Kraftverteilung im Arbeitsspalt von Hochdruck ... - Bauverlag

In this way, statistically significant values and functional relationships
to other variables · · can be determined and that under operating
conditions.
Bild 6: Funktion µ-F(Fspcf) für Klinker, Kurve 1 für die Vormahlung,
Kurve 2 für die Teilfertigmahlung
Fig. 6: Function µ = F(Fspcf) for clinker, Curve 1 for pre-grinding,
Curve 2 for semi-finish grinding
Die Funktion der Kraft in Abhängigkeit vom Drehwinkel beim
Passieren des Mahlgutes durch den Walzenspalt wurde mehrfach
bestimmt und führte zu übereinstimmenden Ergebnissen [5, 6, 11].
Die größte Kraft wird bei einem Winkel zwischen 1 und 2°
gemessen. Die Funktion lässt sich mathematisch wie folgt beschreiben:
F A B −C
= ⋅e
(10)
Das Problem läuft auf die Bestimmung der Konstanten A, B
und C hinaus. Von dieser Funktion ist bekannt, dass sich der
Extremwert (Maximum) bei
max
=- B C
(11)
5. µ Factor Relationships
According to Eq. (7), the µ factor is the sine of the draw-in angle.
How can this · angle be explained?
If a high-pressure roller press is fed with clinker falling from a
kiln, µ results at around 0.08 and thus gives a draw-in angle of 4.6°.
At a roll diameter of 1 m
a working gap of
23 mm
and at a draw-in angle of 4.6 °
a particle of 23+1000*(1-cos 4,6) = 26.22 mm is drawn in
between the rolls.
Evidently, however, even larger pieces with particle sizes > 100
mm can be easily drawn in by rolls with a diameter of 1 m. In this
case, the µ factor must stand at 0.4. If the different µ factors
obtained at different press forces are plotted as a function of the
press force in a double logarithmic · grid, · a straight line results.
Fig. 5 shows the dependence of the µ factor on the specific press
force (µ = F(Fspcf)) for three different cases. Fig. 6 shows the relationships
for the grinding of clinker as an example:
The following applies for the torque:
T F A und damit · T · A F F F
=
specf specf
=
specf specf
= ( specf )
The function of the force dependent on the angle of rotation as
the product passes through the gap between the rolls has been
determined several times and concurring results have been
obtained [5,6,11].
The greatest force is measured at an angle between 1 and 2°. The
function can be described mathematically as follows:
F = A
B ⋅e
* * sin * * ( )
−C
(10)
MRS Greifer
AUFBEREITUNGS TECHNIK 44 (2003) Nr. 8 27