Barley grain pre-drying using a low-energy laser beam

Abstract

A laboratory laser beam method for drying barley grains is presented and the corresponding energy transfer is analyzed. Barley grains were illuminated from one side during a period of 60 seconds with 100 mW 650 nm and 200 mW 650 nm collimated laser beams. The intensity of laser radiation within the illuminated area was 12.74 Wsm-2 for a 100 mW laser and 25.48 Wsm-2 for a 200 mW laser. Barley grain samples with moisture contents of 18 %, 20 % and 25 % were used for analysis. The results obtained show differences in the energy consumption between grains with different initial moisture contents. Compared to convective hot air drying, the energy savings of 51 % were achieved using a 100 mW laser on the grain samples with a moisture content of 25% under laboratory conditions. Moreover, the energy savings were found to depend on the grain wet basis and decrease with the decreasing moisture content.

Keywords

• energy efficiency
• pre-treatment
• drying
• laser power
• barley grain