The development of methods for high-efficient low-temperature drying of loose biomass (including also the ground wood of pine and other species, pelleted peat, pharmaceutical products, etc.) is urgent. As one of the variants of realising this task is the application of the fluidised bed convective drying method with the pneumoimpulse energy supply in the dynamic regime. The process of drying of the layer of loose wood in the pulsing gas stream at the fixed mean filtration rate of gas through the layer was investigated in a pilot plant. It has been shown that the pulses of the speed and pressures of gas at definite regimes results in the intensification of the interface heat exchange and the acceleration of the drying process. To model, upgrade and compare different drying regimes on the homogeneous material, experimental pine wood model material (wood cubes 5×5×5 mm in size) was chosen. It has been shown that the consumption of the main energy carrier, air, depends on the value of its supply frequency and pressure at the constant parameters of other heat carrier components. Characteristic features of the pulsing wavy stream created by a pulsator are investigated; the forms of pulses of pressure, speed and density in all sections of the drying unit are determined.
Keywords: biomass drying; fluidised bed, gas stream, pulses of pressure
Authors
Antons A.
Latvian State Institute of Wood Chemistry, Riga, LATVIA
Dolacis J.
Latvia Forestry Research Institute Silava, Salaspils
Engelbrehts A.
Latvia Forestry Research Institute Silava, Salaspils
Aršaņica A.
Latvia Forestry Research Institute Silava, Salaspils
Labendiks L.
Riga Technical University, Riga, LATVIA
Labendiks V.
Latvia Forestry Research Institute Silava, Salaspils
Kravalis J.
Latvian State Forestry Research Institute “Silava”, Salaspils, LATVIA
Gerdt O.
Ltd. Inc. “ENDOIMPULSS”, Riga, LATVIA
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