Steam atmosphere drying concepts using steam exhaust recompression

Conference · Sat Aug 01 04:00:00 EDT 1992

OSTI ID:6927910

DiBella, F A ^[1]

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1. TECOGEN, Inc., Waltham, MA (United States)

In the US industrial drying accounts for approximately 1.5 quads of energy use per year. Annual industrial dryer expenditures are estimated to be in the $500 million range. Industrial drying is a significant energy and monetary expense. For the thermal drying processes in which water is removed via evaporation from the feedstock, attempts have been made to reduce the consumption of energy using exhaust waste heat recovery techniques, improved dryer designs, or even the deployment of advanced mechanical dewatering techniques. Despite these efforts, it is obvious that a large amount of thermal energy is often still lost if the latent heat of evaporation from the evaporated water cannot be recovered and/or in some way be utilized as direct heat input into the dryer. Tecogen Inc. is conducting research and development on an industrial drying concept. That utilizes a directly or indirectly superheated steam cycle atmosphere with exhaust steam recompression to recover the latent heat in the exhaust that would otherwise be lost. This approach has the potential to save 55 percent of the energy required by a conventional air dryer. Other advantages to the industrial dryer user include: A 35-percent reduction in the yearly cost per kg[sub evap] to dry wet feedstock, Reduced airborne emissions, Reduced dry dust fire/explosion risks, Hot product not exposed to oxygen thus, the product quality is enhanced, Constant rate drying in steam atmosphere, Reduced dryer size and cost, Reduced dryer heat losses due to lower dryer inlet temperatures. Tecogen has projected that the steam atmosphere drying system is most suitable as a replacement technology for state-of-the-art spray, flash, and fluidized bed drying systems. Such systems are utilized in the food and kindred products; rubber products; chemical and allied products; stone, clay, and glass; textiles; and pulp and paper industrial sectors.

• Research Organization: EG and G Idaho, Inc., Idaho Falls, ID (United States); TECOGEN, Inc., Waltham, MA (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FC07-89ID12826
• OSTI ID: 6927910
• Report Number(s): EGG-M-92052; CONF-920871--2; ON: DE93005193
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320303 -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Equipment & Processes
320304* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Waste Heat Recovery & Utilization
COMPRESSION
DRYERS
DRYING
ENERGY CONSERVATION
ENTHALPY
EQUIPMENT
EXHAUST GASES
EXHAUST RECIRCULATION SYSTEMS
EXHAUST SYSTEMS
FEASIBILITY STUDIES
FLUIDS
GASEOUS WASTES
GASES
INDUSTRY
PHYSICAL PROPERTIES
POLLUTION CONTROL EQUIPMENT
STEAM
THERMODYNAMIC PROPERTIES
TRANSITION HEAT
VAPORIZATION HEAT
WASTE HEAT UTILIZATION
WASTE PRODUCT UTILIZATION
WASTES