Regional efficient oxygen-fuel glass kiln and process

Abstract

The present invention provides a zoned oxygen-fuel glass kiln comprising: a primary melting zone for melting a batch fed from a feed port to form a molten glass, the primary melting zone comprising at least one first heater to heat the batch and the molten glass, the first heater may comprise an electrically-boosted heater, an air burner or a total oxygen burner; the clarifying-homogenizing zone is arranged at the downstream of the primary melting zone, is communicated with the primary melting zone and is used for clarifying and homogenizing the molten glass from the primary melting zone; the device is characterized in that at least one second heater is arranged on the side wall of the clarifying-homogenizing area so as to heat the molten glass, and the second heater comprises a total oxygen burner. In the prior art, the processes of primary melting, clarification and homogenization are carried out and completed in one molten pool, however, the molten pool is divided into two physical division areas, namely a primary melting area and a clarification-homogenization area, and efficient oxygen-fuel combustion is adopted in the clarification-homogenization area.

Description

Technical Field

[0001] This invention relates to a zoned, high-efficiency oxygen-fuel glass furnace and process. Background Technology

[0002] In the glass manufacturing process, a glass furnace is used to heat and melt the batch materials at high temperatures into molten glass that meets the forming requirements. This generally includes five stages: 1. Silicate formation stage: After entering the furnace, the batch materials undergo a series of physical, chemical, and physicochemical changes rapidly at 800-1000℃, such as powder heating, moisture evaporation, salt decomposition, and polycrystalline transformation; 2. Molten glass formation stage: The batch materials are heated to 1200℃, forming various silicates and a molten body, until the temperature reaches approximately 1300℃, at which point molten glass begins to form; 3. Molten glass clarification stage: Visible gases are removed from the molten glass. The stage of removing inclusions and eliminating porosity is called the refining stage. This process must be completed at high temperatures because the viscosity of glass decreases rapidly with increasing temperature. 4. Glass molten homogenization stage: After the glass molten glass is formed, the chemical composition and temperature of different parts of the glass molten glass are different, and some inhomogeneities are also included. Therefore, a homogenization process is required. The principle mainly relies on diffusion and convection. 5. Glass molten cooling stage: In order to facilitate glass forming, the glass molten glass must be uniformly cooled to the forming temperature. Generally, the forming temperature is 200-300℃ lower than the refining temperature.

[0003] Figure 1 A prior art glass furnace is shown, comprising a batch feed inlet 1, a molten glass discharge outlet 2, and an exhaust outlet 3. The furnace includes an upstream primary melting zone 4 and a downstream cooling zone 5. Multiple burners 6 are mounted on the sidewalls of the primary melting zone 4. Batch melting and molten glass clarification and homogenization take place in the primary melting zone 4. Molten glass cooling occurs in the cooling zone 5. A furnace sill is provided between the primary melting zone 4 and the cooling zone 5 to prevent molten glass backflow and to select the best-melted molten glass for entry into the cooling zone 5, thereby improving glass quality. However, in this type of glass furnace, the temperature and energy input in the primary melting zone are too high, resulting in low furnace efficiency.

[0004] Therefore, this application provides a zoned, high-efficiency oxygen-fuel glass furnace and process, wherein the molten pool is divided into two physically separated zones: an initial melting zone and a refining-homogenizing zone, in which efficient all-oxygen combustion is employed. Compared to traditional gas combustion methods, this invention can achieve higher temperatures and more complete combustion, thereby improving glass heating efficiency and reducing energy consumption; it reduces air pollutants such as nitrogen oxides in the exhaust gas during combustion; compared to traditional air combustion methods, it has a smaller environmental impact and meets modern environmental protection requirements; it can effectively reduce the impurity content in the glass, improving its purity and transparency; thereby reducing bubbles and defects in the glass and improving its quality; and it can achieve a more efficient combustion process, improving the furnace's thermal efficiency, thereby reducing energy consumption. Summary of the Invention

[0005] Aspects and advantages of the invention will be set forth in part in the description which follows, or may be apparent from the description, or may be learned by practice of the invention.

[0006] The present invention provides a zoned oxygen-fuel glass furnace, comprising: a primary melting zone for melting a batch material input from a feed inlet to form molten glass, the primary melting zone including at least one first heater for heating the batch material and the molten glass; and a refining-homogenizing zone downstream of and in communication with the primary melting zone for refining and homogenizing the molten glass from the primary melting zone; characterized in that at least one second heater is provided on the sidewall of the refining-homogenizing zone for heating the molten glass, wherein the second heater includes an oxygen burner. Attached Figure Description

[0007] The complete and feasible disclosure of the invention, including its preferred mode, to those skilled in the art is set forth in the description with reference to the accompanying drawings, in which:

[0008] Figure 1 The illustration schematically shows a glass furnace of the prior art;

[0009] Figure 2 A perspective view of the glass furnace of the present invention is schematically shown; and

[0010] Figure 3 A cross-sectional view of the glass furnace of the present invention is shown schematically. Detailed Implementation

[0011] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation rather than limitation of the invention. Indeed, it will be apparent to those skilled in the art that various modifications and variations may be made to the invention without departing from its scope. For example, a feature shown or described as part of one embodiment may be used with another embodiment to produce yet another embodiment. Therefore, the invention is intended to cover such modifications and variations as fall within the scope of the appended claims and their equivalents.

[0012] like Figure 2 and Figure 3 As shown, the present invention provides a zoned oxygen-fuel glass furnace, which may include a primary melting zone 11 for melting the batch material fed into the furnace through the feed inlet 12 to form molten glass. After entering the furnace, the batch material undergoes a rapid series of physical, chemical, and physicochemical changes, such as powder heating, moisture evaporation, salt decomposition, polycrystalline transformation, etc., forming various silicates and producing a melt, until molten glass begins to form.

[0013] In some embodiments, the feed inlet 12 may be located at the upstream end of the primary melting zone 11. The primary melting zone 11 includes at least one first heater 13 for heating the batch and molten glass. The first heater 13 may include an electric flux heater disposed at the bottom of the primary melting zone 11. Alternatively, the first heater 13 may include an air burner or an oxy-fuel burner disposed on the sidewall of the primary melting zone 11. The oxy-fuel burner can burn pure oxygen and natural gas. The oxy-fuel burner may be a flat-stage oxy-fuel burner from a gas products and chemicals company (e.g., see US Patent 5611682) or a two-stage oxy-fuel burner (e.g., see US Patent 10,584,051B2).

[0014] In some embodiments, the zoned oxygen-fuel glass furnace may further include a refining-homogenizing zone 14, which is downstream of and connected to the primary melting zone 11. This zone clarifies and homogenizes the molten glass from the primary melting zone 11, removing visible gas inclusions and performing a homogenization process to improve the quality and stability of the glass products. The refining-homogenizing zone 14 may be equipped with a glass melt agitator to further enhance the homogenization of the molten glass.

[0015] In some embodiments, the bottom of the clarification-homogenization zone 14 may be higher than the bottom of the initial melting zone 11.

[0016] In the clarification-homogenization zone 14, heating is performed using a highly efficient oxy-fuel combustion method. In some embodiments, at least one second heater 15 may be provided on the sidewall of the clarification-homogenization zone 14 to heat the molten glass. At least one second heater 15 may be located in the middle of the clarification-homogenization zone 14. The second heater 15 may include an oxy-fuel burner capable of burning pure oxygen and natural gas. The oxy-fuel burner may be the aforementioned flat-stage oxy-fuel burner or dual-stage oxy-fuel burner from a gas products and chemical company.

[0017] The first heater 13 and the second heater 15 are configured such that as much heat from fuel combustion as possible is transferred to the batch and molten glass, and as little heat as possible is transferred to the upper structure of the glass furnace. When the first heater 13 and the second heater 15 are burners, they may have a downward tilt angle, such that the flame runs parallel to and along the surface of the molten glass.

[0018] In some embodiments, the exhaust port 16 may be located at the upstream end of the primary melting zone 11 to discharge exhaust gases. The exhaust port may be connected to a waste heat recovery device (not shown). During the glass melting process, the molten glass absorbs only 40-45% of the heat, while the heat energy in the exhaust gas accounts for 30% of the total heat energy entering the glass furnace. Waste heat recovery can improve the energy efficiency of the glass furnace.

[0019] In some embodiments, the glass melt discharge port 17 may be located at the downstream end of the clarification-homogenization zone 14 for discharging the clarified and homogenized glass melt.

[0020] In some embodiments, a partition wall 18 may be provided between the initial melting zone 11 and the refining-homogenizing zone 14, thereby separating the space above the liquid surface in the initial melting zone 11 and the refining-homogenizing zone 14. A flow hole (not shown) is provided at the bottom of the partition wall 18. The molten glass can flow from the initial melting zone 11 to the refining-homogenizing zone 14 through the flow hole.

[0021] In existing technologies, melting, clarification, and homogenization are completed in the initial melting zone, followed by cooling in the cooling zone. The advantages of this invention are that the glass furnace of this invention completes melting in the initial melting zone and clarification and homogenization in the clarification-homogenization zone, eliminating the cooling zone and optimizing the burner arrangement, thereby reducing process temperature, saving energy, reducing emissions, and improving efficiency.

[0022] Compared to traditional combustion methods, this invention achieves higher temperatures and more efficient combustion, thereby improving glass heating efficiency and reducing energy consumption; it also reduces air pollutants such as nitrogen oxides in exhaust gases during combustion; compared to traditional air combustion, it has a smaller environmental impact and meets modern environmental protection requirements; it can effectively reduce the impurity content in glass, improving its purity and transparency; thus reducing bubbles and defects in glass and improving its quality; and it can achieve a more efficient combustion process, improving the thermal efficiency of the furnace and thus reducing energy consumption.

[0023] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any device or system and performing any incorporated methods. The patentability of the invention is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that are not different from the literal language of the claims, or if they include equivalent structural elements that are not substantially different from the literal language of the claims.

Claims

1. A zoned oxygen-fuel glass furnace, comprising: The primary melting zone (11) is used to melt the batch material fed from the feed port (12) to form molten glass. The primary melting zone (11) includes at least one first heater (13) to heat the batch material and the molten glass. as well as A clarification-homogenization zone (14), which is downstream of and connected to the initial melting zone, is used to clarify and homogenize the molten glass from the initial melting zone; The characteristic feature is that the sidewall of the clarification-homogenization zone (14) is provided with at least one second heater (15) for heating the molten glass, wherein the second heater (15) includes an oxygen burner.

2. The zoned oxygen-fuel glass furnace according to claim 1, characterized in that, The at least one second heater (15) is arranged in the middle of the clarification-homogenization zone.

3. The zoned oxygen-fuel glass furnace according to claim 1, characterized in that, The first heater (13) includes an electric flux heater, which is located at the bottom of the pool in the initial melting zone (11).

4. The zoned oxygen-fuel glass furnace according to claim 1, characterized in that, The first heater (13) includes an air burner or an oxygen burner, which is disposed on the side wall of the initial melting zone (11).

5. The zoned oxygen-fuel glass furnace according to claim 4, characterized in that, The first heater (13) and the second heater (15) have a downward tilt angle, such that the flame runs parallel to and forward along the liquid surface of the molten glass.

6. The zoned oxygen-fuel glass furnace according to claim 1, characterized in that, The oxygen-fuel glass furnace also includes an exhaust port (16) connected to a waste heat recovery device.

7. The zoned oxygen-fuel glass furnace according to claim 1, characterized in that, A partition wall (18) is provided between the initial melting zone and the clarification-homogenization zone, so that the space above the liquid surface of the initial melting zone and the clarification-homogenization zone is separated, and a flow hole is provided at the bottom of the partition wall.

8. A regionalized oxygen-fuel glass process, comprising: In the primary melting zone of a zoned oxygen-fuel glass furnace, the batch material fed from the feed inlet is melted to form molten glass. The primary melting zone includes at least one first heater to heat the batch material and the molten glass. as well as In the clarification-homogenization zone of the oxygen-fuel glass furnace with the subdivided area, the molten glass from the primary melting zone is clarified and homogenized, the clarification-homogenization zone being downstream of and connected to the primary melting zone; The characteristic feature is that the sidewall of the clarification-homogenization zone is provided with at least a second heater to heat the molten glass, wherein the second heater includes an oxygen burner.

9. The regionalized oxygen-fuel glass process according to claim 8, characterized in that, The at least one second heater is arranged in the middle of the clarification-homogenization zone.

10. The regionalized oxygen-fuel glass process according to claim 8, characterized in that, The first heater includes an electric flux heater, which is located at the bottom of the pool in the initial melting zone.

11. The regionalized oxygen-fuel glass process according to claim 8, characterized in that, The first heater includes an air burner or an oxygen burner, which is disposed on the sidewall of the initial melting zone.

12. The regionalized oxygen-fuel glass process according to claim 11, characterized in that, The first heater and the second heater have a downward tilt angle, such that the flame runs parallel to and forward along the surface of the molten glass.

13. The regionalized oxygen-fuel glass process according to claim 8, characterized in that, The oxygen-fuel glass process also includes connecting the exhaust outlet to a waste heat recovery device.

14. The regionalized oxygen-fuel glass process according to claim 8, characterized in that, A partition wall is provided between the initial melting zone and the clarification-homogenization zone, thereby separating the space above the liquid surface in the initial melting zone and the clarification-homogenization zone. A flow hole is provided at the bottom of the partition wall. The oxygen-fuel glass process includes allowing the molten glass to flow from the initial melting zone to the clarification-homogenization zone through the flow hole.

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