Attrition problem

Attrition problems previously noticed by the present authors in the use of pure zeolitic materials were not observed in any of the experiments reported here, indicating that the addition of bentonite as a binder to the zeolites improved the mechanical strength. 

An attrition problem has been observed when they have been employed in fluidized-bed reactors [29]. Consequently, significant improvements in catalyst activity and mechanical strength are needed. 

The attrition of solid particles is an unavoidable consequence of the intensive solids motion resulting from the presence of bubbles in the fluidized bed. The attrition problem is especially critical in processes where the bed material needs to remain unaltered for the longest possible time, as in fluidized-bed reactors for heterogeneous catalytic gas-phase reactions. Catalyst attrition is important in the economics of such processes and may even become the critical factor. 

Centrifugal pumps. Probably the most common source of particle attrition problems is the centrifugal pump. The high shear forces inherent to these pumps, particularly in the eye of the impeller, make some crystal damage... 

Several methods have been suggested to overcome the attrition problem. One is the scanning method, which is an extension of the Rosenbluth and Rosenbluth procedure. The scanning method forms the basis of the local states method and the hypothetical scanning method, enabling one to estimate the entropy from MC and MD simulations. The fundamental concepts of these techniques are described next. 

A clear advantage of this constraction is that every successful construrtion yields a statistically independent configuration. However, the success rate of these attempts decreases exponentially with N ( attrition problem ). From eqn [4] we know that a SAW has a partition function whereas for a... 

Attrition problem is waived by using spherical carbon particles... 

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