Vibrating Hopper for Uniform Powder Feeding in Thermal Spray

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current powder feeders, such as rotary disk and lost weight feeders, face challenges with inconsistent filling of difficult-to-feed materials, high maintenance costs, and vulnerability to oversized specks or foreign objects, leading to inefficiencies and inaccuracies in thermal spray operations.

Innovation Solution

A hopper assembly with a vibration imparting device and a vibration source, coupled to a feeder device, which uses pneumatic or electric actuators to generate vibrations that prevent bridging and ratholing, ensuring consistent filling and protecting against foreign objects, while simplifying construction and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If mechanically driven built-in stirrers are employed to ensure difficult-to-feed powder fills metering groove without large voids or over-compression, then filling uniformity is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvefilling uniformityVSAvoidhopper construction complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies mechanical vibration through an externally mounted vibrator that shakes the hopper to maintain powder in a loose free-flowing state. This vibration prevents bridging and ratholing during groove fill-up, achieving uniform filling without requiring complex built-in stirrers. The vibrator is flexibly mounted on the hopper, which is mounted on a weight sensor, creating a simple yet effective system that addresses the filling uniformity problem while avoiding increased device complexity.

Inventive Principle:
Principle #18Mechanical vibration

2Manufacturing precision

If externally mounted vibrator is used to maintain powder in loose free-flowing state, then filling uniformity is improved, but time delay in weight change detection increases

Engineering Contradiction:
Improvefilling uniformityVSAvoidtime delay in weight change detection
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The externally mounted vibrator maintains powder in a loose free-flowing state, improving filling uniformity. The vibrator is flexibly mounted on the hopper, which is mounted on a weight sensor. By reducing the vibrational component of total force acting on the weight sensor, the system achieves both good filling uniformity and reduced time delay in weight change detection.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The flexible mounting of the vibrator on the hopper allows vibration transmission to the powder while isolating the weight sensor from excessive vibrational forces. This flexible connection reduces the vibrational component of total force on the sensor, thereby reducing time delay in weight change detection while maintaining filling uniformity.

Inventive Principle:
Principle #30Flexible shells and thin films

3Device complexity

If conventional hopper configurations are used, then construction is simpler, but protection against oversized specks or foreign objects is insufficient

Engineering Contradiction:
Improvehopper construction simplicityVSAvoidoversized specks or foreign objects entering feedstock line
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The mechanically vibrating hopper assembly creates a free-flowing powder state that prevents bridging and ratholing. The vibration also helps prevent oversized specks and foreign objects from causing blockages or entering the feedstock line, as the continuous vibrational motion keeps all materials in constant movement and prevents settling or accumulation that could allow contaminants to enter the system.

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 provides uniform and precise powder feeding, reduces maintenance time, and effectively prevents oversized specks from entering the feedstock line, enhancing the accuracy and efficiency of thermal spray operations.

Implementation Method 1

A hopper assembly with a vibration imparting device and a vibration source, coupled to a feeder device, which uses pneumatic or electric actuators to generate vibrations that prevent bridging and ratholing

Methodology Applied
Scientific EffectVibration: Vibration

Data Source

PatentEP3386620B1Powder hopper for difficult-to-flow powders for use in thermal spraying and method making and using the same
Publication Date: 2021.07.28 OERLIKON METCO (US) INC
  • EP3386620B1 patent drawingFigure 1
  • EP3386620B1 patent drawingFigure 2
  • EP3386620B1 patent drawingFigure 3

AI summary

A hopper assembly includes a hopper configured to contain a feedstock material. A vibration imparting device is arranged inside the hopper and a vibration source coupled to the vibration imparting device. Embodiments of the instant invention are believed to provide various improvements in feeding uniformity by providing various hopper configurations that ensure a more consistently uniform filling of the metering device for a variety of difficult-to-feed materials and not-so-difficult-to-feed materials. One, more or all of these embodiments are also believed to improve accuracy and add precision to control, and, in addition, offer more simplified hopper construction - which is less costly to manufacture and maintain.