Research on the Operating Process of Crushers(二)

(5) According to the matrix theory of comminution, which involves the concepts of the classification matrix and breakage matrix, the mathematical models of roll crushers and rotary breakers of coal preparation plants have been investigated in this paper. For the roll crusher model, the classification matrix is expressed by a certain equation. The breakage matrix is developed firstly by a single particle pendulum breakage test, and then by a computing calculation for the test data using a multidimensional cubic spline regression technique. The rotary breakage involves three subprocesses: prescreening, crushing and, rescreening. The prescreening and rescreening subprocesses are represented by a simple efficiency curve model. Modelling the crushing subprocess uses the same concept as the roll crusher model, but needs more assumptions. The feed of the rotary breaker is considered to be divided into two components( "coal" and "ash"). These two components have the same classification function but different breakage function. They are also selected for breakage at different rates. The crushing and rescreening subprocesses repeat for several stages. The above two models have been tested using a number of industrial experimental data. It has been found that they can be used to predict the size distribution of crushing products with reasonable accuracy. In addition, an empirical model has been developed to predict the ash content of the broken coal fractions. 

(6)Based on working mechanism and working performance research of compressive crusher, the multi-objective planning of crusher productivity, product grain size distribution and chamber geometry was built up, which provided the basis for developing new style and high efficiency modern compressive crusher. Combined with multi-objective planning of cone crusher, the solving methodology of multi-objective planning of compressive crusher was deeply studied, and the serial quadratic programming based on K-T equation was adopted to solve this multi-objective problem.

(7)Based on compressive crusher working performance models and multi-planning model, the cone crusher optimization system was developed. This system could optimize and analyze the working performance and design parameters of cone crusher.  Through the related physical prototype full scale test further verified the feasibility and reliability of working performance models and multi-objective models. Based on working mechanism and working performance research, the parameters’ optimization system was developed and successfully applied in the related crusher manufacturer. This optimization system has got many compliments for its good effect.

(8)The future research works, including research aims, contents, and methods, are put forward to outlook。

Research on the Operating Process of Crushers(一)

This research mainly included these research contents and conclusions as follows:

(1) Summarizing the interparticle breakage theory and the related achievements of domestic and foreign countries, discussing the advantages, basic premises and feasibilities of applying interparticle breakage in compressive crushers, the key technology of applying interparticle breakage in compressive crushers was summed up.

(2) Based on kinematic and dynamic characters of stone crusher and rock material, the motion track model of rock material in chamber was built up, and the crushing zones’ characters were also studied, which provided the basis for designing and researching the chamber by the method of crushing zones. The motive characters of compressive crushers and rock material in the chamber were deeply studied and the influences between motive states of crusher and rock material and crusher working performance also were discussed. Based on motive character of crusher and rock material, the productivity model of compressive crusher was achieved. Beside, the key structure and working parameters of crusher also deeply researched, and the relationship model between productivity and various key factors was built up. Affecting crusher performance was quantitatively and qualitatively researched, which verified the reliability and feasibility of productivity calculation model.

 (3) Based on advanced breakage theory—interparticle breakage, population balance model and crushing zones’ characters, the interparticle breakage process of rock material in chamber of jaw crusher was deeply studied. Combined with the matrix model of rock material breakage, the operating model of rock material interparticle breakage process in chamber of compressive crusher was built up, which opened out the essential causes of interparticle breakage of compressive crushers and also provided the basis for simulating and optimizing product grain size distribution.

(4) Based on the characters of crushing zones, combined with the working character of compressive chamber, the fixed mass theory was put forward, and it was used to study the curved chamber geometry of compressive crushers, and the stroking and awaiting characters of compressive crusher lessened or got rid of. Moreover, the concept of working nip angle was introduced into chamber geometry research, which guaranteed the nipping requirement and improved the machine’s working performance. Based on interparticle breakage, crushing zones’ characters, the fixed mass theory and working nip angle demand, the interparticle curved chamber geometry was built up and the new method of interpartcle curved chamber geometry was put forward.