Protótipo de um secador de grãos rotativo compacto com sistema fotovoltaico

Abstract

The industrial bioeconomy of açaí, a fruit native to the Amazon, produces food with antioxidant phenolic compounds and lipids. Fractions of the pulping by-product are used to generate bioenergy and are being researched as biopolymers, filler for making furniture and architectural materials. With this in mind, two rotary grain dryers were designed: the first is a commercial model (capable of drying 14 kg of açaí kernels) and the second is a compact model (capable of drying 1.0 kg of material). Due to the practicality of its use in the laboratory, the compact model was selected for manufacture. This prototype consists of: a micro motor (with adjustable torque and frequency, 40W of electrical power and bivolt 127/220VAC), which drives a rotating drum (measuring 24cm in diameter by 24cm in length) at a rotation speed of 57.6rpm, an air heating system (consisting of: air confinement chamber, thermal heating module and temperature controller). The equipment is autonomous for forestry use, with a photovoltaic electricity generation system (configuration: a 60Ah battery, a 540WP monocrystalline photovoltaic module, a 40A PWM charge regulator and a 1000W DC/AC inverter). In the laboratory experiments, 1 kg of açaí kernels were dried (for a period of two hours and forty-three minutes), after which the following fractions were obtained: 5% fiber, 1% insoluble particulate matter from the mesocarp and 63% endocarp. The compact rotary grain dryer is a versatile technology that could be used in biomaterials research in the future, contributing to the region's sustainability and macro-economy.