This study aims to design and implement a 100 CMM (cubic meters per minute) Regenerative Thermal Oxidizer (RTO) to achieve low-emission combustion. The existing RTO system utilizes a cylindrical drum structure with a rotary disc to periodically introd...
This study aims to design and implement a 100 CMM (cubic meters per minute) Regenerative Thermal Oxidizer (RTO) to achieve low-emission combustion. The existing RTO system utilizes a cylindrical drum structure with a rotary disc to periodically introduce and exhaust VOCs (Volatile Organic Compounds) gases, achieving high energy efficiency with a thermal recovery rate of over 95 %.
However, this system faced structural limitations, including wear due to the load on the combustion chamber's lower drive shaft, channeling phenomena between the combustion chamber and the drive shaft, and the emission of untreated gases. Additionally, operating at temperatures above 800 ℃ for extended periods led to performance degradation and instability, caused by issues such as rotation stoppages or explosions due to contaminants, dust accumulation, and thermal expansion of the chamber.
To address these problems, this study presents an improved RTO design. First, a combustion chamber combining a high-heat element and a burner was designed to accommodate temperature rises of up to 920 ℃ during high-concentration VOCs treatment. The burner diameter was set to 125 mm, and the Hot By-Pass Damper outlet dimensions were 650 mm × 650 mm. The combustion chamber was lined with 200 t ceramic insulation to effectively discharge high-temperature waste heat. Second, to distribute the load on the rotary disc distributor, the position of the rotary shaft was modified, and an optimized shaft structure was implemented based on flow analysis. The insulation for the combustion chamber consisted of 200 t thick ceramic blocks, with the chamber's outer diameter and height set to 2,530 mm and 1,875 mm, respectively, optimizing the gas residence time and insulation thickness. Third, a trip control algorithm based on PLC (Programmable Logic Controller) and an intelligent predictive control system based on Edge-IoT were applied to enable fault prediction and ensure safe operation.
After the design and implementation, a demonstration experiment was conducted. The results showed that the proposed 100 CMM RTO achieved a VOCs removal efficiency of 98.2 %, a waste heat recovery rate of 95.78 %, a fuel consumption rate of 21.95 %, and a nitrogen oxide (NOx) emission concentration of 3.9 ppm. The performance of the 100 CMM RTO was verified over a total of 177 hours of operation. These results confirm that the proposed system simultaneously achieves high-efficiency VOCs removal, energy savings, and low-emission performance.
Furthermore, this study implemented remote monitoring of the RTO system by integrating a PLC controller with an IoT application. Data collection and management were handled at the edge, and data storage and analysis were performed in the cloud, enabling real-time monitoring and alarm functionalities. The system provides continuous analysis of temperature, pressure, and VOCs concentration, ensuring that the system remains in normal operating conditions. The predictive capabilities allow for the early detection of abnormalities and contribute to accident prevention and equipment predictive maintenance.
This study presents a technological approach to overcome the limitations of existing RTO systems, achieving high-efficiency, low-emission combustion. Additionally, by integrating IoT-based remote monitoring and fault prediction, it highlights the importance of real-time data analysis and predictive maintenance, enhancing the practicality and applicability of the system in industrial settings.