SU1636352A1 - Process for fusing optical glass in pot furnace - Google Patents

Abstract

This invention relates to a glass melting process technology and can be used to produce highly homogeneous optical glass. The aim of the invention is to improve the optical quality of the glass. During the whole process, the charge is irradiated with monochromatic radiation from a source of the visible or near-IR range. Power density not lower than 105.

Description

This invention relates to a glass melting process technology and can be used to produce highly homogeneous optical glass.

The aim of the invention is to improve the quality of optical glass.

When the charge is irradiated with monochromatic radiation of a source of the visible or near-IR range, the power density is not lower (g begin after the first batch of charge is filled and it is continued until it is completely melted, intensive clarification and homogenization of the glass melt is performed areas of the melt arising in the process of penetration of the poured layers. This is due to the lowering of the melt viscosity in individual melted areas of each poured batch under the action of irradiation charge monochromatic radiation with

specified parameters. The decrease in viscosity that occurs in individual molten areas of the bed to be filled with the mixture, as it penetrates, spreads to the entire molten layer. glass mass is not thermal in nature, i.e. the contribution of energy absorbed by individual molten volumes of the charge from a low-power irradiation source (millivolts) is incommensurable with the total energy expended on penetration and melting of the charge.

Increasing the homogeneity of the molten glass mass that is formed when the charge is boiled under irradiation conditions with monochromatic radiation with specified parameters during the backfilling process.

penetration and melting caused by the intensification of physicochemical reactions in a viscous melt of reduced viscosity.

Example 1. The cooking of optical glass having a chemical composition,%; SiOa 9; Na20 28; Wg0363, produced in two modes. In the first mode, the glass is cooked in the usual way.

Trial glass melting was carried out in an ART automatic oven.

Charging of the charge into the crucible is carried out at 850 ° C, the mixture is kept at this temperature for 2 hours. After penetration, the glass melt is clarified at 900 ° C. In the process of clarification (duration 0.5 h) and homogenization (duration 1 h), the glass melt is stirred with a paddle stirrer. After cooling, the glass is annealed in a muffle furnace for 1 hour at 450 ° C. Get the glass of poor quality.,

According to the second mode of glass melting use:

a) as a monochromatic radiation source, a He-Ne laser of the type LG-79 (fl 0.63 µm, P 15.10-3W), thereby obtaining high-quality glass;

b) as a monochromatic radiation source, KGM 12-100 type film projection lamps with a monochromatic filter on | - 0.63 microns and a condenser with a light diameter

d Ј: 10 located at a distance of 6 from the radiation source, while the system provides a radiation power density on the surface of the charge less than 10, i.e.

E p -Ј-- 35 W / m2,

de p is the transmittance of the optical system that forms the irradiation zone on the surface of the charge (p ≈ 0.8);

e idg - area of the irradiation zone per po

charge surfaces; L03m;

РгШ1Гл ° 14W coef.

ficient ,. characterizing the transmission of a monochromatic filter (p 5.10-ZR);

 four

Р - power of film projection

lamps, W,

At the same time receive glass of poor quality.

Fir is filled into a crucible at 850 ° C, starting from the moment of loading the first batch of charge, it is irradiated with monochromatic irradiation according to (Q mode a) He-Ne laser of type LG-79, mode b) of a KGM 12-type projection lamp 100 with a monochromatic filter on fl 2s0,63 microns and with a condenser. Irradiation of the Gaich is performed in the process5

0

0

after its complete melting (duration 2 hours). After melting, the glass melt is clarified at 900 ° C and homogenized at 800 ° C. In the process of clarification (duration 0.5 h) and homogenization (duration l, t h), the glass mass is stirred with a paddle stirrer. After cooling, the glass is annealed in a muffle furnace for 1 h 5 at 450 ° C.

Example 2. The boiling of optical glass having a chemical composition,%: Vg03 45; A1gOe 6; PbO 37, produced in two peechimes.

But for the first mode of glass melting, the charge in the crucible was filled at 1200 ° C. The mixture was kept at this temperature for 1 hour. After the cooking, the glass mass was clarified and homogenized. In the process of clarification (temperature 1250 ° C, duration 0.5 h) and homogenization (1170 ° C, duration 1 h), the glass mass is stirred with a paddle stirrer. After cooling, the glass is annealed in a muffle furnace for 1 hour at 450 ° C. At the same time receive glass of poor quality.

But to the second mode (the proposed method) the charge in the crucible is filled at 1200 ° C. Starting from the moment of filling the first batch of charge, it is irradiated with monochromatic radiation from an YAG laser: type LTI-501 (ft I - 1.06 µm, P0p 8 W) f 30 kHz, drt2c2 mm (TEM00). Irradiation of the Gaicht is carried out in the process of backfilling, penetration and is finished after its complete melting (duration 1 h). After melting, the glass melt is clarified and homogenized. In the process of clarification (temperature 1250 ° С, duration 0.5 h) and homogenization (1170 ° С, duration 1 h), the glass mass is mixed with a paddle stirrer5

0

45

0

51636352

) Coy. After Ostishan glass is annealed by special changes in the design

in a muffle furnace for 1 hour of a handful furnace. 450 ° C. You get a glass you-.

Claims (1)

of low quality. Formula of the invention Optical glass melting method in a pot furnace, there can be an implementation of the method of cooking an optical glass van in virtually any pot furnace in a pot furnace, which includes layers without any special, variable charge filling of the charge and bo, melts in their design. In test variations, clarification, homogenization, and cooling of the optical glass, which was carried out in an ART furnace, the backfill was irradiated by the fact that, in order to increase the optical charge, glass was produced through in the furnace lid of the process, irradiation is carried out In order to irradiate significant monochromatic radiation of the visible charge, it is necessary to use a non-transmitted or near-IR range, for several or more monochromatic sources of power not lower than at the same time, for example 2-4 pieces, without 10 W / m.