New concepts of crushing plates for increasing efficiency of crushers (technical output increase, loads and energy consumption cut down) – theoretical and experimental studies

Aim of project
The scientific aim of the project formulates new concepts of crushing plates with gradually changing cross section to improve efficiency of the crushing processes. Such an idea comes from simple observations – the plate profile should conform the size of the crushed particles – so it should change along the height of the crushing chamber. Additionally, it has to be shaped considering strength properties of material. In 80-thies and 90-thies of the last century Zawada forwarded the proposition to apply crushing plates with changing profiles. The author made attempts to prove the hypothesis that the plates formed accordingly to theoretical solution, based on the limit analysis, decrease forces of the crushing process. The approach assumed for the studies was related to optimization of plate faces in regard to crushing forces. The machine crushing was treated as an assembly of the elementary processes for which load boundary conditions were available. The introductory tests, fulfilled at a model Blake crusher, brought to an important conclusion, as the obtained results pointed out that plates furnished with the changing profile substantially decreased limit loads (about 30% in respect to traditional plates, for middle-grain marble). In the present project the optimization criteria, together with limit loads, include crushing energy consumption which means wider studies on crushing plate construction concepts.

Expected results
The project framework consists of multidirectional studies, such as strictly scientific and construction based on theoretical solutions, as well as experimental including fundamental and applied tests. For this reason the results would cover analytical and application domains. The expectations might be specified as follows: 1) Formulation of procedures to shape plates profiles in accordance to criterion of the minimal forces and crushing energy consumption 2) Solution of fundamental problems of the mechanics of crushing basing on the limit analysis and finite element method ( estimation of crushing energy, so far unsolved problem) 3) Project and workshop activities for new crushing plates widened by experimental studies on the model Blake toggle crusher 4) Approve that the new plates substantially increase the efficiency of the crushing process (the forwarded assumption, at present, has an essential background) As the new crushing plates may be easily furnished to industrial crushing machines, the important practical meaning of the forwarded aim of the project should be noted.