A manufacturing method of a porous glass preform for optical fiber by depositing glass microparticles on a starting member, including supplying a vaporizer with organic silicon compound raw material in a liquid state and a carrier gas; in the vaporizer, mixing and vaporizing the organic silicon compound raw material in a liquid state and the carrier gas to convert the organic silicon compound raw material and the carrier gas into a raw material mixed gas; supplying a burner with the raw material mixed gas and a combustible gas, combusting the raw material mixed gas and the combustible gas in the burner, and ejecting SiO.sub.2 microparticles generated by the combustion from the burner; and depositing the SiO.sub.2 microparticles ejected from the burner on the starting member by repeatedly moving the vaporizer and the burner together, in a synchronized manner, parallel to the starting member in a longitudinal direction thereof.

An optical fiber preform manufacturing apparatus comprising a seal member, wherein the seal member is attached to a flange portion formed in an open portion of a reaction chamber into which a burner is inserted, the seal member includes a first sheet that is flexible and includes an open portion that is smaller than an outer diameter of the burner, through which the burner is inserted; a second sheet having the same thickness as the first sheet and including an open portion that is larger than an outer diameter of the first sheet; and two third sheets that each include an open portion that is larger than the outer diameter of the burner and smaller than the outer diameter of the first sheet, the second sheet is arranged in the same plane as the first sheet, and the first and second sheets are sandwiched by the two third sheets.

A method for producing a porous glass fine particle body includes: a first layer formation step of continuously forming in a longitudinal direction of a rotating starting base material without a break, a first soot layer on a surface of the rotating starting base material; and an second layer formation step of forming second soot layers on an outside of the first soot layer while supplying a raw material gas to each of a burner among burners of a burner group and moving the burner group in a reciprocating manner in the longitudinal direction relative to the rotating starting base material. The burner group and the starting base material move relatively to each other along the longitudinal direction.

A method of forming an optical fiber preform includes the steps: igniting a burner having a fume tube assembly to produce a first spray size of silicon dioxide particles; depositing the silicon dioxide particles on a core cane to produce a soot blank; and adjusting an effective diameter of an aperture of the fume tube assembly to produce a second spray size of the silicon dioxide particles. The second spray size is larger than the first spray size.

Provided is a glass particulate deposit manufacturing method for manufacturing a glass particulate deposit comprising mounting a fixing jig on an outer periphery of an outermost pipe of a burner; inserting a burner cover from a tip end of the outermost pipe of the burner; and sandwiching and compressing a part of the fixing jig between the burner cover and the outermost pipe of the burner to fix the burner cover to the burner, wherein an outer diameter of a part of the fixing jig that is not compressed is greater than an inner diameter of a part of the burner cover inserted to the tip end of the outermost pipe of the burner.

A method of forming an optical fiber preform includes the steps: igniting a burner having a fume tube assembly to produce a first spray size of silicon dioxide particles; depositing the silicon dioxide particles on a core cane to produce a soot blank; and adjusting an effective diameter of an aperture of the fume tube assembly to produce a second spray size of the silicon dioxide particles. The second spray size is larger than the first spray size.

An apparatus for manufacturing a porous glass soot body to be formed into an optical fiber preform includes: a reaction chamber; a burner to form the porous glass soot body by depositing glass particles onto a seed rod hung inside the reaction chamber; and a heat-blocking element filling a gap between the burner and an opening for inserting the burner into the reaction chamber. A purpose is to prevent damage to the burner in the apparatus for manufacturing a porous glass soot body. In the manufacturing apparatus, the heat-blocking element may include a fibriform material. Also, in the manufacturing apparatus, the heat-blocking element may include a quartz wool material. Further, in the manufacturing apparatus, the content of iron in the quartz wool material may be 1 ppm or less.

A burner head actuator for lubricating glassware molds of a glassware forming machine includes a base mount and a guide post carried by the mount. A gearbox housing carried on the guide post carries a gear train including drive and driven gears. A servomotor is coupled to the gearbox. A burner head arm is carried by the gearbox housing and coupled to the driven gear for rotation relative to the gearbox housing about an arm axis. The arm includes a burner head leveling gear train including a drive sprocket direct-driven by the driven gear about the arm axis and a driven sprocket driven by the drive sprocket via a chain. The servomotor rotates the gearbox drive gear, thereby rotating the gearbox driven gear and burner head arm, and thereby rotating the leveling gear train so that the burner head remains level as the arm is rotated about the arm axis.

Provided is a glass particulate deposit manufacturing method for manufacturing a glass particulate deposit comprising mounting a fixing jig on an outer periphery of an outermost pipe of a burner; inserting a burner cover from a tip end of the outermost pipe of the burner; and sandwiching and compressing a part of the fixing jig between the burner cover and the outermost pipe of the burner to fix the burner cover to the burner, wherein an outer diameter of a part of the fixing jig that is not compressed is greater than an inner diameter of a part of the burner cover inserted to the tip end of the outermost pipe of the burner.

A burner for synthesization to synthesize glass particles that form a porous glass base material is provided, the burner for synthesization including a raw material gas injection portion to inject raw material gas toward a target, a combustion assisting gas injection portion to inject combustion assisting gas in a direction in which the combustion assisting gas is merged with the raw material gas at a first merging point, and a combustible gas injection portion to inject combustible gas in a direction in which the combustible gas is merged with the combustion assisting gas at a second merging point that is positioned closer to the combustion assisting gas injection portion than the first merging point. In the above-described burner for synthesization, the combustion assisting gas injection portion may also include a plurality of injection ports arranged along one straight line.