Energy Consumption Research in the Coal Crushing Process

Date:08/21/2012 05:53:07

The energy consumption of jaw crusher in the process of impacting has always been the emphasis of research. It is not just the foundation for coal crushing, but the key to appropriate, highly efficient crushing equipment. Whereas, due to the limitation of theory and practice, the research on energy consumption law in the process of coal crushing and micro crushing mechanism are not mature enough. The crushing effect can be reflected by the damage accumulation formed by the extension of micro crack in the coal and the macro size reduction caused by fracture. 

For quite a long time, the granularity was treated as equal to grinding effect. As a result, the macro size reduction was the focus of research while the grinding effect was neglected. Actually, granularity reduction is the macroscopic expression of inner micro damage under the effect of stress. So an inseparable relationship exists between them.

The macroscopic expression varies with the extent of granularity reduction. We can see from brittle fracture criterion and energy dissipation law that when energy loading reaches a threshold, the energy will be unavailable without fracture extension or damage.

When energy loading reaches brittle fracture criterion, the coal will be crushed with damage degree of l and 15% unavailable energy. The coal storing capability increases with continuous energy loading. Consequently, the crushing size of coal will continuously reduce, meanwhile, the damage degree will be measured by lumpiness distribution.