Operating Data for Large Grinding Mills
The operational experience with large capacity grinding systems for both cement raw material grinding and cement clinker grinding is discussed. The results show that large capacity units are not at a disadvantage when compared to smaller units.
Large Mills for Dry Raw Material and Clinker Grinding
The development of grinding mills, especially in the last few years, shows a continuing trend to larger units. Particular attention must be given to the drying process during dry grinding. Several grinding methods are available, depending upon the material to be ground, and the optimum method must be carefully selected in each case. Special consideration must be made with large ball mills to assure the utilization of all waste heat from the kiln for the drying process. In many cases a roller mill represents a good alternative.
Study on Electrical Explosion Mechanism and Ignition Characteristics of Copper and Aluminum Powder Under Ignition Solid Propellant
In order to study the characteristic of the electrical explosion of copper and aluminum powders, a multilayer generator was designed, an experimental system was set up, and the parameters of metal powder electrical explosion were measured and analyzed. The results show that the duration of the electrical explosion process increases significantly due to the addition of metal powder. The duration of aluminum powder electrical explosion jet flow is ~86.36 ms due to its self-sustained combustion, which releases a large amount of energy, and a small fraction of aluminum powder particles is not burned. The duration of copper powder electrical explosion jet flow is ~15.84 ms, and most of the copper powder particles are in the solid state. The current pause process is absent; instead, the first discharge process is connected to the second discharge process. The effect of copper powder on the first discharge process is greater than that of aluminum powder. Furthermore, the ignition ability of copper powder electrical explosion to solid propellant is stronger than that of aluminum powder in a closed bomb experiment. These results are indubitably meaningful for the application of metal powder electrical explosion and ignition of solid propellant in an electrothermal chemical gun.