UNDIP, Semarang (November 17, 2025) – Universitas Diponegoro continues to demonstrate its concrete contribution to the development of science and technology aimed at benefiting society. Through innovative research addressing critical issues in the agricultural processing industry, Dr. Sri Utami Handayani, S.T., M.T., a lecturer in the Mechanical Design Engineering Study Program at UNDIP’s Vocational School focusing on Energy Conversion Engineering, successfully earned her Doctoral degree in Mechanical Engineering with research that directly improves the quality of tea drying in Indonesia.
Her dissertation, titled “Development of a Rotary Agitator on a Vibro Fluidized Bed Dryer for Tea Drying to Address Non-Uniformity in Agricultural Products,” originated from a fundamental problem: the mismatch in tea particle size before and after drying often reduces fluidization effectiveness and results in non-uniform final products. Uneven heat distribution and airflow during the drying process remain a significant challenge for the industry, especially at large production scales.
Dr. Sri Utami highlighted the urgency of this issue. She explained that variations in tea leaf size directly affect the performance of the drying system. Larger particles are more easily fluidized, while smaller ones tend not to lift with the airflow, causing uneven drying. These challenges demand adjustments to dryer design and technology to accommodate material variations better.
The proposed solution is to add a rotary agitator to the Horizontal Vibro Fluidized Bed Dryer (HVFBD). This rotating mixing device creates secondary airflow above the bed surface, allowing particles to spread more evenly and optimizing heat and mass transfer processes. The innovation proved effective through both laboratory testing and CFD simulations.
The research produced significant results. The use of a rotary agitator reduced pressure drop by nearly 60%, indicating improved hydrodynamic efficiency. Additionally, particle residence time in the dryer increased by about 40%, providing more prolonged exposure for thorough drying. The impact is clearly visible in the improved uniformity and even maturity of the final tea product.
“The rotary agitator we developed is key to achieving uniform and efficient drying, ensuring the resulting tea products have better and more consistently mature quality,” said Dr. Sri Utami.
This research not only provides technical benefits to the tea processing industry but also demonstrates UNDIP’s real contribution to sustainable development. Dr. Sri Utami’s findings align with SDG 2 (Zero Hunger) through reduced post-harvest losses and improved agricultural product quality; SDG 9 (Industry, Innovation, and Infrastructure) through strengthened processing technology; and SDG 12 (Responsible Consumption and Production) by enhancing energy efficiency in production processes.
The innovation aligns with the spirit of ‘Noble and Valuable UNDIP’and the ‘Diktisaintek Berdampak’ program, reaffirming the university’s commitment to producing excellent research that offers real solutions for society and industry. Dr. Sri Utami’s achievements demonstrate that research grounded in field needs and enriched with scientific approaches can generate breakthroughs with wide-reaching impact. UNDIP continues to encourage the development of strategic research that strengthens academic contributions to national development and improves public welfare. (Public Communication/UNDIP/Riri; Ed. DHW)