DRYING BALED HAY WITH COMBINED SOLAR AND BIOMASS HEAT SOURCES

Autor/autori: René MORISSETTE, Philippe SAVOIEAND Pierre-Luc LIZOTTE (Canada)

Abstract: A heat exchanger system using hot water supplied by a biomass boiler burning wood logs was installed in combination with a passive solar hay batch dryer. The dryer could hold up to 7620 small 22.5-kg bales stacked over 8 rows. Bales were dried down to 12 % moisture content (m.c.) in 20 days. The dryer consisted of four 3.70-kW centrifugal fans mounted with 64-kW heat exchangers that heated a fraction of the total solar pre-heated airflow. The 146-kW boiler could supply 2 heat exchangers for an 8-hour period with a single wood load of 150 kg. The average gain of air temperature was 8.8 ºC and the average wood consumption was 10.6 kg/h. Ash content was 1.3 %. The electrical, solar and biomass net energies were 281, 525 and 1034 MJ/t of hay at 11% m.c., respectively (overall efficiency of 40 %). Energy, labour and fixed costs (in CAD) were 34, 13 and 10 $/t respectively (1.19 $/bale).

Keywords: solar hay dryer, biomass combustion, energy, boiler

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