Sapphire Pellet Feed System Using Load-Cell Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing sapphire crystal growth technologies suffer from imprecise and uneven feed systems, leading to compromised crystal quality and complexity.
Innovation Solution
A controlled sapphire pellet feed system using a load cell-suspended feeder with a vibratory tray, feedback controller, and flexible tubes to maintain a constant feed rate, combined with a vacuum treatment and hydrogen purge to prevent air and moisture contamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional feed system is used, then the structure is simple, but the feed rate is imprecise and uneven
Solution Approach 1:
The patent implements a feedback control system where a load cell measures the weight of the feeder, and a controller adjusts the vibratory tray accordingly to maintain a constant feed rate. This closed-loop feedback mechanism ensures precise feed rate control while managing system complexity through intelligent control rather than mechanical complexity.
Solution Approach 2:
The patent replaces conventional mechanical feed control mechanisms with a vibratory tray system controlled by electrical signals from a load cell and controller. This substitution of mechanical systems with sensor-based control enables more precise feed rate measurement and adjustment.
2Productivity
If the feed rate is high, then productivity is improved, but the pockets may overfill and clog
Solution Approach 1:
The load cell continuously monitors the feeder weight and provides feedback to the controller, which adjusts the vibratory tray operation to maintain the optimal feed rate. This prevents both overfilling (when feed rate is too high) and dry pockets (when feed rate is too low), ensuring reliable feed delivery throughout the crystal growth process.
3Reliability
If air or moisture is present, then the environment is normal, but crystal quality is compromised
Solution Approach 1:
The patent implements a vacuum system that removes air and moisture from the feeding environment before pellets enter the crucible. This inert atmosphere prevention technique ensures that no contaminants are introduced during the critical feeding phase, maintaining crystal quality without requiring complex continuous atmosphere control systems.
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
Ensures a consistent and high-quality sapphire crystal growth by maintaining precise feed rates and purging impurities, thereby enhancing crystal clarity and thermal balance.
Implementation Method 1
The feeder is suspended from a load cell. As feed leaves the hopper and is dropped into the crucible, the feeder becomes lighter, which is registered by the load cell.
Implementation Method 2
Inside the feeder is a vibratory tray, which when vibrating, causes pellets to flow down an inclined trough and drop into tubes leading to the crucible pockets.
Implementation Method 3
the feeder is then vacuumed down to a pressure of 25-50 μ (microns of mercury) using a vacuum pump or equivalent component(s) to remove any trace of air or water
Implementation Method 4
A constant flow of clean, dry hydrogen via the hydrogen port purges the feeder at all times to cleanse it of air or water which may diffuse in.
Implementation Method 5
To melt the feed pellets, heating power to the pockets is in balance with the heat of fusion of the pellets entering at a given rate.
Implementation Method 6
The liquid is conveyed by capillary action to the surface of the die, where it is incorporated into the growing crystal.
Data Source
AI summary
The present disclosure teaches a feed system for growing crystals, and the method thereof. The presently disclosed system includes a feeder suspended from a load cell. The feeder houses a hopper, for holding feed pellets, and a vibrator, for dispensing the feed pellets. The vibrator controls a rate of dispensing the feed pellets. The load cell measures a weight of the feeder and sends the measurement to a feedback controller in real-time. The feedback controller adjusts an operation of the vibrator based on the weight of the feeder. A Y-connector connects to a bottom of the feeder to divide the pellets into two equal streams. Each branch of the Y-connector connects to a flexible feed tube, which has two layers of walls, defining an interstice for hydrogen to flow through, protecting the feed pellets from moisture and air.