Food Quality Magazine January 2016 - Page 18

Food Quality Magazine ISSUE 01 | JANUARY 2016 Coopeldos Coffee Drying; Costa Rica The coffee drying cooperative Coopeldos R.L., located in the province of Guanacaste in Costa Rica, installed a solar drying system on the entire roof of their building. Coopeldos, an ISO 9000 and ISO 14000 registered company, was the perfect candidate to demonstrate state-of-the-art solar air heating crop drying technology, since maintaining the ISO 14000 designation necessitates meeting certain energy conservation standards. A 860 m2 (9,250 ft2) black solar air heating system was installed on the roof at the Coopeldos facility. The warmed air that is collected from the system is used for two purposes: It heats the vertical pre-drying silo, which dries the coffee beans from 60% moisture content, to 35%. It also heats the guardiolas, which are the rotating drums that carry out the final drying stage. Here, the beans are further dried to a 12% moisture content. Following this second drying stage, the beans are packaged in bags. Picture 2 - Coopeldos Coffee Drying; Costa Rica Picture 3 - How Solar Air Heating Works: Solar air heating systems are integrated into the wall or roof of a building and are typically all-metal. Solar radiation strike the surface of the system, and heated air is drawn through tiny micro-perforations in the surface of the collector. This solar heated air is then ducted into a conventional drying system or into a building’s HVAC system, depending on the application. 18