Cement, Energy and Environment

creation of an optimal combined control system the TBM capable of adjusting the static characteristic drift by compensating for external and internal perturbations, stabilizing cement grinding fineness with high accuracy and increasing the productivity 1.5 times. A general-purpose tubular-conical mill with a continuously– variable structure A study of the theory and practice of grinding, especially for mills with a controlled rotational speed and a variable LID ratio, yielded the key concept of grinding and applied it for developing an advanced milling unit, i.e. a general– purpose tubular– conical mill (TCM) with a variable– speed electric drive. The TCM design (Figure 6 for cement, and Figure 7 for coal) differs in that the conical causing size is reduced towards the discharge side. In contrast to other mills, TCM can be mounted on a common frame. This makes it possible to incline the conical casing with respect to the longitudinal axis c.,...,.,., lnc:lhtdF•allle Figure 6. Tubular-conical cement mill. VTF - vibratory tilted feeder; CU - control unit; EP - electric precipitator; MF - mill fan. TCM ~ Common tnclinea f::rame Figure 7. Tubular-conical coal mill. RCB- raw coal bunker; VTF -vibratory tilted feeder; CU - control unit; MF - mill fan; DB -dust bin. within the angle of inclination between the cone generatrix and the horizontal line. Casing tilting helps to control (redistribute) ball filling over the cone length both manually and automatically, and it is a fundamentally new and effective control action. For the first time, the TCM implements the key concept of grinding. It features the only possible and optimal location for each working energy carrier - the grinding ball depending on both its diameter and the entire ensemble of balls in strictly appropriate cross– sections over the entire length of the conical casing, simultaneously providing for optimal ball dropping velocity paths and their turnover in each of these sections. This is the core of the grinding problem. Implementing the key grinding concept immediately yields the gamut of TCM features.. They systemically merge into one unit and in full scope the entire set of advanced technological and design solutions that provide the following: 17