Glass annealing tunnel kiln with controllable humidity and adjustable flatness

Abstract

A glass annealing tunnel kiln with controllable humidity and adjustable flatness, comprising at least one annealing unit and a transmission device. The annealing unit includes an outer furnace chamber, an inner furnace chamber, a support frame, a ventilation device, two flatness adjustment devices, a temperature sensor and a humidity sensor. The transmission device includes roller shafts and a heat-resistant metal mesh belt. A plurality of annealing units are connected end to end and form a glass annealing tunnel kiln together with the transmission device. The number of annealing units and the temperature of each annealing unit can be set separately according to process requirements. The glass annealing tunnel kiln of the present invention has the characteristics of controllable humidity and atmosphere inside the kiln, high flatness at the bottom and uniform temperature field, and is suitable for annealing special glass or optical glass with precise requirements for humidity, atmosphere, temperature and bottom flatness.

Description

Technical Field

[0001] The present invention relates to a glass annealing device, in particular to a glass annealing tunnel kiln with controllable humidity and adjustable flatness. Background Art

[0002] In the production process of glass products, annealing is an essential key process. When producing glass by continuous melting process, the annealing of glass needs to be carried out in a tunnel annealing kiln with a certain temperature gradient. Invention patents CN102491628A and CN104930849A related to glass production respectively mention a glass mesh belt annealing furnace and a glass tunnel kiln with bottom electric heating, but these patent applications do not mention humidity control. Utility model patent CN201660549U mentions an electric firing tunnel kiln dedicated to crystal glass plates and utensils, which is applicable to the production of corrugated plates and utensils and has the characteristic of high energy efficiency utilization rate, but does not mention the methods and measures for controlling the humidity and temperature field in the kiln. In addition, for annealing tunnel kilns with a relatively long length (greater than 16 meters), the adjustment technology for multiple units to maintain the same horizontal plane has not been publicly reported.

[0003] In recent years, due to their special optical properties, phosphate glass and fluorophosphate glass have been widely used in the market. However, compared with traditional silicate glass, phosphate glass and fluorophosphate glass have disadvantages such as poor chemical stability, large expansion coefficient and poor mechanical properties. Such glasses are prone to react with water in the air at annealing temperature, generating microcracks, resulting in phenomena such as easy explosion and fracture of the glass during the annealing process, seriously affecting the product yield of glass production. Especially when producing large-sized glass, factors such as high humidity in the kiln and uneven temperature field will exacerbate the explosion risk of this type of glass. The annealing tunnel kiln required for large-sized glass has a relatively long length, and it is difficult to ensure that its bottom is flat. Especially after a period of use, problems such as deformation and settlement are likely to occur, making the bottom of the tunnel kiln uneven, resulting in fracture of large-sized glass during the annealing process; once it is found that the bottom of the tunnel kiln is deformed, the tunnel kiln needs to be demolished for repair, seriously affecting the production efficiency of glass.

[0004] Therefore, it can be seen that traditional glass annealing tunnel kilns are difficult to meet the requirements of strictly controlling the humidity, bottom flatness and temperature field uniformity in the kiln. To solve this problem, the tunnel kiln for the production of phosphate glass and fluorophosphate glass must have the following characteristics:

[0005] 1. The humidity inside the tunnel kiln needs to be strictly controlled at a relatively low level to reduce the risk of crack generation during the glass annealing process;

[0006] 2. The bottom of the tunnel kiln should have a high flatness, that is, the change in height should be as small as possible, and at the same time, it should have the function of quickly adjusting the height of the bottom of the tunnel kiln;

[0007] 3. The tunnel kiln should have a small lateral temperature difference, that is, on the same cross-section of the tunnel kiln, the temperature difference should be as small as possible to reduce the annealing stress. SUMMARY OF THE INVENTION

[0008] The object of the present invention is to provide a glass annealing tunnel kiln with controllable humidity and adjustable flatness, which has the functions of reducing the humidity inside the kiln and adjusting the flatness of the bottom, and at the same time has high temperature control accuracy and temperature uniformity, so as to meet the application requirements of continuous melting and annealing of large-size optical glass with a large expansion coefficient and poor mechanical properties.

[0009] The object of the present invention is achieved through the following technical solutions:

[0010] A glass annealing tunnel kiln with controllable humidity and adjustable flatness, including at least one annealing unit and a transmission device, characterized in that:

[0011] The annealing unit is composed of an outer furnace chamber, an inner furnace chamber, a support frame, a ventilation device, two flatness adjustment devices, a temperature sensor, and a humidity sensor;

[0012] The transmission device drives a heat-resistant metal mesh belt to translate inside the inner furnace chamber by two roller shafts;

[0013] The support frame includes at least four support legs and a support plate placed on the support legs;

[0014] The outer furnace chamber is composed of heat-insulating refractory materials and is fixed on the support plate;

[0015] The inner furnace chamber is placed inside the outer furnace chamber and is composed of infrared-transmitting refractory materials. A heating device is provided inside the infrared-transmitting refractory materials. Inside the inner furnace chamber, a heat-resistant metal plate is provided at the bottom side, and the metal mesh belt is laid on the heat-resistant metal plate;

[0016] The ventilation device includes an intake pipeline, a flow controller, and an exhaust pipeline; dry gas passes through the heat-insulating refractory materials and the infrared-transmitting refractory materials in sequence through the intake pipeline, and is heated and discharged into the inside of the inner furnace chamber from the bottom of the inner furnace chamber; the exhaust pipeline passes through the infrared-transmitting refractory materials and the heat-insulating refractory materials in sequence to discharge gas from the top; the humidity sensor is arranged on the exhaust pipeline; the intake pipeline is provided with a flow controller;

[0017] The flatness adjustment device is connected to the support plate by an adjustment screw, and the length of the adjustment screw is adjustable for supporting and adjusting the height of the heat-resistant metal plate.

[0018] The heat-resistant metal mesh belt is wound around the roller shaft, and the roller shaft can be driven by a motor to rotate, and the rotation of the roller shaft drives the heat-resistant metal mesh belt to operate.

[0019] Both the temperature sensor and the exhaust gas pipeline are arranged in the central area at the top of the inner furnace chamber; the temperature measurement point of the temperature sensor is located in the middle of the inner furnace chamber, and the exhaust gas pipeline discharges gas from the exhaust port in the central area at the top of the outer furnace chamber; the humidity sensor is arranged at the exhaust port of the exhaust gas pipeline.

[0020] The flatness adjusting device successively includes a support brick, a support brick backing plate and an adjusting screw from top to bottom; the support brick is arranged below the heat-resistant metal plate, and the adjusting screw is connected to the support plate by threads; the adjusting screw drives the support brick to lift and lower to adjust the height of the heat-resistant metal plate.

[0021] The length of the annealing unit is 0.5 - 2.0 m, and multiple annealing units are connected end to end.

[0022] When there are two or more heat-resistant metal plates, the gap between the plates is 5 - 30 mm.

[0023] The heat-insulating refractory material of the outer furnace chamber is insulating bricks or other refractory materials, with a thickness of 100 - 230 mm.

[0024] The infrared-transmitting refractory material is alumina ceramics, silicon carbide ceramics, quartz or a mixed ceramic phase of quartz and alumina.

[0025] The outlet of the intake gas pipeline is arranged at both ends inside the inner furnace chamber.

[0026] The gas in the intake gas pipeline is dry gas, including air, nitrogen, oxygen or inert gas.

[0027] The beneficial effects of the present invention are as follows:

[0028] The ventilation device of the present invention can effectively reduce the air humidity in the inner furnace chamber after introducing dry gas. The flow rate of the introduced dry gas can be adjusted according to the requirements of the annealed glass and the measurement results of the humidity sensor. The introduced gas is heated at the bottom of the outer furnace chamber and the bottom of the inner furnace chamber, which can avoid thermal shock to the annealed glass.

[0029] The flatness adjusting device of the present invention can adjust the height of the heat-resistant metal plate at the bottom of the tunnel kiln within a certain range. When it is found that the height difference of the heat-resistant metal plates is relatively large, there is no need to dismantle the tunnel kiln for maintenance. Only by adjusting the flatness adjusting screw can the height difference between different heat-resistant metal plates be reduced, thereby improving the overall flatness of the tunnel kiln, effectively avoiding the fracture of the glass during annealing, and improving the production efficiency of the glass.

[0030] Heating devices are arranged on the top, bottom and side of the inner furnace chamber of the glass annealing tunnel kiln of the present invention, and heat-resistant metal plates are also arranged in the inner furnace chamber, effectively improving the temperature uniformity of the inner furnace chamber.

[0031] The glass annealing tunnel kiln of the present invention can flexibly set the number of annealing units, the temperature and the ventilation volume of each annealing unit according to the type of glass to be annealed, which is beneficial to expanding the application range of the glass annealing tunnel kiln. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic cross-sectional view of the glass annealing tunnel kiln of the present invention.

[0033] Figure 2 It is a schematic longitudinal sectional view of the glass annealing tunnel kiln of the present invention.

[0034] Figure 3 It is the humidity comparison inside the glass annealing tunnel kiln under different ventilation conditions. The gas introduced is dry air with a water content of 0.5 g / m 3 . The ventilation volume is 0 m 3 / h, 1 m 3 / h, 2 m 3 / h, 4 m 3 / h, 6 m 3 / h, 8 m 3 / h. The water content inside the tunnel kiln is 13.9 g / m 3 , 9.2 g / m 3 , 6.9 g / m 3 , 2.3 g / m 3 , 1.4 g / m 3 , 1.2 g / m 3 .

[0035] Figure 4 It shows the height difference at the bottom of the glass annealing tunnel kiln before and after being adjusted by the flatness adjusting device. The height difference before adjustment is 12 mm, and the height difference after adjustment is 5 mm. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] The present invention will be further described below in conjunction with the drawings and embodiments, but the protection scope of the present invention is not limited thereby.

[0037] As Figure 1 and Figure 2 shown, the glass annealing tunnel kiln with controllable humidity and adjustable flatness of the present invention includes at least one annealing unit 7 and a transmission device 6. The annealing unit 7 includes an outer furnace chamber 1, an inner furnace chamber 2, a ventilation device 3, two flatness adjusting devices 4, a support frame 5, a temperature sensor 21 and a humidity sensor 31. As Figure 2 shown, a plurality of annealing units 7 are connected end to end and form a glass annealing tunnel kiln together with the transmission device 6.

[0038] The support frame 5 includes support legs 501 and a support plate 502, and is used to carry other components of the glass annealing tunnel kiln.

[0039] The outer surface of the outer furnace chamber 1 is coated with heat-insulating refractory material 101 all around and is fixed on the support plate 502; the outer surface of the inner furnace chamber 2 is coated with infrared-transmitting refractory material 201 all around, and a heating device 202 is arranged inside the infrared-transmitting refractory material; a heat-resistant metal plate 203 is provided at the bottom of the inner furnace chamber 2; the inner furnace chamber 2 is placed inside the outer furnace chamber 1.

[0040] The ventilation device 3 includes an intake pipeline 301, a flow controller 302 and an exhaust pipeline 303; the intake pipeline 301 is fixed to the bottom of the support plate 502, externally connected to the flow controller 302, the air inlet of the intake pipeline 301 is located at the center of the bottom of the outer furnace chamber 1, and after passing through the heat-insulating refractory material 101 at the bottom of the outer furnace chamber 1 and the infrared-transmitting refractory material 201 at the bottom of the inner furnace chamber 2 in sequence, it enters the inner space of the inner furnace chamber 2; the exhaust pipeline 303 passes through the infrared-transmitting refractory material 201 at the top of the inner furnace chamber 2 and the heat-insulating refractory material 101 at the top of the outer furnace chamber 1, and then discharges gas from the top; a humidity sensor 31 is arranged at the exhaust port of the exhaust pipeline 303. A temperature sensor 21 is arranged at the center of the top of the inner furnace chamber 2, and the temperature measurement point of the temperature sensor 21 is located in the middle of the inner furnace chamber 2 for measuring the central temperature of the inner furnace chamber 2.

[0041] The flatness adjusting device 4 is installed on the support plate 502 for supporting and adjusting the height of the heat-resistant metal plate 203. The flatness adjusting device 4 includes a support brick 401, a support brick backing plate 402 and an adjusting screw 403. The support brick 401 is placed on the support brick backing plate 402, the support brick backing plate 402 is placed on the adjusting screw 403, and the adjusting screw 403 is connected to the support plate 502 through threads.

[0042] The heat-resistant metal plate 203 is placed on the support brick 401. When there are multiple heat-resistant metal plates 203, gaps are left between them to prevent the influence of thermal expansion and contraction. The adjusting screw 403 can drive the support brick 401 to rise and fall, thereby adjusting the height of the heat-resistant metal plate 203.

[0043] The transmission device 6 includes two roller shafts 601 and a heat-resistant metal mesh belt 602. The heat-resistant metal mesh belt 602 is wound around the roller shafts 601, and the roller shafts 601 are driven by a motor to rotate, driving the heat-resistant metal mesh belt 602 to operate. The length of the heat-resistant metal mesh belt is set according to the total length of the glass annealing tunnel kiln. The part of the heat-resistant metal mesh belt located inside the inner furnace chamber 2 is placed on the heat-resistant metal plate 203. After the glass enters the annealing tunnel kiln, it is placed on the heat-resistant metal mesh belt and is driven by the heat-resistant metal mesh belt to operate.

[0044] The number of annealing units 7, the temperature of each annealing unit, and the ventilation volume can all be set according to the requirements of glass annealing.

[0045] Embodiment

[0046] In this embodiment, the inner furnace net space of the glass annealing tunnel kiln has a width of 0.5 m and a height of 0.4 m. A total of 30 annealing units 7 are provided, and the length of each annealing unit 7 is 0.8 m, with a total length of 24 m. As Figure 2 shown, the annealing units are connected end to end and form a glass annealing tunnel kiln together with the transmission device 6.

[0047] The first 6 annealing units of the glass annealing tunnel kiln are set as the heat preservation area, and the last 24 annealing units are set as the cooling area; the temperature of the heat preservation area is set at 500 °C, and the temperature of the cooling area is set from high to low between 490 °C and 50 °C. The heat preservation refractory 101 is heat preservation bricks with a thickness of 230 mm, the infrared-transmitting refractory 201 is silicon carbide ceramics, and the heating device 202 is nickel-chromium alloy wire; the length of the heat-resistant metal plate 203 is 780 mm, and the gap between the heat-resistant metal plates is 20 mm. The length of the adjusting screw 403 is 180 mm. The heat-resistant metal mesh belt 602 is wound around the roller shaft 601, and the roller shaft 601 is driven by a motor to drive the heat-resistant metal mesh belt 602 to operate. The gas introduced is dry air with a water content of 0.5 g / m 3 , and the flow rate set by the flow controller 302 is 6 m 3 / h. The dry air enters from the bottom of the outer furnace 1 through the air inlet pipeline 301, enters the inner furnace 2 after being heated at the bottom of the outer furnace 1 and the bottom of the inner furnace 2, which can avoid thermal shock to the annealed glass. The gas is discharged from the exhaust port at the top of the tunnel kiln through the exhaust pipeline 303, and a humidity sensor 31 is provided at the exhaust port. As Figure 3 shown, after being tested by the humidity sensor 31, the water content of the discharged gas is 1.4 g / m 3 . When the tunnel kiln was built, its bottom was adjusted to the same horizontal height. One year after the tunnel kiln was built and put into use, due to ground settlement and equipment deformation at high temperature, the maximum height difference of its bottom measured by the height measuring device was 12 mm, as Figure 4 shown; according to the height measurement results, the adjusting screw 403 on the flatness adjusting device 4 was adjusted, the adjusting screw at the part with a higher height was lowered, and the adjusting screw at the part with a lower height was raised. After the adjustment, the maximum height difference of the bottom of the tunnel kiln measured by the height measuring device was 5 mm, as Figure 4 shown.

[0048] Connect the glass annealing tunnel kiln to the rear end of the glass forming device, and the formed glass directly enters the glass annealing tunnel kiln with controllable humidity and adjustable flatness of the present invention for annealing. Experiments show that the glass annealing tunnel kiln with controllable humidity and adjustable flatness of the present invention can be used for the production of phosphate glass and fluorophosphate glass, and phosphate glass and fluorophosphate glass with complete shape and no cracks can be obtained.

[0049] The glass annealing tunnel kiln with controllable humidity and adjustable flatness can adjust the type and quantity of the gas introduced according to the type of glass, and set the corresponding temperature and length, and is applicable to the annealing of special glass or optical glass with precise requirements for humidity, atmosphere and temperature.

[0050] The above are only used to explain the preferred embodiments of the present invention and are not intended to limit the present invention. Any modification or equivalent replacement made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A glass annealing tunnel kiln with controllable humidity and adjustable flatness, comprising at least one annealing unit (7) and a transmission device (6), characterized in that: The annealing unit consists of an outer furnace chamber (1), an inner furnace chamber (2), a support frame (5), a ventilation device (3), two flatness adjustment devices (4), a temperature sensor (21), and a humidity sensor (31); The inner furnace chamber (2) is placed inside the outer furnace chamber (1) and is coated with an infrared-transmitting refractory material (201). A heating device (202) is provided inside the infrared-transmitting refractory material (201). A heat-resistant metal plate (203) is provided on the bottom side inside the inner furnace chamber (2). The transmission device (6) is laid on the heat-resistant metal plate (203); The outer furnace chamber (1) is coated with a heat-insulating refractory material (101) and is fixed on the support frame (5); The flatness adjustment device (4) is connected to the support frame (5) and is used to support and adjust the height of the heat-resistant metal plate (203); The flatness adjustment device (4) includes a support brick (401), a support brick backing plate (402), and an adjustment screw (403) connected in sequence. The support brick (401) is arranged below the heat-resistant metal plate (203). The adjustment screw (403) is connected to the support frame (5) by threads. By driving the adjustment screw (403), the support brick (401) is lifted or lowered to adjust the height of the heat-resistant metal plate (203); The ventilation device (3) includes an inlet pipeline (301), a flow controller (302), and an exhaust pipeline (303). Dry gas passes through the heat-insulating refractory material (101) and the infrared-transmitting refractory material (201) in sequence through the inlet pipeline (301), and is discharged into the inner furnace chamber (2) after being heated from the bottom of the inner furnace chamber. The exhaust pipeline (303) passes through the infrared-transmitting refractory material (201) and the heat-insulating refractory material (101) in sequence to discharge gas from the top. The humidity sensor (31) is arranged on the exhaust pipeline (303). The inlet pipeline (301) is provided with a flow controller (302); The temperature sensor (21) is arranged in the central area at the top of the inner furnace chamber (2), and the temperature measurement point of the temperature sensor (21) is located in the middle of the inner furnace chamber (2). The humidity sensor (31) is arranged at the exhaust port of the exhaust pipeline (303); 2. The humidity-controllable and flatness-adjustable glass annealing tunnel kiln according to claim 1, wherein The transmission device (6) drives a heat-resistant metal mesh belt (602) to translate inside the inner furnace chamber (2) by two roller shafts (601). The heat-resistant metal mesh belt (602) is wound around the roller shafts (601). The roller shafts (601) can be driven by a motor to rotate, and the rotation of the roller shafts (601) drives the heat-resistant metal mesh belt (602) to operate; 3. A glass annealing tunnel kiln with controllable humidity and adjustable flatness as described in claim 1, characterized in that, The exhaust pipeline (303) is arranged in the central area at the top of the inner furnace chamber (2). The exhaust pipeline (303) discharges gas from the exhaust port in the central area at the top of the outer furnace chamber (1); 4. A glass annealing tunnel kiln with controllable humidity and adjustable flatness according to claim 1, characterized in that, The support frame (5) includes at least four support legs (501) and a support plate (502) placed on the support legs (501).

5. A glass annealing tunnel kiln with controllable humidity and adjustable flatness according to claim 1, characterized in that, The length of the annealing unit (7) is 0.5 to 2.0 m, and a plurality of annealing units (7) are connected end to end.

6. A glass annealing tunnel kiln with controllable humidity and adjustable flatness according to claim 1, characterized in that, When there are two or more heat-resistant metal plates (203), the gap between the plates is 5 to 30 mm.

7. A glass annealing tunnel kiln with controllable humidity and adjustable flatness according to claim 1, characterized in that, The thickness of the heat-insulating refractory material (101) of the outer furnace chamber (1) is 100 to 230 mm.

8. A glass annealing tunnel kiln with controllable humidity and adjustable flatness according to claim 1, characterized in that, The infrared-transmitting refractory material (201) is alumina ceramics, silicon carbide ceramics, quartz, or a mixed ceramic phase of quartz and alumina.

9. A glass annealing tunnel kiln with controllable humidity and adjustable flatness according to claim 1, characterized in that, The outlets of the intake gas pipelines (301) are arranged at both ends inside the inner furnace chamber (2).

10. A glass annealing tunnel kiln with controllable humidity and adjustable flatness according to claim 1, characterized in that, The gas introduced into the intake gas pipeline (301) is a dry gas, including air, nitrogen, oxygen, or inert gas.

Images