An analysis of ball-and-race milling part II. The babcock E 1.7 mill

Simulation study of the energy-size reduction of MPS vertical spindle pulverizer

“…Austin used a Hardgrove ball-race machine, modified by the addition of a torque device, to investigate the basic principle of mill action of E type pulverizer [8]. The mathematical models were then developed for the Babcock E 1.7 mill based on the specific rates of breakage and primary fragment distributions, and finally scaled up to predict capacity and energy consumption of industrial mill [9,10]. K. Sato conducted grinding experiments using a batch roller mill, which was also modified from the standard HGI mill, to develop mathematical models to describe steady and unsteady grinding behaviors of ring-roller mill, based on the size-mass balance calculation [11,12].…”

Energy-Size Reduction of Coals in the Hardgrove Machine

“…But due to the difference of particle size among these experimental materials, size ratio among the ground products with the size of t 10 ranges from ffiffi ffi 2 p to 4. Just as we have known, the specific surface area of the smaller particle is much bigger than that of the larger one [22,23]. Thus, more energy will be consumed when the sample is ground to a finer level, according to the area hypothesis of break-up theory developed by Rittinger [24].…”

Modelling of vertical spindle mills. Part 1: Sub-models for comminution and classification

“…The literature shows that many attempts have been made in the past to model coal size reduction, such as Broadbent and Callcott [2,3] developing a matrix model, and Austin et al [4] using a population balance model. Austin et al [5] applied the population balance model to fit a laboratory E-type of ball-race VSM mill (modified from the standard HGI mill), and developed a model of grindingclassification to simulate a continuous Babcock E1.7 ball-race mill performance, using a scale up factor deduced from coal and air flow rates. Problems in running the simulations were identified.…”

“…The data were utilised to fit the population balance model parameters, using a similar approach to that of Austin et al [5]. The fitted model parameters were scaled up to run simulations for a full scale VSM operation in steady state.…”