SCIENTIFIC PAPERS

Scientific Papers, USAMV Bucharest, Series A, Vol. LII, 2009, ISSN 1222-5339INTERMITTENT VIBRATION EFFECT IN THE SEPARATION WITHSIFTING OF MIX POLIDISPERSE SYSTEMS USED IN FOOD INDUSTRYAND ANIMAL SCIENCEM. MUNTEAN, I. DROCAŞ, S. STANILĂ, O. RANTA, A. MOLNAR, O. MARIANUniversity of Agricultural Science and Veterinary Medicine of Cluj-NapocaKeywords: processing raw materials, separation process, sieving machine, testsieve diskAbstractIn frequent technological processes of food industry or animal science, the use ofclassification, gradation, calibration or sifting operation becomes a necessity. Sifting is amechanical operation realized through separation in granulometric factions of somepolidisperse mixtures of granules and powder on the basis of particle shape and size.Sifting can be achieved as a stand-alone operation or as a preliminary operation for thepreparation of raw materials for further processing operations. Sift method consists inlocating the plates one in extension of another, the later having the dimensions of theorifices of the sieves arranged in ascending order. This method presents the advantage ofusing a small space from the sieving machine, a slight supervision and a good accessibilityto perform proper maintenance operations. The vibration motion used in the separationoperation can be an advantage only for some raw materials, while for the others it can be adisadvantage because of the congestion particle phenomenon on the plate surface.316