| 摘要 |
<p>The present invention relates to a method for producing a porous quartz glass body (400), including feeding a silicon raw material to a central nozzle (1) of a multitubular burner (100) having a plurality of gas feeding nozzles arranged concentrically pattern, hydrolyzing the silicon raw material in a flame (200) projected from the multitubular burner (100) to form silica fine particles in a reactor, and depositing and growing the formed silica fine particles on a rotating target (300), in which the multitubular burner (100) includes a combustible gas feeding nozzle and a combustion supporting gas feeding nozzle, in which an angle between a central axis of the multitubular burner or a line obtained by projecting the central axis of the multitubular burner onto a plane that includes a rotation axis of the target and is parallel to the central axis of the multitubular burner, and the rotation axis of the target is less than 10°, in which a distance between an end face of the central nozzle of the multitubular burner and an intersection point of a central axis of the multitubular burner with a surface of the target or a surface of the porous quartz glass body deposited on the target is from 3d to 6d mm, in which d is a diameter of an outermost periphery of the multitubular burner, and in which an amount of a gas fed to the central nozzle is 0.30S c liter/min or less under the standard state (0°C and 1 atm), in which S c is an opening area of the central nozzle (1) of the multitubular burner.</p> |
