Investigation of the reproducibility of projection sieving operations
Télécharger en PDFIn a development project the task was to reduce the production-related effort of the vibration drives of sieve shakers for the different mains frequencies of 50 Hz and 60 Hz respectively.
At first it seemed an appropriate solution to excite at natural frequency instead of at power frequency.
A closer examination revealed, however, that then the parameters which have to be specified to ensure reproducible sieving, "amplitude" and "sieving time", are no longer applicable. A study of the physical sequences in shaker sieving on the one hand, revealed the reason for this and, on the other, prompted the idea that sieving performed with different frequency, but the same acceleration should yield reproducible results. It was possible to verify this experimentally.
According to this, sieve shakers where the shaking frequency is to be set as a function of the load or is selected automatically by an electronic system must satisfy the requirement of specifying the sieve bottom acceleration instead of the amplitude and the number of shaker lifts instead of the sieving time. Otherwise it is not possible to ensure reproducible sieving operations. (...)
