Vacuum Coating Apparatus Using Atmospheric Air Suction
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Solution Overview
Problem
Conventional cold spray and aerosol deposition methods require pressurized inert gases, struggle with feeding a fixed amount of powder continuously, and face difficulties in coating powders with low specific gravity, highly agglomerated particles, or sub-micrometer size particles due to velocity decreases and agglomeration issues.
Innovation Solution
A method and apparatus that coat powders using air sucked in at atmospheric pressure, without an extra gas supplier, by controlling pressure inside a vacuum chamber to maintain powder velocity and using a system with a feeder unit, carrier pipe, spray nozzle, and ventilation pump to ensure uniform and continuous coating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pressurized inert gas is used to transport and spray powder, then powder can be delivered to the nozzle, but production cost increases and device complexity increases
Solution Approach 1:
The patent removes the gas compressor and inert gas supply system from the conventional cold spray apparatus. Instead of using pressurized inert gas, the invention uses a vacuum chamber with controlled pressure to enable powder transport and spraying, thereby eliminating expensive gas suppliers and reducing device complexity
Solution Approach 2:
The invention changes the pressure parameter from positive pressure (conventional cold spray) to negative pressure (vacuum environment). By controlling the pressure inside the vacuum chamber, the system enables powder to be transported and sprayed without requiring additional pressurization equipment
2Manufacturing precision
If conventional cold spray is used, then coating can be applied, but fine particles and low specific weight particles are not coated due to velocity decrease
Solution Approach 1:
The patent changes the pressure environment from atmospheric to vacuum, which eliminates shock waves and aerodynamic drag that cause velocity loss in conventional cold spray. This parameter change enables fine particles and low specific weight particles to maintain sufficient velocity for effective coating
Solution Approach 2:
The invention uses a vacuum environment as an inert atmosphere to eliminate harmful aerodynamic effects. The vacuum chamber provides a controlled environment where particles can be accelerated and deposited without the negative effects of atmospheric resistance, improving coating uniformity for all particle types
3Speed
If powder is transported under atmospheric pressure to the nozzle, then powder can be fed, but velocity decreases and coating velocity is insufficient
Solution Approach 1:
The patent changes the pressure condition from atmospheric pressure to vacuum pressure. This parameter change enables powder to be transported and sprayed at high velocity without requiring complex pressurization systems, as the pressure differential itself provides the driving force for powder acceleration
4Speed
If compressed air pressure is increased to increase spraying velocity, then coating speed improves, but powder backflow occurs and feeding becomes more difficult
Solution Approach 1:
The invention changes the pressure parameter from positive (compressed air) to negative (vacuum). This eliminates the backflow problem entirely, as the pressure gradient naturally draws powder toward the nozzle without creating the counter-pressure conditions that cause backflow in conventional systems
Solution Approach 2:
Instead of pushing powder with compressed air from the feeder, the invention uses suction created by the vacuum chamber to draw powder toward the nozzle. This inverted approach eliminates backflow and feeding reliability issues while maintaining high spraying velocity
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
Enables uniform and continuous coating of powders without the need for pressurized gases, effectively handling powders with low specific gravity and sub-micrometer sizes, reducing production costs and improving coating efficiency.
Implementation Method 1
controlling pressure inside the vacuum chamber
Implementation Method 2
air which is sucked in from the outside at atmospheric pressure
Implementation Method 3
spraying the powder entrained on the carrier air
Implementation Method 4
The particles are coated as being deformed plastically by the kinetic energy caused by the velocity of gas and heat of gas when they collide with a substrate
Data Source
AI summary
The present invention relates to an apparatus which coats a substrate inside the vacuum chamber with the powder transported and entrained on the air from the outside without any extra gas supplier. Namely, the apparatus can coat the powder transported and entrained on the air naturally sucked in from the outside on a substrate through the spray nozzle inside the vacuum chamber as the pressure of the vacuum chamber is controlled and the pressure of the front of the spray nozzle is set under the atmospheric pressure.