Double-tank kiln with liquid depth difference between front tank and rear tank and method

Abstract

The invention discloses a double-tank kiln with liquid depth difference between a front tank and a rear tank and a method, the kiln comprises the front tank and the rear tank, the liquid depth of the front tank is larger than that of the rear tank, and the liquid depth difference between glass liquid in the front tank and the liquid depth difference between glass liquid in the rear tank is larger than or equal to 300 mm. The kiln comprises a forebay combustion furnace, a forebay electrode, a feeding port, a afterbay combustion furnace, a discharging port, a afterbay electrode and a throat. The method comprises the following steps: introducing pure oxygen into a forebay combustion furnace for combustion, so that the added raw materials are quickly melted into molten glass; air is introduced into the afterbay combustion furnace to support combustion, and high temperature is kept to facilitate bubble discharge. The kiln disclosed by the invention is suitable for special glass, has higher quality requirements on glass, and is particularly suitable for melting refractory glass (high-silicon and high-aluminum glass and the like), glass with higher clarification requirements and the like; and the melting efficiency and quality of the molten glass are effectively improved, and the glass raw material can be fully and uniformly melted, clarified and homogenized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of special glass melting equipment, and relates to a kiln, in particular to a double-pool kiln with liquid depth difference between front and rear pools and a method. BACKGROUND

[0002] In the field of glass fiber manufacturing, especially in the production of ultra-fine fibers and other high-performance special fibers, the purity, chemical homogeneity and thermal stability of the glass liquid directly determine the performance of the final product. Similarly, in the high-end manufacturing field of optical glass (such as camera lenses, optical fiber preforms) and special glass (such as display screen substrates, radiation-proof glass), the glass liquid must meet the almost stringent standards of bubble rate, striation degree and impurity content. Therefore, the core equipment for melting high-quality glass liquid, the glass kiln, directly restricts the product yield and the industrial upgrading process.

[0003] Traditional single-pool kilns have significant limitations when dealing with such high requirements. The single-melt pool structure is difficult to optimize both the melting and the clarification homogenization processes, which are inherently contradictory: increasing the melting temperature can accelerate the reaction of raw materials, but excessively high temperature will hinder the escape of bubbles (clarification process) and intensify the erosion of refractory materials, introducing impurities; while reducing the temperature is beneficial to clarification, but will lead to a sharp decline in melting efficiency. Therefore, single-pool kilns often fall into the dilemma of "trade-off", making it difficult to stably produce ultra-low defect high-quality glass liquid.

[0004] Some ordinary double-pool kilns attempt to solve the contradiction by physically separating the melting zone and the clarification zone, but in actual application, their structural design and heating methods often have key defects. For example, if the flow liquid hole between the melting pool and the clarification pool is designed unreasonably, it will cause uneven glass liquid flow rate or local retention, forming new composition segregation or micro-bubble aggregation zones. This leads to large fluctuations in glass liquid quality, poor product consistency, and high energy consumption costs, making it difficult to meet the economic and environmental requirements of high-end glass manufacturing. Therefore, a special kiln is needed that can optimize the glass liquid melting and clarification homogenization process and improve the quality of the glass liquid. SUMMARY

[0005] In view of the defects and deficiencies of the prior art, the purpose of the present application is to provide a double-pool kiln with liquid depth difference between front and rear pools and a method, which solves the technical problems of unstable glass liquid quality, high energy consumption and poor clarification homogenization effect when using a kiln to melt high-quality glass liquid in the prior art.

[0006] To solve the above technical problems, the present application adopts the following technical solutions: A kind of front and rear pool has the double-pool furnace with liquid depth difference, including front pool and rear pool, the liquid level depth L1 of glass liquid in front pool is greater than or equal to 800mm, the liquid level depth L2 of glass liquid in rear pool is less than or equal to 800mm, the liquid level difference of glass liquid in front pool and rear pool is greater than or equal to 300mm;The top of the front pool is provided with front pool combustion furnace, the front wall of front pool combustion furnace is provided with feeding port, the bottom of the front pool is provided with multiple front pool electrodes;The top of the rear pool is provided with rear pool combustion furnace, the rear wall of rear pool is provided with discharge port, the bottom of the rear pool is provided with multiple rear pool electrodes;Flow liquid hole is arranged between the front pool and the rear pool.

[0007] The present application also has the following technical features: Specifically, the feeding port is located on the front pool wall along a height greater than 150mm, and is located at the transverse middle position of the front wall of the front pool.

[0008] Specifically, the height L3 of the discharge port is 150mm-250mm.

[0009] Specifically, the front pool and the rear pool are each provided with a temperature monitoring device and a liquid level monitoring device.

[0010] The present application also protects a method for melting glass, which is implemented using the double-pool furnace with liquid level difference as described above; the method comprises: feeding raw materials for preparing glass into the front pool combustion furnace from the feeding port, and burning pure oxygen in the front pool combustion furnace to rapidly melt the added raw materials into glass liquid; the glass liquid then flows into the front pool and continues to be accelerated in melting and clarified and homogenized under the action of the front pool electrodes; the glass liquid flows into the rear pool through the flow liquid hole, and is further accelerated in melting and clarified and homogenized under the action of the rear pool electrodes, and air is fed into the rear pool combustion furnace for combustion to maintain a high temperature to facilitate bubble discharge.

[0011] Specifically, the front pool combustion furnace adopts horizontal combustion when burning pure oxygen, and the center of the flame is between 350mm and 500mm from the surface of the glass liquid.

[0012] Specifically, the rear pool combustion furnace adopts air combustion, and the center of the flame is between 400mm and 600mm from the surface of the glass liquid.

[0013] Compared with the prior art, the present application has the following beneficial technical effects: (Ⅰ) The furnace of the present application has front and rear double pools, the liquid depths of the two pools are different, and the two pools are connected by a raised flow liquid hole, so that high-quality glass liquid that is well melted and free of impurities enters the rear pool for clarification and homogenization; at the same time, the front pool adopts a combination of lower electrode heating and upper pure oxygen combustion for melting, and the rear pool adopts a combination of lower electrode heating and upper air combustion for clarification and homogenization, which effectively improves the melting efficiency and quality of the glass liquid, and enables the glass raw materials to be more fully and uniformly melted, clarified and homogenized.

[0014] (II) The present application brings obvious production efficiency and product quality improvement to the special glass fiber and special glass industry, and plays a huge social and economic benefit in promoting the kiln design technology and application. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The structural schematic diagram of the double-pool kiln with liquid depth difference between the front pool and the rear pool.

[0016] The meanings of the reference numbers in the figure are as follows: 1-front pool, 2-rear pool, 3-front pool combustion furnace, 4-feeding port, 5-front pool electrode, 6-rear pool combustion furnace, 7-discharge port, 8-rear pool electrode, and 9-flowing liquid hole.

[0017] The technical solutions of the present application are further described below in combination with the embodiments. DETAILED DESCRIPTION

[0018] It should be noted that the components used in the present application are all conventional components known in the prior art unless otherwise specified.

[0019] In accordance with the above technical solutions, the specific embodiments of the present application are given below. It should be noted that the present application is not limited to the following specific embodiments, and any equivalent variations made on the basis of the technical solutions of the present application fall within the protection scope of the present application.

[0020] Embodiment 1 This embodiment gives a double-pool kiln with liquid depth difference between the front pool and the rear pool, as shown in Figure 1 The double-pool kiln includes a front pool 1 and a rear pool 2. The liquid level depth L1 of the glass liquid in the front pool 1 is greater than or equal to 800 mm, and the liquid level depth L2 of the glass liquid in the rear pool 2 is less than or equal to 800 mm. The liquid depth difference (i.e. the height of the flowing liquid hole 9, L1-L2) of the glass liquid in the front pool 1 and the rear pool 2 is greater than or equal to 300 mm. A front pool combustion furnace 3 is arranged on the top of the front pool 1. A feeding port 4 is formed on the front wall of the front pool combustion furnace 3. A plurality of front pool electrodes 5 are arranged in the bottom of the front pool 1. A rear pool combustion furnace 6 is arranged on the top of the rear pool 2. A discharge port 7 is formed on the rear wall of the rear pool combustion furnace 6. A plurality of rear pool electrodes 8 are arranged in the bottom of the rear pool 2. A flowing liquid hole 9 is arranged between the front pool 1 and the rear pool 2.

[0021] In this embodiment, the kiln has front and rear double pools. The front pool 1 mainly plays the role of rapid melting and homogenization, and the rear pool 2 has the roles of homogenization and clarification. The liquid depths of the two pools are different, and the high flowing liquid hole 9 is connected to make the high-quality glass liquid with good melting and no impurities enter the rear pool for clarification and homogenization, so as to produce high-quality glass liquid. The discharge port with a certain height makes the better quality glass liquid enter the product manufacturing process again.

[0022] As a specific scheme of the embodiment, the feeding port 4 is connected with the inner cavity of the fore-pool combustion furnace 3, the inner cavity of the fore-pool combustion furnace 3 is connected with the fore-pool 1, the fore-pool 1 is connected with the back-pool 2 through the liquid flow hole 9, the back-pool combustion furnace 6 is connected with the inner cavity of the back-pool 2, and the inner cavity of the back-pool 2 is connected with the discharging port 7.

[0023] As a specific scheme of the embodiment, the feeding port 4 is located on the pool wall of the fore-pool 1 at a height greater than 150 mm and at the transverse middle position of the front wall of the fore-pool 1.

[0024] As a specific scheme of the embodiment, the height L3 of the discharging port 7 is 150 mm to 250 mm.

[0025] As a specific scheme of the embodiment, the pool wall and the pool bottom of the fore-pool 1 and the back-pool 2 are made of high-quality refractory materials resistant to high temperature and corrosion, such as dense chrome or dense zirconium bricks, high-silicon oxygen fiber, and other special glasses such as microcrystalline glass kiln, etc. 41# AZS electrically fused bricks are often used to ensure the stability and service life of the kiln in a high-temperature environment. The specific material can be selected according to the requirements of different glasses.

[0026] As a specific scheme of the embodiment, the fore-pool 1 and the back-pool 2 are both provided with temperature monitoring devices and liquid level monitoring devices, which can monitor the temperature and liquid level changes of the glass liquid in real time, so that the operator can timely adjust the heating power and the feeding amount and other parameters, to ensure the stable operation of the kiln and the quality of the glass liquid.

[0027] As a specific scheme of the embodiment, the double-pool kiln is equipped with a waste gas treatment system to purify and treat the waste gas generated during the combustion process, reducing the pollution to the environment.

[0028] Embodiment 2: The embodiment provides a method for melting high-quality glass, which uses the double-pool kiln with different liquid depths of the fore-pool and the back-pool in the embodiment 1. The method is as follows: the raw materials for preparing glass are fed into the fore-pool combustion furnace 3 from the feeding port 4, pure oxygen is introduced into the fore-pool combustion furnace 3 for combustion, so that the added raw materials are quickly melted into glass liquid; the glass liquid then flows into the fore-pool 1 and continues to be accelerated and clarified and homogenized under the action of the fore-pool electrode 5; the glass liquid flows into the back-pool 2 through the liquid flow hole 9, and is further accelerated and clarified and homogenized under the action of the back-pool electrode 8, air is introduced into the back-pool combustion furnace 6 for combustion, and high temperature is maintained to facilitate bubble discharge.

[0029] In this embodiment, electrode heating can precisely control the temperature of the lower part of the glass liquid, ensuring that the glass raw materials can be fully melted at the bottom, and the pure oxygen combustion of the front tank combustion furnace 3 provides strong heat to accelerate the melting process of the glass raw materials. The upper and lower parts are heated cooperatively, which greatly improves the melting efficiency and quality of the glass liquid; the heating of the rear tank electrode plays an obvious role in homogenization and clarification, and the air combustion of the rear tank combustion furnace 6 is beneficial to the removal of bubbles and clarification; the front tank and the rear tank are connected through the raised liquid flow hole, and the raised hole opening can prevent impurities at the bottom of the front tank from entering the rear tank.

[0030] As a specific solution of this embodiment, the way adopted by the front tank combustion furnace 3 when performing pure oxygen combustion is horizontal combustion, which can be misburning or counterburning, and the selection can be determined according to the width of the kiln.

[0031] As a specific solution of this embodiment, when the rear tank combustion furnace 6 performs air combustion, the center of the flame is between 400 mm and 600 mm away from the surface of the glass liquid.

[0032] Effect verification: Using the method of embodiment 2, the final product obtained is a high-quality lithium-aluminum-silicon-based microcrystalline glass suitable for mobile phone covers, and the specific components are: 71.5 wt% of silicon dioxide, 14.5 wt% of aluminum oxide, 7.3 wt% of lithium oxide, 2 wt% of calcium oxide, 1.5 wt% of titanium dioxide, 1.5 wt% of zirconium oxide, 1.2 wt% of boron oxide, 0.5 wt% of other trace components, etc. In the daily production of 2 tons of microcrystalline glass, the amount of natural gas used for pure oxygen combustion in the front tank is 32 Nm 3 / h, the electrode power is 26 kw / h, the amount of natural gas used for air combustion in the rear tank is 25 Nm 3 / h, and the electrode power is 20 kw / h. According to relevant data, it can also be calculated that 6350 large calories of energy are consumed to melt each kilogram of microcrystalline glass, which has a significant energy-saving advantage compared with the consumption of more than 7500 large calories per kilogram of glass in the prior art. But the most important thing is the obvious advantage of being able to produce high-quality glass: for example, there are no visible bubbles in the glass product, and the number of pores in the glass used for mobile phone covers is ≤1 / mm 2 , the number of micro-bubbles in the related glass can be very stably controlled at ≤3 / 10 kg of glass, and there are no stones and stripes. As shown in Table 1, compared with the traditional single-tank kiln, the glass produced by the present invention has better production quality.

[0033] Table 1, performance comparison of the same type of glass produced by the traditional single-tank kiln and the kiln of the present invention

Claims

1. A double-pool kiln with a difference in liquid depth between the front and rear pools, comprising a front pool (1) and a rear pool (2), characterized in that, The liquid level depth L1 of the glass melt in the front pool (1) is greater than or equal to 800 mm, the liquid level depth L2 of the glass melt in the rear pool (2) is less than or equal to 800 mm, and the liquid depth difference between the glass melt in the front pool (1) and the rear pool (2) is greater than or equal to 300 mm. A fore-pool combustion furnace (3) is provided on the top of the fore-pool (1), and a feeding port (4) is provided on the front wall of the fore-pool combustion furnace (3). Multiple fore-pool electrodes (5) are provided in the bottom of the fore-pool (1). A rear-pool combustion furnace (6) is provided on the top of the rear-pool (2), and a discharge port (7) is provided on the rear wall of the rear-pool (2). Multiple rear-pool electrodes (8) are provided in the bottom of the rear-pool (2). A flow hole (9) is provided between the fore-pool (1) and the rear-pool (2).

2. The double-pool kiln with a difference in liquid depth between the front and rear pools as described in claim 1, characterized in that, The feeding port (4) is located at a height of more than 150mm above the wall of the forepool (1) and in the middle of the transverse direction of the front wall of the forepool (1).

3. The double-pool kiln with a difference in liquid depth between the front and rear pools as described in claim 1, characterized in that, The height L3 of the discharge port (7) is 150mm to 250mm.

4. The double-pool kiln with a difference in liquid depth between the front and rear pools as described in claim 1, characterized in that, Temperature monitoring devices and liquid level monitoring devices are installed in both the forepool (1) and the rearpool (2).

5. A method for melting glass, wherein the method is implemented using a double-pool furnace with a difference in liquid depth between the front and rear pools as described in any one of claims 1 to 4, characterized in that, The method includes: The raw materials for preparing glass are fed into the forepool combustion furnace (3) through the feeding port (4). Pure oxygen is introduced into the forepool combustion furnace (3) for combustion, so that the added raw materials are quickly melted into glass liquid. The glass liquid then flows into the forepool (1) and continues to melt and clarify under the action of the forepool electrode (5). The glass liquid flows into the rear pool (2) through the flow hole (9), and melts and clarifies under the action of the rear pool electrode (8). Air is introduced into the rear pool combustion furnace (6) to assist combustion and maintain high temperature to facilitate the discharge of bubbles.

6. The method for melting glass as described in claim 5, characterized in that, When the forepool combustion furnace (3) performs pure oxygen combustion, it adopts horizontal combustion, and the flame center is 350mm to 500mm away from the glass liquid surface.

7. The method for melting glass as described in claim 5, characterized in that, When the back pool combustion furnace (6) is used for air-assisted combustion, the distance between the flame center and the glass liquid surface is between 400mm and 600mm.

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