JPH0619539Y2 - Glass melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a glass melting furnace used for manufacturing glass.

[Prior Art and Problems] Using a closed nitrogen gas atmosphere furnace, high temperature (1500 ° C.)
When glass is manufactured in the above manner, when the glass raw material is supplied as powder to the atmosphere furnace, the fine powder raw material is fixed in the small-diameter supply pipe from the raw material storage tank to the melting furnace, which eventually triggers the pipe. Blockage, making it impossible to supply raw materials.

For this reason, conventionally, the glass raw material powder is press-formed into a spherical shape in advance, or the raw material powder is once subjected to pretreatment such as vitrification into a cullet in a batch furnace and then supplied to the melting furnace.

However, there is a risk that impurities may be mixed in the pretreatment process, and the treatment cost also increases.

The present invention is directed to an atmosphere furnace having a narrow portion in a raw material supply system, particularly a pipe portion having a small diameter from a raw material storage tank to a crucible,
It is an object of the present invention to provide an atmosphere furnace that can directly supply a glass raw material to a molten crucible without pretreatment.

[Means for Solving the Problems] The present invention provides a closed glass melting furnace having a raw material supply tank, a melting crucible, and a raw material supply pipe for supplying a glass raw material from the raw material supply tank to the melting crucible. The glass melting furnace is provided with a cooling layer movable in the axial direction of the pipe in the vicinity of the melting crucible.

Feed the raw material with the cooling layer close to the crucible,
Even if the raw material sticks at a certain point, once the raw material supply is stopped and the cooling layer is raised, the temperature at the sticking point rises, the stuck raw material becomes a semi-molten state, falls into the crucible, and falls in the pipe. The clogging can be removed. As a cooling medium to be introduced into the cooling layer, an aqueous solution of ethylene glycol or the like may be used in addition to water.

[Operation] In the present invention, since the cooling layer that can move freely in the axial direction of the raw material supply pipe (the raw material supply direction or the opposite direction) is provided around the raw material supply pipe, the sticking point of the raw material can be set on the melting crucible side. By moving the cooling layer, the temperature gradient in the raw material supply pipe can be arbitrarily changed. Therefore, the raw material once fixed can be made into a semi-molten state again and dropped into the crucible. In addition, in the method in which a heater is provided at the raw material fixing point to melt, the structure of the furnace becomes complicated,
The frequency of troubles is high, and the temperature gradient is not obtained as much as when the cooling layer is provided.

[Embodiment] Next, the present invention will be described more specifically with reference to an embodiment.

1 (a) and 1 (b) are schematic sectional views showing the structure of the entire glass melting furnace of the present invention. The glass melting furnace 1 comprises a melting crucible 10 for melting glass, a heater 11 for heating the melting crucible, and a heat insulating layer 12 for keeping the temperature and heat. The crucible 10 has a hopper 2 as a raw material supply tank.
0 is attached via the raw material supply pipe 21.
The hopper 20 is provided with a vibrating feeder 22 to supply the glass raw material from the hopper 20 to the molten crucible 10.

Further, the melting crucible 10 is provided with a dam plate 13 for overflowing the melted glass, and a melting portion 14 of the crucible.
And an outlet 16 with an outlet 15 at the bottom. In addition,
The in-furnace gas generated by melting is discharged from the in-furnace gas outlet 17 provided through the heat insulating layer 12.

As shown in FIG. 2 (a), a cooling unit 30 is provided at a portion where the raw material supply pipe 21 penetrates the heat insulating layer 12 toward the melting crucible 10. The cooling unit 30 includes a raw material supply pipe 21.
A ring-shaped water cooling layer 32 movable along the axis of the pipe, a water conduit 33 for supplying cooling water to the water cooling layer, and a heat insulating layer 34 provided in a portion facing the melting crucible 10. Is surrounded by an alumina tube 35.

In order to melt glass using the glass melting furnace 1 of the present invention, glass raw material powder is directly charged into the hopper 20 and the vibrating feeder 22 quantitatively supplies the raw material. The raw material powder passes through the raw material supply pipe 21, enters the melting crucible 10, is melted and vitrified, and flows out as glass from the glass outlet 15.

FIG. 2 (b) is a graph showing the temperature distribution of the raw material supply pipe. The vertical axis of FIG. 2 (b) shows each position of the raw material supply pipe of FIG. 2 (a), and the horizontal axis shows the temperature.

When the water cooling layer 32 was located at the bottom (curve A in FIG. 3), the bottom of the pipe was 1350 ° C. and the raw material was fixed. However, when the supply of the raw material was temporarily stopped and the water cooling layer was raised to the uppermost portion, the temperature of the raw material fixing point rose to 1450 ° C. (curve B in FIG. 3), and the clogging of the raw material could be removed. Next, the water cooling layer was lowered again to restart the supply of raw materials. The time required during this period was about 3 minutes. It should be noted that a sharp temperature gradient was obtained because the heat conduction was reduced when the wall thickness of the raw material supply pipe was reduced.

[Advantage of the Invention] In the glass melting furnace of the present invention, the sticking point of the raw material is set on the melting crucible side, and the water cooling layer can move freely, so that the temperature gradient in the raw material supply pipe can be arbitrarily changed. The raw material once fixed can be melted again and dropped into the crucible.

[Brief description of drawings]

1 (a) and 1 (b) are sectional views showing a specific example of the melting furnace of the present invention, FIG. 2 (a) is a detailed sectional view showing the cooling part thereof, and FIG. 2 (b) is a raw material of the cooling part. It is a graph which shows the temperature distribution of a supply pipe. The main symbols in the figure are as follows. 10: molten crucible, 20: hopper, 21: raw material supply pipe, 30: cooling part, 32: water cooling layer.

Claims (1)

[Scope of utility model registration request] 1. A closed glass melting furnace having a raw material supply tank, a melting crucible, and a raw material supply pipe for supplying a glass raw material from the raw material supply tank to the melting crucible, wherein the pipe of the raw material supply pipe is provided near the melting crucible. A glass melting furnace comprising a cooling layer movable along an axial direction.