Assessment of thermal comfort in non-centrifugal cane sugar through WBGT index

ABSTRACT The production process of non-centrifuged cane sugar (NCS) involves a significant release of steam and heat due to the evaporation of cane juices in saucepans over a solid fuel oven. This results in a warm and moisture-saturated environment, which can be suffocating for workers. This study aimed to evaluate the bioclimatic behavior of an NCS processing facility, based on the wet bulb globe temperature (WBGT) index. In addition, solutions are suggested to mitigate possible adverse effects of heat stress. This evaluation utilized computational simulations to determine the thermal comfort perceived by the workers. The accuracy of simulations was verified against temperature and relative air humidity data collected from the facility. Bioclimatic simulations encompassed twelve treatments, involving modifications to the enclosure on the walls and lantern window, incorporating three types of roof material. The WBGT index was determined by considering the effects of the radiant heat generated by the oven and the natural ventilation area on the facility’s temperature and relative air humidity. This helps to assess the comfort experienced by the workers. The thermal zone of the oven presented heat stress conditions; therefore, rest periods and mechanical ventilation were suggested when dissipating heat and steam through natural ventilation is not possible. For workers exposed to high temperatures and thermal radiation, the use of an aluminized apron and infrared goggles for eye protection was recommended. RESUMO O processo de produção de rapadura gera alta concentração de vapor e calor devido à evaporação do caldo da cana em panelas sobre forno a combustível sólido. Isso gera um ambiente quente e saturado de umidade que pode ser sufocante para os trabalhadores. Este estudo teve como objetivo avaliar as condições ambientais de uma instalação de processamento de rapadura, com base no Índice de Bulbo Úmido e Temperatura de Globo (IBUTG) e sugerir soluções para mitigar possíveis efeitos adversos do estresse térmico. Esta avaliação utilizou simulação computacional para determinar o conforto térmico dos trabalhadores. A simulação foi validada com dados de temperatura e umidade relativa do ar da instalação. As simulações bioclimáticas foram realizadas em doze tratamentos, modificando o fechamento nas paredes e lanternim, com três tipos de materiais de cobertura. Foi determinado o Índice IBUTG, considerando os efeitos do calor radiante gerado pelo forno, e pela áre