Analysis of the Prospects of Using a Screenless Hammer Crusher for Solid Fuel Production Lines

This article analyzes the processes of secondary biomass grinding for pellet and briquette production, substantiating the choice of grinder type and defi ning its parameters. The aim of this work is to increase the effi ciency of solid biofuel production by using a promising hammer-mill-type screenless crusher. Methods. The object of research is the technological process and design of a direct-fl ow hammermill- type screenless crusher, intended for grinding plant materials to a normative fractional composition for the production of fuel pellets or briquettes. The research was based on a comparative analysis of impact grinding, impact theory, and mathematical modeling. Results. For granulation or briquetting, it is necessary to grind raw materials to 0.1-5 mm. It was found that traditional screen crushers have 12-18% higher energy consumption, rapid wear, and problems with clogging openings when moisture content is high. It was determined that for grinding solid fuel raw materials at small and medium-capacity enterprises, the most effective is the screenless crusher model DMB-F (0.5-1.5) with a hammer rotor mechanism. It eliminates biomass circulation, ensuring a direct-fl ow grinding cycle and increasing productivity by up to 18%. The optimal tangential speed of the hammers is not less than 60 m/s, and the minimum radius of the rotor disk is 0.2 m at 2800-3000 rpm. The technological process of the DMB-F (0.5-1.5) model involves the effective use of the kinetic energy of the hammers and the recirculation of unground particles, which ensures high effi ciency and quality of the fi nal product. The use of such a crusher signifi cantly increases the effi ciency of solid biofuel production. Conclusions. Research into the technological processes and designs of hammer crushers has revealed signifi cant advantages of direct-fl ow hammer-mill-type screenless crushers compared to traditional screen models. The proposed theoretical provisions, in particular methods for calculating crushing energy, impact impulse, and the dynamic moment of inertia of the rotor, form the basis for further design and optimization of the parameters of direct-fl ow screenless crushers.