Determining Optimum Productivity of a Ball Drum Mill When Milling Brown Coals
| Autor: | A. N. Kudryashov, S. D. Ivanov, V. V. Oshchepkov |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
business.industry
Energy Engineering and Power Technology 02 engineering and technology Drum Coal dust Combustion 01 natural sciences 010305 fluids & plasmas Grinding 020401 chemical engineering Nuclear Energy and Engineering 0103 physical sciences Environmental science Specific energy Mill Coal 0204 chemical engineering business Process engineering Ball mill |
| Zdroj: | Thermal Engineering. 68:136-141 |
| ISSN: | 1555-6301 0040-6015 |
| Popis: | Ball drum mills (BDM) are one of the main types of coal-grinding equipment in Russia. A significant drawback of BDM is high power consumption (a significant part of the TPP’s own needs). With a huge scale of production, reducing these costs even by a few percent gives a significant economic effect. The problem of minimizing the specific energy consumption for grinding and transporting Azean coal in an ShK-32 ball drum mill is considered. For moist brown coals, the efficiency of grinding and transport of coal dust is usually achieved in the mode of equality of the grinding and drying capacities of the mill. The implementation of this regime is a necessary but insufficient condition. A system of equations is obtained that describe the processes of grinding and transport of coal dust. The analysis of the equations shows that the specific energy consumption for grinding is inversely proportional to the air consumption, and the specific costs for the transport of the dust and gas flow are proportional to the square of the air consumption. This fact ensures the presence of a minimum specific energy consumption for pulverization. A comparison is made of the estimated consumption of specific energy for pulverizing in an ShK-32 ball drum mill with experimental results obtained during routine commissioning tests of the dust system of the Irkutsk CHPP-9. The average deviations of the calculation results from the experimental data are in the range of ±10%. Comparison of the calculated and experimental data indicates that the mathematical model of the mode of equality of the grinding and drying capacities of the BDM adequately describes the processes occurring during the preparation of fuel for combustion. It is shown that an increase in the efficiency of dust systems with BDM can be achieved only after a detailed study of the transport of coal dust. In the proposed method for determining the optimal performance of the ball mill, the effect of the polydispersity of coal dust on the aerodynamic resistance of the mill is consistently taken into account. |
| Databáze: | OpenAIRE |
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