or powder coating composition into the conduit before rotation begins. The coating material is positioned and distributed within the conduit in advance, then rotation is initiated to achieve uniform distribution. This preliminary positioning ensures that the entire surface receives consistent coating coverage without gaps or excessive accumulation.

Inventive Principle:

Principle #10Preliminary action

2Use of energy by moving object

If conventional coating methods are used, then the coating can be applied to the heat exchanger surface, but the heat transfer efficiency remains low due to high temperature difference and heat transfer resistance

Engineering Contradiction:

Improveheat transfer efficiencyVSAvoidpower consumption

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent utilizes porous materials by creating a porous coating layer on the heat exchanger surface through the rotation and distribution of slurry or powder compositions. The porous structure increases surface area and enhances heat transfer efficiency by promoting better thermal contact between the coating and the heat exchanger surface, thereby reducing temperature difference and heat transfer resistance while improving energy utilization.

Inventive Principle:

Principle #31Porous materials

3Device complexity

If the injection nozzle is stationary during slurry application, then the coating process is simple, but the coating thickness varies significantly along the inner surface of the conduit

Engineering Contradiction:

Improvecoating apparatus simplicityVSAvoidcoating thickness control

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by transforming the stationary injection nozzle into a rotating system. The conduit containing the coating composition rotates during the coating process, creating dynamic motion that distributes the coating material uniformly along the inner surface. This dynamic rotation ensures consistent coating thickness throughout the conduit while maintaining relative simplicity in the apparatus design.

Inventive Principle:

Principle #15Dynamics

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 produces coatings with significantly reduced thickness variation and defects, enhancing heat transfer efficiency by minimizing the temperature difference required for boiling, resulting in more efficient processes with lower power consumption.

Implementation Method 1

rotating said conduit, thereby allowing the discharged slurry be spread and distributed substantially uniformly along the inner surface of the conduit

Methodology Applied

Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

combined with convective heating to evaporate solvents and solidify the coating

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS10520265B2Method for applying a slurry coating onto a surface of an inner diameter of a conduit

Publication Date: 2019.12.31 PRAXAIR TECH INC

AI summary

A method for creating a coating onto an inner diameter of conduit, whereby an injection nozzle is moved in a forward direction until its tip is aligned with the end of the conduit. Slurry is pumped from a reservoir into the injection nozzle and then is discharged through the tip of the injection nozzle. The slurry flows, distributes and spreads onto the surface of the conduit. The conduit is rotated and the nozzle is retracted as slurry continues to discharge from the nozzle to coat the remainder of the conduit.