Hopper Vibration and Pressure Control for Thermal Spraying

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Solution Overview

Problem

Thermal spraying apparatuses face challenges in forming dense films due to the porosity of thermally sprayed films and the inability to effectively melt fine particle materials, which are necessary for improved film properties, as larger particle sizes may not melt completely and can block the hopper's discharge holes.

Innovation Solution

A hopper and thermal spraying apparatus that utilize a container for fine particle materials (0.1 µm to 10 µm) with a pressure controller to create periodic pressure differences and a shaker to apply vibration, ensuring the material is carried by a carrier gas through a hole, and a heating unit to melt the material for spraying onto a processing target, forming a dense film.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If fine particle material (0.1 µm to 10 µm) is used to form dense films, then film density is improved, but the discharge holes of the hopper may be blocked

Engineering Contradiction:
Improvefilm densityVSAvoidhopper discharge reliability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The hopper is equipped with a vibration mechanism that applies mechanical vibration to the container walls and discharge holes. This vibration prevents fine particle material from accumulating and blocking the discharge holes, ensuring continuous reliable flow of fine particles while maintaining the ability to form dense films with the fine material

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The vibration mechanism operates periodically with controlled frequency and amplitude cycles. During vibration phases, fine particles are agitated to prevent blockage; during non-vibration phases, normal discharge occurs. This periodic action maintains discharge reliability while preserving film density quality

Inventive Principle:
Principle #19Periodic action

2Reliability

If granular powder with larger particle diameter is used, then hopper discharge reliability is improved, but the material may not be completely melted and film density deteriorates

Engineering Contradiction:
Improvehopper discharge reliabilityVSAvoidfilm density
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system changes the particle size parameter from conventional granular powder to fine particle material (0.1 µm to 10 µm). This parameter change enables complete melting during thermal spraying, achieving dense film formation. The vibration mechanism compensates for the discharge reliability issues that would otherwise result from using such fine particles

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If fine particle material is used to ensure complete melting, then film density is improved, but spitting may occur in the hopper

Engineering Contradiction:
Improvefilm densityVSAvoidspitting phenomenon
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The vibration mechanism agitates fine particle material in the hopper, preventing localized accumulation and the conditions that lead to spitting. By maintaining uniform particle distribution and preventing clogging, the vibration eliminates the pressure buildup that causes spitting while allowing fine particles to be supplied for dense film formation

Inventive Principle:
Principle #18Mechanical vibration

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 enables the formation of high-density thermally sprayed films by ensuring complete melting of fine particle materials and preventing blockages, enhancing the film's properties and efficiency in the thermal spraying process.

Implementation Method 1

a pressure controller configured to apply a pressure difference to an inside of the container periodically

Methodology Applied
Scientific EffectPressure difference: Pressure Gradient

Implementation Method 2

a shaker configured to apply vibration to the container

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 3

the material accommodated in the container is supplied through a hole, which is formed at the container, by the periodic pressure difference and the vibration, and is carried by a carrier gas

Methodology Applied
Scientific EffectFluidization: Fluidisation

Implementation Method 4

a heating unit configured to supply a heating gas configured to melt the material carried by the carrier gas

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP2774688B1Hopper and thermal spraying apparatus
Publication Date: 2018.05.16 TOKYO ELECTRON LTD
  • EP2774688B1 patent drawingFigure 1A~1B
  • EP2774688B1 patent drawingFigure 2
  • EP2774688B1 patent drawingFigure 3

AI summary

A hopper is configured to supply a fine particle material. The hopper includes a container configured to accommodate therein a material in a powder form having a diameter ranging from about 0.1 µm to about 10 µm; a pressure controller configured to apply a pressure difference to an inside of the container periodically; and a shaker configured to apply vibration to the container. Further, the material accommodated in the container is supplied through a hole, which is formed at the container, by the periodic pressure difference and the vibration, and is carried by a carrier gas.