Addressing Thermal Challenges in Rotary-Airlock Valves: An Industrial Perspective

Abstract

Rotary airlocks are pivotal components in a wide range of industrial systems, serving the dual function of regulating material flow and maintaining pressure differentials between connected environments. Due to their ability to prevent air leakage while enabling consistent material transfer, which is critical to the reliable pneumatic conveying of bulk materials in various sectors such as food processing, chemical manufacturing, cement production, and pharmaceuticals. At the heart of a rotary airlock is a cylindrical rotor fitted with multiple vanes that create sealed compartments, enabling the controlled transfer of materials from the inlet to the outlet while maintaining pressure isolation. In industrial applications—particularly those involving a wide range of powders and varying operating temperatures—rotary airlocks face several performance challenges. These include air leakage, thermal expansion, material jamming, and accelerated wear, especially when dealing with abrasive or cohesive materials. Such challenges can compromise efficiency, reliability, and the overall lifespan of the equipment, making robust design and regular maintenance essential. In high-temperature environments, such as cement kilns or chemical reactors, thermal effects further complicate performance by altering component clearances and weakening sealing integrity, which in turn can degrade system functionality and increase the risk of failure. Recent research underscores the critical importance of understanding heat transfer and thermal behavior in rotary systems, emphasizing the need for accurate thermal modeling to minimize efficiency losses and prevent operational failures. In this context, the present study investigates the thermal characteristics of rotary airlocks, with a particular focus on analyzing heat transfer mechanisms, thermal expansion effects, and their influence on air leakage and rotor-to-casing clearance. By incorporating insights from recent advancements, this work aims to contribute to the development of improved design strategies and to enhance the reliability and performance of rotary airlocks operating in thermally challenging industrial environments.