A float glass tin bath outlet structure

Abstract

The present invention provides a float glass tin bath outlet structure, belonging to the field of float glass production technology. The float glass furnace comprises a tin bath, a slag box located outside the tin bath outlet, and a lip plate located on the furnace sidewall near the slag box. A strip-shaped bypass channel parallel to the width of the tin bath is provided on the furnace sidewall. The bottom of the bypass channel communicates with the tin bath, and the upper edge of the bypass channel is above the tin bath liquid level. A gap is formed between the upper edge of the bypass channel and the lower surface of the glass above it. This invention has the advantages of effectively protecting the tin bath.

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 glass is produced using the float glass forming process, the formed glass with a certain strength is lifted from the tin bath outlet and enters the slag box, and is then 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, a 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 between the slag box and the tin bath lifting area causes large fluctuations in the air flow, so that part of the air entering the slag box will enter the tin bath from the tin bath outlet lifting area, which will oxidize the metallic tin to form pollutants on the one hand and pollute the transition roller to damage the quality of the lower surface of the glass on the other hand. Oxygen will also penetrate into the surface of the glass to cause tempered rainbow defects. Structural defects on the glass surface 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. This gap is a blind spot for nitrogen isolation, and oxygen can enter the tin bath through this blind spot. 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-mentioned 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 objectives of the present invention can be achieved through the following technical solutions: a float glass tin bath outlet end structure, a float furnace comprising a tin bath, a slag box located outside the tin bath outlet end, and a lip plate located on the furnace side wall near the slag box, characterized in that a strip-shaped bypass groove parallel to the width direction of the tin bath is provided on the furnace side wall, 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 gas bag located below the cooling water bag. A nitrogen heating channel is provided in the protective gas bag. A nitrogen inlet pipe and a transversely arranged air curtain steel pipe are provided on the protective gas bag. The air curtain steel pipe is provided with longitudinally upward-facing air jet holes. Nitrogen can be discharged from the air jet holes after being heated in the protective gas bag to form an upward air curtain.

[0010] The logic behind this solution is to use the tin liquid in the bypass trough as an "oxygen target." Before entering the tin bath, oxygen can oxidize with the tin liquid in the wider bypass trough, forming a floating layer of oxidized tin oxide in the bypass trough. This floating layer only needs to be cleaned regularly. This is one of the purposes of the bypass trough. In addition, the bypass trough significantly reduces the temperature difference between the elevated tin bath area where the bypass trough is located and the tin bath. The airflow fluctuations caused by the temperature difference are 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 solution changes the nitrogen air curtain to a bottom-up method, eliminating the air curtain blind spot formed between the air curtain starting point and the lower surface of the glass. This can reduce the air curtain jet intensity to avoid the negative impact of strong airflow on the lower surface of the glass. However, it does provide better nitrogen coverage of the "tin bath opening" in the elevated area on the lower surface of the glass. Combined with the bypass trough, the protection effect of the tin liquid in the tin bath and the forming quality of the glass can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0014] In the figure, 1. Tin bath; 2. Slag box; 3. Lip plate; 4. Bypass trough; 5. Cooling water bag; 6. Protective gas 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 solutions 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 glass furnace includes 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 provided on the side wall of the furnace. The bottom of the bypass groove 4 is connected to the tin bath 1, and the upper edge of the bypass groove 4 is higher than the liquid level of the tin bath 1. 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 gas bag 6 located below the cooling water bag 5. A nitrogen heating channel is provided in the protective gas bag 6. A nitrogen inlet pipe and a transverse air curtain steel pipe 7 are provided on the protective gas bag 6. The air curtain steel pipe 7 is provided with longitudinal upward-facing injection holes. Nitrogen can be discharged from the injection holes after being heated in the protective gas bag 6 to form an upward air curtain.

[0019] The logic behind this solution is to utilize the tin liquid in bypass trough 4 as an "oxygen target." Before oxygen enters tin bath 1, it can oxidize with the tin liquid in the wider opening of bypass trough 4, forming a floating layer of oxidized tin oxide within bypass trough 4. This floating layer can be cleaned periodically, which is one of the purposes of bypass trough 4. Furthermore, the presence of bypass trough 4 significantly reduces the temperature difference between the elevated area of ​​tin bath 1 and the tin bath 1 itself. Airflow fluctuations caused by this temperature difference are suppressed in the area between tin bath 1 and bypass trough 4, significantly reducing the probability of oxygen entering tin bath 1. Thirdly, this solution changes the nitrogen curtain to a bottom-up approach, eliminating the blind spot between the curtain's starting point and the lower surface of the glass. This reduces the curtain's jet intensity and prevents the negative impact of strong airflow on the lower surface of the glass. However, it does provide a good nitrogen blanket to the elevated "tin bath 1 opening" on the lower surface of the glass. Combined with the presence of bypass trough 4, this improves the protection of the tin liquid in tin bath 1 and the quality of glass forming.

[0020] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of the appended claims.

Claims

1. A float glass tin bath outlet structure, wherein the float glass 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 provided on the side wall of the kiln. 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). 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 gas bag (6) located below the cooling water bag (5); a nitrogen heating channel is provided in the protective gas bag (6); a nitrogen inlet pipe and a transversely arranged air curtain steel pipe (7) are provided on the protective gas 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 gas bag (6) to form an upward air curtain.

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