Raw material supply device for production of glass fine particle deposits and raw material supply method

A raw material supply device that supplies a raw material for manufacturing a glass particle deposited body to a burner, the device comprising:

• a liquid raw material tank;
• a liquid raw material pipe with one end connected to the liquid raw material tank;
• a liquid raw material pressure feed pump that pressure-feeds a liquid raw material from the liquid raw material tank to a liquid mass flow controller (MFC) via the liquid raw material pipe;
• a pressure adjustment valve that is provided on a secondary side of the liquid raw material pressure feed pump in the liquid raw material pipe;
• the liquid MFC that is provided on the secondary side of the liquid raw material pressure feed pump, and connected to another end of the liquid raw material pipe;
• and
• a vaporizer that is connected to a secondary side of the liquid MFC, and vaporizes the liquid raw material,
• wherein the liquid raw material is siloxane,
• a pipe on a secondary side of the pressure adjustment valve is connected to a location with a pressure lower than a pressure on a primary side thereof, and
• an opening degree of the pressure adjustment valve is configured to be adjusted according to a change in pressure on the primary side of the pressure adjustment valve.