Can the fluidized bed of a vertical tube furnace accommodate multiple gases?

The fluidized bed of a vertical tube furnace can accommodate multiple gases, and its design achieves flexible adjustment of atmosphere composition through a multi-channel gas switching system to meet complex process requirements such as oxidation and reduction. The following is a specific analysis:

1. Implementation method of multi-channel gas system
Gas distribution and control
Vertical tube furnace fluidized beds are usually equipped with multiple gas inlets, and each gas channel is precisely regulated by an independent float flowmeter or mass flowmeter to adjust the flow rate. For example, a certain model of equipment can simultaneously introduce gases such as nitrogen, acetylene, air, etc., with a flow range covering 0-10L/min to 0-10L/min, meeting the gas ratio requirements of different processes.
Gas mixing and fluidization
After mixing multiple gases at the bottom of the furnace, they are evenly distributed through the gas distribution plate and flow upward through the solid particle bed at a certain velocity. When the gas flow rate reaches a critical value, the particle layer enters a fluidized state, forming a flow characteristic similar to that of a liquid. This design ensures sufficient contact between gas and solid particles, improving heat transfer and reaction efficiency.

2. Advantages of Multi Channel Gas Systems
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 process of oxidizing copper sulfide powder to copper oxide, the introduction of oxygen enriched air can significantly improve the conversion rate of mineral 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.

3. Typical application scenarios
Catalyst preparation
Scenario: Spray a metal salt solution into a fluidized bed, react with a metal powder carrier, and prepare a supported catalyst.
Gas configuration: Nitrogen gas is introduced as a protective atmosphere, while hydrogen gas is introduced for reduction reaction.
Effect: The active components are evenly distributed on the surface of the metal powder, which enhances the catalytic activity.
3D printing material processing
Scenario: Surface modification of metal powder to improve its flowability to meet 3D printing requirements.
Gas configuration: Introduce a nitrogen protective atmosphere while introducing acetylene for surface coating treatment.
Effect: Improved powder flowability and increased interlayer bonding strength in printing.
Metal powder sintering
Scenario: Sintering metal powders such as iron powder and copper powder in a fluidized bed to prepare dense parts.
Gas configuration: Introduce a nitrogen protective atmosphere to prevent metal powder from oxidizing at high temperatures.
Effect: Increased part density and tensile strength.