dense phase pneumatic conveying

Dense phase pneumatic conveying

As the superficial gas velocity increases, the particle density becomes uniform, the force of particle suspension and acceleration is equal to the particle static pressure head, the gas-solid phase approaches plug flow, and the radial void ratio is evenly distributed.

What is dense phase conveying?

• Dense phase transportation is a process that uses airflow to transport solid powdery materials. When the density of the particle flow in the pipeline is close to the bed density in the critical fluidized state, it is called dense phase transportation‌.
• Characteristics of dense phase transportation
• ‌Small gas flow‌: The gas flow required for dense phase transportation is small, and generally the material mass transported by unit mass of air is relatively large.
• ‌Large air flow pressure drop‌: The air flow pressure drop is large, the movement speed of particles is low, but the wear between particles and pipelines is small.
• ‌Short conveying distance‌: Commonly found in catalyst circulation pipes in petroleum catalytic cracking and overflow pipe equipment in multi-jet fluidized beds, the conveying distance is generally relatively short.

What is the difference between dilute and dense phase pneumatic conveying?

Dilute phase pneumatic conveying usually refers to a gas-solid two-phase mixture with smaller particles suspended in the gas, also known as gas suspension conveying. In dilute-phase pneumatic conveying, the interaction force between gas and solid particles is smaller, and there are fewer contacts and collisions between particles. Dilute phase pneumatic conveying is suitable for conveying smaller particles and powders. The conveying speed is fast, but the conveying volume is relatively small, and it is prone to problems such as particle clogging and gas leakage.

• Dense phase pneumatic conveying refers to a gas-solid two-phase mixture with larger particles suspended in the gas, also known as gaseous fluidized bed conveying.
• In dense phase pneumatic conveying, the interaction force between gas and solid particles is relatively large, and contact and collision between particles often occur.
• Dense phase pneumatic conveying is suitable for conveying larger particles and materials with greater adhesion between particles.
• The conveying volume is relatively large, but the conveying speed is relatively slow.
• Therefore, the difference between dilute phase pneumatic conveying and dense phase pneumatic conveying lies in the particle size of the conveyed material and the interaction force between the gas and solid phases, as well as the applicable conveying conditions and restrictions.