84
Z. Xiao et al.
2.6.3.2 Parameters of Pressing Process for Oilseeds
Figure 2.9 illustrates the influence of the volume of oilseeds on different pressing
pressure. As shown in Fig. 2.9, pressure of oil squeezed out (P 1 ) and pressure of
fruits crushed (P 2 ) are changing slowly with the increase of oilseeds. It means the
amount of oilseeds has a low influence on the two kinds of pressures. P 2 is about
16 MPa higher than P 1 . The average values of the pressure from 30 to 50 mm are
55.7 MPa for P 1 and 71.5 MPa for P 2 .
Figure 2.9 illustrates the influence of pressing time on compression ratio in different volumes of oilseeds. The curves showed obvious changes in compression ratio
with the increase of pressing time. The final compression ratios are too close which
is about 3.1. With the increasing volume of oilseeds, pressing time for achieving
a final uncompressed stage increases gradually. All in all, it is easy for oilseeds to
achieve a relative uncompressed stage when pressed within 30 s. Through Matlab
fitting, equation of relation between pressing time and volume of oilseeds ranging
from 9.424 to 15.707 cm
3 could be got as follows
t = 2.7370 V 1 − 0.0328 V 2 − 0.001 V 3 + 0.0011
(2.8)
The actual compression ratio, closely related to the pressing pressure and pressing
time, can directly reflect the actual stage of both the oilseeds and the meal when
pressed. Figure 2.10 illustrates the influence of pressing pressure on compression
ratio in different volumes of oilseeds. As shown in Fig. 2.10, curves are similar.
The actual compression ratio increases with the increase of pressing pressure. But
when the pressing pressure increases to a certain value, the increase of compression
ratio is smaller, and when it reaches 80 MPa, the slope of the curve is 0.0056 which
means the pressing pressure has so little influence on compression ratio that can be
neglected, and the oilseeds entered a non-compressible phase. Taking 80 MPa as
Fig. 2.9 Influence of
volume of oilseeds on
different pressing pressure
0
10
20
30
40
50
60
70
80
30
35
40
45
50
H/mm
P/MPa
pressure of oil squeezed out
pressure of fruits crushed
Z. Xiao et al.
2.6.3.2 Parameters of Pressing Process for Oilseeds
Figure 2.9 illustrates the influence of the volume of oilseeds on different pressing
pressure. As shown in Fig. 2.9, pressure of oil squeezed out (P 1 ) and pressure of
fruits crushed (P 2 ) are changing slowly with the increase of oilseeds. It means the
amount of oilseeds has a low influence on the two kinds of pressures. P 2 is about
16 MPa higher than P 1 . The average values of the pressure from 30 to 50 mm are
55.7 MPa for P 1 and 71.5 MPa for P 2 .
Figure 2.9 illustrates the influence of pressing time on compression ratio in different volumes of oilseeds. The curves showed obvious changes in compression ratio
with the increase of pressing time. The final compression ratios are too close which
is about 3.1. With the increasing volume of oilseeds, pressing time for achieving
a final uncompressed stage increases gradually. All in all, it is easy for oilseeds to
achieve a relative uncompressed stage when pressed within 30 s. Through Matlab
fitting, equation of relation between pressing time and volume of oilseeds ranging
from 9.424 to 15.707 cm
3 could be got as follows
t = 2.7370 V 1 − 0.0328 V 2 − 0.001 V 3 + 0.0011
(2.8)
The actual compression ratio, closely related to the pressing pressure and pressing
time, can directly reflect the actual stage of both the oilseeds and the meal when
pressed. Figure 2.10 illustrates the influence of pressing pressure on compression
ratio in different volumes of oilseeds. As shown in Fig. 2.10, curves are similar.
The actual compression ratio increases with the increase of pressing pressure. But
when the pressing pressure increases to a certain value, the increase of compression
ratio is smaller, and when it reaches 80 MPa, the slope of the curve is 0.0056 which
means the pressing pressure has so little influence on compression ratio that can be
neglected, and the oilseeds entered a non-compressible phase. Taking 80 MPa as
Fig. 2.9 Influence of
volume of oilseeds on
different pressing pressure
0
10
20
30
40
50
60
70
80
30
35
40
45
50
H/mm
P/MPa
pressure of oil squeezed out
pressure of fruits crushed