Mapeamento dos perfis de secagem de um secador de leito fixo utilizado para secar sementes de milho

Abstract

In the present study, the drying efficiency of a fixed bed dryer for drying corn seeds was evaluated. It was noted that the efficiency in processing this material is crucial for the sustainability of agriculture and the profitability of the agricultural sector. An efficient process ensures the production of high-quality seeds while minimizing waste of valuable resources such as water, energy, and agricultural inputs. This not only contributes to environmental conservation but also reduces production costs. The artificial drying of corn seeds proved to be an effective method, allowing precise control over temperature and humidity. This technique ensures rapid drying until the ideal moisture level for storage is reached, significantly reducing the risk of quality loss due to fungi and other microorganisms, as well as preserving the nutritional qualities and germination capacity of the seeds. To achieve these results, it was essential to understand the drying mechanisms, select appropriate technologies, and optimize drying parameters. The evaluation of the efficiency and performance of the fixed bed dryer began with the collection of technical specifications of the equipment, including its drying capacity, dimensions, heating system, and ventilation. The upward airflow of the dryer was measured with a digital anemometer, allowing for an understanding of the differences in thermal performance related to the distribution of the samples. Following this initial phase, the dryer was divided into six identical sections, each containing the same amount of material. In this first part of the experiment, a single layer of shelled ears was placed in each section, with similar initial moisture contents. The moisture of the samples was monitored through five ears processed in the AM 5200 Grain Analyzer, while relative humidity and temperatures were measured with digital hygrometers and an infrared thermometer, with monitoring every four hours until the samples reached a moisture content below 12.5%. In the second part, a scenario with multiple layers of material was analyzed in the sections with the best and worst performance, with monitoring every eight hours. It was observed that the thermal efficiency of the studied dryer was 29%, with position 6 being the most efficient, showing the highest drying rates and temperatures, whereas position 1 was identified as the least efficient. From the experiment with multiple layers of ears, it was noted that position 1 practically maintained its drying efficiency, while position 6 had its moisture loss rate reduced by half.