Optical glass cooling device and cooling method thereof
阅读说明:本技术 光学玻璃降温装置及其降温方法 (Optical glass cooling device and cooling method thereof ) 是由 郭富强 于 2020-08-19 设计创作,主要内容包括:本发明提供一种可改善玻璃产品质量的光学玻璃降温装置。光学玻璃降温装置,包括墙体和冷却管,所述冷却管设置在墙体内部,所述冷却管与墙体相交位置形成玻璃液入口和玻璃液出口,且所述冷却管的中心线将墙体内部分为上下两个空间,所述上下两个空间分别构成上加热腔和下加热腔。玻璃液在本发明的降温装置中无自由液面,从而避免了玻璃液在降温装置中产生气、液、固三相界面而形成铂金粒子、挥发凝结物等杂质缺陷造成的玻璃产品内部异物缺陷;玻璃液在降温装置中停留时间集中度明显提高,缓流区域显著减少,从而提高了玻璃液流动一致性,降低了析晶缺陷产生的可能性,提高了产品常数一致性和产品内在质量。(The invention provides an optical glass cooling device capable of improving the quality of glass products. Optical glass heat sink, including wall body and cooling tube, the cooling tube sets up inside the wall body, the crossing position of cooling tube and wall body forms glass liquid entry and glass liquid export, just two spaces about the central line of cooling tube is divided into with wall body inside, two spaces constitute heating chamber and lower heating chamber respectively from top to bottom. The glass liquid has no free liquid level in the cooling device, so that the defect of foreign matters in the glass product caused by the defect that the glass liquid generates gas, liquid and solid three-phase interfaces in the cooling device to form platinum particles, volatile coagulants and other impurities is avoided; the residence time concentration of the molten glass in the cooling device is obviously improved, and the slow flow area is obviously reduced, so that the flow consistency of the molten glass is improved, the possibility of generating crystallization defects is reduced, and the constant consistency of products and the internal quality of the products are improved.)
1. Optical glass heat sink, its characterized in that includes wall body (14) and cooling tube (6), cooling tube (6) set up inside wall body (14), cooling tube (6) and wall body (14) crossing position form glass liquid entry (7) and glass liquid export (8), just the central line of cooling tube (6) is with wall body (14) inside two spaces about being divided into, two spaces constitute respectively from top to bottom heating chamber (10) and lower heating chamber (15) about two spaces.
2. The optical glass cooling device according to claim 1, wherein heating elements (13) are disposed in the upper heating chamber (10) and the lower heating chamber (15), the heating elements (13) control the temperature of the upper heating chamber (10) and the lower heating chamber (15) to be lower than the temperature of the glass liquid in the cooling pipe (6), and the temperature of the glass liquid on the wall surface of the cooling pipe is higher than the upper limit of the glass crystallization temperature.
3. The optical glass cooling device according to claim 1, wherein the cooling pipe (6) is externally wrapped with a heat insulating layer (11).
4. The optical glass cooling device according to claim 1, wherein the cooling tube (6) is divided into five sections, in order: the cooling structure comprises an inlet section cooling pipe (61), a second section cooling pipe (62), a third section cooling pipe (63), a fourth section cooling pipe (64) and an outlet section cooling pipe (65), wherein the diameter of the third section cooling pipe (63) is the largest, the second section cooling pipe (62) is used as a transition pipeline of the inlet section cooling pipe (61) and the third section cooling pipe (63), the cross section shape of the second section cooling pipe is in transition change according to the cross section shapes of the inlet section cooling pipe (61) and the third section cooling pipe (63), the fourth section cooling pipe (64) is used as a transition pipeline of the third section cooling pipe (63) and the outlet section cooling pipe (65), and the cross section shape of the fourth section cooling pipe is in transition change according to the cross section shapes of the third section cooling pipe (63) and the outlet section cooling pipe (65).
5. The optical glass cooling device according to claim 4, wherein the cross-sectional shapes of the inlet section cooling pipe (61), the third section cooling pipe (63) and the outlet section cooling pipe (65) are circular, and the cross-sectional shapes of the second section cooling pipe (62) and the fourth section cooling pipe (64) are bell mouth shapes.
6. The optical glass cooling device according to claim 1, wherein a plurality of baffle rings (5) are arranged in the cooling tube (6), the outer wall of each baffle ring (5) is abutted against the inner wall of the cooling tube (6), and the shape of the outer wall of each baffle ring (5) is matched with the shape of the inner wall of the cooling tube (6).
7. The device for cooling optical glass according to claim 6, wherein when the cross section of the cooling tube (6) is circular, the height D of the baffle ring (5) is 0.05-0.2D of the inner diameter D of the cooling tube (6), and the thickness of the baffle ring (5) is 0.5-2.5 mm.
8. The optical glass cooling device according to claim 6, wherein the baffle ring (5) is divided into a plurality of independent small areas (51) along the circumferential direction, and the molten glass flows through the gaps between the small areas (51) to prevent the molten glass from flowing unsmoothly at the joint of the baffle ring (5) and the inner wall of the cooling pipe (6); or a plurality of holes (52) are arranged on the baffle ring (5) along the circumferential direction, and the molten glass flows through the holes (52) on the baffle ring (5).
9. An optical glass cooling device according to claim 1, wherein a plurality of flow deflectors (9) are provided in the cooling pipe (6), the plurality of flow deflectors (9) being provided along a circumferential inner wall of the straight pipe portion of the cooling pipe (6).
10. The optical glass cooling device according to claim 9, wherein the height h of the baffle (9) is 0.01-0.2D of the inner diameter D of the cooling tube (6), the length of the baffle (9) is less than or equal to the length of the straight tube part of the third section of the cooling tube (63) of the cooling tube (6), and the width W of the baffle (9) is less than 0.2 times of the circumference of the inner wall of the cooling tube (6) on the cross section where the baffle (9) is located.
11. The optical glass cooling device according to claim 1, wherein a discharge pipe (12) is provided at the lowest position of the third stage cooling pipe (63) of the cooling pipe (6).
12. An optical glass cooling device according to claim 1, wherein the cooling pipe (6) has the same pipe diameter size at all positions, and the total length of the cooling pipe (6) is designed to satisfy the staying time of the molten glass in the cooling pipe (6).
13. The method for cooling the optical glass melt is characterized by comprising the following steps of:
1) the heating element (13) is electrified to provide heat for the upper heating cavity (10) and the lower heating cavity (15), so that the overall temperature of the upper heating cavity (10) and the lower heating cavity (15) reaches the temperature required by the cooling process, and the temperature is lower than the lowest temperature of the molten glass which is about to enter the cooling pipe (6);
2) high temperature glass liquid after the clarification is accomplished gets into cooling tube (6) by glass liquid entry (7), and glass liquid flows in cooling tube (6), and the inner wall of cooling tube (6) is given partial heat transfer through the heat transfer, and the inner wall of cooling tube (6) is given heat transfer to heat preservation (11) through heat conduction, and heat transfer is given heat transfer to last heating chamber (10) and lower heating chamber (15) and wall body (14) again in heat preservation (11), and the glass liquid that accords with process temperature at last flows by glass liquid export (8).
14. The method for cooling optical glass melt according to claim 13, wherein the step 1) of energizing the heating element (13) is to control the heating elements (13) in the upper heating chamber (10) and the lower heating chamber (15) respectively, so as to precisely control the temperature change of the upper heating chamber (10) and the lower heating chamber (15) and achieve the fluctuation value of the temperature of the glass melt flowing out from the glass melt outlet (8) along with the time.
15. The method for reducing the temperature of an optical molten glass according to claim 13, wherein the molten glass in the step 2) flows in the cooling pipe (6), and the lowest temperature in the flowing process of the molten glass is higher than the upper limit of the glass crystallization temperature, so that the crystallization defect is prevented from occurring when the temperature crosses the crystallization temperature zone.
Technical Field
The invention relates to a cooling device for cooling high-temperature molten glass in the production process of optical glass, and a cooling method for improving the temperature uniformity in the cooling process of molten glass and improving the retention time consistency in the cooling process of glass by using the cooling device.
Background
The optical glass production process mainly relates to main process processes such as powder melting, high-temperature clarification, stirring homogenization, strip material forming and the like, the temperature of molten glass needs to be reduced from the highest temperature to a temperature process state suitable for homogenization and subsequent discharging between the high-temperature clarification and the stirring homogenization, a clarification tank and a homogenization tank are generally connected by straight pipes in the prior art to complete the temperature reduction process, but the time required for cooling the molten glass at the position is increased along with the increase of the glass yield by the structure, and the length of a connecting pipe is limited by the overall length of a production line.
Therefore, there is a proposal in the literature to extend the cooling time of molten glass by providing a cooling tank between a clarifier and a homogenizer to cool the molten glass. According to the design of the existing cooling pool shown in figure 1, glass liquid enters the cooling pool from an
The scheme can obviously improve the problem of insufficient cooling capacity of the glass liquid for optical glass which is not easy to generate defects of volatilization, crystallization and the like, but has limited applicability to optical glass containing fluorine and phosphorus. In optical glass containing fluorine and phosphorus, the glass forming ability is weak due to the existence of a large amount of fluoride and phosphate in the formula, the crystallization ability is strong, and the volatilization at a free interface is serious. At a gas-solid-liquid three-phase interface at high temperature, oxygen and moisture are more sufficient, so that platinum is more easily corroded to form a platinum phosphate compound, and the platinum phosphate compound is easily reacted with free oxides in glass liquid due to the increase of the concentration of the compound to reduce the platinum phosphate compound into platinum particles, so that platinum microparticles enter the glass liquid to cause light scattering in the glass, the internal transmittance of the glass is reduced, and the internal defects of the optical glass are caused; on the other hand, the free liquid surface can accelerate the volatilization of fluoride at high temperature, the composition of glass components near the interface is influenced, the glass components with high melting point are formed, and the adhesion substances of the components are difficult to dissolve in molten glass, so that stone foreign matters are generated, and the defects of the optical glass are formed. In addition, the design of the cooling tank leads the glass liquid to easily form a supercooled area in a region near the bottom of the tank where the glass liquid slowly flows, and leads part of the glass liquid to enter a crystallization temperature region to generate tiny grains, thereby further reducing the inherent quality of products. Therefore, the cooling pool has a room to be improved in solving the above problems.
Disclosure of Invention
The invention aims to solve the technical problem of providing an optical glass cooling device capable of improving the quality of glass products.
The invention also provides a glass liquid cooling method.
The technical scheme adopted by the invention for solving the technical problem is as follows: optical glass heat sink, including wall body and cooling tube, the cooling tube sets up inside the wall body, the crossing position of cooling tube and wall body forms glass liquid entry and glass liquid export, just two spaces about the central line of cooling tube is divided into with wall body inside, two spaces constitute heating chamber and lower heating chamber respectively from top to bottom.
Furthermore, heating elements are arranged in the upper heating cavity and the lower heating cavity, the heating elements control the temperature of the upper heating cavity and the temperature of the lower heating cavity to be lower than the temperature of glass liquid in the cooling pipe, and the temperature of the glass liquid on the wall surface of the cooling pipe is higher than the upper limit of glass crystallization temperature.
Furthermore, the cooling pipe is wrapped with a heat insulation layer.
Further, the cooling pipe is divided into five sections, which are respectively: the cooling device comprises an inlet section cooling pipe, a second section cooling pipe, a third section cooling pipe, a fourth section cooling pipe and an outlet section cooling pipe, wherein the diameter of the third section cooling pipe is the largest, the second section cooling pipe is used as a transition pipeline of the inlet section cooling pipe and the third section cooling pipe, the section shape of the second section cooling pipe is in transition change according to the section shapes of the inlet section cooling pipe and the third section cooling pipe, the fourth section cooling pipe is used as a transition pipeline of the third section cooling pipe and the outlet section cooling pipe, and the section shape of the fourth section cooling pipe is in transition change according to the section shapes of the third section cooling pipe and the outlet section cooling pipe.
Furthermore, the cross sections of the inlet section cooling pipe, the third section cooling pipe and the outlet section cooling pipe are circular, and the cross sections of the second section cooling pipe and the fourth section cooling pipe are bell mouth shaped.
Furthermore, a plurality of baffle rings are arranged in the cooling pipe, the outer walls of the baffle rings are close to the inner wall of the cooling pipe, and the shape of the outer walls of the baffle rings is matched with that of the inner wall of the cooling pipe.
Further, when the section of the cooling pipe is circular, the height D of the baffle ring is 0.05-0.2D of the inner diameter D of the cooling pipe, and the thickness of the baffle ring is 0.5-2.5 mm.
Furthermore, the baffle ring is divided into a plurality of independent small areas along the circumferential direction, and the molten glass flows through gaps between the small areas to prevent the molten glass from flowing unsmoothly at the joint of the baffle ring and the inner wall of the cooling pipe; or a plurality of holes are arranged on the baffle ring along the circumferential direction, and the molten glass flows through the holes on the baffle ring.
Further, a plurality of guide vanes are provided in the cooling pipe, the guide vanes being provided along the circumferential inner wall of the straight pipe portion of the cooling pipe.
Further, the height h of the flow deflector is 0.01-0.2D of the inner diameter D of the cooling pipe, the length of the flow deflector is less than or equal to the length of the straight pipe part of the third section of the cooling pipe, and the width W of the flow deflector is less than 0.2 times of the perimeter of the inner wall of the cooling pipe on the cross section where the flow deflector is located.
Further, a discharge pipe is provided at the lowest position of the third stage of the cooling pipe.
Furthermore, the pipe diameters of all positions of the cooling pipe are the same, and the total length of the cooling pipe is designed to meet the residence time of the molten glass in the cooling pipe.
The method for cooling the optical glass melt comprises the following steps:
1) the heating element is electrified to provide heat for the upper heating cavity and the lower heating cavity, so that the overall temperature of the upper heating cavity and the lower heating cavity reaches the temperature required by the cooling process, and the temperature is lower than the lowest temperature of the glass liquid to enter the cooling pipe;
2) the high-temperature molten glass after the clarification is accomplished gets into the cooling tube by the molten glass entry, and the molten glass flows in the cooling tube, gives the inner wall of cooling tube with partial heat transfer through the heat transfer, and the inner wall of cooling tube gives the heat preservation with heat transfer through heat conduction, and the heat preservation gives last heating chamber and lower heating chamber and wall body with heat transfer again, and the molten glass that accords with process temperature at last flows by the molten glass export.
Further, the heating elements in the upper heating cavity and the lower heating cavity are respectively controlled in the step 1) of electrifying the heating elements, so that the temperature change of the upper heating cavity and the lower heating cavity is accurately controlled, and the fluctuation value of the glass liquid flowing out from the glass liquid outlet along with the time is controlled.
Further, the molten glass in the step 2) flows in the cooling pipe, and the lowest temperature in the flowing process of the molten glass is higher than the upper limit of the glass crystallization temperature, so that the crystallization defect is prevented from occurring when the temperature passes through the crystallization temperature zone.
The invention has the beneficial effects that: the glass liquid has no free liquid level in the cooling device, so that the defect of foreign matters in the glass product caused by the defect that the glass liquid generates gas, liquid and solid three-phase interfaces in the cooling device to form platinum particles, volatile coagulants and other impurities is avoided, the internal transmittance of the glass product is improved, and the pollution of volatile matters to the environment is reduced; the respective control of the upper and lower space temperatures of the cooling pipe is realized, so that the space temperature control precision is improved; compared with the prior art, the problem that the consistency of the flowing and the composition of the glass liquid is poor in the cooling process is solved, the concentration of the glass liquid in the cooling device is obviously improved, and the slow flow area is obviously reduced, so that the flowing consistency of the glass liquid is improved, the possibility of generating crystallization defects is reduced, and the constant consistency of products and the internal quality of the products are improved.
Drawings
Fig. 1 is a schematic structural diagram of a conventional cooling tank.
Fig. 2 is a schematic structural diagram of the cooling device of the present invention.
Fig. 3 is a schematic structural view of the retainer ring of the present invention.
FIG. 4 is a schematic cross-sectional view of the baffle ring of the present invention disposed in a cooling tube.
FIG. 5 is a schematic cross-sectional view of another configuration of the present invention with the slinger disposed within the cooling tube.
Fig. 6 is a schematic cross-sectional view of the guide vane of the present invention disposed in a cooling tube.
FIG. 7 is a schematic diagram showing the comparison of the residence time concentration of the glass particles between the cooling device of the present invention and the existing cooling tank.
Detailed Description
In the production process of optical glass, after bubbles are removed from glass liquid through a clarification tank, the glass liquid is transferred to a stirring tank for homogenization, and finally a product in a required shape is formed.
As shown in fig. 2, the cooling device of the present invention includes a
The main function of the
The heat-insulating
The inside of the
The lowest position of the third section of
The material of the
The
In order to improve the cooling and heat exchange efficiency of the glass liquid, a plurality of
In another embodiment, a plurality of baffles 9 may be further provided in the
The
The cooling device has the advantages of no free liquid level, high concentration of glass liquid staying time, few slow flow rate areas and the like. The glass liquid has no free liquid surface, so that the problem of the reduction of the internal transmittance of a glass product caused by the dispersion defect in the glass due to the formation of platinum particles, volatile impurities and the like in a cooling device by the glass liquid can be prevented, and the pollution of the volatile to the environment is also reduced; the improvement of the residence time concentration ratio and the slow flow rate area can prevent the problems of local crystallization caused by overlong local residence time of the glass liquid and physicochemical constant fluctuation caused by component difference. The residence time concentration ratio is the percentage of the outflow of the same batch of glass liquid in the total flow in a period of time, and the larger the value is, the better the concentration ratio is, the better the consistency of the glass components is, and the more ideal the physical and chemical properties are. The slow flow rate region is a flow region occupied by the molten glass, and the flow rate of the molten glass is 1% or less of the fastest flow rate in the whole molten glass flowing process.
The invention can provide the following method for cooling the optical glass liquid by adopting the cooling device with the structure, and the method comprises the following steps:
1) the
2) the high-temperature molten glass after the clarification is finished enters the
The minimum temperature of the molten glass in the flowing process of the
By adopting the above temperature reduction method, the
The invention also carries out verification experiments, evaluates the structures shown in figures 1 and 2 by means of numerical simulation analysis, analyzes the flow field distribution of the glass liquid flowing through the cooling device under two conditions of the cooling pool with the existing structure and the cooling device adopting the cooling device of the invention, records the residence time of 5000 glass liquid particles which are evenly distributed on the cross sections of the
The optical glass cooling device and the method thereof are suitable for cooling glass liquid of conventional optical glass, optical glass containing volatile components, optical glass easy to crystallize and the like, and are particularly suitable for cooling environment-friendly heavy flint glass, lanthanide glass, low-softening-point glass and low-refraction low-dispersion glass.
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