| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Research Abstract |
Many works have been done about the bubble formation at an orifice under atmospheric pressure, while a few works have been done under high system pressure.
In this work, the volumes of bubbles formed at an orifice in high pressure bubble column or suspended bubble column were measured experimentally and the effects of various factors on bubble formation, such as the system pressure, gas flow rate, orifice diameter, gas chamber volume and particle holdup were investigated. By the theoretical consideration, the non-spherical bubble formation model was proposed and the calculated results were compared with the experimental ones. The following results were obtained :
1. The bubble volumes, increase with increases in gas flow rate and orifice diameter, and with decreases in system pressure and particle holdup. The calculated results by the non-spherical bubble formation model show the similar tendency with the experimental results.
2. In high gas flow rate or high pressure regions, the effect of gas chamber volume on the bubble volume is negligible. This result is also supported by the bubble formation model calculation.
For the design of bubble formation apparatus in high pressure bubble column or suspended bubble column, it is recommended the bubble formation condition to take close to the constant flow condition, which is written by the dimensionless capacitance number N_C(=4V_C rho _Lg/ pi D_O ^2P_s) < 1, owing to increase effective interfacial area.
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