Efficiencies Of Natural Convection In Passive Pallet Shippers

By Iftekhar Ahmed, Ben VanderPlas, and Stu Krupnick

Bulk transportation of temperature sensitive pharmaceuticals and biologics has become a common practice due to complex global supply chains. This imperative has prompted pharmaceutical companies to look at more efficient and economical means of temperature controlled distribution. Passive packaging systems are one of the proven and repeatable methods for international bulk shipments of temperature sensitive products.

Currently, many bulk shipments of pharmaceutical and biological products utilize passive pallet shippers consisting of six panels assembled to form a container. Given the large size of a bulk shipping container a significant amount of product surface area is exposed to ambient conditions. Therefore, a considerable mass of refrigerants is required to maintain product temperatures within the specified criteria. Placement and quantity of refrigerants is critical to maintain stable product temperatures. The conventional approach for refrigerant placement is to position refrigerant on all six sides of the product. This would ensure that all exposed product will be protected. This approach, however, has several disadvantages.