Float glass tin bath outlet end structure

Abstract

The invention provides a float glass tin bath outlet end structure, and belongs to the technical field of float glass production. The float kiln comprises a tin bath, a slag box located outside the outlet end of the tin bath and a lip plate located on the side wall, close to the slag box, of the kiln, a strip-shaped bypass groove parallel to the width direction of the tin bath is formed in the side wall of the kiln, the bottom of the bypass groove is communicated with the tin bath, and the upper end edge of the bypass groove is higher than the liquid level of the tin bath. A gap is formed between the upper end edge of the bypass groove and the lower surface of the glass above the bypass groove. The method has the advantages of good tin bath protection effect and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of float glass production and relates to an outlet end structure of a float glass tin bath. Background Art

[0002] When the float glass forming process is used to produce glass, the formed glass with a certain strength is lifted from the tin bath outlet and enters the slag box, and is pulled into the annealing kiln by the transmission system through the slag box transition roller.

[0003] As the hot air flow in the tin bath is discharged from the upper surface of the glass above the slag box, negative pressure is formed in the environment on the lower surface of the glass. Due to the jet effect, part of the air is sucked into the slag box from the gap between the slag box and the outside world. The temperature difference in the lifting area between the slag box and the tin bath causes large fluctuations in the air flow, so that part of the air entering the slag box will enter the tin bath from the lifting area of ​​the tin bath outlet. On the one hand, it will oxidize the metallic tin to form pollutants, and on the other hand, it will pollute the transition roller and damage the quality of the lower surface of the glass. Oxygen will also penetrate into the surface of the glass to cause tempered rainbow defects. Structural defects on the surface of the glass will cause tin-sticking defects on the lower surface of the glass.

[0004] In the current practice, a nitrogen protective gas curtain is generally sprayed onto the glass lifting area at the tin bath outlet to prevent oxygen from entering the tin bath. However, this method has the following shortcomings: the nitrogen protective gas is sprayed from top to bottom, and there is still a gap between the nozzle position and the lower surface of the glass. The gap is a blind area for nitrogen isolation, and oxygen can enter the tin bath from this blind area. Summary of the invention

[0005] The purpose of the present invention is to provide a float glass tin bath outlet structure in view of the above problems existing in the prior art. The technical problem to be solved by the present invention is how to reduce the probability of oxygen entering the tin bath.

[0006] The object of the present invention can be achieved through the following technical scheme: a float glass tin bath outlet end structure, the float furnace comprises a tin bath, a slag box located outside the tin bath outlet end, and a lip plate located on the side wall of the furnace near the slag box, characterized in that a strip-shaped bypass groove parallel to the width direction of the tin bath is arranged on the side wall of the furnace, the bottom of the bypass groove is connected to the tin bath, the upper edge of the bypass groove is higher than the liquid level of the tin bath, and there is a gap between the upper edge of the bypass groove and the lower surface of the glass above it.

[0007] Furthermore, the bypass tank is connected to the tin tank through a ceramic pipe.

[0008] Furthermore, the width of the bypass groove gradually increases from bottom to top.

[0009] Furthermore, the lip plate includes a cooling water bag and a protective air bag located below the cooling water bag, a nitrogen heating channel is arranged in the protective air bag, a nitrogen inlet pipe and a transversely arranged air curtain steel pipe are arranged on the protective air bag, and a longitudinally upward jet hole is opened on the air curtain steel pipe, and the nitrogen can be discharged from the jet hole after being heated in the protective air bag to form an upward air curtain.

[0010] The logic of this scheme is: using the tin liquid in the bypass trough as an "oxygen target", before oxygen enters the tin bath, it can be oxidized with the tin liquid in the bypass trough with a wider opening, forming an oxide floating layer in the bypass trough after the oxidation of the tin liquid, and the floating layer can be cleaned regularly. This is one of the purposes of the bypass trough. In addition, the setting of the bypass trough greatly reduces the temperature difference between the tin bath lifting area where the bypass trough is located and the tin bath, and the air flow fluctuation caused by the temperature difference is suppressed in the area between the tin bath and the bypass trough, which can also greatly reduce the probability of oxygen entering the tin bath. Thirdly, this scheme changes the nitrogen air curtain to a bottom-up method, eliminating the air curtain blind area formed between the starting point of the air curtain and the lower surface of the glass. In this way, the jet intensity of the air curtain can be reduced to avoid the negative impact of strong airflow on the lower surface of the glass, but the "tin bath opening" in the lifting area on the lower surface of the glass can be better covered with nitrogen. With the setting of the bypass trough, the protection effect of the tin liquid in the tin bath and the molding quality of the glass can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a structural schematic diagram of the lifting area of ​​the float kiln.

[0012] Figure 2 It is a schematic diagram of the structure of the lip plate.

[0013] Figure 3 yes Figure 1 Enlarged view of part A in the figure.

[0014] In the figure, 1. Tin bath; 2. Slag box; 3. Lip plate; 4. Bypass trough; 5. Cooling water bag; 6. Protective air bag; 7. Air curtain steel pipe. DETAILED DESCRIPTION

[0015] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0016] like Figure 1 , Figure 2 and Figure 3As shown, the float furnace comprises a tin bath 1, a slag box 2 located outside the outlet end of the tin bath 1, and a lip plate 3 located on the side wall of the furnace near the slag box 2. A strip-shaped bypass groove 4 parallel to the width direction of the tin bath 1 is arranged on the side wall of the furnace. The bottom of the bypass groove 4 is communicated with the tin bath 1, the upper edge of the bypass groove 4 is higher than the liquid level of the tin bath 1, and there is a gap between the upper edge of the bypass groove 4 and the lower surface of the glass above it.

[0017] The bypass groove 4 is connected to the tin bath 1 through a ceramic pipe. The width of the bypass groove 4 increases gradually from bottom to top to increase the area that can contact with oxygen.

[0018] The lip plate 3 includes a cooling water bag 5 and a protective air bag 6 located below the cooling water bag 5. A nitrogen heating channel is arranged in the protective air bag 6. A nitrogen inlet pipe and a transversely arranged air curtain steel pipe 7 are arranged on the protective air bag 6. The air curtain steel pipe 7 is provided with longitudinally upward injection holes. Nitrogen can be discharged from the injection holes after being heated in the protective air bag 6 to form an upward air curtain.

[0019] The logic of this scheme is: using the tin liquid in the bypass groove 4 as an "oxygen target", before oxygen enters the tin bath 1, it can be oxidized with the tin liquid in the bypass groove 4 with a wider opening, forming an oxide floating layer after the oxidized tin liquid in the bypass groove 4, and the floating layer can be cleaned regularly. This is one of the purposes of the bypass groove 4. In addition, the setting of the bypass groove 4 greatly reduces the temperature difference between the lifting area of ​​the tin bath 1 where the bypass groove 4 is located and the tin bath 1. The air flow fluctuation caused by the temperature difference is suppressed in the area between the tin bath 1 and the bypass groove 4, which can also greatly reduce the probability of oxygen entering the tin bath 1. Thirdly, this scheme changes the nitrogen air curtain to a bottom-up method, eliminating the air curtain blind area formed between the starting point of the air curtain and the lower surface of the glass. In this way, the jet intensity of the air curtain can be reduced to avoid the negative impact of strong airflow on the lower surface of the glass, but the "tin bath 1 opening" in the lifting area on the lower surface of the glass can be better covered with nitrogen. With the setting of the bypass groove 4, the protection effect of the tin liquid in the tin bath 1 and the molding quality of the glass can be improved.

[0020] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A float glass tin bath outlet structure, wherein the float furnace comprises a tin bath (1), a slag box (2) located outside the outlet of the tin bath (1), and a lip plate (3) located on the side wall of the furnace near the slag box (2), characterized in that: A strip-shaped bypass groove (4) parallel to the width direction of the tin bath (1) is arranged on the side wall of the kiln, the bottom of the bypass groove (4) is connected to the tin bath (1), the upper edge of the bypass groove (4) is higher than the liquid level of the tin bath (1), and there is a gap between the upper edge of the bypass groove (4) and the lower surface of the glass above it.

2. The float glass tin bath outlet structure according to claim 1, characterized in that: The bypass tank (4) is connected to the tin tank (1) via a ceramic pipe.

3. The float glass tin bath outlet structure according to claim 2, characterized in that: The width of the bypass groove (4) gradually increases from bottom to top.

4. A float glass tin bath outlet structure according to claim 1, 2 or 3, characterized in that: The lip plate (3) comprises a cooling water bag (5) and a protective air bag (6) located below the cooling water bag (5); a nitrogen heating channel is arranged in the protective air bag (6); a nitrogen inlet pipe and a transversely arranged air curtain steel pipe (7) are arranged on the protective air bag (6); and an air jet hole facing upward in the longitudinal direction is opened on the air curtain steel pipe (7); and nitrogen can be discharged from the air jet hole after being heated in the protective air bag (6) to form an upward air curtain.

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