What gases can be passed through the fluidized bed of a vertical tube furnace?

There are various types of gases that can be introduced into the fluidized bed of a vertical tube furnace, including inert gases (such as nitrogen and argon), active gases (such as hydrogen, oxygen, and air), and process gases (such as ammonia and hydrocarbons). The specific selection should be based on process requirements and material characteristics. The following is a detailed explanation of the gas that can be introduced:

1. Inert gas
nitrogen
Function: As a protective atmosphere, it prevents metal powder from oxidizing at high temperatures.
Application scenario: In processes such as metal powder sintering and 3D printing material processing, nitrogen can ensure the surface purity of materials, improve part density and mechanical properties.
argon
Function: Provides a higher level of inert protection, suitable for oxygen sensitive materials such as titanium alloy powder.
Advantage: The chemical properties of argon gas are extremely inert, which can completely avoid contact between the material and oxygen, ensuring the accuracy of experimental results.

2. Active gas
hydrogen
Function: As a reducing agent, it participates in the reduction reaction of metal powders or accelerates the heating process.
Application scenario: In catalyst preparation, hydrogen can reduce metal salt solutions to metal particles, improving catalyst activity.
Oxygen/Air
Function: Provide an oxidizing environment, promote combustion processes or redox reactions.
Application scenario: In the process of oxidizing copper sulfide powder to copper oxide, introducing oxygen enriched air can significantly improve the conversion rate of mineral powder.
Attention: It is necessary to strictly control the oxygen concentration to prevent excessive oxidation of materials or potential safety hazards.

3. Process gas
ammonia
Function: Participate in nitriding reactions and prepare nitride materials (such as aluminum nitride and silicon nitride).
Application scenario: In ceramic material sintering, ammonia can provide a nitrogen source to promote material densification.
hydrocarbon
Function: As a carbon source, participate in carbonization reactions or deposit carbon layers.
Application scenario: In the surface coating treatment of metal powder, the introduction of hydrocarbons such as methane can form a carbon layer and improve the wear resistance of the material.

4. Advantages of Multi channel Gas Configuration
Process flexibility
By adjusting the flow rate and proportion of multiple gases, complex environments such as oxidation and reduction can be simulated to meet the processing needs of different materials. For example, in metal powder sintering, a nitrogen protective atmosphere can be introduced to prevent oxidation; In catalyst preparation, hydrogen gas can be introduced for reduction reaction.
Improved reaction efficiency
A multi-channel gas system can achieve rapid mixing of gas and solid particles, promoting diffusion of reactants and desorption of products. For example, in the oxidation process of copper sulfide ore powder, introducing oxygen enriched air can significantly improve the conversion rate of ore powder.
Operational safety
The system is equipped with a pressure control system to maintain a slight positive pressure (0-0.02MPa) inside the furnace, prevent external pollution, and ensure fluidization stability. At the same time, by monitoring the pressure and exhaust gas composition in real-time, the gas flow rate can be adjusted in a timely manner to avoid safety hazards.