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6.
Technical Description
This chapter provides information on the configuration and way in which your metal
separator operates.
The Mesep Extractor 38..70 Metal Separator consists of three main functional units:
o
Ring detector / Chapter 6.1.
o
Evaluation electronics / Chapter 6.1.
o
Cyclone and separating unit / Chapter 6.2
6.1. Ring detector and evaluation electronics
The toroid’s metal detector operates using an analog evaluation principal, which is briefly
explained below.
A high frequency electromagnetic alternating field is produced in a ring sensor by means
of an oscillator. If a metal piece or electrically conductible materials fall through the ring
sensor, eddy currents are produced inside it. These remove the energy from the
electromagnetic field. This energy loss causes dampening of the oscillator, which in turn
reduces the signal amplitude. The size of the dampening is a measure for the size of the
metal piece and has a direct relationship with the magnetic and electric properties of the
metal particle:
Large metal particles draw more energy from the field than small metal particles.
Magnetic metals (e.g. steel) draw more energy from the field than non-magnetic metals
(e.g. aluminium).
This measuring principle is suitable for all types of metal and makes it possible to detect
metal participles within product or in non-metallic packaging.
The examined products are not affected or changed in any way by this kind of measuring.
The threshold value, the size from which metal is detected, is set using a potentiometer.
Once this value is exceeded, the device trips an electrical impulse. A flap is addressed
with this impulse in metal separators by means of the evaluation electronics and the metal
particle is then discharged into the flow of rejects.
6.2. Cyclone and separating unit
The conveyor system sucks the material through the metal separator. There, it passes the
metal sensor first, and then flows through a cyclone and subsequently leaves the device
via a separating filter.
If metal is detected, this separating filter opens, in order to discard the metal foreign
matter. A slight quantity of the good material is also discharged in the process.
Compressed air is blown into the cyclone through the ring at the same time; this removes