Predicting the Dynamics of Coal Disintegration under Various Conditions

摘要

The dynamics of coke disintegration is of practical interest in many cases. Perhaps the most important case is to optimize coke processing and the related task of organizing the coke handling system between the coke plant and the point of use. No less important is to decide whether and how to break up the coke before it is shipped as a commercial product. These issues include the design and operating practices for coke bins, the use of so-called coke cushions or striker plates at conveyor transfer stations, and many other aspects of coke handling. Answers to these questions can be obtained by calculations, because the various types of coke testing devices have different rates of mechanical action by different mechanisms of disintegration. For example, the action is primarily abrasive in a Sundgren drum, but mainly shattering in a drop tester. The standard Micum drum (per GOST 5953) is intermediate between the two. Functions were obtained relating the number of revolutions in a standard small dram (Micum) to the number of Sundgren drum revolutions and to the number of test drops from a height of 1.85 m for the equivalent disintegration of different coke sizes. A new method is proposed for calculating the coke disintegration constants in a Sundgren drum and a drop tester based on the constants obtained by testing in a Micum dram at two numbers of revolutions. Experiments confirmed the possibility of predicting the disintegration (to a certain extent) in a Sundgren dram and a drop tester based on quasi constant nominal values determined by recalculating data from standard tests (at one level of comminution) in a Micum dram. Suitable values of these nominal constants were obtained for describing disintegration in a Sundgren dram and a drop tester. A method is presented for predicting the change in the size consist of coke when disintegrative actions of different intensities are applied. This method can be used to select ways of improving the post-oven processing of coke. The dynamics of degradation of the amount of coke in different sizes; i.e., the size consist, under any conditions of a disintegrative process follow the same law, and thus are predictable from experimental findings of disintegration under some set of conditions. Therefore, there is little prospect of obtaining new information on "cold" disintegration by developing new testing devices to evaluate coke quality.