A tin bath with automatic tin flow to the edge

Abstract

The application discloses a tin tank with tin ash automatically flowing to the edge, and belongs to the technical field of float glass manufacturing. The tin tank comprises a tin liquid pool and a small lug pool. The inlet end of the tin liquid pool is connected with a melting furnace, and the outlet end is connected with an annealing furnace. The tin liquid pool comprises a tin liquid pool bottom, an end wall and an edge wall. The tin liquid pool bottom is provided with intercommunicating opposite deep pool areas near the end wall of the outlet end of the tin tank. The edge wall on the two sides of the tin liquid pool is provided with the small lug pool, and a linear motor is installed in the small lug pool. The inlet of the small lug pool is communicated with the opposite deep pool areas next to the end wall of the tin liquid pool, and the outlet of the small lug pool is communicated with the opposite deep pool areas away from the end wall. The intercommunicating opposite deep pool areas surround a pair of opposite shallow pool areas, and the intercommunicating opposite deep pool areas and the small lug pool form a wide road circulation. The depth of the tin liquid at the outlet end of the tin tank is changed, a wide road circulation passage is formed with the small lug pools on the two sides, and the tin ash cleaning effect near the central position of the wide tin tank is strengthened.

Description

Technical Field

[0001] This invention relates to the field of float glass manufacturing technology, and in particular to a tin bath that automatically directs tin ash to the edge. Background Technology

[0002] The tin bath is a crucial piece of equipment in float glass manufacturing technology. One end of the tin bath connects to the melting furnace, and the other end connects to the annealing furnace. A typical tin bath is a rectangular space formed by the bottom and sidewalls of the molten tin pool. The tin bath contains molten tin, and the glass ribbon floats on this molten tin, which acts as a buoyancy medium. As the glass ribbon moves from upstream to downstream, its lower surface comes into contact with the molten tin. The purity of the molten tin has a significant impact on the quality of the glass, especially since tin ash tends to accumulate in the triangular area of ​​the endwall at the outlet of the tin bath.

[0003] The float glass process inevitably produces tin ash in the molten tin. Various methods are typically employed to remove this tin ash and reduce the number of tin defects under the glass ribbon. A common method for cleaning tin ash is to install cleaning devices on both sides of the tin bath near the outlet. The working principle is that when the natural flow of molten tin, carried by the glass plate, encounters the outlet wall of the tin bath, a portion of the molten tin turns 90 degrees towards the side, carrying the tin ash to both sides where it is captured by the cleaning devices installed on either side. There are usually two types of cleaning devices: one type consists of a pair of small ear tanks symmetrically installed on the side wall near the tin bath outlet, as described in invention application CN117623594A. Each ear tank is equipped with a linear motor, which uses electromagnetic force to attract the molten tin and floating tin ash into the ear tank. After filtration, the clean molten tin is returned to the tin bath. The first method, due to the short-circuit circulation of molten tin, has a limited range of effect. It can only attract tin ash within about 1 meter of the tin bath's edge into the small ear pool. However, the width of the tin bath is usually over 5 meters, so at least 3 meters in the middle are outside its effective range. The electromagnetic force of the linear motor cannot attract the tin ash from the triangular area below the glass strip in the center of the tin bath, and natural tin flow must be relied upon to carry the tin ash from the center to the edge. The second method involves setting up a mechanical slag remover in a large ear pool, using a graphite wheel to collect the tin ash into the large ear pool. This method has an even smaller effective range and is more dependent on natural molten tin flow. As the tin bath becomes wider, the speed of glass plate pulling, especially for thick glass, becomes slower, and the natural tin flow becomes very weak, practically unable to move the tin ash from the center to the edge. In practice, workers need to periodically insert a long, flat wooden strip or a steel strapping from both sides of the tin bath, pulling the strip or strapping to move the molten tin and tin ash towards the edge, where it is then attracted by the linear motor into the small ear pool or collected by the wheel into the large ear pool. Clearly, this manual method is inefficient and ineffective, only partially reducing the number of tin defects under the glass strip, and it introduces additional contamination.

[0004] In addition to the methods mentioned above, utility model application CN219670354U discloses a device that uses an air blowing pipe to blow tin ash from the central area to both sides, attempting to solve the problem of tin ash not flowing in the middle. This method, by adding an air blowing pipe in a confined space, greatly increases the risk of the glass ribbon coming into contact with foreign objects, causing surface scratches or even breakage. Utility model application CN218478675U discloses a device for removing tin ash using a second linear motor. However, this second linear motor has a large mechanical structure, occupying the space that must be left empty at the end of the tin bath, posing a significant risk. This area is an emergency work station for handling glass ribbon breakage accidents, and its importance is no less than that of a fire escape; it should not be obstructed. The utility model application CN206799422U discloses a method of setting a guide plate at the end of the tin bath, with the aim of guiding the natural flow of molten tin passing through the guide plate from the middle to both sides. However, because float glass production technology has developed to a wide plate and slow speed, the natural tin flow is particularly weak, and it can be said that there is almost no flow to guide. In addition, there is a short-circuit circulation between the inlet and outlet of the traditional small ear pools on both sides. This short-circuit circulation can promote the cleaning of tin ash near the side wall to a certain extent. However, in this solution, the short-circuit circulation between the inlet and outlet of the small ear pools is blocked by the guide plate. The clean molten tin flowing out of the small ear pools is forced to flow back upstream, which affects the cleaning effect of tin ash near the side wall. More importantly, this method also cannot solve the problem of cleaning tin ash near the center of the wide tin bath. Utility model application CN218841940U discloses another method attempting to guide the natural flow of molten tin to the edges, hoping to improve the working effect of a mechanical slag remover in a large tin bath. However, as mentioned earlier, the natural tin flow is already very weak and does not generate enough molten tin to guide the tin ash to the edges; there is almost no flow to guide. Furthermore, based on its design with two side vents, this large tin bath lacks a molten tin circulation loop; it only uses a graphite rotor to collect the tin ash floating on the surface of the molten tin at the edges. In short, both of these utility models aim to guide the natural flow of molten tin in the middle to the edges. How to achieve tin ash removal near the center of a wide tin bath without adding extra equipment or machinery is a pressing problem that needs to be solved in this field. Summary of the Invention

[0005] To overcome the above problems, this invention is based on a new approach and provides a tin bath that automatically directs tin ash to the edge. The externally controlled flow of molten tin, in addition to the natural tin flow, is guided from the edge to the vicinity of the central axis of the molten tin bath. According to the principle of mass conservation, the molten tin in the central region will inevitably flow back to the edge, thereby driving the tin ash to automatically flow to the edge. This changes the depth of the molten tin at the outlet end in the tin bath and forms a wide circulation path with the small ear pools on both sides, enhancing the tin ash cleaning effect near the center of the wide tin bath.

[0006] The technical solution adopted in this invention is as follows:

[0007] A tin bath with automatic tin ash flow to the side is disclosed. The tin bath includes a tin pool and small ear pools. One end of the tin pool inlet is connected to a melting furnace, and the other end of the tin pool outlet is connected to an annealing furnace. The tin pool includes a bottom, an end wall, and side walls. The bottom of the tin pool has interconnected relatively deep pool areas near the end wall of the tin pool outlet. Small ear pools are provided on both sides of the tin pool side walls, and linear motors are installed in the small ear pools. The inlet of the small ear pool is connected to the relatively deep pool area adjacent to the end wall of the tin pool, and the outlet of the small ear pool is connected to the relatively deep pool area away from the end wall. The interconnected relatively deep pool areas form a pair of relatively shallow pool areas, and the interconnected relatively deep pool areas and small ear pools form a wide circulation path.

[0008] Preferably, the small ear pool is equipped with a molten tin cooler.

[0009] Preferably, the distance between the edge of the downstream side of the relatively shallow pool area and the end wall of the tin bath outlet is 100-1500mm, and more preferably 300-600mm.

[0010] Preferably, the relatively shallow pool area is a raised structure located at the bottom of the molten tin pool, and the number of such raised structures is two. Two far-away sidewalls in a pair of relatively shallow pool areas are connected to two side walls, respectively, while two close-away sidewalls are separated by a gap with a width of 100-3000 mm, more preferably 300-1000 mm. The depth of the molten tin pool bottom at the gap is the same as or significantly deeper than the depth of the upstream and downstream sides of the relatively shallow pool area.

[0011] Preferably, the boss structure is a right triangle, with the hypotenuse of the right triangle facing the upstream side of the relatively shallow pool area.

[0012] Preferably, the relatively deep pool area is an open groove, and the upstream side groove and the downstream side groove are connected by a central groove at the central axis position of the molten tin pool.

[0013] Preferably, the depth difference between the relatively shallow pool area and the relatively deep pool area is 10-200 mm, and more preferably 20-40 mm.

[0014] Preferably, the small ear pool outlet is a submerged outlet located below the surface of the molten tin, with the submerged outlet close to the bottom of the molten tin pool.

[0015] Preferably, from the inside of the tin bath outlet wall upstream, the depth of the tin bath bottom is as follows: relatively deep pool, relatively shallow pool, and relatively deep pool.

[0016] The beneficial effects of this invention are as follows: The tin ash automatically flows to the edge of the tin bath disclosed in this invention. By setting up interconnected relatively deep pool areas near the outlet of the tin bath, the inlet of the small ear pool is connected to the relatively deep pool area adjacent to the end wall of the tin bath, and the outlet of the small ear pool is connected to the relatively deep pool area away from the end wall. The interconnected relatively deep pool areas form a pair of relatively shallow pool areas. By controlling the linear motors of the small ear pools on both sides of the tin bath, the relatively shallow pool area located between the inlet and outlet of the small ear pool plays a certain role in obstructing the clean tin liquid discharged from the small ear pool, forcing the bottom flow to bypass the center line area of ​​the tin bath along the interconnected relatively deep pool areas, thereby further enhancing the ash removal effect. Attached Figure Description

[0017] Figure 1 This is the first embodiment of the tin bath that automatically flows tin ash to the edge, as shown in the embodiments of the present invention;

[0018] Figure 2 This is a second embodiment of the tin bath that automatically flows tin ash to the edge, as shown in the embodiments of the present invention;

[0019] In the diagram: 1-molten tin pool, 2-small ear pool, 3-end wall, 4-side wall, 5-relatively shallow pool area, 6-linear motor, 7-upstream side groove, 8-downstream side groove, 9-middle groove, 10-glass strip. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides a tin bath with automatic tin ash flow to the side. The tin bath includes a tin pool 1 and small ear pools 2. One end of the tin pool 1 is connected to a melting furnace, and one end of the tin pool 1 is connected to an annealing furnace. The tin pool 1 includes a bottom, an end wall 3, and a side wall 4. The bottom of the tin pool has interconnected relatively deep pool areas near the end wall of the tin bath outlet. The interconnected relatively deep pool areas surround to form a pair of relatively shallow pool areas 5. The depths of the upstream and downstream sides of the relatively shallow pool areas are the same or significantly deeper than the relatively shallow pool areas. The depth difference between the relatively shallow pool areas and the relatively deep pool areas is 10-200 mm, preferably 20-40 mm. Small ear pools 2 are located on both sides of the tin pool. The inlet of the small ear pool connects to the relatively deep pool area adjacent to the end wall of the tin pool, and the outlet of the small ear pool connects to the relatively deep pool area away from the end wall. A linear motor 6 and a tin cooler are installed in the small ear pool. The interconnected relatively deep pool areas and the small ear pools form a wide-path circulation. Here, upstream and downstream refer to the direction in which the glass moves from upstream to downstream.

[0022] The relatively shallow pool area of ​​this invention obstructs the shortest path for molten solder to return, thus weakening the short-circuit circulation caused by the traditional method of setting small ear pools on both sides of the solder bath. This forces most of the circulating molten solder to flow through the middle, enhancing wide-path circulation. The design of the relatively shallow and relatively deep pool areas does not affect the natural flow of molten solder caused by the movement of the glass belt 10. Short-circuit circulation refers to the molten solder only circulating in the vicinity of the small ear pool, unable to reach the molten solder dust near the center of the wide solder bath. Wide-path circulation refers to the circulating molten solder covering the molten solder dust near the center of the wide solder bath or spanning the entire width of the solder bath. Since the small ear pools are located outside the solder bath, their temperature is lower than that inside the molten solder pool. The linear motor itself has water cooling pipes, which have a certain cooling effect on the molten solder. The temperature of the molten solder in the small ear pool can be further reduced by installing a molten solder cooler. The density of the cooled molten solder increases, and the molten solder flowing back to the molten solder pool forms a bottom flow, enabling wide-path circulation along the relatively deep area.

[0023] The small ear pool has an inlet and an outlet at its two ends. The inlet is open, and the outlet is a submerged outlet located below the surface of the molten tin. After the molten tin containing tin ash touches the outlet end wall, it flows into the small ear pool under the action of the wide-path circulating liquid flow and the linear motor. The temperature of the molten tin decreases and its density increases as it flows through the small ear pool. Because the outlet is submerged, the tin ash floating on the surface of the molten tin is intercepted at the submerged outlet. It can be manually removed periodically or an automatic channel for flowing into the tin ash collection pool can be set up. The clean molten tin near the bottom of the molten tin pool flows back into the tin bath.

[0024] In one specific embodiment of the invention, the submerged outlet is located near the bottom of the molten tin pool, and preferably the highest height of the submerged outlet is lower than the lowest height of the relatively shallow pool area.

[0025] like Figure 1As shown, this invention provides an implementation method for the automatic flow of tin ash to the edge of the tin bath. The upstream depth of the tin bath is designed to be 50-250mm. A right-angled triangular boss structure is set as a pair of relatively shallow pool areas 5. The hypotenuse of the right-angled triangle faces the upstream side of the boss. There are two bosses. The two far-away sidewalls of the pair of bosses are respectively connected to the two side walls, and there is a gap between the two close sidewalls. The depth of the bottom of the tin pool at the gap is the same as the depth of the upstream and downstream sides of the boss or significantly deeper than the boss. Taking the direction in the figure as an illustration, the small ear pool end near the outlet end wall of the tin bath is used as the inlet, and the small ear pool end on the upstream side of the boss is used as the outlet. The pair of small ear pools are set up in the same way. At this time, the linear motors 6 in the small ear pools are controlled. The thrust direction of both linear motors 6 in the small ear pools is from downstream to upstream. The small ear pool and the area near the boss at the top of the figure form a counterclockwise circulation, while the small ear pool and the area near the boss at the bottom of the figure form a clockwise circulation. The two circulations converge in the central axis area of ​​the wide solder bath. This circulation flow mode can completely eliminate any stagnation area near the center line of the solder bath, effectively enhancing the cleaning effect of solder ash near the center position of the wide solder bath. The two linear motors 6 mentioned above are controlled by a program. The thrust magnitude and direction of the motors, working time, and other parameters can all be set according to actual requirements. The shape of the boss is not limited to a right triangle; it can also be other shapes.

[0026] like Figure 2 As shown, this invention provides another implementation of the automatic flow of tin ash to the edge of the tin bath. An open groove channel is set at the bottom of the tin bath, wherein the upstream side groove 7 and the downstream side groove 8 are connected by a central groove 9 at the central axis of the tin bath. The upstream side groove, the downstream side groove, and the central groove form a relatively deep pool area, and the part enclosed by the three forms a relatively shallow pool area. Taking the direction in the figure as an illustration, a pair of small ear pools are set at the side walls on both sides. In the small ear pool located at the top of the figure, one end connected to the upstream side groove serves as the outlet, and the other end connected to the downstream side groove serves as the inlet. The arrangement of the pair of small ear pools is the same. At this time, the linear motors 6 in the small ear pools are controlled. The thrust direction of the two linear motors 6 in the small ear pools is from downstream to upstream. The small ear pool located at the top of the figure, together with the upstream side groove, the middle groove, and the downstream side groove, forms a counterclockwise cycle. The small ear pool located at the bottom of the figure, together with the upstream side groove, the middle groove, and the downstream side groove, forms a clockwise cycle. The two cycles converge in the central axis area of ​​the wide tin bath. This circulating flow mode can completely eliminate any stagnation area near the center line of the tin bath and effectively enhance the cleaning effect of tin ash near the center position of the wide tin bath. The two linear motors 6 mentioned above are controlled by a program. The thrust magnitude and direction of the motors, working time, and other parameters can all be set according to actual requirements. The shape of the grooves is not limited to the rectangle shown in the figure, but can also be other shapes.

[0027] The principle behind the two wide-path circulation methods described above that enhance the cleaning effect of tin ash near the center of the wide tin bath is as follows: When the molten tin flows through the small ear pool, the temperature decreases and the density becomes relatively high. At the same time, under the action of the submerged outlet of the small ear pool, the molten tin stream returning to the tin bath is mainly a bottom flow. The relatively shallow pool area between the inlet and outlet of the small ear pool can hinder it, forcing the bottom flow to bypass the relatively deep pool area along the interconnected area and flow through the center line area of ​​the tin bath, further enhancing the ash cleaning effect.

[0028] The above examples are merely specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A tin bath with automatic tin ash flow to the side, the tin bath comprising a tin liquid pool (1) and a small ear pool (2), the inlet end of the tin liquid pool (1) being connected to a melting furnace, and the outlet end of the tin liquid pool (1) being connected to an annealing furnace, the tin liquid pool (1) comprising a tin liquid pool bottom, an end wall (3) and a side wall (4), characterized in that, The bottom of the molten tin pool has interconnected relatively deep pool areas near the outlet end wall of the molten tin pool. Small ear pools are provided on both sides of the molten tin pool. A linear motor (6) is installed in the small ear pool. The inlet of the small ear pool is connected to the relatively deep pool area adjacent to the end wall of the molten tin pool, and the outlet of the small ear pool is connected to the relatively deep pool area away from the end wall. The interconnected relatively deep pool areas form a pair of relatively shallow pool areas (5). The interconnected relatively deep pool areas and the small ear pools form a wide circulation path. The relatively shallow pool area (5) is a boss structure set at the bottom of the molten tin pool, and the number of bosses is 2. The two side walls that are far apart in a pair of relatively shallow pool areas are respectively connected to the two side walls, and there is a gap between the two side walls that are close to each other, with a gap width of 100-3000mm; or, the relatively deep pool area is an open groove, and the upstream side groove (7) and the downstream side groove (8) are connected through the middle groove (9) at the central axis position of the molten tin pool; The outlet of the small ear pool is a submerged outlet located below the surface of the molten tin, and the submerged outlet is close to the bottom of the molten tin pool.

2. The tin ash automatically flowing to the edge tin bath according to claim 1, characterized in that, The small ear pool is equipped with a molten tin cooler.

3. The tin ash automatically flowing to the edge tin bath according to claim 1, characterized in that, The protrusion structure is a right triangle, with the hypotenuse of the right triangle facing the upstream side of the relatively shallow pool area.

4. The tin bath with automatic tin ash flow to the edge according to claim 1, characterized in that, The depth difference between the relatively shallow pool area and the relatively deep pool area is 10-200 mm.

5. The tin bath with automatic tin ash flow to the edge according to claim 1, characterized in that, From the inside of the outlet wall of the tin bath upstream, the depths of the bottom of the tin bath are as follows: relatively deep pool, relatively shallow pool, and relatively deep pool.

Images