An innovative prototype for solid flow characterisation in severe stress and temperature conditions

Accurate characterisation of granular flow behaviour is necessary for the effective design of equipment used in the processing, storage, and handling of solid materials. Conventional laboratory devices often fail to replicate the extreme conditions encountered in industrial applications, particularly regarding temperature, normal stress, and reactive atmospheres. This study presents a torque-based shear testing prototype capable of quantifying flow properties under conditions reaching 1000°C and 800 kPa, including reactive environments. Designed to extend the investigative range beyond the limitations of commercial rotational shear testers. The device was validated using quartz sand, a standard, non-cohesive granular material, through comparative testing with the Schulze ring shear tester. Dedicated experiments explored the sand behaviour up to 800°C, indicating that its purely frictional flow behaviour is unaffected by temperature. Therefore, this quartz sand can be considered a reference material to assess the consistency of instrument shear test results at high temperature and throughout the instrument's lifetime, ensuring stability even under harsh testing conditions. The preliminary tests reported demonstrate the prototype's potential as a powerful tool for advancing the design and optimisation of industrial systems subjected to variable stresses and elevated temperatures. By enabling the replication of harsh process environments on a laboratory scale, the device bridges the gap between controlled testing and real-world application. • A novel torque-based shear tester operates up to 1000 °C and 800 kPa. • The prototype enables testing in reactive and high-temperature environments. • The validation was performed using quartz sand and a Schulze tester. • Quartz sand confirmed as a stable reference material up to 800 °C. • The prototype bridges lab-scale shear testing and industrial process conditions.