A method and an apparatus for producing a porous glass preform by using organosiloxane raw material is provided. The apparatus for producing the porous glass preform 12 according to the present embodiment is configured to mix organosiloxane in a liquid state being a raw material with a carrier gas in a vaporizer 6, heat this mixture to be vaporized, supply this vapor to a burner 13 as a gas raw material, and produce a porous glass preform by depositing a glass fine particle produced by combusting the gas raw material on a starting material, herein the apparatus for producing a porous glass preform includes a moisture removing apparatus 8 configured to remove moisture in the carrier gas and supply the vaporizer with the carrier gas.

Vaporizers and systems for vaporizing liquid precursor for forming glass optical fiber preforms are provided. The vaporizer includes an expansion chamber at least partially enclosed by a side wall, the expansion chamber comprising an upper end and a lower end with the side wall disposed between the upper end and the lower end. The vaporizer further includes a closed-loop liquid delivery conduit positioned in the expansion chamber proximate to the upper end of the expansion chamber, wherein the closed-loop liquid delivery conduit comprises a plurality of nozzles oriented to direct a spray of liquid precursor onto an inner surface of the side wall. Further, the vaporizer includes at least one supply conduit positioned proximate the upper end of the expansion chamber and coupled to the closed-loop liquid delivery conduit, and a vapor delivery outlet coupled to the expansion chamber and configured to direct vaporized liquid precursor from the expansion chamber.

A method for the production of synthetic quartz glass using a special cleaning device is provided. The method includes (a) evaporating a production material containing a polymerizable polyalkylsiloxane compound while forming a production material vapor, (b) passing the production material vapor resulting from step (a) through a cleaning device to purify the production material vapor, (c) supplying the purified production material vapor resulting from step (b) to a reaction zone in which the purified production material vapor is converted to SiO.sub.2 particles through oxidation and/or through hydrolysis, (d) depositing the SiO.sub.2 particles resulting from step (c) on a deposition surface, and optionally drying and vitrifying the deposited SiO.sub.2 particles resulting from step (d) to form synthetic quartz glass. The cleaning device includes a bulk of porous silica particles which have a BET specific surface area of at least 2 m.sup.2/g. A device for carrying out the method is also provided.

A method and an apparatus for producing a porous glass preform by using organosiloxane raw material is provided. The apparatus for producing the porous glass preform 12 according to the present embodiment is configured to mix organosiloxane in a liquid state being a raw material with a carrier gas in a vaporizer 6, heat this mixture to be vaporized, supply this vapor to a burner 13 as a gas raw material, and produce a porous glass preform by depositing a glass fine particle produced by combusting the gas raw material on a starting material, herein the apparatus for producing a porous glass preform includes a moisture removing apparatus 8 configured to remove moisture in the carrier gas and supply the vaporizer with the carrier gas.

The porous glass base material manufacturing apparatus releases gas of organic siloxane raw materials into the flame of a group of burners that moves relative to a starting base material along the longitudinal direction of the starting base material rotating around a rotation axis along the longitudinal direction to form soot of porous glass particles on the surface of the starting base material. The porous glass base material manufacturing apparatus is equipped with a vaporizer that vaporizes liquid raw materials containing organic siloxane in a liquid state supplied from a raw material tank to make a raw material mixed gas mixed with raw material gas and carrier gas and a raw material gas pipe that supplies the raw material mixed gas to the burner. The raw material gas pipe is insulated and kept warm by double insulation.

A process for producing a fluorinated quartz glass is described, including providing an SiO.sub.2 soot body; reacting the SiO.sub.2 soot body with a fluorinating agent having a boiling point of greater than or equal to −10° C. to obtain a fluorinated SiO.sub.2 soot body; and vitrifying the fluorinated SiO.sub.2 soot body.

A process for the production of a fluorinated quartz glass including the steps of generating SiO.sub.2 particles in a synthesis burner; depositing the resulting SiO.sub.2 particles into a body; and vitrifying the resulting body, wherein a fluorinating agent having a boiling point greater than or equal to −10° C. is supplied to the synthesis burner.

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 a single body, in which the vaporizer and the burner are synchronized, parallel to the starting member in a longitudinal direction thereof.

A method and an apparatus for producing a porous glass preform by using organosiloxane raw material is provided. The apparatus for producing the porous glass preform 12 according to the present embodiment is configured to mix organosiloxane in a liquid state being a raw material with a carrier gas in a vaporizer 6, heat this mixture to be vaporized, supply this vapor to a burner 13 as a gas raw material, and produce a porous glass preform by depositing a glass fine particle produced by combusting the gas raw material on a starting material, herein the apparatus for producing a porous glass preform includes a moisture removing apparatus 8 configured to remove moisture in the carrier gas and supply the vaporizer with the carrier gas.

This raw material supply device supplies a raw material for producing glass fine particle deposits, to a burner and includes a raw material tank; a liquid raw material pipe having one end thereof connected to the raw material tank; a liquid raw material pressure feed pump that pumps siloxane, being a liquid raw material, from the raw material tank via the liquid raw material pipe; a pressure adjustment valve provided on a secondary side of the liquid raw material pressure feed pump in the liquid raw material pipe; an MFC for liquid, connected to the other end of the liquid raw material pipe; and an aeration device that is connected to the secondary side of the MFC for liquid and aerates the liquid raw material. The pipe on the secondary side of the pressure adjustment valve is connected to a location having lower pressure than the primary side pressure.