SBIR-STTR Award

A direct engine-driven heat pump dryer is being developed that would eliminate massive electrical power demand, increase drying capacities and fully utilize all of the fuel consumed by the engine. The two-thirds of the fuel normally lost as heat by an engine would be captured and used directly for drying. The remaining third of the fuel which is converted into shaft work would operate the heat pump compressor to recover the latent heat of vaporization from the dryer exhaust airstream, using the heat pump's inherent coefficient of performance as an effective energy lever.

Keywords:
1. Industrial energy processes and utilization2. Food. nutrition. agriculture

Feasibility study outlines an LP/Nat. gas engine or tractor PTO powered heat pump grain dryer with counter flow/concurrent flow deep bed processes and recovery of latent heat, engine waste heat, and grain cooling heat with low fuel use (750-1100 BTU/lb water removed) and high grain quality. Dryer is inherently fire safe due to drying temperature range of 100 F to 280 F and structural design. Key research goals are: (1) very low operating costs, (2) improved grain quality, (3) low cost structure, (4) simple, efficient compressors, (5) rugged, efficient heat exchangers, and (6) microprocessor controls.