Fluorophosphorus glass smelting device and smelting method capable of preventing volatile matter from falling

Abstract

This invention is entitled "A Fluorophosphate Glass Melting Apparatus and Melting Method for Preventing Volatile Material Dropping," belonging to the technical field of optical glass melting production equipment. It primarily solves the problem of volatile material dropping from the feeding port and crucible top, affecting product quality. Its main features are: a melting crucible and a cylindrical screw feeder; the melting crucible includes a crucible body, a feeding port, a chimney, a liquid outlet, and a drain pipe; the feeding port is a feed pipe, located on opposite sides of the crucible body, separate from the chimney; the cylindrical screw feeder is connected to the feed pipe; the melting crucible is made of platinum, and the top is a non-flat top. This invention features the ability to avoid the generation of foreign matter in the product, improve the production yield, and enable uninterrupted melting production of fluorophosphate glass. It is mainly used for single-crucible melting or continuous melting of a portion of a crucible for fluorophosphate optical glass.

Description

Technical Field

[0001] This invention belongs to the technical field of optical glass melting production equipment, and relates to a glass melting device and melting method, particularly to a fluorophosphorus glass melting device for preventing volatiles from falling into the crucible and a melting method using the melting device. Background Technology

[0002] Fluorophosphate glass is a special type of optical glass with low refractive index and low dispersion. It can eliminate second-order spectral chromatic aberration and improve the image quality of optical lenses. It also has a low softening point and can be molded into aspherical lenses using single or double molding processes, making it an excellent optical material for producing advanced digital products. However, fluorophosphate glass exhibits strong volatility during the smelting and production process due to its high fluoride content.

[0003] During the melting process of fluorophosphorus glass, volatilization occurs before the glass melt solidifies, with the most severe stage being the melting of the glass raw materials. To avoid affecting the glass's transmittance due to impurities, existing fluorophosphorus glass melting equipment often uses a crucible made entirely of platinum for direct melting, with the feeding port located at the top of the crucible. Simultaneously, to accelerate melting and homogenization, a vent pipe is often installed at the top of the crucible. However, this design, as the production cycle lengthens, causes a large amount of fluorine-containing volatiles to condense at the feeding port or inside the crucible top. Furthermore, because some components of these volatiles have been lost, they are difficult to remelt. Especially during the clarification and homogenization stages, when a large amount of volatiles condense at the top of the crucible, they fall into the crucible and mix with the already melted glass, ultimately resulting in a large amount of unmelted foreign matter inside the fluorophosphorus glass product, severely affecting the quality of the product and even leading to its scrapping. Summary of the Invention

[0004] The purpose of this invention is to provide an apparatus and a melting method for fluorophosphorus glass melting, which solves the problem of volatiles falling from the feed port and the top of the crucible affecting product quality, avoids the generation of foreign matter in the product, improves the production yield, and realizes uninterrupted melting and production of fluorophosphorus glass.

[0005] The technical solution of the smelting apparatus of the present invention is: a fluorophosphorus glass smelting apparatus to prevent volatiles from falling, comprising a melting crucible, the melting crucible including a crucible body, a feeding port, a chimney, a liquid outlet and a discharge pipe, characterized in that: it further includes a cylindrical screw feeder; the feeding port is a feed pipe, which is located on both sides of the crucible body separately from the chimney; the cylindrical screw feeder is connected to the feed pipe; the melting crucible is made of platinum material and the top of the crucible is a non-flat top.

[0006] In the technical solution of the smelting apparatus of the present invention, the top of the crucible is a dome-shaped top, which is smoothly tangent to the side wall of the crucible and the spout of the chimney.

[0007] In the technical solution of the smelting apparatus of the present invention, the top of the crucible is an inclined top, and the angle between it and the horizontal direction is ≥30°.

[0008] In the technical solution of the smelting device of the present invention, the melting crucible and the cylindrical screw feeder are designed separately; the feed pipe is provided with a docking interface; before smelting, the feeder docking interface of the cylindrical screw feeder is used to connect with the docking interface.

[0009] In the technical solution of the smelting apparatus of the present invention, a heating electrode is provided at the connection between the feed pipe and the crucible body.

[0010] In the technical solution of the smelting apparatus of the present invention, the feed pipe is arranged in a horizontal direction or an upward oblique direction; the chimney is arranged in a horizontal direction or an downward oblique direction.

[0011] In the technical solution of the smelting apparatus of the present invention, the chimney is set at an angle downwards, and the spout of the chimney is located in the middle of the chimney.

[0012] In the technical solution of the smelting apparatus of the present invention, the crucible body is provided with a vent pipe.

[0013] The technical solution of the melting method of the present invention is: a method for melting fluorophosphorus glass to prevent volatiles from falling, characterized in that: a cylindrical screw feeder is connected to a feed pipe, fluorophosphorus glass production raw materials are fed into the feed port of the cylindrical screw feeder, and the cylindrical screw feeder and motor gearbox are started. After the raw materials enter the crucible, melting begins under high temperature. Throughout the production process, the temperature at the top of the crucible must be kept no lower than the temperature of the molten glass. After the glass is fully melted, it is discharged from the furnace through a discharge pipe or connected to other parts of the furnace through a flow outlet for continuous production.

[0014] The technical solution of the melting method of the present invention can also be: a method for melting fluorophosphorus glass to prevent volatiles from falling, characterized in that: the completed melting crucible is connected to the cylindrical screw feeder through the crucible body interface and the feeder interface; an air inlet pipe is set as needed; fluorophosphorus glass production raw materials are put into the feeding port; and the feeder and motor gearbox are started. After the raw materials enter the crucible, melting begins under high temperature; the temperature of the top of the crucible must be kept not lower than the temperature of the glass melt during the entire production process; after the glass is fully melted, it is discharged from the furnace through the leakage pipe or connected to other parts of the melting furnace through the liquid outlet for continuous production; after long-term operation of fluorophosphorus glass melting production, volatiles will condense at the spout and the feed pipe. The volatile condensate at the spout should be cleaned regularly with a cleaning shovel with a receiving spoon, and the semi-molten material at the feed pipe should be softened by running the heating electrode regularly and allowed to flow into the crucible.

[0015] The beneficial effects of this invention are: 1. Extend the feed inlet and chimney outside the crucible body to minimize the condensation of volatiles at the feed inlet and chimney; 2. A spiral feeder is used to feed the material from the side of the crucible, while also achieving a semi-sealed feed inlet, thereby avoiding or reducing the accumulation of semi-molten material and the condensation of volatiles at the feed inlet; 3. The chimney is located on the high side of the top of the crucible, and the cylindrical screw feeder is located on the low side of the top of the crucible to reduce the condensation of volatiles at the feed inlet; 4. Set the top of the crucible to a non-flat top to allow the gas to flow smoothly, reduce and avoid the condensation of volatiles at the top of the crucible, and allow the volatile components to flow quickly along the top of the crucible towards the spout and chimney. 5. The melting crucible and the cylindrical screw feeder adopt a separate design. The two are connected before the furnace is started, which makes it easier to clean, maintain or replace the cylindrical screw feeder regularly during the furnace operation interval. 6. A heating electrode is installed at the connection between the feed pipe and the crucible. The heating electrode is operated periodically to heat up the semi-molten material accumulated at the feed pipe, soften it and allow it to flow into the melting crucible. 7. The crucible body can be used as a single crucible to independently complete the trial production or small-scale production of fluorophosphorus glass, or it can be combined with homogenizing crucibles, refining crucibles, and cooling crucibles to be used as part of a continuous melting crucible. Alternatively, the cylindrical screw feeder section can be eliminated, and the melting crucible structure can be used as a homogenizing crucible, refining crucible, or cooling crucible.

[0016] This invention features the ability to avoid the generation of foreign matter in products, improve the yield rate of production, and enable uninterrupted melting production of fluorophosphate glass. It is mainly used for the single-crucible melting or continuous melting of a portion of the crucible for fluorophosphate optical glass. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the inclined feeding inclined chimney dome melting crucible of the present invention.

[0018] Figure 2 This is a schematic diagram of the structure of the flat-feed, flat-chimney, inclined-top melting crucible of the present invention.

[0019] Figure 3 This is a schematic diagram of the sloping feed, sloping chimney, and sloping top melting crucible of the present invention.

[0020] Figure 4 This is a schematic diagram of the structure of the flat-feed inlet externally moved flat-chimney inclined top smelting crucible of the present invention.

[0021] Figure 5 This is a schematic diagram of the smelting crucible with an inclined feed inlet and an inclined chimney top, as described in this invention.

[0022] Figure 6 This is a schematic diagram of the structure of the dome melting crucible A of the present invention used as a cooling crucible in a continuous melting furnace.

[0023] In the diagram: 1-Crate body; 2-Chimney; 3-Spouse; 4-Crate top; 5-Vent pipe; 6-Heating electrode; 7-Feeder interface; 8-Feeding port; 9-Raw material; 10-Motor gearbox; 11-Crate body interface; 12-Feed pipe; 13-Liquid outlet; 14-Discharge pipe; A-Melting crucible; B-Cylindrical screw feeder. Detailed Implementation

[0024] The invention will now be described in further detail with reference to the accompanying drawings.

[0025] This invention features an inclined feed, inclined chimney, and dome-shaped melting crucible, as shown in the following example. Figure 1 As shown, the melting crucible A includes a crucible body 1, a feed pipe 12, a chimney 2, and a liquid outlet 13, and is made of platinum. The feed pipe 12 and the chimney 2 are located on opposite sides of the crucible body 1, with the chimney 2 positioned on the higher side of the crucible top 4, and the cylindrical screw feeder B positioned on the lower side of the crucible top 4. The crucible top 4 is a dome-shaped top, smoothly tangent to the side wall of the crucible body 1 and the spout 3 of the chimney 2. The melting crucible A and the cylindrical screw feeder B are separate designs. The feed pipe 12 has a connecting interface 11, and the cylindrical screw feeder B includes a feeder connecting interface 7, a feeding port 8, and a motor gearbox 10. Before melting, the feeder connecting interface 7 of the cylindrical screw feeder B is connected to the connecting interface 11. A heating electrode 6 is provided at the connection between the feed pipe 12 and the crucible body 1. The feed pipe 12 is angled upwards, the chimney 2 is angled downwards, and the spout 3 is located at the connection between the chimney 2 and the crucible body 1. The top of the crucible 4 is equipped with a vent pipe 5 that extends into the crucible body 1.

[0026] As mentioned earlier, the most severe volatilization of fluorophosphorus glass components occurs during the raw material melting stage. As production continues, the volatilization and condensation of fluorophosphorus glass components upon cooling are almost inevitable. To prevent a large amount of volatiles from condensing at the top of the crucible (4) and falling into the crucible, the feed inlet and chimney (2) are extended and moved outside the crucible body (1) to minimize the accumulation of volatiles at these locations. A cylindrical screw feeder (B) is used to feed material from the side of the crucible body (1), while simultaneously achieving a semi-sealed feed inlet, thereby preventing or reducing the accumulation of semi-molten material and the condensation of volatiles at the feed inlet.

[0027] For ease of operation, chimney 2 and cylindrical screw feeder B are respectively set on both sides of the crucible. In order to reduce the condensation of volatiles at the feed inlet, chimney 2 is set on the higher side of the crucible top, and cylindrical screw feeder is set on the lower side of the crucible top.

[0028] To ensure smooth gas flow at the top of the crucible and reduce or prevent condensation of volatiles, the top of the crucible 4 is designed as either a dome or a sloping dome. If a dome-shaped top is used, the top of the crucible 4 needs to be smoothly tangent to the side wall of the crucible body 1 and the spout 3 of the chimney 2. If a sloping top is used, the angle between the top of the crucible 4 and the horizontal direction needs to be ≥30°. The purpose is to ensure that the volatile components flow rapidly along the dome or sloping top towards the spout 3 and the chimney 2 when passing over the top of the crucible 4.

[0029] Although the above optimization measures were taken in the structural design, since production is continuous, the feed inlet, as the initial point of contact between the raw materials and high temperatures, makes it difficult to completely avoid the adhesion of semi-molten material and the condensation of volatiles. To reduce the impact of volatiles falling on product quality, the crucible body 1 and the cylindrical screw feeder B are designed as separate units, connected before the furnace is started. This makes it easier to periodically clean, maintain, or replace the cylindrical screw feeder during furnace operation intervals. Meanwhile, the feed pipe 12 is set horizontally or diagonally upwards to ensure smooth feeding. To continuously ensure smooth feeding, a heating electrode 6 is installed at the connection between the feed pipe 12 and the crucible body 1. The heating electrode 6 is periodically operated to heat the semi-molten material accumulated at the feed pipe 12, softening it and allowing it to flow into the melting crucible.

[0030] This invention features a flat-feed, flat-chimney, and sloping-top smelting crucible, as shown in the following example. Figure 2 As shown, with Figure 1 The difference between the inclined feed inclined chimney dome melting crucible shown is that the crucible top 4 is an inclined top with an angle of ≥30° with the horizontal direction, the feed pipe 12 is set in the horizontal direction, and the chimney 2 is set in the horizontal direction.

[0031] This invention features an inclined feed, an inclined chimney, and an inclined top smelting crucible, as shown in the example. Figure 3 As shown, with Figure 1 Unlike the inclined feeding inclined chimney dome melting crucible shown, the top of the crucible 4 is an inclined top, and the angle with the horizontal direction is ≥30°.

[0032] This invention relates to a flat-feed inlet, an externally moved flat chimney, and an inclined-top smelting crucible, as shown in the following example. Figure 4 As shown, with Figure 2 Unlike the flat-feed, flat-chimney, sloping-top smelting crucible shown, the spout 3 of chimney 2 is located in the middle of chimney 2.

[0033] This invention relates to a flat-feed inlet, an externally moved flat chimney, and an inclined-top smelting crucible, as shown in the following example. Figure 5 As shown, with Figure 4 The difference between the inclined feed, inclined chimney, and inclined top smelting crucible shown is that the feed pipe 12 is set in an upward inclined direction, while the chimney 2 is set in an downward inclined direction.

[0034] The dome-shaped melting crucible of this invention is used as a cooling crucible for a continuous melting furnace, as follows: Figure 6 As shown, with Figure 1Unlike the inclined-feed, inclined-chimney, dome-shaped melting crucible shown, this one has a drain pipe 14 at the bottom of the crucible body 1, eliminating the feed pipe 12 and the cylindrical screw feeder B. The melting crucible structure can be used as a homogenizing crucible, a clarifying crucible, or a cooling crucible.

[0035] The crucible body in this invention can function as a single crucible to independently complete the trial production or small-scale production of fluorophosphorus glass, or it can be combined with homogenizing crucibles, clarifying crucibles, and cooling crucibles to be used as part of a continuous melting crucible.

[0036] The completed melting crucible A is connected to the cylindrical screw feeder B through the crucible body interface 11 and the feeder interface 7. The air inlet pipe 5 is set as needed, and the raw material 9 for fluorophosphorus glass production is put into the feed port 8. The feeder and motor gearbox 10 are started. After the raw material 9 enters the crucible body 1, it begins to melt and smelt under high temperature. During the entire production process, the temperature of the top of the crucible 4 must be kept no lower than the temperature of the glass melt. After the glass is fully melted, it is discharged from the furnace through the liquid outlet 13 or connected to other parts of the melting furnace for production. After long-term operation of fluorophosphorus glass melting and production, volatiles will condense at the spout 3 and the feed pipe 12. The volatile condensate at the spout 3 should be cleaned regularly. The semi-molten material at the feed pipe 12 should be softened by running the heating electrode 6 regularly and allowed to flow into the crucible body 1.

[0037] The following are embodiments of the present invention, which are for illustrative purposes only and do not limit the invention. Example

[0038] This smelting apparatus is designed for single-crucible operation, with the crucible top angled at 45° to the horizontal. It employs an inclined feed inlet and a horizontal chimney outlet. The chimney spout is cleaned with a stainless steel ladle once every 10 days. The feed inlet motor is run once every 5 days to clean the semi-molten material. The cylindrical screw feeder is cleaned and replaced once a month. After implementation, the frequency of volatile material spillage causing foreign matter and quality fluctuations in the product decreased from 1.5 times / month to 0.25 times / month. Example

[0039] This smelting unit is used as a continuous melting furnace melting crucible. The crucible top is designed and manufactured at a 60° angle to the horizontal direction. It adopts horizontal feeding and an inclined chimney outlet with an outward-moving spout. The chimney spout is cleaned with a stainless steel spoon once every 7 days. The feed inlet motor is run once every 4 days to clean the semi-molten material. The cylindrical screw feeder is cleaned and replaced once every 20 days. After implementation, the number of times volatile substances fall and cause foreign matter and quality fluctuations in the product decreased from 2.5 times / month to 0.42 times / month.

Claims

1. A fluorophosphorus glass melting apparatus for preventing volatiles from falling, comprising a melting crucible (A), the melting crucible (A) comprising a crucible body (1), a feeding port, a chimney (2), a liquid outlet (13), and a discharge pipe (14), characterized in that: It also includes a cylindrical screw feeder (B); the feeding port is a feed pipe (12), which is located on both sides of the crucible body (1) and the chimney (2); the cylindrical screw feeder (B) is connected to the feed pipe (12); the melting crucible (A) is made of platinum material and the top of the crucible (4) is a non-flat top.

2. The fluorophosphorus glass melting apparatus for preventing volatile matter from falling as described in claim 1, characterized in that: The top of the crucible (4) is a dome-shaped top, and is smoothly tangent to the side wall of the crucible body (1) and the spout (3) of the chimney (2).

3. The fluorophosphorus glass melting apparatus for preventing volatile matter from falling as described in claim 1, characterized in that: The top of the crucible (4) is a sloping top, and the angle between it and the horizontal direction is ≥30°.

4. A fluorophosphorus glass melting apparatus for preventing volatile matter from falling as described in claim 1, 2, or 3, characterized in that: The melting crucible (A) and the cylindrical screw feeder (B) are designed separately; the feed pipe (12) is provided with a docking interface (11); before melting, the feeder docking interface (7) of the cylindrical screw feeder (B) is connected to the docking interface (11).

5. A fluorophosphorus glass melting apparatus for preventing volatile matter from falling as described in claim 1, 2, or 3, characterized in that: A heating electrode (6) is provided at the connection between the feed pipe (12) and the crucible body (1).

6. The fluorophosphorus glass melting apparatus for preventing volatile matter from falling as described in claim 4, characterized in that: A heating electrode (6) is provided at the connection between the feed pipe (12) and the crucible body (1).

7. A fluorophosphorus glass melting apparatus for preventing the falling of volatiles according to any one of claims 1-3 and 6, characterized in that: The feed pipe (12) is arranged horizontally or diagonally upward; the chimney (2) is arranged horizontally or diagonally downward.

8. The fluorophosphorus glass melting apparatus for preventing volatile matter from falling as described in claim 7, characterized in that: The chimney (2) is set at an angle downwards, and the spout (3) of the chimney (2) is located in the middle of the chimney (2).

9. A melting method using a fluorophosphorus glass melting apparatus for preventing volatile matter from falling as described in any one of claims 1-8, characterized in that: Connect the cylindrical screw feeder (B) to the feed pipe (12), and put the fluorophosphorus glass production raw material (9) into the feed port (8) of the cylindrical screw feeder (B). Start the cylindrical screw feeder (B) and the motor gearbox (10). After the raw material (9) enters the crucible (1), it begins to melt under high temperature. During the entire production process, the temperature of the top of the crucible (4) should not be lower than the temperature of the glass melt. After the glass is fully melted, it is discharged from the furnace through the leakage pipe (14) or connected to other parts of the continuous melting furnace through the liquid outlet (13) for continuous production.

10. The method for melting fluorophosphorus glass to prevent volatile matter from falling off, as described in claim 9, is characterized in that: The completed melting crucible (A) is connected to the cylindrical screw feeder (B) through the crucible body interface (11) and the feeder interface (7). An air inlet pipe (5) is set up as needed. Fluorophosphorus glass production raw material (9) is put into the feed port (8), and the feeder and motor gearbox (10) are started. After the raw material (9) enters the crucible body (1), it begins to melt under high temperature. During the entire production process, the temperature of the top of the crucible (4) should not be lower than the temperature of the glass melt. After the glass is fully melted, it is discharged from the furnace through the leakage pipe (14) or connected to other parts of the continuous melting furnace through the liquid outlet (13) for continuous production. After long-term operation of fluorophosphorus glass melting production, volatiles will condense at the spout (3) and feed pipe (12). The volatile condensate at the spout (3) should be cleaned regularly with a cleaning shovel with a receiving spoon. The semi-molten material at the feed pipe (12) should be softened by running the heating electrode (6) regularly and flow into the crucible body (1).

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