PRODUCTION DEVICE FOR PREFORM OF OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To prevent changing of a flame shape and flame flickering of a multiple pipe burner. SOLUTION: In this device for producing a preform of optical fiber, a first hood 23a is formed in a cylindrical form having an inner diameter slightly larger than the outer diameter of a multiple pipe burner 1 and attached to cover the top opening of the multiple burner. The internal peripheral surface 23f of the cylindrical wall 23d of a second hood 23b is separated from the top opening periphery 23e and the cylindrical and closed-end second hood is fixed to be inserted outside to form a circular space P between the outer peripheral surface 23g of the first hood and the inner peripheral surface in the side from the top opening periphery to the base wall 23c. Changing of a flame is prevented by covering the flame with the first and second hoods to prevent from flickering of the flame and by the circular space to prevent from spreading of the flame of the multiple pipe burner.