JP2009179529A - Method for producing glass gob and apparatus for recovering glass gob - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing glass gob and an apparatus for recovering the glass gob, capable of securely producing nearly spherical glass gob, even by dropping a liquid droplet from a lower position so it falls a shorter distance. <P>SOLUTION: The method for producing the glass gob involves dropping of molten glass to form the glass gob and comprises a step of catching the dropped glass with liquid, provided that bubbles are formed at surface of the liquid. The apparatus for recovering the glass gob comprises a liquid tank for filling the liquid and a gas vent formed inside the liquid tank. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a glass lump manufacturing method and a glass lump collection apparatus.

  Conventionally, optical pickup lenses such as DVDs, CDs, and magneto-optical disks, lenses for mobile phones with cameras, lenses for optical communication, lenses for optical devices, etc., and lens members for LEDs are directly polished by polishing glass. Processed and formed. However, polishing was very expensive and took a lot of time. For this reason, a lens is often molded from a preform that is a fine spherical glass by a precision press, and a technique for producing a nearly spherical glass is rapidly required.

  As a method for producing preformed and nearly spherical glass with high accuracy and low cost in large quantities, the molten glass droplets are cooled and arranged into particles while cooling, and the dropped droplets are grounded. Methods of receiving and collecting have been studied.

  As a method of dropping the molten glass into a granular shape, in Patent Documents 1 and 2, the molten glass flows down as a continuous flow from the nozzle, and after the molten glass that has flowed down falls into a drop-like glass lump, A method for recovering these glass lumps and producing a preform is disclosed.

  Patent Document 3 discloses a method for producing a substantially spherical glass gob, in which a droplet of molten glass is dropped from the nozzle tip, and the droplet is dropped until the surface temperature of the droplet becomes lower than the softening temperature of the glass. Is disclosed.

And, as a method of receiving the falling droplets and collecting the glass lumps, as described in Patent Documents 1 to 3, the droplets are received with a liquid at room temperature and the dropping speed is reduced, so that the scratches on the glass lumps are received. A method for preventing the occurrence of this is disclosed.
JP 09-235122 A JP 2005-179145 A JP-A 61-146721

  However, when a glass lump is formed by the method disclosed in Patent Documents 1 to 3, in order to obtain a substantially spherical glass lump, the liquid drop or the heat-resistant sponge is brought into contact with the liquid droplets falling to some extent. There was a need to do. Here, in order to harden the falling droplets, it was necessary to secure the distance between the nozzle and the liquid surface where the molten glass flows or drops as a continuous flow, in other words, the droplet dropping distance.

  The present invention has been made in view of the above-mentioned problems, and its object is to more reliably produce a substantially spherical glass lump even when a droplet is dropped at a shorter drop distance from a lower position. An object of the present invention is to provide a glass lump manufacturing method and a glass lump recovery device that can be used.

  In order to solve the above-mentioned problems, the present inventors have conducted earnest test research, and as a result, the bubbles formed on the liquid surface are dropped from the liquid surface by dropping the molten glass into the liquid in which bubbles are generated on the liquid surface. The inventors have found that a drop impact transmitted to a droplet can be reduced and a glass lump having a shape close to a sphere can be more reliably produced, and the present invention has been completed. More specifically, the present invention provides the following.

  (1) A method of manufacturing a glass lump that drops molten glass to form a glass lump, and includes a step of receiving the dropped glass with a liquid in which bubbles are generated on the liquid surface.

  (2) The method for producing a glass lump according to (1), further comprising a step of introducing a bubble source gas into the liquid.

  (3) The method for producing a glass lump according to (2), wherein a porous body is immersed in a liquid, the bubble source gas is discharged from the porous body and introduced into the liquid.

  (4) A method for producing an optical element, comprising a step of precision press-molding a glass lump produced by the method according to any one of (1) to (3).

  (5) A method for producing a lens member for LED, comprising a step of molding a glass lump produced by the method according to any one of (1) to (3).

  (6) A glass lump recovery apparatus having a liquid tank filled with a liquid and a gas jet port installed in the liquid tank.

  (7) The glass lump recovery device according to (6), wherein the gas jetting port is made of a porous material.

  (8) A glass lump production apparatus for recovering the molded glass lump in the glass lump recovery apparatus according to (6) or (7).

  (9) The apparatus for producing a glass lump according to (8), which has a flow channel for dropping molten glass or flowing down as a continuous flow.

  According to the present invention, the drop impact transmitted from the liquid surface to the liquid droplets is reduced by the bubbles by dropping the molten glass onto the liquid in which bubbles are generated on the liquid surface. Therefore, it is possible to provide a glass lump manufacturing method and a glass lump recovery apparatus that can more reliably manufacture a substantially spherical glass lump even when a droplet is dropped from a lower position at a shorter drop distance. it can.

  The method for producing a glass lump according to the present invention is a method for producing a glass lump that drops molten glass to form a glass lump, and includes a step of receiving the dropped glass with a liquid in which bubbles are generated on the liquid surface.

  Moreover, the glass lump collection | recovery apparatus of this invention has the liquid tank filled with a liquid, and the gas jet nozzle installed in the liquid tank.

  Hereinafter, embodiments of a glass lump production apparatus having a glass lump recovery apparatus of the present invention and a method for producing a glass lump will be described in detail, but the present invention is not limited to the following embodiments at all. Within the scope of the object of the invention, it can be implemented with appropriate modifications. In addition, although description may be abbreviate | omitted suitably about the location where description overlaps, the meaning of invention is not limited.

[Glass lump manufacturing equipment]
FIG. 1 is a diagram schematically showing a glass lump production apparatus 1 according to the present invention. The glass lump production apparatus 1 of the present invention has a glass lump recovery apparatus 10, which is a liquid tank 31 filled with a liquid 32 that receives falling glass, and a gas installed in the liquid tank 31. And a spout 23.

  The liquid tank 31 may be any container that can hold the liquid 32. For example, a known liquid tank made of metal, plastic, or the like can be used. The depth of the liquid tank 31 is preferably 20 cm or more, more preferably 40 cm or more, and most preferably 50 cm or more. By setting the depth of the liquid tank 31 in this range, the glass is deprived of heat until the droplet contacts the bottom of the liquid tank 31, so that the glass temperature is lowered to a temperature at which deformation and breakage of the glass are reduced. be able to.

  An opening is provided on the upper surface of the liquid tank 31. At this time, the liquid droplet passes through the opening of the liquid tank 31 and falls into the liquid 32. The width of the opening of the liquid tank 31 is appropriately set in consideration of the drop distance of the liquid droplets. That is, the lower limit of the diameter of the opening is preferably 2% or more, more preferably 4% or more, and more preferably 6% or more of the distance between the channel tip 41 and the liquid surface of the liquid 32. Most preferred. By setting the lower limit of the diameter of the opening within this range, the droplet falls into the liquid 32 even when the drop trajectory of the droplet swings, so that it becomes easier to obtain a substantially spherical glass lump more reliably. On the other hand, the upper limit of the diameter of the opening is preferably 200 cm or less, more preferably 150 cm or less, in order to easily suppress unnecessary exposure and contamination of the liquid 32 and reduce the replacement frequency of the liquid 32. Preferably, it is 100 cm or less.

  The gas outlet 23 is provided in a liquid tank 31 filled with the liquid 32 and is connected to the gas supply source 21 via the pipe 22. Thereby, the bubble source gas can be ejected from the gas ejection port 23 to form bubbles on the liquid surface of the liquid 32. Here, the gas outlet 23 may be integrated with the tip of the pipe 22. In this embodiment, bubbles are formed by jetting gas into the liquid. However, the present invention is not limited to this. For example, the bubbles may be formed on the liquid surface by vigorous stirring.

  The gas outlet 23 is preferably made of a porous material. Thereby, a fine bubble can be formed efficiently. Specifically, as the porous material, it is more preferable to use a known material such as a metal, a ceramic, or a resin. In particular, when water or alcohol is used as the liquid 32, it is most preferable to use a metal. The pore diameter of the porous material is preferably 100 μm or less, more preferably 50 μm or less, and most preferably 20 μm or less. By setting the pore diameter of the porous material within this range, minute bubbles are generated on the surface of the liquid 32, and the bubble layer formed on the liquid surface becomes thick. Impact can be reduced.

  The gas outlet 23 is preferably provided at a position that does not overlap the drop trajectory of the droplet. Thereby, it is possible to make it difficult for the gas ejection port 23 to be damaged by the dropped droplet. At the same time, it is preferable to direct the direction in which the bubble source gas is discharged from the gas ejection port 23 to the drop orbit of the droplet. By releasing the bubble source gas toward the drop orbit of the droplet, more bubbles are generated in the vicinity of the drop orbit of the droplet on the liquid surface, so the drop impact of the droplet can be more efficiently mitigated. it can.

  Using such a glass lump recovery apparatus 10, it is preferable to receive the falling glass and recover the molded glass lump. Here, in order to drop the glass into the glass lump collecting apparatus 10, for example, as shown in FIG. 1, a holding container 51 for holding the molten glass A, a furnace body 52 for supporting and heating the holding container 51, and holding. The molten glass A held in the holding container 51 is flowed using the glass lump manufacturing apparatus 1 including the flow path 42 provided at the lower portion of the container 51 and the flow path tip 41 provided at the tip of the flow path 42. It is preferable to drop from the flow path tip 41 through the path 42 or flow down as a continuous flow.

  The holding container 51 is for producing and holding the molten glass A. For example, a known holding container such as a refractory container, a gold crucible, a platinum crucible, a platinum alloy crucible, or an iridium crucible can be used.

  The holding container 51 is provided with a raw material inlet 53. When the raw material charging port 53 is closed, it is preferable that the holding container 51 is in a hermetically sealed state, particularly when a pressure adjusting means (not shown) for adjusting the pressure inside the holding container 51 is provided in the holding container 51. It is more preferable that the holding container 51 has pressure resistance. Since the holding container 51 has pressure resistance, it can endure pressurization or decompression by the pressure adjusting means. In the present embodiment, the raw material is introduced from the raw material inlet 53. However, the present invention is not limited to this, and a configuration in which the molten glass A is introduced from the raw material inlet 53 may be used.

  Further, the holding container 51 is preferably provided with a heater and / or a stirrer 54. By providing the heater in the holding container 51, the held molten glass A can be maintained at a predetermined temperature. Moreover, by providing the holding container 51 with the stirrer 54, the molten glass A can be stirred and homogenized.

  The furnace body 52 is made of a heat-resistant material such as a refractory brick that covers the periphery of the holding container 51, and is installed at a high place by a tower (not shown). The material of the furnace body 52 is not particularly limited as long as it can withstand the temperature of the holding container 51.

  The flow path 42 is connected to the lower part of the holding container 51, guides the molten glass A in the holding container 51 to the flow path tip 41, drops the molten glass A from the flow path tip 41, or flows down as a continuous flow. To do. Thereby, the glass lump shape | molded spherically can be obtained. As the flow path 42 and the flow path tip 41, a known glass outflow nozzle shape can be used. The flow path tip 41 is connected to the flow path 42 so as to communicate with the flow path 42. Here, the flow path tip 41 may be integrated with the flow path 42.

  The flow path 42 and the flow path tip 41 are preferably provided with heating means (not shown). Thereby, since the viscosity of the molten glass A in the flow path 42 becomes constant and a certain amount of the molten glass A flows out from the flow path tip 41, spherical particles having a constant mass can be easily formed. At the same time, the flow path 42 and the flow path tip 41 are heated, and the molten glass A can be kept in the flow path 42 and the flow path tip 41.

[Glass lump manufacturing method]
The method for producing a glass lump according to the present invention includes a step of dropping the molten glass A and receiving the glass dropped with the liquid 32 in which bubbles are generated on the liquid surface to form a glass lump, for example, as shown in FIG. It can manufacture using such a glass lump manufacturing apparatus 1. In addition, description is abbreviate | omitted about the location which overlaps with the content mentioned above.

  For example, the molten glass A is melted and held in a holding container 51, dropped from the holding container 51 through the flow path 42 and the flow path tip 41 toward the liquid 32, or flows down as a continuous flow.

  When the molten glass A is held in the holding container 51, it is preferable to rotate the stirrer 54 and stir the molten glass A with a stirring blade to homogenize it. Here, the molten glass A may be produced by melting the glass raw material by other melting means and then transferred to the holding container 51, or may be produced by melting the glass raw material in the holding container 51.

  Further, when the molten glass A is dropped or flows down as a continuous flow, a pressure adjusting means for adjusting the pressure inside the holding container 51 is operated to adjust the amount of the molten glass A flowing out from the flow path tip 41. It is preferable. More specifically, using the pressure adjusting means, the inside of the holding container 51 is pressurized to increase the outflow amount of the molten glass A into the flow path 42, and the inside of the holding container 51 is depressurized to The amount of outflow to the flow path 42 can be reduced.

  The molten glass A dropped from the flow path tip 41 or flowing down as a continuous flow is formed into a spherical shape by gravity and surface tension while dropping. At this time, a trajectory changing means (not shown) for changing the dropping trajectory of the molten glass A may be provided between the flow path tip 41 and the liquid tank 31.

  And in the liquid tank 31 filled with the liquid 32 which produced the bubble on the liquid level, the glass formed spherically by dropping is received. By dropping the glass into bubbles formed in the liquid 32, the drop impact when the glass collides with the liquid surface of the liquid 32 is absorbed, and the drop impact transmitted from the liquid surface to the dropped glass is reduced. For this reason, it can collect | recover more reliably as a glass lump of a shape close | similar to a spherical shape, without destroying the shape of the glass which fell in the shape close | similar to a spherical shape largely.

  The liquid 32 filled in the liquid tank 31 is not particularly limited as long as it does not easily react with the dropped glass and can cool the dropped glass. For example, various known liquids such as water, alcohols, and oils can be used. It is preferable to use it. These may be used alone or in combination. Among them, it is more preferable to use water, alcohols, a mixture thereof, or the like because the heat capacity is large and the glass can be efficiently cooled. Among these, it is most preferable to use alcohols because the recovered glass lump can be dried without washing, or can be easily washed and dried and used as an optical element such as a preform material or a lens. Known alcohols such as ethanol and isopropyl alcohol can be used as the alcohols.

  It is preferable to introduce a bubble source gas into the liquid 32. Thereby, since bubbles are generated on the liquid surface of the liquid 32, it is possible to further enhance the action of reducing the drop impact transmitted to the liquid droplets. Examples of the method of introducing the bubble source gas include a method of jetting the bubble source gas from the gas outlet 23 through the pipe 22 from the gas supply source 21. The bubble source gas is appropriately selected in consideration of the liquid 32 to be used. That is, it is preferable to use a gas having a low solubility in the liquid 32. In particular, when a flammable liquid is used as the liquid 32, it is more preferable to use an inert gas and / or nitrogen gas, and compression is performed from the viewpoint of cost. Most preferably, air is used.

  At this time, the gas jet port 23 made of a porous material is immersed in the liquid 32, the bubble source gas is discharged from the gas jet port 23, and the bubble source gas is introduced into the liquid 32 through the gas jet port 23. It is more preferable. As a result, minute bubbles are generated on the surface of the liquid 32 and the bubble layer formed on the liquid surface becomes thick, so that the impact when the glass drops on the liquid surface can be further alleviated. Here, the size of the bubbles formed on the liquid surface of the liquid 32 is, for example, preferably 50 μm to 30 mm, more preferably 50 μm to 10 mm, and most preferably 50 μm to 5 mm.

  A known foaming agent can be added to the liquid 32. By adding a foaming agent, more bubbles are generated on the liquid surface, so that the impact when the glass falls on the liquid surface can be effectively reduced.

  Thereafter, the glass lump collected in the liquid tank 31 is subjected to a precision press molding process using a precision press molding apparatus, and a desired optical element can be manufactured. Moreover, the glass lump collect | recovered in the liquid tank 31 can be shape | molded, and the lens member for LED can also be manufactured.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to a following example.

A glass raw material is introduced into a holding container 51 made of a platinum crucible and covered with a furnace body 52, and a glass melt (molten glass) of optical glass mainly composed of La ₂ O ₃ and B ₂ O _3. A) was prepared and held at 1000 ° C. The molten glass A was flown out from the holding container 51 to the channel tip 41 through the channel 42, and the molten glass A was dropped from the channel tip 41. At this time, the inner diameter of the flow path tip 41 was 3 mm.

  On the other hand, the liquid tank 31 was filled with isopropyl alcohol as the liquid 32, and compressed air was introduced into the liquid 32 to generate bubbles having a diameter of about 40 mm on the liquid surface. At this time, the distance between the tip of the flow path tip 41 and the liquid level of the liquid 32 is 20 m.

  The droplet of molten glass A dropped from the channel tip 41 was received by the liquid 32 that generated bubbles on the liquid surface after dropping by 20 m. And after taking out and drying the glass lump collect | recovered in the liquid tank 31, it evaluated about the shape of the glass lump.

  As a comparative example, the same test as in the example was performed for the case where compressed air was not introduced into the liquid 32.

  As a result, when bubbles were generated on the liquid surface, the shape of the glass lump was nearly spherical. On the other hand, when the compressed air was not introduced into the liquid 32, the glass lump did not have a spherical shape due to the drop impact when the glass collided with the liquid surface of the liquid 32. Comparing the shapes of the glass lumps of the example and the comparative example, it can be seen that when compressed air is introduced into the liquid 32, the glass lumps can be made closer to a spherical shape.

It is a figure which shows the outline of a glass lump manufacturing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass lump manufacturing apparatus 10 Glass lump collection | recovery apparatus 21 Gas supply source 22 Piping 23 Gas outlet 31 Liquid tank 32 Liquid 41 Flow path tip 42 Flow path 51 Holding container 52 Furnace body 53 Raw material inlet 54 Stirrer A Molten glass

Claims (9)

A method for producing a glass lump that drops molten glass to form a glass lump,
A method for producing a glass lump comprising a step of receiving a dropped glass with a liquid in which bubbles are generated on a liquid surface.   The method for producing a glass lump according to claim 1, further comprising a step of introducing a bubble source gas into the liquid.   The method for producing a glass lump according to claim 2, wherein a porous body is immersed in a liquid, and the bubble source gas is discharged from the porous body and introduced into the liquid.   The manufacturing method of the optical element including the process of carrying out the precision press molding of the glass lump manufactured by the method in any one of Claim 1 to 3.   The manufacturing method of the lens member for LED including the process of shape | molding the glass lump manufactured by the method in any one of Claim 1 to 3.   A glass lump recovery apparatus comprising a liquid tank filled with a liquid and a gas jet port installed in the liquid tank.   The glass lump recovery apparatus according to claim 6, wherein the gas outlet is made of a porous material.   The glass lump manufacturing apparatus which collect | recovers the shape | molded glass lump with the glass lump collection | recovery apparatus of Claim 6 or 7. The glass lump manufacturing apparatus according to claim 8, further comprising a flow path for dropping molten glass or flowing down as a continuous flow.

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