Glass body manufacturing apparatus, glass body manufacturing method, soot conveying mechanism, and soot heating mechanism

A glass body manufacturing method comprising:

• in a first heating furnace, accommodating a soot having a porous portion in a furnace core tube made of glass, supplying a dehydration gas into the furnace core tube, and heating the soot at a first treatment temperature, which is lower than a softening point of the porous portion;
• connecting a conveyance container and the first heating furnace together while keeping airtightness with respect to an outside atmosphere, accommodating and holding the soot in the conveyance container, and conveying the soot to the second heating furnace;
• and
• connecting the conveyance container and the second heating furnace together while keeping airtightness with respect to the outside atmosphere, accommodating the soot in a structural body of the second heating furnace, disconnecting the conveyance container from the second heating furnace while keeping airtightness with respect to the outside atmosphere, and heating the soot at a second treatment temperature, which is equal to or higher than the softening point.

A soot conveying mechanism to convey a soot between a first heating furnace and a second heating furnace, the soot conveying mechanism comprising:

• a conveyance container accommodating the soot;
• and
• a moving mechanism moving the conveyance container to a position above the first heating furnace and to a position above the second heating furnace,
• wherein the conveyance container includes:
• an operating mechanism capable of lifting and lowering the soot
• an airtight mechanism capable of making an inside of the conveyance container airtight, and
• a connection unit configured to be connectable to the first heating furnace or the second heating furnace,
• the conveyance container is configured to move the operating mechanism into the first heating furnace with the soot when the soot is heated by the first heating furnace, and
• the conveyance container is configured to move the operating mechanism into the second heating furnace with the soot when the soot is heated by the second heating furnace.

A soot heating mechanism to convert a soot having a porous portion into a fiber preform, the soot heating mechanism comprising:

• a first heating furnace including a furnace core tube accommodating the soot, a first heater, a first gas supply unit supplying a dehydration gas into the furnace core tube, and a first gas discharge unit discharging the dehydration gas, the first heating furnace heating the soot at a first treatment temperature, which is lower than a softening point of the porous portion, by the first heater under an atmosphere of the dehydration gas;
• and
• a second heating furnace including a structural body configured to accommodate the soot, a second heater, a second gas supply unit supplying an inert gas into the structural body, and a second gas discharge unit discharging the inert gas, the second heating furnace heating the soot at a second treatment temperature, which is equal to or higher than the softening point, by the second heater under an atmosphere of the inert gas, wherein
• each of the first heating furnace and the second heating furnace comprises a shut-off mechanism which keeps airtightness of the respective heating furnace with respect to an outside atmosphere.