Sealless Powder Feed Assembly for Thermal Spraying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional powder feeding apparatuses for thermal spraying suffer from wearing seals that require frequent replacement and non-uniform powder metering, leading to operational inefficiencies and increased costs, especially when used with abrasive powders.
Innovation Solution
A powder feed assembly featuring a selectively rotating blade and a porous hopper design that utilizes a carrier gas to control powder flow and prevent wear, ensuring consistent and controlled powder delivery to the thermal spray apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional powder feeding apparatus uses seals to contain powder, then powder containment is achieved, but seals wear frequently requiring replacement
Solution Approach 1:
The patent removes seals entirely from the powder feeding apparatus. Instead of using seals to contain powder, the invention uses a rotating blade mechanism that metering powder through a controlled gap, eliminating the need for seals and their associated wear and maintenance issues.
Solution Approach 2:
The patent replaces the mechanical seal-based containment system with a rotating blade metering system. The blade rotates within a housing to control powder flow through a gap, using rotational mechanics rather than static sealing to achieve both containment and metering functions.
2Productivity
If conventional powder feeder uses fixed volume slots or holes for metering, then powder delivery is achieved, but pulsation occurs in the powder stream
Solution Approach 1:
The patent uses a rotating blade that continuously moves to meter powder, replacing static slots or holes with a dynamic system. The rotation creates a continuous, controlled flow of powder through the gap, eliminating the pulsating effect caused by batch dispensing from fixed-volume chambers.
Solution Approach 2:
The rotating blade performs periodic scooping and dispensing actions as it rotates, but the continuous rotation ensures these actions overlap to create a steady, non-pulsating powder stream. The periodic motion of the blade is transformed into continuous flow through proper rotational speed and geometry selection.
3Ease of repair
If conventional powder feeder requires seal replacement, then maintenance is performed, but powder feeder must be removed from service
Solution Approach 1:
By removing seals entirely from the design, the patent eliminates the maintenance activity of seal replacement. The sealless rotating blade system requires no periodic removal or replacement, allowing continuous operation without shutting down the thermal spray coating process.
4Productivity
If conventional powder feeding apparatus is used with abrasive powders, then coating application is achieved, but operating costs increase due to frequent seal replacement
Solution Approach 1:
The patent removes seals that are vulnerable to abrasion from abrasive powders. The rotating blade system uses no seals, eliminating the need for frequent replacements and reducing operating costs associated with maintenance downtime and seal procurement.
Solution Approach 2:
The rotating blade is designed as a durable, long-lasting component that can withstand abrasive powders without requiring frequent replacement. By using a single robust metering mechanism instead of consumable seals, the system reduces ongoing operating costs.
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 reduces the need for frequent seal replacements and minimizes pulsation in the powder stream, providing a more reliable and uniform powder feeding process that maintains operational efficiency and reduces waste.
Implementation Method 1
At least a portion of the hopper wall may be porous. The porous portion may have a plurality of holes defined therein, a size of the holes selected to permit a carrier gas to exit the chamber through the porous portion but to not permit the powder to exit the chamber through the porous portion
Implementation Method 2
A height of the gap and/or a width of a portion of the floor which extends circumferentially beyond an interior surface of the wall adjacent the gap may be selected based on an angle of repose of the powder
Data Source
AI summary
A powder feed assembly comprises a powder hopper and a selectively rotating blade. The powder hopper has a wall and a floor together forming a chamber. A circumferential horizontal gap is defined between the wall and the floor to enable powder to exit the chamber. The selectively rotating blade has a body portion positioned within the chamber and one or more blade portions at least partially extending into the gap.