Pulverizer

Abstract: Particle size reduction is a critical unit process in many industries including mineral processing, cement, food processing, pigments and industrial minerals and pharmaceuticals. The aim is to take large feed material and as efficiently as possible reduce the size of the particles to a target size range. Over time, a very large range of equipment has been developed to perform this for many materials and in many different conditions. Discrete element method (DEM) modelling is a computational tool that can allow detailed exploration of the particle flow and breakage processes within comminution equipment and can assist in developing a clearer and more comprehensive understanding of the detailed processes occurring within. In this paper, we examine the particle and energy flows in representative examples of the equipment used in many grinding processes. We study a 36′ semi-autogenous mill used in primary grinding for mineral processing, a ball mill used for cement clinker grinding, a grinding table also used for cement grinding, a tower mill used for fine grinding both in mineral processing and for industrial minerals and finally for an Isamill, which is used for ultra-fine grinding in mineral processing. Copyright

Abstract: A pulverized coal burner for a furnace adapted to be used in conjunction with a pulverizer which reduces coal to approximately 40 microns size in the presence of inert steam which conveys it under pressure to said burner tangentially to spiral the same within a fuel tube around a coaxial central tube axially adjustable within the fuel tube to adjust the relation between flared distribution and mixing members respectively on the discharge ends of said tubes. Combustion air is fed coaxially around the discharge end of the fuel tube for thorough mixture with the coal which is conveyed with a minimum amount of steam through said tube so as not to deter combustion in the combustion zone which is immediately adjacent the discharge end of the fuel and central tubes.