Design of a ball mill with a capacity of 12 tm/h of coal milling anthracite, to improve the operation of the TSX-G fluidized bed boiler of the company TRUPAL S. A

Abstract

The present study was carried out to design a ball mill for the grinding of anthracite coal in order to improve the performance of the operation of the TSX-G fluidized bed tank of Trupal S.A. The first chapter presents the urgent need to have a ball mill, justifying the environmental and economic side; Likewise, the necessary theory for the design of this equipment is mentioned. Specific objectives were set so that the design of the ball mill was carried out in an orderly manner to cover the need for grinding 12 tonnes per hour. The flow of activities to achieve the objective pursued by this thesis was reflected in a flow chart in the second chapter, followed by the identification of independent and dependent variables and how they are operationalized. In the third chapter, the performance of the aquotubular boiler was determined by means of mass and energy balances, making use of the information gathered from the existing mills and boiler operating parameters. The performance of the boiler can be increased by increasing the area of heat transfer, i.e. by decreasing the size of the coal. An ASTM A36 steel ball mill was designed with an inner diameter of 1000mm and a length of 1000mm, in order to bring the size of the coal from 75mm to 0.1mm. The ball diameters and their masses were calculated in conjunction with the operating speed to achieve optimum pulverization of the anthracite feed coal to the boiler. A motor was designed and selected with its respective speed reducer, with a power and speed of rotation according to the supplier. The transmission system, composed of 4-strand chain that reduced the speed of the reducer until the revolutions necessary for the operation of the mill. The transmitted axis was designed, obtaining an acceptable safety factor, for which it was necessary to select a SCH120 tube. The NPV was calculated obtaining 1,296,259.14 US $, with a TIR of 976.11%. Compare the results obtained in this thesis with the other authors. It was finally concluded that the ball mill presents an economic improvement.