Assessment of thermal comfort in non-centrifugal cane sugar through WBGT index¹

Avaliação do conforto térmico em instalação de processamento de rapadura por meio do índice IBUTG

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.

Key words:
heat stress; computational simulation; bioclimatic; passive conditioning strategies; agro-industry

HIGHLIGHTS:

NCS agro-industrial facilities emit high amounts of heat and steam, which can create thermal stress for workers.

The WBGT index values suggest a ventilated environment to reduce negative impacts on workers’ health and work performance.

Statistical treatments with open perimeter walls and lantern windows presented the best bioclimatic conditions for workers.