Brush-Sieve Powder Fluidizing Apparatus for Nano Powders
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Solution Overview
Problem
Conventional powder feeders struggle with maintaining a uniform flow of ultra-fine and nano-size powders with broad particle size distributions, often leading to agglomeration and non-uniform feeding due to the inability to break up agglomerated particles and control feed rates effectively, especially when switching between different powder fluidizing units.
Innovation Solution
A powder-fluidizing apparatus that uses a pressure vessel as both a containment for pressurized carrier gas and a reservoir for powder, employing a rotating three-prong brush in contact with a removable sieve disc to break up agglomerated particles and control the feed rate, allowing for independent switching of powder feed without perturbing gas flow conditions, and incorporating features like ultrasonic waves and reactive gases for enhanced de-agglomeration and coating processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional powder feeders are used to feed ultra-fine powders, then the feeding process is simple, but the powders agglomerate into larger particles and do not feed uniformly
Solution Approach 1:
The device segments the powder feed control into multiple independent components: a rotating brush with bristles for powder collection, a sieve for particle size control and agglomerate breakdown, and a scraper for discharge. This segmentation allows each component to perform its specific function optimally, ensuring uniform feeding of ultra-fine powders without excessive agglomeration.
Solution Approach 2:
The brush acts as an intermediary between the powder reservoir and the discharge mechanism. It collects powder between its bristles and transfers it to the sieve, providing controlled interaction that prevents direct contact between large quantities of powder and the discharge mechanism, thereby reducing agglomeration.
2Reliability
If conventional fluidized bed apparatus is used to fluidize powder, then the powder is agitated by gases, but only finer particles are fluidized causing segregation of particle size distribution
Solution Approach 1:
The sieve provides local quality control by having specific aperture sizes that allow only particles within a certain size range to pass through. This local filtering action ensures that particles of consistent size are fed into the fluidization chamber, preventing segregation while maintaining efficient fluidization of the desired particle size distribution.
3Reliability
If brush-type devices are used to feed powders by collecting between bristles, then the powder is fluidized, but small agglomerates are not broken up into individual particles
Solution Approach 1:
The device merges the brush collection mechanism with the sieve filtering mechanism into a single integrated assembly. The brush collects powder and directs it onto the sieve surface, where the sieve simultaneously breaks up agglomerates and selects particles by size. This merging of functions achieves both particle dispersion and size control without requiring separate devices.
4Reliability
If sieve is used to meter powder through holes, then uniform distribution of particle size is achieved, but the sieve or scraper wears out quickly due to abrasion from metal powders
Solution Approach 1:
The sieve is designed as a replaceable, relatively simple component that can be easily removed and replaced when worn. This approach accepts that the sieve will wear from metal powder abrasion but minimizes the impact by making it a low-cost, easily replaceable part rather than a permanent, maintenance-free component. The brush and other components can be replaced similarly.
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 feeding of ultra-fine and nano-size powders over a long period, prevents powder build-up, and allows for precise control of feed rates and gas flow, facilitating consistent coating deposition and efficient use of powders by maintaining independent control over powder feed and gas pressure, even when switching between different powder units.
Implementation Method 1
a rotating three-prong brush in contact with a removable sieve disc to break up agglomerated particles
Implementation Method 2
incorporating features like ultrasonic waves and reactive gases for enhanced de-agglomeration
Implementation Method 3
A powder-fluidizing apparatus that uses a pressure vessel as both a containment for pressurized carrier gas and a reservoir for powder
Implementation Method 4
The entrained powder and gas then flow through the funnel and into an outlet fitting
Implementation Method 5
Another aspect of the invention permits a process to film coat or passivate powders prior to deposition with an applicator
Data Source
AI summary
Powder fluidizing apparatus includes a unitary pressure vessel having a powder compartment and a transfer compartment, a lid on a first open end of the powder compartment and a base on a second end of the unitary pressure vessel, the second end sealing an open end of the transfer compartment. A plate separates the powder compartment from the transfer compartment, the plate being located between the lid and the base. A coupling collar secures a sieve disk packet in an opening in the plate. A tube extends from the transfer compartment to the powder compartment, the tube extending to a location near the lid of the unitary pressure vessel. When the transfer compartment is pressurized with a carrier gas, pressure in the transfer compartment and pressure in the powder compartment are equalized by the tube. The unitary pressure vessel is configured to contain the carrier gas in both the powder compartment and the transfer compartment and simultaneously perform as a reservoir for holding a quantity of powder in the powder compartment.