RU2392235C1 - Method for loading charge into glass furnace - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: method of loading charge into glass furnace includes mixing initial components of charge in mixer, its moistening and supply into furnace. Prior to delivery to furnace, charge is transported into mixer of continuous action with wall throwing blades arranged with displacement on shaft and installed directly over hopper of charge loader into furnace. At the same time crushed glass is added with size of pieces 5-30 mm in amount of 5-25%, moistening agent with temperature of 40-120°C. Mixture is additionally mixed by throwing-in loose materoal into space of mixer and its lifting from wall of mixer until Froude number becomes more than 1. Charge after additional mixing has a specified complex of properties: temperature 35-60°C, moisture 4-7%, homogeneity of charge with permissible deviations by components 0-0.5% - of at least 80%; 0.51-0.8% - not more than 20%.

EFFECT: improved quality of glass in process of melting and reduced consumption of energy for glass melting, improved conditions of operation and increased service life of glass melting furnace.

1 tbl

Description

The invention relates to the glass industry, in particular to the cooking of glass in bath furnaces.

There are various methods of preparing the mixture before loading it into a glass melting furnace.

So, the preparation of the mixture, implemented during glass melting in the bathroom direct heating furnace, includes feeding the mixture through the chimney, where it is heat treated and poured into the furnace through the riser (SU 289976). The disadvantages of this invention are heat treatment of the mixture at high temperature, which leads to the removal of moisture from it and a low rate of silicate formation reactions, as well as to high dust removal and the possibility of stagnation of the charge agglomerate when it is heated.

A known method of loading a charge into a glass melting furnace, including mixing the prepared components of the charge, their moistening and preliminary heat treatment of the charge before loading (SU 5741342).

Closest to the invention in technical essence and the achieved result is a method of loading a charge, implemented in a device for loading a charge (RU 2242436). A known method is that the mixture goes through several stages of preparation for glass melting. So, the components of the charge preheated to (50-60) ° C are mixed in a mixer, where the resulting mixture is moistened with water at a temperature of (60-70) ° C until the moisture content is (4-5)% and granulated in a screw granulator, which prevents sticking components of the charge and provides its higher thermal conductivity. Then, the charge is fed to inclined partitions, where it is subjected to heat treatment with flue gases at a temperature of (820-830) ° С, and due to the interaction of water vapor with soda, caustic soda is formed, which accelerates the reaction of silicate formation.

The disadvantages of the known methods of loading the mixture into a glass melting furnace are insufficient moisture and homogeneity of the mixture and, as a result, the low cooking speed and quality of the glass melt, which are explained by the fact that the mixture prepared in the composite workshop has high uniformity and humidity (4.5-5)% ( higher humidity cannot be ensured due to its sticking to the walls of the mixer and equipment for transporting and feeding the mixture into the furnace (elevators, conveyors, feeders, bins, etc.), however, it is ready in the process of transportation the charge of a composite plant to the place of its loading to the furnace are significantly reduced charge humidity (0.5-2%) and uniformity (due peresypok, vibration belts, etc.). When working in the winter season, this is supplemented by a decrease in the temperature of the charge by (10-20) ° C, which also negatively affects the quality of the charge and, accordingly, the operation of a glass melting furnace.

The technical result of the claimed invention is to improve the quality of glass and reduce energy consumption for glass melting by accelerating the glass melting process, increasing the uniformity of the mixture of the charge-cullet (with a significant improvement in the quality of the mixture itself) and the uniform distribution in the volume of the mixture along the width of the furnace. The proposed method also allows to reduce dusting and charge transfer to regenerators, thereby reducing the wear of refractories of the furnace upper structure and nozzles of regenerators and to increase the duration of the campaign of a glass melting furnace.

The specified technical result is achieved by the fact that in the method of loading the mixture into a glass melting furnace, including mixing the initial components of the mixture in the mixer, moistening it and feeding it into the furnace, before feeding the furnace into the furnace, the mixture is transported into a continuous mixer with wall-mounted casting blades located offset from the shaft installed directly above the hopper of the charge loader in the furnace, add a cullet with a size of pieces (5-30) mm in the amount of (5-25)%, a moisturizing agent with a temperature of (40-120) ° С and additionally mix by throwing bulk material into the space of the mixer and raising it from the wall of the mixer until the Froude number is greater than 1. Moreover, the mixture after additional mixing has a given set of properties: temperature (35-60) ° C, humidity (4-7)%, uniformity with permissible deviation for components (0-0.5)% - at least 80%, with a deviation (0.51-0.8)% - not more than 20%.

The applicant experimentally established that it is precisely such a set of properties of the charged charge that provides an increase in the quality of glass, a decrease in the energy consumption (natural gas) for glass melting, and a decrease in the dust extraction of the charge.

When the charge temperature at the outlet of the mixer is above 60 ° C and humidity above 7%, the process of clumping of the charge begins, which leads to a sharp decrease in uniformity, delamination and partial sticking to the walls of the hopper of the charge of the glass furnace furnace, increase fuel consumption and reduce glass quality.

When the charge temperature at the outlet of the mixer is lower than 35 ° С and humidity below 4%, the process of silicate formation and the rate of penetration of the charge slows down, which necessitates an increase in fuel consumption for glass melting, and worsens the quality of the glass. In addition, under these conditions there is an increased dust removal of the charge, accelerating the corrosion of refractories of the upper structure and regenerators of the glass melting furnace.

The proposed method of loading the mixture into a glass furnace is as follows. In the composite workshop, the components of the charge are dosed in accordance with a given recipe, mixed in a mixer and moistened with water to the required humidity (4-5)%. Then the charge is transported to the production workshop to the loading pocket of the glass melting furnace. Before feeding into the furnace, the charge is loaded into a continuous mixer with wall-mounted casting blades located with mixing on a shaft mounted directly above the hopper of the charge loader in the furnace. At the same time, a cullet with a size of pieces (5-30) mm in the amount of (5-25)% is added, a moisturizing agent with a temperature of (40-120) ° С and additionally mixed until a mixture of a charge and cullet with the required quality indicators is obtained.

The mixer is a horizontal cylindrical mixing tank, with mixing tools displaced and similar to a plow share turning on the shaft, whose size, position and speed, as well as the geometrical shape of which are designed and adjusted to each other so that they cast bulk material from lower layer into the mixing free space and lift it from the drum wall in spite of centrifugal force. When the Froude number is more than 1, the generated mechanical vortex layer with constant coverage of the entire volume of the mixed material provides intensive mixing even with a large throughput of the mixed material and a short aging time. Due to the shape of the mixing tool, the mixed material rises from the drum wall and thereby eliminates crushing / crushing of particles between the wall and the tool. For other specific requirements, stirring tools can also be adjusted without the effect of lifting. The described continuous mixer can be used on glass melting furnaces in the production of various types of glasses.

The table shows the specific modes of execution of the mixing method.

Table Mixer Performance 80 m ³ / h when mixing in a stream Product Charge and cullet The composition of the mixture on one plumb line: - charge 2200 kg Cullet 330 kg (15%) The grain size of the components of the charge (0.1-2.0) mm The size of the pieces of cullet (10-15) mm Moisturizing agent Hot water Agent Temperature 80 ° C Froude number 1,2 Mixture humidity: - at the entrance to the mixer 3.5% - at the exit of the mixer 5.5% Mixture temperature: - at the entrance to the mixer 20 ° C - at the exit of the mixer 50 ° C The homogeneity of the mixture in terms of tolerances for the components: - at the entrance to the mixer (0-0.5)% - 60% (0.51-0.8)% - 40% - at the exit of the mixer (0-0.5)% - 90% (0.51-0.8)% - 10%

The results shown in the table show that the mixture after additional mixing has a given set of properties: temperature 50 ° C, humidity 5.5%, uniformity with tolerances on components (0-0.5)% - 90%; (0.51-0.8)% - 10%.

From the data given in the table it follows that the proposed method of loading the mixture into a glass melting furnace allows to obtain a mixture with a given set of properties, namely: temperature (35-60) ° C, humidity (4-7)%, uniformity with allowable deviations for the components ( 0-0.5)% - not less than 80%, with deviations (0.51-0.8)% - not more than 20%, which ensures an increase in the quality of welded glass and a decrease in fuel consumption for glass melting.

Thus, the proposed method of loading the mixture into a glass melting furnace eliminates almost all the disadvantages of the existing method:

- additional mixing and moistening of the mixture occurs directly above the place of supply of the mixture into a glass melting furnace;

- eliminates the decrease in the uniformity of the mixture that occurs during its transportation;

- compensated for the loss of moisture in the mixture during its transportation and intermediate storage in stock bins;

- allows you to bring the moisture content of the mixture before feeding into the furnace to the optimum value (5-7)% without reducing its uniformity and the deterioration of the working conditions of the transport equipment;

- allows you to restore the heat loss of the charge during transportation and increase its temperature before loading into the furnace to (35-60) ° C;

- feeding the heated mixture into the feed hopper above the loader, having a temperature of more than 80 ° C due to heat radiation from the glass melting furnace, allows you to accelerate the process of silicate formation in the mixture itself;

- allows you to drastically reduce and virtually eliminate the dusting and entrainment of charge components into regenerators and thereby reduce the corrosion rate of upper refractories and regenerators and increase the duration of the overhaul period of operation of a glass melting furnace.

Claims (1)

A method of loading a mixture into a glass melting furnace, comprising mixing the initial components of the mixture in a mixer, moistening it and feeding it to the furnace, characterized in that before being fed into the furnace, the mixture is transported to a continuous mixer with wall-mounted casting blades located with an offset on the shaft mounted directly above with the bunker of the charge loader in the furnace, a cullet with a size of 5-30 mm in the amount of 5-25%, a moisturizing agent with a temperature of 40-120 ° C is added and further mixed by throwing on the bulk material into the space of the mixer and raising it from the wall of the mixer to reach the Froude number is greater than 1, and the mixture after additional mixing has a given set of properties: temperature 35-60 ° C, humidity 4-7%, uniformity with a tolerance of 0-0 for components 5% - not less than 80%, with a deviation of 0.51-0.8% - not more than 20%.