String stepped screen design and main parameters

Introduction. Obtaining energy is the most important problem of mankind. Coal-fired generation has solved, and will solve this problem in the foreseeable future due to its extensive resource base and relatively stable and low price. At the same time, the efficiency of the generating enterprises depends on the quality of the fuel supplied. For generating enterprises and domestic household using a layered method of burning fuel, it is very important to use high-grade coal, which increases the efficiency of their work. Obtaining high-grade coal, i.e. its separation by size classes is carried out by gravity screens. The advantages of the gravity screens are simple design and the absence of a drive during the sorting operation. Low sorting quality is the disadvantage. Therefore, the creation of new gravity screen designs and the development of existing ones to improve the sorting quality is of great importance. Methods of research. The Siberian Federal University has developed a design of a string stepped screen which uses a gravitational method of sorted material separation by size classes. To introduce it to industry, it is important to know the basic design parameters inherent in the proposed design. The article offers a mathematical model for calculating string stepped screen parameters and presents the results of calculating screen dimensions depending on other changing parameters. Mathematical modeling (construction of a mathematical calculation model) and analysis for string stepped screen design have been carried out to determine its basic parameters. Research results. A string stepped screen design is presented. A mathematical model for basic parameters calculation has been developed. Graphs have been constructed showing the dependence of the changing screen dimensions on other changing values. The string stepped screen design has been analysed. Conclusion. Based on the conducted research, a mathematical model for string stepped screen parameters calculation is constructed. The dependences of length and height on the front wall and screening section angles are constructed. The obtained dependences will allow to determine the string stepped screen parameters for the specified values of the screened material size.