RU2250198C2 - Glass melting in bath furnace - Google Patents

Abstract

FIELD: glassmaking.

SUBSTANCE: process is performed in such a way that broken glass is loaded non-uniformly relative to side walls and center of doghouse thus allowing 20 to 95% of broken glass to be loaded at both sides of the charge between the charge and side walls of melting bath in the furnace. Rest of broken glass mixed with charge is loaded in the center of doghouse. Broken glass with particle size 10-60 mm is fed under the charge mixed with broken glass having particle size 0.2-5 mm.

EFFECT: increased service time of bath furnace due to reduced wear of refractory parts of melting bath, and increased productivity of furnace.

2 cl, 1 dwg, 3 ex

Description

1 area of use.

The invention relates to methods for glass melting in continuously operating bath furnaces with a capacity of 50 to 800 tons of glass melt per day in the production of flat glass and glass containers. It can be most effectively used on all types of multifunctional lines in the production of colorless and colored float glass.

2. The prior art.

Known methods of glass melting in a bathroom glass melting furnace in the production of sheet glass [1], according to which the loading of the charge and cullet is carried out over the entire width of the loading pocket, articulated with the end wall of the cooking pool, opposite the production end of the furnace. Moving along the furnace, the mixture with cullet under the influence of high temperatures turns into finished glass melt, having passed through all stages of glass making in succession.

The disadvantage of this method of glass melting is the increased destruction of refractories around the perimeter of the side walls of the cooking pool at the level of the glass “mirror” due to the aggressive action of alkalis, freshly formed charge melt and the effect of the charge itself. Also in these methods the use of glass combat from other enterprises is excluded.

The prototype of the alleged invention is the method of glass melting described in the book of G. Goerk “Production of drawn sheet glass” on pages 100-101 [2]. It is shown that the mixture without cullet can be loaded in the middle of the loading pocket, and cullet on both sides of the charge. At the same time, it is supposed to use glass battle, which is formed in our own production.

The disadvantages of this method of glass melting are the low specific removals of the glass melt, the need for prolonged homogenization of the glass melt and the deterioration of its clarification due to the formation on the glass melt of a high siliceous film.

The alleged invention eliminates the disadvantages of analogues and prototype.

3. The invention.

In accordance with the proposed invention, the cullet is loaded unevenly with respect to the side walls and the middle of the loading pocket, loading from 20 to 95% of the cullet on both sides of the charge between the charge and the side walls of the furnace cooking basin, and the rest of the cullet mixed with the charge is loaded in the middle of the loading pocket . Also under the charge, mixed with cullet with a particle size of 0.2-5 mm, serves cullet with a size of pieces of 10-60 mm.

Since modern methods of glass melting in bath furnaces with a capacity of 50 to 800 tons of glass per day with high averaging ability allow to obtain high-quality glass, as a rule, there is not enough own cullet and there is a need to either sharply reduce the charge-to-fight ratio to reduce cullet , which is technologically impractical, or to use glass breakage of other glass factories from a glass similar in composition, cooking and production properties.

In addition to mixing the cullet with the charge, it is possible to feed the mixture with medium loaders to the “sublayer” of cullet. For this, cullet of sheet glass is crushed into pieces from 10 to 60 mm in size and poured out equally distributed in the middle part of the loading pocket onto the surface of the molten glass, and the charge is poured onto it from above. This speeds up the process of penetration of the charge, allows you to get a more homogeneous glass mass and increase the specific productivity of the furnace.

When the mixture of batch and cullet is loaded through middle loaders, the chemical uniformity of the molten glass melt improves, since the freshly welded batch melt is mixed and averaged with the molten cullet by vigorously mixing the gaseous compounds released during cooking. Pre-mixing the mixture with cullet is most appropriate when cooking stained glass.

Cullet crushing is carried out to sizes comparable to the particle sizes of sand, chalk, dolomite and can be from 0.2 to 5 mm. When mixing the mixture with crushed cullet, it is necessary to ensure a statistically uniform distribution of cullet in the mixture. For this method of glass melting, the risk of the formation of a high-siliceous film on the surface of the glass melt, making it difficult to clarify, is reduced.

The supply of cullet by ridges along the side walls of the cooking pool allows to reduce the temperature of the glass by 20-50 ° C at the level of the glass melt along the perimeter of the refractories of the side walls of the cooking pool. Thus, the massive supply of cullet and its active advancement along the side walls of the furnace in the area of cooking ridges of the mixture and individual heaps of the mixture, as well as in the area of dense cooking foam, can reduce the aggressive effect of components, products of cooking the mixture and the mixture itself on the destruction of refractories. The resulting reagents of the charge interact primarily with the cullet melt and their aggressive effect on the refractory is reduced. Also, the possibility of contacting individual charge heaps with refractories of the side walls of the cooking pool is sharply reduced.

Cullet loading along the side walls of the cooking pool can be carried out not only through the loading pocket, but also through windows in the end wall of the furnace or windows in the side walls.

4. The list of drawings.

The drawing schematically shows a plan view of one embodiment of a device for implementing the method, where

1 - the cooking pool of the bathroom glass melting furnace.

2 - loading pocket, paired with the end wall of the cooking pool.

3 - charge loader.

4 - ridges of the mixture with cullet.

5 - cullet ridges.

6 - separate heap of the charge with cullet.

7 - side walls of the cooking basin of the furnace.

8 - cooking foam.

9 - regenerative burners of the furnace.

5. Information confirming the possibility of carrying out the invention.

A glass-melting bathtub furnace 1 with a capacity of 250 tons of float glass sheets per day has a cooking basin width of 9 m and a loading pocket 2 of 8.2 m wide and 0.8 m long. The charge and cullet are loaded mechanically by eight loaders 3 of a table type with an electric drive. The glass melting furnace is fed with a charge and cullet by a command from a level gauge, by the signal of which the loaders 3 are switched on when the glass level in the furnace is reduced, for example, by 0.2 mm.

The loading unit consists of eight table loaders installed across the entire width of the loading pocket 2. Each loader has a feed hopper, a table and a pusher. The mixture or cullet comes from the feed hopper onto the table and is pushed from the table by the pusher onto the surface of the glass in the loading pocket. The table has a certain amount of stroke, for example from 120 to 300 mm, when it is informed of reciprocating motion. When moving forward, the table with its visor pushes the previously poured charge or cullet into the cooking pool of the furnace, providing a longitudinally ridge loading of the charge 4 and cullet 5. The ridges of the charge 4 and cullet 5 under the influence of the glass mass flows of the filling cycle and during cooking diverge to the side walls of the cooking pool .

Cullet is loaded through the extreme loaders No. 1 and No. 8. The mixture, mixed with cullet, is loaded through the middle loaders No. 2-No. 7.

The drawing schematically shows a cartogram of the boundaries of the cooking zone with the location of the longitudinal ridges of the charge 4 and cullet 5; the area of location of individual heaps of the charge 6 and the area of the cooking foam 8 relative to each pair of burners 9.

Cullet 5 runs along the side walls 7 of the cooking pool. In the region of the second pair of burners, the beds of the charge 4 are divided into separate heaps of the charge 6, which are boiled in the middle part of the cooking pool, without touching the side walls 7 of the cooking pool.

Depending on the productivity of bath furnaces (50-800 tons of glass melt per day) and maximum cooking temperatures of 1450-1600 ° C, the continuous operation of the furnaces when using the proposed invention is extended by 5-30% of the planned. Cooking the mixture with cullet in the middle of the cooking pool, i.e. in the zone of maximum temperatures, it allows to increase specific removals of glass by 3-8%.

There are many options for the distribution of cullet along the front loading into the bathroom furnace.

Example 1

Productivity of the bathroom glass melting furnace is 250 tons of glass per day.

The ratio of the mixture: cullet 80:20, the amount of cullet 20%.

The number of charge and cullet loaders 8 pcs.

Loading the charge and its own cullet is carried out in the following way: 7% cullet through the extreme loaders No. 1 and No. 8, and the remaining 6% are mixed with the mixture and fed through the middle loaders No. 2-No. 7.

The method allows to extend the life of the bathroom furnace by 10-15% and increase its productivity by 3-5%.

Example 2

Productivity of a glass melting bathtub is 150 tons of glass per day, colored in bulk. The ratio of the mixture: cullet 70:30.

The amount of cullet formed in own production is 20%.

The amount of colorless cullet of other glassworks is 10%.

Number of charge and cullet loaders 6 pcs.

The charge and cullet are loaded in the following way: 10% of their cullet is mixed with 10% of colorless cullet of other glass factories and with the charge and loaded through extreme loaders No. 1 and No. 6, 10% of cullet each, and the remaining 10% of their cullet is loaded through medium loaders No. 2-No. 5.

The method allows to extend the life of the bath furnace by 20-30% and increase its productivity by 7-10%.

Example 3

Productivity of a glass melting bathtub is 600 tons of glass per day.

The ratio of the mixture: cullet 80:20.

The amount of cullet formed in own production is 16%.

The amount of cullet of other glass factories is 4%.

The number of charge and cullet loaders 8 pcs.

The charge and cullet are loaded in the following way: 8% of their cullet is mixed with 4% of cullet of other glass plants and 6% of cullet are fed through extreme loaders No. 1 and No. 8. The remaining 8% of their cullet is mixed with the charge and fed evenly through the middle loaders No. 2-No. 7 into the bathroom furnace.

The method allows to extend the life of the bath furnace by 3-5% and increase the productivity of the furnace by 2-3%.

1. Solinov F.G. Flat glass production. - M .: Stroyizdat, 1976 - p. 74, 102, 110-111.

2. Goerk G. Production of stretched sheet glass. - M.: Stroyizdat, 1972 - p. 100-101.

Claims (2)

1. The method of melting glass in a bath furnace by loading the mixture and cullet on the surface of the molten glass through a loading pocket, paired with the end wall of the cooking pool, opposite the production end of the furnace, moving the mixture and cullet along the furnace and their cooking between the side walls of the cooking pool, characterized in that the cullet is loaded unevenly relative to the sides and the middle of the loading pocket, providing loading from 20 to 95% of the cullet on both sides of the charge between the charge and the sides tenami melting tank furnace, and the remaining glass, mixed with the charge charged in the middle of the loading pocket. 2. The method according to claim 1, characterized in that under the charge, mixed with cullet with a particle size of 0.2-5 mm, serves cullet with sizes of pieces of 10-60 mm