Fig. 15 Droplet trajectories
3.7 Experimental study
The experimental study has also been carried out with the theoretical study. The experimental apparatus is shown in Fig.16. Here, the experimental conditions are explained in the outline.
The experimental number of times is equal to or more than 1080 times, the kind of the test section is four of L=154, 308, 462 and 616mm, the impressed voltage of 0〜9kV, the velocity of air-flow of 2.5〜4.5m/s. The separation efficiency is shown in Fig, 17. The correlation between the data by the experiment and by the theory could be satisfactory approximately but the higher data of the precision have to be gathered.
Fig. 16 Experimental apparatus
Fig. 17 Separation efficiency of cylindrical separator
4. WIRE-MESH DEMISTER
Effects of the number of layers on the separation performance of wire-mesh demisters have been studied in a horizontal flow of air entrained water droplets. Two kinds of the demisters used are constructed by galvanized iron wires φ 300 μ m and φ 850 μ m in diameter respectively, which are held perpendicular to the air-flow direction.
Experiments have been made varing 1 to 4 layers for each, demister and varing 1.0 to 6.0 m/s in mean air velocity, respectively. And the water droplets have been obtained in various sizes 5 to 150 μm. The separation efficiency is shown in Fig. 18.
Fig. 18 Separation efficiency of wire-mesh demister
4. CONCLUSIONS
In these studies theoretically the separation performance of air-water separators with zigzag plates and by Coulomb force has been calculated using a theoretical as well as an experimental approach. A theoretical equation has been derived which predicts the separation efficiency based on the droplet trajectories obtained at each bent part of the eliminator and obtained by Coulomb force of the separator.
The separation efficiencies of these two separators are sufficiently in good agreement with those predicted by theoretical analysis. But for wire-mesh demister, the separation efficiencies are larger than those predicted by theoretical analysis which has been presented by published theories.
These three separators have some good characteristics respectively, therefore we must use them under the most suitable conditions and must make an effort to improve the performance.
5. REFERENCES
[1] S. Isigai, S. NakanisiH. Sugita, H. Nagasawa, MESJ., Vol. 12, No. 6 (1977), p11.
[2] S. Isigai, S. NakanisiH. Sugita, MESJ., Vol. 15, No. 3, (1980), p12.
[3] H. Sugita, T. Nakazawa, H. Arioka, MESJ., Vol. 31, No. 11 (1998), p781.
[4] T. Xu, Master's thesis (1999), Kobe Univ. M. M.
[5] H. Sugita, S. Ishigai, S. Nakanishi, MESJ., Vol. 17, No. 7 (1982), p61.
