Cold Spray Gun Cooling Powder Feed Path

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Solution Overview

Problem

Existing cold spray nozzles face clogging issues due to the adhesion of raw material powders to the powder port and particle supply pipe, particularly when the temperature of the working gas is set close to the melting point or softening point of the powders, leading to reduced coating film quality and efficiency.

Innovation Solution

A cold spray gun equipped with a cooling means for the raw material powder feeding flow path, which maintains the powder at a low temperature and inclines the powder outlet towards the downstream or upstream side of the working gas flow path, preventing adhesion and clogging, and uses a water-cooled cooling unit to efficiently cool the flow path and nozzle inner wall.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the temperature of the working gas is set close to the melting point or softening point of the raw material powder, then the coating film quality is improved, but the raw material powder adheres to the powder port and particle supply pipe causing clogging

Engineering Contradiction:
Improvecoating film qualityVSAvoidpowder feeding reliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The particle supply pipe is divided into a heated section (within the heating chamber) and a non-heated section (outside the chamber). The powder port is positioned in the non-heated section, separating the powder feeding function from the heating function, thereby preventing adhesion while maintaining heating effectiveness for coating quality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The chamber wall acts as an intermediary structure that isolates the heated working gas from the powder port. The powder port is positioned outside the heated chamber, using the chamber wall as a thermal barrier to prevent heat transfer to the powder feeding path, thus avoiding adhesion while allowing high-temperature gas to maintain coating film quality.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If the working gas temperature is increased to improve coating density and adhesion, then the coating film becomes more compact and highly dense, but the raw material powder adheres to contact surfaces causing clogging

Engineering Contradiction:
Improvecoating film densityVSAvoidpowder adhesion
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The powder port and powder feeding path are extracted from the heated chamber environment and positioned outside the chamber. This separates the powder feeding function from the high-temperature working gas environment, eliminating the harmful adhesion effect while preserving the high-temperature gas for achieving dense coating films.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Different sections of the system have different temperature characteristics: the chamber interior maintains high temperature for coating quality, while the powder port and feeding path remain at lower temperatures to prevent adhesion. This local quality differentiation allows simultaneous achievement of dense coatings and adhesion-free powder feeding.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the powder port is positioned inside the chamber to facilitate powder supply, then the powder feeding is simplified, but the powder port temperature rises causing adhesion and clogging

Engineering Contradiction:
Improvepowder supply convenienceVSAvoidpowder port temperature
Core Design Contradiction:
Ease of operationVSTemperature

Solution Approach 1:

The powder port is repositioned from inside the chamber to the outer peripheral surface of the chamber, changing its spatial dimension. This dimensional relocation allows the powder port to remain close to the chamber for convenient powder supply while being thermally isolated from the high-temperature gas inside, thus preventing temperature rise and adhesion.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

This configuration allows the working gas to be sprayed at a temperature closer to the melting point or softening point of the raw material powder, effectively suppressing clogging and enhancing the formation of dense, high-quality coating films with improved adhesion efficiency.

Implementation Method 1

a cooling means for cooling the raw material powder feeding flow path

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

uses a water-cooled cooling unit to efficiently cool the flow path and nozzle inner wall

Methodology Applied
Scientific EffectConvection cooling: Convection

Implementation Method 3

the working gas containing the raw material powder is sprayed as a supersonic flow

Methodology Applied
Scientific EffectSupersonic flow: Jet

Implementation Method 4

a raw material powder transported by a carrier gas is sprayed out from a powder port and charged into a chamber of a cold spray gun supplied with a high-pressure working gas

Methodology Applied
Scientific EffectGas acceleration: Pressure Gradient

Data Source

PatentEP3650581B1Cold spray gun and cold spray device equipped therewith
Publication Date: 2022.05.18 PLASMA GIKEN CO LTD
  • EP3650581B1 patent drawingFigure 1
  • EP3650581B1 patent drawingFigure 2
  • EP3650581B1 patent drawingFigure 3

AI summary

An object of the present invention is to provide a cold spray gun and a cold spray apparatus equipped with the same, which are capable of effectively suppressing clogging of a raw material powder feeding port and operating the cold spray apparatus equipped with the cold spray gun by maintaining a working gas temperature at a high temperature closer to a melting point or a softening point of the raw material powder. In order to achieve the above described object, there is provided a cold spray gun configured to spray out a raw material powder transported by a carrier gas, together with a working gas heated to a temperature equal to or lower than a melting point or a softening point of the raw material powder as a supersonic flow and to cause the raw material powder to collide with a base material in a solid state, thereby to form a coating film. The cold spray gun is characterized by being equipped with: a chamber containing the working gas; a cold spray nozzle having a working gas flow path formed therein, at an outlet of which the working gas discharged from the chamber is sprayed out as a supersonic flow; a raw material powder feeding flow path that supplies the raw material powder to the working gas discharged from the chamber; and a cooling means for cooling the raw material powder feeding flow path.