ATTRITION IN PNEUMATIC CONVEYING LINES

Pneumatic conveying systems and in particular dilute phase conveying systems are known to create a high stress on particulate solids leading to significant attrition. In contrast to fluidized beds, it is not the material loss which is the main problem. Depending on the application, problems may rather occur in a number of different areas. Attrition may, for example, 

Despite these potential problems, remarkably little work has been published on particle degradation in pneumatic conveying systems. That may be explained by experimental problems that are even much more serious than with fluidized beds. According to the different problems mentioned above, there are more individual measurement techniques and assessment procedures required than with fluidized bed attrition. Usually, the assessment is restricted to the comparison of the particle size distribution before and after conveying. Moreover, there is no steady-state attrition that could be measured. It is only possible to measure an integrated value, which 

Despite the little experimental data, there are two models available in the literature. Adams etal. (1992) considered dense phase conveying. They tried to predict the amount of attrition as a function of conveying distance by coupling a Monte Carlo simulation of the pneumatic conveying process with data from single-particle abrasion tests. Salman et al. (1992) focused on dilute phase conveying. They coupled a theoretical model that predicts the particle trajectory with single particle impact tests (cf. Mills, 1992). 

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