Perancangan Mesin Ball Mill dan Analisis Pola Pergerakan pada Bola Penggiling

Abstract

The ball mill is a machine used for grinding and mixing powdered materials, with the aim of reducing their size and producing homogeneous powder materials. The role of the ball mill machine is crucial for the learning and research processes of Mechanical Engineering students at the University of North Sumatra. This research aims to design a ball mill machine that suits the user's needs, calculate and plan machine components, and analyze the motion patterns of grinding balls. The designed ball mill machine is a horizontal laboratory-scale type. The design process involves identifying user requirements, concept development, concept selection, and concept testing. The analysis of the motion of grinding balls is performed through simulation using discrete element method software, with variations in rotations at 30%, 60%, 90%, 100%, 120%, 150%, and 180% of the critical rotation speed (163 rpm). The designed ball mill machine components include an electric motor, a frame with a motor mount inside, rubber frame mounts, V-belt, pulleys, a shaft, pillow block bearings, a jar, a jar seal, an inner jar cover, an outer jar cover, left-right frame covers, front-back frame covers, and a top cover for the machine. The calculation and design of machine elements in the designed ball mill include the use of grinding balls with a diameter of 10 mm, a critical rotation speed of 163 rpm, a jar volume of 423.5 cm3, an AC electric motor with 0.5 HP power and 1400 rpm rotation, a drive pulley with a diameter of 76.2 mm, a driven pulley with a diameter of 254 mm, type A V-belt with a length of 1143 mm, a shaft with a diameter of 25 mm and a length of 294 mm made of stainless steel, and pillow block bearings with a diameter of 25 mm. The analysis of motion patterns in grinding balls indicates that the optimal rotation is 120% or 195.6% rpm, with a cascade and cataract motion pattern. The head height measures 73.5 mm, and the impact zone length is 55.85 mm.