Development of a novel automatic robotic cleaning system and the associated technology for blades in mixing process of vertical mixer

Abstract

The vertical mixer is a core piece of equipment widely used in the mixing processes of energetic materials, such as composite solid propellants. During these processes, multiple rounds of blade cleaning are typically required. Blade cleaning alone accounts for 30%–50% of the total mixing time. At present, blade cleaning is predominantly conducted through manual face-to-face operations, which not only take more than 15 min per cleaning session (using a 25 L vertical mixer as an example) but also pose significant safety hazards. The primary challenge in achieving automated cleaning of vertical mixer blades lies in their unique shape and complex motion. Driven by hydraulic pressure, the blades follow intricate trajectories that are difficult to accurately locate and detect. This paper addresses this technical issue by conducting an in-depth study of the blade’s running trajectory based on the gear transmission principle of the vertical mixer’s blade rotation system. The periodic variation law of the blade’s motion is revealed. An explosion-proof robot automatic cleaning device is designed, which is highly integrated and interlocked with the vertical mixer itself, without relying on a 3D optical scanning system. Additionally, an automatic generation algorithm for the robot cleaning trajectory is developed to enable “remote, one-click” automatic cleaning operations during the mixing process. For a 25 L vertical mixer, the single cleaning time is reduced to less than 12 min, representing a 20% improvement in cleaning efficiency and eliminating the potential safety hazards associated with manual face-to-face operations.