First International Conference on MOLDAVIAN RISKS – FROM ...

<strong>First</strong> <strong>International</strong> <strong>Conference</strong> on MOLDAVIAN RISKS - FROM GLOBAL TO LOCAL SCALE
16-19 May 2012, Bacau, Romania
STUDIES REGARDING THE BEHAVIOR OF SOLID
PARTICLES ON A FLAT OSCILATING SURFACE
Ovidiu Bontas 1 , Valentin Nedeff 2 , Emilian Florin Mosnegutu 2 ,
Mirela Panainte 2 , Oana (Irimia) Tirtoaca 2
1 “George Bacovia” University of Bacau
2 “Vasile Alecsandri” University of Bacau
Corresponding author: Bontas Ovidiu, ovidiu.bontas@ugb.ro
Abstract: In many industrial applications much of the solid particles are separated by size
and for this purpose are used oscillating sieves. The separation on site is a complex process
that depends on several factors, such as:
- the properties of solids particle which will be separate;
- operating regimes of separation equipment.
To streamline the process of separation there has been studied the behavior of solid
particles on the grain surface, by drawing up a series of mathematical models aimed at
identifying the solid particle trajectory. This paper presents a study realized at the "Vasile
Alecsandri" University in Bacau, which aimed to determine the ideal particle travel path
and for the different types of real particles. To highlight just the oscillating behavior of
solid surfaces in the experimental measurements there has been used a blind screen. The
experimental determinations were performed on a laboratory bench with flat oscilating
sieves. The movement of the solid particle on the working surface has been monitored by
two cameras positioned in perpendicular planes, the system aimed at obtaining the spatial
trajectory of the particle on the stage. Films obtained from experimental measurements
were processed using the software SynthEyes, obtaining files *.txt which contain the data
to visualize the trajectory of a particle studied on one working plan. By combining the two
paths obtained one can view the three-dimensional trajectory of the solid particle. The
present study aimed to determine the trajectory for different types of particles, namely:
ideal spherical particle, particle with cube form, various other forms of real particles: soy,
pod and grain. Within the experimental measurements, we also studied the solid particle
behavior for different operating conditions, namely:
- different angles of work surfaces;
- different operating modes of the block sieves.
After processing the data obtained from experimental measurements one could calculate
the velocity of solid particle on a flat oscillating surface.
Key words: solid particle, friction coefficient, block sieves.
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