STUDY OF A DIRECT INJECTION PULVERIZING SYSTEM FOR INDIVIDUAL BOILER SUPPLY

This paper examines an individual pulverizing system with a hammer mill and direct injection, serving a hot water boiler of the KVT–116.3–150 type. The relevance of the study lies in the crucial role of fuel pulverization in ensuring stable, efficient, and environmentally safe operation of coal-fired boiler plants.A functional diagram of the pulverizing system is presented, covering drying, grinding, classification, and conveying of the air-fuel mixture to the boiler burner. The schematic provides a clear representation of the equipment interconnections, identifies key technological nodes, determines the paths of heat carrier, air, and fuel movement, and highlights zones most sensitive to operational parameters. This lays the foundation for further analysis of thermal efficiency and potential optimization reserves.During the operation of the system, key parameters were recorded: the temperature of the air-fuel mixture at the mill outlet did not exceed 85 °C, the coal dust fineness was R₉₀ = 45 ÷ 55%, and the fuel moisture and consumption values corresponded to the operating charts. The data analysis confirmed the stability and efficiency of the system under boiler load variations in the range from 60% to 100% of the nominal capacity.Special attention is given to the design and technological features of the equipment: the hammer mill with an integrated separator, a recuperative air heater, a downward drying unit, the air supply system, and control elements. Advantages of the individual system include enhanced automation, reduced heat loss, flexible operation control, and adaptability to variable loads or unstable fuel characteristics.Recommendations are made for optimizing the drying process and implementing a monitoring system for the mill and separator condition. The study concludes that the system is technologically complete, efficient, and promising for retrofitting existing solid fuel-fired boiler units.