(480a) Why and How to Select and Design a Dense Phase Conveying System?

One of the key processing technologies that have been widely utilized in many industries, such as chemicals, food, and pharmaceutics, is pneumatic conveying, regardless of whether it is for unloading raw ingredients from bags/drums/trucks/railcars, transporting ingredients from its storage to their next process step, or moving final products to their packaging area. Many applications can be easily achieved by choosing a dilute phase conveying system. However, there are many situations where the high velocity causes problems of bend wear, reduction in product quality through attrition, or excessive power requirements. Dense phase conveying, due to the use of significantly lower velocity, can address these issues.

Because of the lower gas velocity produced with dense phase conveying, a much slower, gentler conveying action on the material. This gentle action also reduces segregation and attrition issues often experienced with the more aggressive dilute-phase operation. For these reasons, in food operations, dense-phase conveying is often used to convey the pre-blends before going to the next process step as well as the final products going to packaging.

This presentation not only discusses how to determine the dense phase conveyability of bulk solids, but also explains the mechanisms of available dense phase conveying methods. Finally, a case study will be added to describe the details on how to design a blow tank dense phase conveying system.