Fluidizer Selection

Key Parameters for Fluidizer Selection and Design The selection of a fluidizer must consider the injection tank specifications, pulverized coal characteristics, and coal injection process requirements. Core parameters are as follows:

 1. Injection Tank Parameters • Tank Volume and Diameter: For large-volume tanks (≥10m³), bottom fluidizers are preferred; for small-diameter tanks (≤3m), side-mounted fluidizers can be used to avoid insufficient installation space at the bottom. • Internal Working Pressure: The design pressure of the fluidizer must be 1.2-1.5 times higher than the internal working pressure of the tank (typically design pressure ≥1.0MPa) to ensure stable gas penetration.

 2. Pulverized Coal Characteristics • Coal Particle Size: Fine coal (average particle size ≤50μm) is easily fluidized, and fluidizing elements with larger pores (pore size 80-100μm) can be selected; coarse coal (average particle size ≥80μm) requires smaller pore sizes (50-60μm) to ensure uniform gas dispersion. • Coal Moisture: High-moisture coal (moisture content ≥8%) is prone to agglomeration, requiring anti-clogging metal porous plates or flexible permeable membranes, along with reverse blow cleaning functionality. • Bulk Density of Coal: Coal with high bulk density (≥800kg/m³) requires higher fluidizing gas velocity (0.2-0.3m/s) and a gas source with higher flow capacity.

 3. Fluidizing Gas Parameters • Gas Type: Compressed air is commonly used; if the coal is prone to spontaneous combustion (e.g., bituminous coal), nitrogen (inert gas) must be used to avoid safety risks. • Gas Velocity and Pressure: The critical fluidizing velocity is typically 0.1-0.3m/s, and the pressure must be adjusted based on the height of the coal in the tank (higher coal levels require higher pressure, typically 0.3-0.6MPa).