| 摘要 |
PURPOSE:In preparation of ultrafine particles of oxide using dust explosion, to make dust explosion take place stably, and to aim improvement in heat efficiency and mass production, by contriving a heat source. CONSTITUTION:In preparing ultrafine particles of oxide such as ultrafine particles of SiO2, the hopper 6 is equipped with Si powder as a raw material, the valve 15 is opened, a mixed gas of Ar and O2 is introduced into the closed container 1, and atmosphere is replaced with the gas. Then, the valves 12 and 13 are opened, O2 and H2 are fed to the burner 2, it is ignited by the igniter 4, and the chemical flame 18 is formed in an O2-containing atmosphere. Then, the lower part of the hopper 6 is opened, the valve 9 is opened and the Si powder is fed to the burner 2 by H2 that is pressurized by gas pressure at about 1kg/cm<2> while the ball valve 7 is opened and closed at about 0.5sec interval by the control device 8. The Si powder is blown up from the mouth of the burner 2 to form a dust cloud. The cloud is ignited with the flame 18, a large amount of ultrafine particles of SiO2 are obtained by deflagration, and the cloud 19 is collected by the electric dust collector 17. |
