Performance enhancement of an old Endless Chain Pressure (ECP) tea dryer for black tea manufacturing

Ceylon tea, which is well known in the world market, is a major export commodity produced by Sri Lanka, placing the country among the most significant global tea producers. The drying process is a crucial and energy-intensive stage in black tea manufacturing which aims to decrease the moisture content of the tea leaves. As endless chain pressure (ECP) tea dryers age, their performance tends to decline. Especially, energy consumption increases and dried tea quality decreases with time. Therefore, optimizing their performance is critical to uphold the quality standards of tea. This study aimed to optimize the drying temperature of the ECP dryer at the Houpe tea factory in Ratnapura, Sri Lanka. Currently, the tea drying temperature at this factory is 250 °F. In this study, tea dhools were dried under five drying temperature levels: 240, 245, 250, 255, and 260 ⁰F. The specific heat consumption (SEC), energy wastage, and organoleptic parameters were measured. The replicate data of each treatment were analyzed using one-way ANOVA. It was found that SEC and energy wastage were significantly (P<0.05) lower for 240 and 245 °F compared to other temperatures. Tea dhool dried at 245 °F outperformed other samples in terms of liquor colour, aroma, infusion colour, leaf appearance, leaf colour, and overall acceptability. These results have led to the determination that the ideal drying temperature for this ECP dryer was 245°F, as it resulted in a superior quality tea and lower energy consumption. The adoption of this drying temperature will not only improve the quality of the tea but also reduce energy expenditure.