This is the annual progress report on the Particle Attrition project which is being partially carried out at the University of Delft. The project is part of a collaborative effort, at present a complementary project is being carried out at the University of Birmingham. The project was started in February 1982.
The project follows the initial literature survey made by Dr. J. van Brake1 of this University of Technology. In that report the sub-division of the subject was identified as being basically in three parts:
1. Tests on Single Particles
2. Tests on Groups of Particles
3. The Attrition Behaviour of Particles in Kcal Systems
In this department we are currently concentrating on the relationship between the tests on single particles and the behaviour in real systems. This necessarily means that such a relationship will most easily be established for particle handling systems in which the particles are in diluted phase. The two systems in which we have made measurements of particle attrition are in a pneumatic conveying line, where the criteria of lean phase is maintained and in a fluidised bed where the process is more complicated. In defining the objects of this programme there is of course no real distinction between the attrition of particles and the fracture of particles. In our minds we basically perceive the fracture as being the splitting of particles to a number of fragments of roughly comparable size, while the attrition behaviour on the other hand is the gradual wearing away of one large particle. In real processes both features are occuring simultaneously.
At the Clausthal meeting in june 1982 the overall objectives were defined as follow:
To develop
I) means of predicting particle attrition in process equipment based on unambiguous small scale tests.
2) insight into the influence of particle design and equipment design and operation on attrition.