Pneumatic Conveying Design Guide

Pneumatic conveying systems are typically used in industry for transporting bulk granular or powdered materials, such as foodstuffs, minerals and plastics. The essential components of a pneumatic conveying system are a source of compressed gas, feed device, conveying pipeline and receiver.

Conveying Medium

If the material to be conveyed is hygroscopic, or tends to absorb water from the air, dry compressed air can be used as the conveying medium. Similarly, if the material is potentially explosive in air an inert, or chemically unreactive, gas, such as nitrogen, can be used instead.

Dilute Phase

In dilute phase pneumatic conveying, particles of material are held in suspension by air blown or sucked through the conveying pipeline at high velocity. The material does come into contact with the pipeline in places, particularly at bends, so this design of conveyor may not be suitable for abrasive materials.

Dense Phase

Dense phase pneumatic conveying is a high pressure, but low velocity, alternative to dilute phase conveying and is suitable for abrasive materials. Small amounts of air -- typically at a pressure in excess of 15 pounds per square inch (psi) -- move a large amount of bulk material in plug, or slug, form through the conveying line.

References

• "Pneumatic Conveying Design Guide"; David Mills; 2004
• New Equipment Digest: A Primer on Dense Phase Pneumatic Conveying Systems