How Things Work: Refrigerated transport

By land, sea and air, the use of temperature-controlled or refrigerated transportation (reefer) solutions is rising. Cold chain management of the movement of food, pharmaceuticals and chemicals, among other products, is garnering interest around the globe. A case in point is the first-ever Cold Chain China Summit that will be held next month in Shanghai.

Magnus Welander, CEO of Envirotainer (www.envirotainer.com), a developer of a temperaturecontrolled air cargo container, points out that the emerging bio-med industry's temperature-sensitive products are its fastest growing segment. He notes that the temperature-sensitive product market for pharmaceuticals is projected to grow at least 15% per year for the next ten years, driven by more than 370 biotechnology products now in clinical trial stages.

On the water, carriers like Crowley (www.crowley.com) offer refrigerated cargo transportation services. All of Crowley's reefers are built with advanced microprocessors to keep internal temperature stabilized to within plus or minus one-half degree F, despite external temperatures.

In earlier times truck reefers — adapted for use on railroad cars - used carbon dioxide and ammonia refrigeration. In today's truck and trailer units, manufacturers like ThermoKing (www.thermoking.com) now use chlorine-free refrigerants that have ozone-deletion factors of zero. The manufacturer explains that newer reefer systems for trucks adapt the concept of the thermos bottle. A vacuum vessel is fitted inside a standard truck cargo container. The vacuum has slightly curved, airtight double walls. Temperature-sensitive product is loaded cold or frozen and will remain that way for long periods without the need for additional refrigeration.