Can a vertical tube furnace fluidized bed be evacuated?

The vertical tube furnace fluidized bed can be evacuated, and its design combines fluidized bed technology with vacuum environment, which can achieve high-temperature treatment of materials under closed conditions. At the same time, the vacuum function creates an oxygen free or low oxygen environment to avoid material reactions with oxygen, water vapor, etc. at high temperatures. The following is a specific analysis:

1. Implementation of Vacuum Extraction Function
Vacuum system configuration
Vertical tube furnace fluidized beds are usually equipped with mechanical pumps or vacuum units, which can significantly reduce the pressure inside the furnace. Further increase the vacuum by using a molecular pump to ensure that the furnace environment is close to an oxygen free state.
The role of vacuum environment
Preventing oxidation: In metal powder processing, a vacuum environment can reduce oxide impurities and improve material density. For example, the oxidation efficiency of iron-based powder in a vacuum fluidized bed can be reduced, much lower than in an air environment.
Lowering boiling point: Vacuuming can reduce the flow resistance of the working fluid inside the tube, which is suitable for processes that require low-temperature evaporation (such as nanomaterial preparation).
Reduce pollution: Avoid contact between materials and impurities in the air to ensure surface purity, suitable for high-precision experiments (such as catalyst preparation).

2. The advantages of combining fluidized bed and vacuum environment
Efficient heat transfer and uniform reaction
A fluidized bed uses gas to blow metal powder, causing it to suspend and form a liquid like flow state. In a vacuum environment, this flow state can be further optimized to eliminate local overheating and improve heat transfer efficiency. For example, the preheating time of aluminum powder in a vacuum fluidized bed can be shortened, and the temperature uniformity can be improved to within ± 5 ℃.
Multi process compatibility
Inert gas protection: After vacuuming, inert gases such as nitrogen and argon can be filled to create a low oxygen environment, suitable for oxygen sensitive materials (such as titanium alloy powder).
Reactive gas reaction: Hydrogen, acetylene and other reactive gases can be introduced to participate in material synthesis or surface treatment (such as low-pressure carburizing process).
CVD experiment: Combining vacuum and fluidized bed technology can achieve uniform deposition of nano metal particles and improve catalyst activity.
Operational flexibility
Temperature control: Adopting an intelligent program temperature control system (such as PID controller), combined with thermocouple sensors, to achieve precise temperature control (error ≤± 1 ℃).
Gas flow regulation: By using a float flowmeter or mass flowmeter, the flow rate and pressure of process gas can be accurately controlled to achieve partial pressure control.

3. Typical application scenarios
Metal powder sintering
Scenario: Sintering metal powders such as iron powder and copper powder in a vacuum fluidized bed to prepare dense parts.
Advantages: Vacuum environment can reduce oxide impurities, improve part density and mechanical properties. For example, iron-based parts have better density and increased tensile strength.
Catalyst preparation
Scenario: Spray a metal salt solution into a vacuum fluidized bed, react with a metal powder carrier, and prepare a supported catalyst.
Advantages: The uniform mixing characteristics of fluidized beds can achieve uniform distribution of active components on the surface of metal powders, improving catalyst activity. For example, the activity of platinum based catalysts can be enhanced.
3D printing material processing
Scenario: Surface modification of metal powder to improve its flowability to meet 3D printing requirements.
Advantages: Vacuum fluidized bed treatment can improve powder flowability, increase interlayer bonding strength, and significantly improve printing quality.