Design And Model-choosing Study Of 220T/H Boiler’s Coal Mill And Pulverizing System At East Kalimantan In Indonesia

Electric power is important energy of national economic development, and thermal power generation is the major technique for power generation in China and many other countries in the world. As more and more project companies move towards overseas electricity market, only the company that can meet the buyer’s rational requirement and offer high-quality service can stand out in the competitions. Coal mill is an important auxiliary equipment of the power plant and pulverizing system is crucial to the whole boiler. Therefore, a simple and stable design proposal of pulverizing system is of great importance to safe and reliable operation for the whole unit.This paper starts with the analysis to the effect of coal quality on coal mill model selection and pulverizing system. And it summarizes conventional pulverizing system proposals and makes comparison and summary of different coal mills and pulverizing systems. Finally, this paper determines the pulverizing system, Medium Speed Mill Positive Pressure Direct Firing Coal Pulverizing System of Desiccant, which conforms to the project. By calculation of three important parts of pulverizing system, i.e. the calculation of coal mill performance parameters, the thermodynamic calculation of pulverizing system, the aerodynamic calculation of pulverizing system, this paper determines the final coal mill model and formulates the pulverizing system diagram.Regarding the defects in the operation, this paper analyzes the defects from six different aspects, i.e. serious dust flying caused by untight sealing of coal mill slagging outlet,serious air leakage caused by the untightness of the fast shut-down door of primary hot air pipe, output rise of coal mill as the result of modification from static separator to dynamic separator, coal feeding difficulty caused by serious coal blockage in the raw coal bunker, output reduction of coal mill caused by big gap between coal mill grinding roller and grinding bowl, serious abrasion of pulverized coal feed pipe in the exit of multi-outlet facility within 1 meter,and it optimizes the system from the above six aspects. As a result, the defects are rectified and the unit is handed over to the owner smoothly for safe production. The facts indicate that the pulverizing system is stable and reliable after operation. Regarding how to design pulverizing system, this paper has certain reference value.