Experimental Study on Gas-Solid Two-Phase Flow Characteristics of a Vertical Cyclone Combustor System.

Area of Science:

• Combustion Engineering
• Fluid Dynamics
• Particle Technology

Background:

• Cyclone burners are crucial components in boilers for efficient combustion.
• Understanding flow dynamics and pressure drop in vertical risers is key to optimizing burner performance.

Purpose of the Study:

• To investigate the impact of various parameters on the flow distribution and pressure drop characteristics of a vertical cyclone burner.
• To establish a correlation formula for predicting pressure drop in gas-solid two-phase flow within the vertical riser.

Main Methods:

• A cold-state experimental platform for a cyclone burner was designed and constructed using the principle of similarity.
• Systematic experiments were conducted to analyze the effects of swirl-vane angles, coal concentration, operating parameters, and particle size.
• Dimensional analysis and Barth's additional pressure drop theory were applied to derive a pressure drop formula.

Main Results:

• The most uniform flow distribution was achieved with a primary air swirl-vane angle of 30°.
• Pulverized coal concentration and particle size significantly increased pressure drop; higher concentrations and larger particles led to greater pressure drops.
• Optimal primary air velocity for minimum pressure drop was found to be 7.5 m/s, while secondary air velocity of 22 m/s resulted in maximum pressure drop.

Conclusions:

• Optimizing swirl-vane angles and primary air velocity is critical for efficient flow distribution and reduced pressure drop in cyclone burners.
• Particle size and concentration directly influence the pressure drop, necessitating careful control in boiler operations.
• A derived correlation formula provides a predictive tool for gas-solid two-phase flow pressure drop in vertical risers.