World population has gradually increased and, as the result
of this increase, cultivation areas of grain group which is one of the basic
requirements of human have been expanded. As parallel with this expansion the
grain group should be stored for short and long term. Since the grain group is
not in pure situation within the place stored after harvesting, it should be
cleaned from foreing matters i.e. from grass, stones and sands. While screening
process made manually in sieves continued day after day in the past, the
systems which sieve tons of grain per hour have been developed thanks to
state-of- the-art technology nowadays. The name of this unit is pre-cleaning
unit. Precleaning consists of 5 main components as of its general strcture:
Drum case, drum, upper chamber. It has high resistance against corrosion. 10,9
quality class bolts have been used as fastening element. Bolts ant nuts are
dacromate plated and have high yield strength. St 37 quality black sheet has
been used for cyclone and its parts have been joined by means of welding.
In order to increase resistance against corrosion, 2 coats of primer have been
applied and 1 coat of paint has been applied over primer.
Product which enters hopper placed in upper chamber (aspiratör) through the elavator which is the silo equipment is transported to rotary durm within the main case While product is ﬂowing into drum, dusts and substances lighter than air within product is drawn by radial fan mounted back of upper chamber and transmitted to cyclone mounted near the radial fan, It is ensurded that the product ﬂows as horizontal by gving suitable inclination angle to rotary drum so that product sieving process will be carried out in rotary drum and the product is passed out in rotary drum and the product is passed through screens winded around rotary drum. Intermediate chambers within main case avoid materials which are separated after being passed through screens from mixing with the others and allow the materials to transfer into conveyor through bottom pouring compartments.