JPH0260612B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for supplying a predetermined amount of glass raw material to a melting crucible set in a room with a clean atmosphere without contamination.

In order to melt multi-component glass, which is the raw material for optical fibers, etc., conventionally, the multi-component glass raw materials are mixed, placed in a polyethylene bag, and the bag is placed in a clean atmosphere isolated from the outside called a melting booth. It is kept indoors, and when melting, a worker enters the melting booth, uses a quartz spoon to take out a predetermined amount of raw material from the bag, and supplies it to the melting crucible, which is also installed inside the melting booth. There is.

With such conventional means, contaminated outside air enters the melting booth each time a worker enters or exits the melting booth. In particular, if transition metals are mixed into the raw material, this will cause a significant attenuation of the optical power transmitted through the optical fiber over a distance, and if water is mixed into the raw material, it will be a cause of attenuation in the long wavelength range.

The present invention has been developed in view of the conventional circumstances, and its purpose is to melt the melting crucible installed in a room with a dry and clean atmosphere without the need for workers to enter the room. An object of the present invention is to provide a method and apparatus for automatically supplying glass raw materials from raw materials without contaminating them.

In order to achieve this object, the supply method according to the first invention involves inserting a glass raw material supply pipe from the outside into a clean chamber in which a melting crucible is installed, and using this supply pipe when supplying glass raw materials to the melting crucible. The gist is that the supply device moves forward and then moves backward after supplying, and the supply device according to the second invention is installed outside a clean chamber in which the melting crucible is installed, and intermittently moves back and forth. The gist is that a glass raw material supply pipe is attached via a vibrator to a frame for carrying out the process, the tip of this supply pipe faces into the chamber, and a raw material hopper is attached to the rear end of the supply pipe. .

Embodiments of the present invention will be described below with reference to the accompanying drawings.

A chamber 3 is formed on the floor 1 and is isolated from the outside by a partition wall 2, and is kept in a clean atmosphere with a low dew point by filling the chamber 3 with nitrogen gas or the like. Further, in the chamber 3, a high frequency melting crucible 5 is installed on a support stand 4.

On the other hand, a glass raw material supply device 6 is provided outside the chamber 3. This supply device 6 has an upper pedestal 10 movably mounted on a lower pedestal 7 fixed on the floor 1 via Teflon sliding plates 8 and 9, and a small electric motor 11 with a speed reducer mounted on the upper surface of the lower pedestal 7. One end of a link bar 13 is connected to a crank disk 12 which is fixed and rotated by this electric motor 11, and the other end of this link bar 13 is connected to a bracket 14 vertically provided on the lower surface of the upper frame 10. By driving the electric motor 11, the upper frame 10 moves forward and backward relative to the melting crucible 5.

Further, a vibrator 15 is provided on the upper surface of the upper frame 10 on the partition wall 2 side, and a glass raw material supply pipe 16 made of quartz is attached to the vibrator 15. The vibrator 15 is hermetically sealed with a flexible vinyl cover 17 to prevent dust from the vibrator 15 from contaminating the surrounding environment. Furthermore, the entire supply pipe 16 is attached in a forward downward state, and its front half is inserted into the chamber 3 through a hole 18 formed in the partition wall 2, and the tip opening of the supply pipe 16 is inserted into the chamber 3 through a hole 18 formed in the partition wall 2. is arranged to face above the melting crucible 5. Further, the rear half of the supply pipe 16 is extended from the rotary vibrator 15 to the side opposite to the melting crucible 5 by about the same length as the front half, for example, 1 m.
It is extended to a certain extent to balance vibrations.

In addition, a support stand 19 is erected at the upper rear part of the upper surface of the upper frame 10 (on the left side in the figure), and is slanted forward slightly, and a Y-shaped quartz pipe 20 branched into the rear half is fixed to the front part of this support stand 19. The front end of this quartz pipe 20 is connected to the branch pipe 16a of the supply pipe 16 via a silicone tube 21 for vibration insulation.
is connected to. Further, a screw feeder 22 made of quartz is disposed inside one branch pipe 20a of the quartz pipe 20, and this screw feeder 22
A small electric motor 23 with a reducer fixed to a support stand 19
It is rotated by Furthermore, a valve 24 for purging an inert gas such as nitrogen gas is attached to the other branch pipe 20b.

Furthermore, the vibrator 1 is installed at the rear of the support base 19.
5, a vibrator 26 covered with a flexible vinyl sheet 25 is provided, and an aluminum band 2 with silicone rubber lined inside the vibrator 26.
7 is used to attach the raw material hopper 28.
As shown in FIG. 2, this hopper 28 accommodates raw materials mixed with multi-component glass inside, and is provided with a pot 29 near its opening. Pinch kettle 30 to close the opening of 28
A silicone tube 31 is fixed thereto.

Next, a method for supplying glass raw materials using the above-mentioned supply device 6 will be described.

First, open the inert gas purge valve 24 attached to the quartz pipe 20, and while keeping the inside of the quartz pipe 20 clean, insert the tip of the silicone tube 31 fixed to the hopper 28 into the branch pipe of the quartz pipe 20. 20b. Next, the pinch bottle 30 is opened to communicate the hopper 28 and the inside of the quartz pipe 20, and the bottle 29 is opened to introduce high purity and low dew point gas, and the hopper 28,
Nitrogen gas is supplied into the chamber 3 via the silicone tube 31, the quartz pipe 20, the silicone tube 21, and the quartz pipe 16. Then, in parallel with the supply of nitrogen gas, the raw material for glass is supplied.

The supply of this glass raw material is as follows. That is, the electric motors 11 and 23 and the vibrators 15 and 26
are each driven by a timer setting, and the upper pedestal 10 and the supply pipe 16 attached to this upper pedestal 10 are moved forward by the drive of the electric motor 11, and the tip of the supply pipe 16 is connected to the melting crucible 5.
Bring it to the top. In parallel with this forward movement, the electric motor 23 is driven, and the screw feeder 22 feeds out a certain amount of the glass raw material from the hopper 28, and the vibrators 15 and 26 are used to feed the glass raw material from the hopper 28.
The glass raw material inside the supply pipe 16 is moved.

After supplying a certain amount of the glass raw material to the melting crucible 5, the upper frame 10 and the supply pipe 16 are immediately moved back to prevent the glass raw material from being fused to the tip outlet of the supply pipe 16 by the heat from the melting crucible 5. It is prevented. Also, at the same time as the supply of a certain amount of glass raw material is finished, the electric motor 23 and the vibrator 15, 26
stops, and the glass raw material does not fall outside the melting crucible 5. As described above, the glass raw material is intermittently supplied in a constant amount.

FIG. 3 shows another embodiment of the supply device, in which, like the previous embodiment, a chamber 3 for accommodating a melting crucible 5 is formed on the floor 1 by partition walls 2, and a supply device 6 is provided outside of this chamber 3. has been established. This supply device 6 is connected to the upper mount 1 to the fixed lower mount 7.
0 is slidably provided, and a glass raw material supply pipe 16 is attached to this upper frame 10 via a vibrator 15. In this embodiment, the Y-shaped quartz pipe 20 of the previous embodiment is not provided, and the tip of the silicone tube 31 directly fixed to the hopper 28 is connected to the branch pipe 16a of the supply pipe 16. A weir 32 is provided within the supply pipe 16 as a member in place of the screw feeder 22 of the previous embodiment.

This weir 32 is formed with a vent hole through which the nitrogen gas passes through the upper part, and by providing this weir 32, the glass raw material is deposited in a constant cross-sectional area in the supply pipe 16, and the amount of glass material is deposited in proportion to the operating time of the vibrator 15. will be supplied.

Further, a support stand 33 corresponding to the support stand 19 of the above embodiment has a front end that is connected to a support column 33 that is erected on the upper frame 10.
The rear end portion is provided at the rear of the upper frame 10 via a connecting member 35 and is pivotally connected to a bracket 36. By having the above configuration,
Similar to the embodiment described above, glass raw materials can be intermittently supplied in fixed amounts to the melting crucible without contaminating them.

As explained above, according to the present invention, a certain amount of glass raw material can be supplied without an operator entering a clean, low dew point chamber in which a melting crucible is installed, and the glass raw material can be supplied. Since the glass material is transported to the melting crucible along with the inert gas from the clean hopper without being exposed to the outside air, there is no possibility that water or transition metals will be mixed into the glass raw material. Therefore, when producing an optical fiber, a high-quality product can be obtained in which attenuation of optical power can be suppressed as much as possible. In addition, the supply pipe is immediately retracted from the melting crucible after the glass raw material is supplied, which prevents the glass raw material from fusing near the outlet of the supply pipe.Furthermore, automation improves work efficiency. In addition to greatly improving the width of the glass, it also eliminates contamination of workers due to flying powder from glass raw materials, which helps to improve the environment.

[Brief explanation of drawings]

The drawings show embodiments of the present invention.
FIG. 2 is a front view of a hopper, and FIG. 3 is a front view of another embodiment of the frit supply device according to the present invention. In the drawing, 3 is a chamber, 5 is a melting crucible, 6 is a frit supply device, 10 is a pedestal, 15 and 26 are vibrators, 16 is a frit supply pipe, and 28 is a hopper.

Claims (1)

[Claims] 1. A melting crucible is installed, and a glass raw material supply pipe is exposed from the outside into a clean atmosphere chamber that is isolated from the outside, and when glass raw materials are supplied to the melting crucible, the supply pipe is moved forward. A method for supplying a glass raw material, characterized in that after the glass raw material is supplied, the supply pipe is retracted to intermittently supply a fixed amount of the glass raw material to a melting crucible. 2. A device for supplying glass raw materials to a melting crucible installed in a room with a clean atmosphere and isolated from the outside, which includes a pedestal that can be moved forward and backward intermittently, and a pedestal that is attached to the pedestal via a vibrator.
A glass raw material supplying apparatus characterized in that a front end faces into the room having a clean atmosphere, and a rear end includes a glass raw material supply pipe connected to a glass raw material hopper.