RU2338701C1 - Method of sheet polished glass production line operation - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: furnace charge is supplied with six table loaders with capacity of each from 1.8 t/hour to 6.5 t/hour. Travel of loader table makes from 0.14 m to 0.25 m. Gas supply is performed through chamber burners with total flow rate of natural gas from 400 m³/hour to 2000 m³/hour, with ventilation flow rate of ventilatory air from 2975 m³/hour to 21625 m³/hour, with total thermal capacity of burners from 7.9 GJ/hour to 60.61 GJ/hour, and pressure of the first burner from 0.3 MPa to 0.4 MPa, and pressure from the second to the sixth burner of 0.0025 MPa - 0.069 MPa. Homogenising and reduction of liquid glass temperature is carried out by means of its cooling with submersible axial element with water flow of 340 l/min-360 l/min and inlet temperature from 20°C to 40°C.

EFFECT: improvement of produce quality, higher efficiency, increase of sheet polished glass production line service life.

4 dwg, 1 tbl

Description

Technical field

The invention relates to the building materials industry, in particular to devices for the production of glass by a continuous method.

State of the art

The prior art method of operating a continuous production line for the production of sheet glass. The line includes a bathroom furnace, a rolling machine, a glass annealing furnace, a polariscope, a flanging mechanism, a fragmentation mechanism, an accelerator roller table, an end stacker roller table, an end stacker, a hoist with a suction frame and a table cutter. In the continuous rolling process, the molten glass welded in the bath furnace through a special trough (drain tray) enters the rolling mill and, as a continuous strip, into the tunnel annealing furnace. With one-sided processing of glass sheets, the tape exiting the furnace is cut into separate sheets. In double-sided processing, the tape is fed onto the uncut conveyor (see L. M. Butt, Glass Technology, State Publishing House of Literature on Construction, Architecture and Building Materials, Moscow, 1960, pp. 251-256).

With this continuous rolling method, a clear sheet glass is produced, which is used for grinding and polishing. Continuous rental is a high-performance production method. One machine with a width of 3 m is capable of producing up to 250 tons of glass melt per day. However, this method also has disadvantages: they produce glass with a thickness of more than 4-5 mm; In addition, glass produced by continuous rolling requires grinding and polishing. In order to reduce processing costs and glass losses, they strive to obtain a tape of the most uniform thickness and with a smoother surface. With good quality rolled products on each side of the sheets removed when grinding only 0.3-0.5 mm glass.

In the late 1950s, the English company Pilkington Brothers Limited developed a completely new method for producing polished glass by forming a ribbon of glass on molten tin, called the float process (floating glass). The new method turned out to be so promising, economically viable and technically perfect that in a short time (10-15 years) it completely replaced mechanical conveyors for glass processing and became dominant in the world (N.M. Pavlushkin, Chemical technology of glass and glass, Moscow, Stroyizdat, 1983, pp. 233-234).

The principle of molding is that a strictly dosed amount of glass melt from the working part of the glass melting furnace flows down the drain tray onto the mirror surface of the molten tin and spreads over it and turns into a tape of equilibrium thickness. The molded glass tape further advances along the surface of the tin, gradually cools (up to 600 ° C) and is transferred to the annealing furnace.

The closest analogue of the proposed technical solution is the method of operating a continuous continuous line for the production of building polished glass, known from "PRODUCTION OF GLASS", V.V. Tarbeev and others, FGUIPP "Nizhpolygraph", Nizhny Novgorod, 2002, pp. 136-138. A known method of operating a line for the production of sheet polished glass includes loading the charge into the bathroom of a glass melting furnace through a loading pocket, melting the mixture in the cooking pool by supplying gas through the chamber burners and burning it in the cooking pool of the bathroom of the glass melting furnace to form glass melt and subsequent homogenization of the glass melt with simultaneous lowering the temperature before serving in the float bath.

All processes in sections of the production line are as automated as possible.

From the glass melting furnace through the feed channel, the molten glass enters the float bath, where it is converted into a glass ribbon and through the lifting shafts from the other end of the bath it enters the annealing furnace and then to the rolling table. The moving belt undergoes visual inspection of defects and annealing control. Then, at the cross-cutting section, the tape is divided into blanks entering the cutting section. According to a special program, glass sheets are automatically fed from the rolling table to carved tables, where they are cut into semi-finished products and installed automatically on the pyramids, which are then transported by forklift trucks to the warehouse. Defective billets, battle are dumped in the bunker or in special containers for the battle. The productivity of all production line equipment is determined by the cooking ability of the glass melting furnace.

Among the shortcomings, it can be noted that the unmelted charge in the cooking pool of the glass melting furnace extends to the side towards its side walls, accumulates in the latter, clogs the passage for both entering the charge into the cooking pool, and the outlet from it, moreover, the interaction of the charge with the lining of the furnace leads to the destruction of the latter and thereby reduces the service life of the glass melting furnace, which in turn leads to a decrease in line productivity; in addition, the well-known technical solution does not provide for the possibility of controlling the circulation flows of the glass melt in the longitudinal and cross sections of the bathtub of the glass melting furnace, which does not ensure uniformity of the glass melt in temperature and chemical composition when it enters the production channel of the glass melting furnace, and also does not allow moving the charge from the side walls of a glass melting furnace.

Disclosure of invention

The objective of the present invention is to provide the ability to control temperature fields, as well as longitudinal and transverse convection flows of the glass melt in a glass melting furnace, and regulate the location of the charge over the area of the glass melting furnace, stabilize the position of the boundaries of the charge at the required distance from the side walls, ensure uniformity of the glass melt mainly due to the chemical as well as thermal averaging.

The solution of this problem allows us to improve the quality and increase the number of products produced, as well as extend the life of the line for the production of sheet polished glass.

The problem is solved in that in the method of operation of the line for the production of polished sheet glass, including loading the charge into the bathroom of a glass melting furnace through a loading pocket, melting the mixture in the cooking pool by supplying gas through the chamber burners and burning it in the cooking pool of the glass melting furnace to form glass melt, subsequent homogenization of the glass melt with a simultaneous decrease in temperature before being fed to the float bath, according to the invention, gas is supplied through a chamber burner and with a total consumption of natural gas from 400 m ³ / h to 2000 m ³ / h, and with a total heat output of burners from 7.9 GJ / h to 60.61 GJ / h, moreover, the homogenization and lowering of the temperature of the glass melt is carried out due to its cooling with a submersible axial element with a flow rate of 340 l / min - 360 l / min and an inlet temperature of 20 ° C to 40 ° C.

As a result, the quality of building glass is improved and the service life of the line is increased, and it was experimentally established that the selected above ranges improve the uniformity of the glass melt and protect the lining of the glass melting furnace.

Kvelpunkt - the zone of maximum temperatures in the bathroom glass melting furnace.

For a glass melting bathtub with a capacity from 170 t / day to 270 t / day of glass melt, the quellpoint, respectively, is installed at a distance from the end wall of the loading pocket from 11.21 m to 13.02 m due to the heat input by burning natural gas supplied to the heated zone of the glassmaking bathtub with 6 pairs of burners. Therefore, the length of the water-cooled element is made from 11.46 m to 13.27 m, and the length of the refrigeration section is from 8.88 m to 13.02 m, provided that the length of the mounting section is from 0.25 m to 1.81 m and the length of the intermediate sections 0.769 m.

Brief Description of the Drawings

The technical solution is illustrated by drawings, where Fig. 1 shows a plan of a line for the production of polished glass sheets, Fig. 2 shows a top view of a glass melting furnace bath, Fig. 3 is a longitudinal section of a glass melting furnace bath, and Fig. 4 is a longitudinal section of a glass melting bath furnaces with circulation flows of glass melt.

The line for the production of sheet polished glass will include (see Fig. 1): 1 - a glass melting bathtub, 2 - a production channel, 3 - a float bath, 4 - annealing furnace, 5 - a cold blowing section, 6 - a tape viewing cabin glass, 7 - cutting beam, 8 - side breaking, 9 - haulers (3 pcs.), 10 - pyramid (6 pcs.), 11 - spraying beam (2 pcs.), 12 - controller cabin, 13 - glass receiving table ( 4 pcs.), A cut table, 15 - live rolls (2 pcs.), 16 - blowing off scree "blowing sheets", 17 - hot air blowing, 18 - stretching machines (4 pcs.), 19 - charge loaders (6 pcs.) , 20 - axial refrigerator, 21 - slag chamber, 22 - amer burner.

Bathroom glass melting furnace 1 includes (see figure 2) loading pocket - 23 (figure 2), six bootloaders charge - 19 continuous operation.

The glass melting bath furnace 1 is equipped with a submersible axial element (axial cooler) 20 (Fig. 3) containing fastening sections 20a and cooling sections connected by the transition section 20b and placed along the longitudinal axis of the glass melting furnace bath 1 perpendicular to the end wall of the loading pocket 23 between the charge loaders 19.

An example implementation of the invention

The invention was implemented with the values of the parameters indicated in the table.

The total consumption of natural gas (m ³ / hour) 300 400 1000 2000 2500 Total burner heat output (GJ / h) 3.2 7.9 30,2 60.61 70 Water consumption (l / min) 300 340 350 360 400 Inlet water temperature (° C) fifteen twenty thirty 40 fifty

The table shows the values of the parameters at which the method was implemented: the total consumption of natural gas, the total thermal productivity of the burners, water consumption, water temperature at the inlet. In the indicated ranges of parameter values, the homogeneity of the glass melt and stabilization of the position of the charge boundaries at the required distance from the side walls were ensured.

When the total consumption of natural gas is less than 400 m ³ / h and the total thermal productivity of the burners is less than 7.9 GJ / h, it is difficult to heat the glass and its homogenization.

With a total natural gas flow rate above 2000 m ³ / h and a total burner heat output above 60.61 GJ / h, the maximum temperature zone in the glassmaking bathtub approaches the end wall of the loading pocket, which complicates the regulation of conventional flows along the length of the bathtub and dramatically increases water consumption to reduce the temperature of the glass before serving in the float bath. For a similar reason, you should not reduce the water flow below 340 l / min and increase the temperature of the inlet water above 40 ° C. An increase in water flow above 360 l / min leads to supercooling of the glass melt around the submersible axial element and, as a result, to a violation of the homogeneity of the glass melt.

The technical result of the invention is achieved using a combination of features, including a range of parameters specified in the claims.

The implementation of the invention

The method of operation of the line for the production of sheet polished glass is as follows.

The mixture is loaded into the bathroom glass melting furnace 1 using six loaders 19 table type and continuous operation with a capacity of each of them from 1.8 t / h to 6.5 t / h, and the stroke of the loader table is from 0.14 m to 0 , 25 m.

The mixture is melted in the cooking basin of the bathtub of a glass melting furnace 1 by supplying gas through a chamber burner 22 with a total flow rate of natural gas from 400 m ³ / h to 2000 m ³ / h, with a total flow rate of fan air from 2975 m ³ / h to 21625 m ³ / hour, with a total heat output of burners from 7.9 GJ / h to 60.61 GJ / h, and a pressure of the first burner from 0.3 MPa to 0.4 MPa, and a pressure from the second to the sixth burner from 0.0025 MPa up to 0.069 MPa.

The mixture melts and forms a glass melt 24 and it continuously moves under the influence of generation and thermal convection. By lowering the temperature of the glass melt 24 along the longitudinal axis of the bath of the glass melting furnace 1 below the temperatures established at the side walls, the immersion axial element (axial cooler) 20 redistributes the circulation flows of the glass melt 24, directing them from the side walls of the bathroom of the glass melting furnace 1 to the longitudinal axis - the center of the bathroom of the glass melting furnace 1, figure 4 shows the circulation flows of the glass melt 24 in a longitudinal section of the bathtub of a glass melting furnace 1. The water flow of the submersible axial element 340 l / min - 360 l / min, and the inlet temperature is from 20 ° C to 40 ° . The mixture floating on the surface of the glass melt 24, moves the circulation flows to a certain distance from the side walls of the bathroom glass melting furnace 1 to its center.

After the production channel 2, the molten glass 24 enters the float bath 3. A strictly dosed amount of the molten glass 24 flows onto the mirrored surface of the molten tin and, spreading over it, turns into a ribbon of equilibrium thickness. The molded glass tape further advances along the surface of the tin, gradually cools (up to 600 ° C) and is transferred to the annealing furnace 4. The moving glass tape passes through 8 thermal zones and leaves cooled to 60 ° C with an internal voltage within the permissible limits.

After the annealing furnace 4, the glass tape enters the roller conveyor of terminal operations 15. The quality of the glass is determined in the viewing cabin of the glass tape 6. The glass tape passes under the beams of longitudinal and transverse cutting 7, while longitudinal and transverse cuts are applied. The breaking shaft breaks off the incised sheet and the sheet enters the side-breaking section 8, where the incised sides break off with rollers installed in a fixed position. A sheet of glass is blown off by a device for blowing off scree 16 to clean the glass sheet from small glass particles and passes by a control cabin 12, after which it is sent to a specific pick-up (reception) table 13, in accordance with the glass brand. The sheets are sent to the pick-up table (on an air cushion) by the scavengers 9. The protective coating is applied by the spraying beam 11 before the glass sheets arrive on the scooters, the glass sheets are manually removed from the pick-up tables and vertically installed in the prepared boxes on the pyramids 10. There is also a cut-off table 14, which serves for separating high quality glass from low quality.

The removal of glass sheets from the cut table is carried out manually in horizontally installed drawers.

The present invention can be implemented using known materials and means and is most effectively used in the operation of lines for the production of polished glass sheets containing a glass melting bath furnace with a capacity of 170 tons / day to 270 tons / day.

Claims (1)

A method of operating a line for the production of sheet polished glass, including loading the charge into the bathroom of a glass melting furnace through a loading pocket, melting the mixture in the cooking pool by supplying gas through chamber burners and burning it in the cooking pool of the glass melting furnace with the formation of glass melt, which is homogenized, while reducing temperature before serving in the float bath, where it is converted into a glass ribbon and then enters the annealing furnace, then to the roller table, and then fed to the cutting section, where it is bonded onto glass blanks, which are then packed in containers for finished products, characterized in that the charge is supplied by six table loaders with a productivity of each from 1.8 to 6.5 t / h, and the stroke of the loader table is from 0.14 to 0.25 m, while the gas supply is carried out through chamber burners with a total flow rate of natural gas from 400 to 2000 m ³ / h, with a total flow rate of fan air from 2975 to 21625 m ³ / h, with a total heat output of burners from 7.9 up to 60.61 GJ / h and pressure of the first burner from 0.3 to 0.4 MPa, and a pressure from the second to the sixth burner from 0.0025 to 0.069 MPa, moreover, the homogenization and lowering of the temperature of the glass melt is carried out by cooling it with a submersible axial element with a water flow rate of 340 - 360 l / min and a temperature of inlet from 20 to 40 ° C.

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