RU2612180C1 - Device for vacuum degassing of molten glass mass - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: invention relates to a device for vacuum degassing of molten glass mass. The device for vacuum degassing of molten glass mass comprises a crucible and a vacuum bell jar. The crucible is mounted on a pusher rod with a movable hearth. A cushion of granular material is sprinkled on the floor. The device has an extensible cover, under which the vacuum bell jar is mounted with possibility of contact with the cushion of the movable hearth when the extensible cover is open.

EFFECT: vacuum degassing device which improves the quality of molten glass mass.

4 cl, 2 dwg

Description

The invention relates to the glass industry and relates to vacuum degassing of molten glass to improve the quality of glass products.

In the implementation of some artistic and technical solutions, it is necessary to obtain clean glass melt, devoid of bubbles and other inclusions.

To solve such problems, various techniques were used, in particular, heating glass to high temperatures or the use of mixing devices, which requires a significant investment of time and energy.

In the patent for invention No. 2515443, publ. 05/10/2014, proposed vacuum clarification of glass. To do this, in a vessel with molten glass melt, a multi-stage set of vacuum is produced (up to 9 steps) with extracts at each step up to 12 hours. Such a device also requires a lot of energy and time.

The closest technical solution to the proposed device can be considered the device according to the patent of the Russian Federation No. 2552567, the priority of Japan on 06/30/2010, the application was published on 08/10/2014, the patent of the Russian Federation was published on 10.06.2015. The patent proposes a device that contains two compartments: a cooking pool and a vacuum vessel above it. The pool and vessel are connected by a supply pipe. The molten glass melt from the cooking pool enters the vacuum vessel through the inlet pipe, and after degassing through the outlet pipe it enters the forming device.

However, the vacuum system proposed in the patent has significant drawbacks. The device does not work with a full vacuum, but with a vacuum. At full vacuum, this device will not be able to work, since at full vacuum the glass melt will fill the upper (vacuum) tank and will not flow out of the discharge pipe from it. The absence of a full vacuum does not allow to achieve high quality clarification of glass. In addition, in the device according to patent No. 2552567, the glass melt is in a dynamic (mobile) state. In this case, the degassing control is carried out only at the exit from the system, which is possible only for well-established processes. In this case, a change in temperature conditions significantly changes the speed of passage of the glass melt in the evacuating chamber, and, consequently, changes the degree of purification of the glass melt, since a thicker glass melt moves more slowly and more liquid moves faster. In this regard, as indicated in the patent, the device only works with certain types of glasses.

The technical result of the proposed solution is to improve the quality of molten glass, and, therefore, products from it.

To achieve the claimed technical result in a device for vacuum degassing of molten glass containing a cooking chamber (crucible) and a vacuum chamber, the crucible is mounted on a rod-ejector with a movable hearth, on the floor of which a pillow of granular material is poured, the device is made with a sliding cover over which is mounted a vacuum cap with the ability to contact with the cushion of the movable hearth with the sliding cover open.

As the bulk material of the cushion of the moving hearth, sand or finely ground fireclay can be used.

The housing of the cooking chamber can be made of quartz or fireclay.

The proposed design allows you to create a deep vacuum in the degassing zone, and, therefore, to improve the quality of molten glass.

The operation of the device is illustrated in FIG. 1 and 2.

In FIG. 1 shows a cross section of the device, the moment of molten glass;

in FIG. 2 - transverse section of the device, the moment of vacuum degassing.

The housing of the device 1 is made with a sliding cover 2. Inside the housing of the device 1, side electric heaters 3 are mounted, as well as an ejector rod with a movable hearth 4. A pillow 5 of bulk material, in particular sand or finely ground fireclay, is poured onto the floor of the movable hearth, and installed on top of it crucible 6, in which the melting (cooking) of glass 7. The crucible can be quartz or from fireclay. A quartz cap 8 is mounted above the sliding cover 2 of the housing of the device 1, connected to an air evacuation line to create a vacuum under the cap.

The device operates as follows. Raw material is loaded into crucible 6, electric heaters 3 are turned on, and glass melt is melted or melted according to technological conditions corresponding to the type of glass ordered. In the resulting melt, air bubbles appear inside the glass melt, which in the future can lead to a deterioration in the quality of products molded from such glass melt.

To eliminate bubbles, vacuum degassing of molten glass is carried out. To do this, open the cover 2 of the furnace body 1, extend the ejector rod 4, which lifts the crucible 6 with molten glass 7 up. The crucible 6 falls under the quartz cap 8, the edges of which are immersed in the sand (chamotte) cushion 5, thereby sealing the space around the crucible 6. At the same time, air is pumped out from under the cap 8. The degree of rarefaction is controlled according to the type of molten glass and the temperature at which forced degassing (clarification) of the glass melt occurs. The quality of glass degassing is determined visually through the transparent walls of the hood 8.

After removing the bubbles from the glass melt, the vacuum is turned off, the cap 8 is removed, and the rod-pusher 4 together with the crucible 6 is returned back to the furnace, where then the glass melt temperature is brought to the set one.

In contrast to the prototype, molten glass melt is in a static (stationary) state. Degassing in this case does not depend on the viscosity of the glass melt, nor on the temperature regime of cooking. In such a device, not only glass can be evacuated, but also viscous systems of molten glass metals.

The control of the exit of gas bubbles from the glass melt is carried out visually, which allows, if necessary, to quickly change the vacuum conditions.

In addition, in the proposed device, vacuum degassing is carried out with deep evacuation, which improves the efficiency of evacuation and, consequently, the quality of molten glass and finished products.

The design of the device is simpler than the prototype, which allows it to be implemented in laboratories without significant financial costs.

The proposed evacuation procedure is suitable when using cooking crucibles of various designs and from various materials.

Claims (5)

1. A device for vacuum degassing of molten glass melt containing a crucible and a vacuum hood, characterized in that the crucible is mounted on a rod-ejector with a movable hearth, on the floor of which a pillow is made of granular material, the device is made with a sliding cover over which a vacuum hood is mounted with the possibility contacting the cushion of the movable hearth with the sliding cover open. 2. The device according to claim 1, characterized in that sand is used as the bulk material of the cushion of the moving hearth. 3. The device according to claim 1, characterized in that finely ground fireclay is used as the bulk material of the cushion of the moving hearth. 4. The device according to claim 1, characterized in that the crucible body is made of quartz. 5. The device according to claim 1, characterized in that the crucible body is made of fireclay.

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