PURPOSE: To obtain a soot body of pulverized glass particles having a uniform bulk density by blowing a flame toward a starting raw material at the blowing rate of a gaseous raw material and combustion gas varied so as to make the temp. higher as the position of the deposited soot body of the pulverized glass particles is nearer the periphery of the soot body.
CONSTITUTION: While a soot body 1 under rotation is pulled upward, a gaseous raw glass material, combustion gas, etc. are ejected from a burner 2 and are mixed and burned. The burning flame is blown to the body 1 and the soot of the pulverized glass particles formed within said flame deposits on the body 1. Since the blow-out port (b) of the combustion gas of the burner 2 is wider as it is nearer the outside, the temp. of the flame is higher as it is nearer the outside. Although the body 1 heated by the flame radiate heat more easily as it is nearer the outside circumferential part, the entire part is heated roughly to an equal temp.; therefore, the soot body 1 is successively grown and synthesized without having a nonuniform bulk density.
YOSHIOKA NAOKI
YOKOTA HIROSHI
