Concentration_-_Falling_Film | FoodTechInfo.com

Falling Film Tubular – Tubular Evaporation – Steam-Based

Industry: Fruit and Vegetables (NAICS 3114) Dairy (NAICS 3115)

NAICS process:

Process Brief: Water is removed using a vacuum to draw condensate and water vapor downward inside a tube that is heated by steam on the outside.

Energy source: Steam/natural gas

Energy Intensity:

Falling film evaporators are the dominant technology in the food industry, representing an important advance over earlier rising film evaporators. The basic configuration is similar to a rising film unit, except that the liquid film moves downward in the tubes due to gravity. Creating a uniform film in the tube is difficult and is achieved by using specially designed nozzles or spray distributors at the top of the tube. The tubes are about 30 feet long and 1 – 2 inches in diameter. Process control is more expensive than rising film systems but the cost is justified by high throughput rates. Residence times are 20 – 30 seconds, compared to 3 – 4 minutes in a rising tube system. One concentrated orange juice facility installed a falling film evaporator with a capacity of 500,000 gallons per day. The evaporator had a capital cost of $2 million.