Abstract: The turbulent in the liquid gallium under the travelling magnetic field was observed, and the reason for its formation was discussed. It was found that the distribution of the magnetic flux density in the travelling magnetic field will dominate the formation of the turbulent. The factor named inhomogeneity of the magnetic field was adopted to assess the distribution of the magnetic field. It is very helpful for designing the purifying equipment and for the sake of the ways of increasing the inclusionremoval efficiency by adopting this factor. The simulative experiments were carried out to study the particles' migrating behavior in different pipes under different Hom , the reason why the shape of the pipe affected the migration of the particles was discussed too.
Formation and control of turbulent in metal melts purified by alternating magnetic field
Abstract:
The turbulent in the liquid gallium under the travelling magnetic field was observed, and the reason for its formation was discussed. It was found that the distribution of the magnetic flux density in the travelling magnetic field will dominate the formation of the turbulent. The factor named inhomogeneity of the magnetic field was adopted to assess the distribution of the magnetic field. It is very helpful for designing the purifying equipment and for the sake of the ways of increasing the inclusion removal efficiency by adopting this factor. The simulative experiments were carried out to study the particles' migrating behavior in different pipes under different H om , the reason why the shape of the pipe affected the migration of the particles was discussed too.
Fig.2 Free surface macrostructures of liquid gallium at different positions in magnetic field (End of arrow is free surface of liquid gallium)
(a) —X=20 mm, Z=10 mm; (b) —X=20 mm, Z=15 mm; (c) —X=20 mm, Z=20 mm; (d) —X=60 mm, Z=10 mm; (e) —X=60 mm, Z=15 mm; (f) —X=60 mm, Z=20 mm; (g) —X=40 mm, Z=10 mm; (h) —X=40 mm, Z=15 mm; (i) —X=40 mm, Z=20 mm
图3 行波磁场空间中不同位置处磁场分布
Fig.3 Distribution of magnetic flux density (MFD) in travelling magnetic field
Table 1 Average MFD and Hom in different space in magnetic fields
Position
Z/mm
Average MFD/mT
Hom (B) /%
Turbulent
10
106.359 0
4.351 8
Weak
Over core
15
103.076 9
1.641 8
Weak
20
95.102 6
0.349 8
Weak
10
57.274 5
12.793 3
Strong
Over slot
15
65.102 6
9.190 0
Weak
20
65.884 6
3.068 5
Weak
10
92.735 3
17.587 4
Strong
Over neighboring
15
89.544 1
10.841 2
Weak
20
81.900 0
10.154 7
Weak
图4 颗粒分布与磁场分布不均度的关系
Fig.4 Distribution of particles under different Hom
(a) —Without EMF, section in y=40 mm; (b) —Without EMF, section in y=120 mm; (c) —Without EMF, section in y=40 mm, Hom=4.35%; (d) —Without EMF, section in y=120 mm, Hom=4.35%; (e) —Without EMF, section in y=40 mm, Hom=12.79%; (f) —Without EMF, section in y=120 mm, Hom=12.79%