Part rotating with screw blades

5. analysis of studies conducted

As a result of the study of the main parameters, the following patterns were found:

1. The capacity of pipe mill Q is one of its main characteristics. By changing the load factor of grinding bodies, we can increase or decrease Q. The maximum value of the productivity is 11.4761 t/h at sound= 0.32, the minimum value of the productivity is 9.11680 t/h at sound= 0.24. The graphical dependence Q = f (a) is linear. Increasing the load factor of grinding bodies leads to a proportional increase in mill productivity. Change φ in the range of 0.24÷0.32 is chosen, proceeding from passport characteristics of a pipe mill of Ø2x10.5 of m. Use φ <0.24 is not desirable because of small values of performance of a mill, and application φ> 0.32 leads to an overload of its electric motor.

2. The grinding bodies of different sizes used in the pipe mill have different loosening factors. An increase in the diameter of the balls used leads to a decrease in the coefficient of their loosening. Based on the size of the grinding bodies used in the industry, their loosening coefficients are in the range μ= 0.45 sound0.65. The graphical relationship Q = f ([mu]) represented has a linear character. The maximum productivity value is 12.1916 t/h at mu = 0.45, the minimum productivity value is 9.08445 t/h at mu = 0.65. Decreasing the diameter of the grinding bodies results in a proportional increase in mill productivity. This can be explained by an increase in the number of balls in the mill drum and, accordingly, an increase in the number of interactions between the particles of the material to be ground and the grinding bodies.

3. Dependence of mill capacity on mill drum radius within specified limits has nonlinear, parabolic appearance. The maximum value reaches at a drum radius of 2 m, equal to 48.3036 t/h. Minimum output value at drum radius 1 m, equal to 12.0759 t/h.

4. The dependence of the power consumed by the mill drive on the relative speed of rotation of the drum. The considered range A = 0.6 A 0.85 is taken close to the operating value A = 0.76 of the industrial mill Ø2x10.5 m. An increase in the relative rotation speed of the drum leads to a proportional increase in the power consumed by the drive. It reaches a maximum of 357 kW at A = 0.85, a minimum of 252 kW at a drum radius of A = 0.6.

Conclusion

In this course work, the processes taking place in the grinding chamber of the 2x10.5 m pipe mill were investigated, its design, device and principle of operation were considered, the main parameters were calculated: power and productivity. Experimental studies were also conducted on the dependence of productivity and power on varying values, as a result of which an increase in Q productivity from 9.08445 to 12.1916 t/h and the power of the main motor P from 252 to 357 kW were observed.