JP2016037437A - Method of manufacturing glass article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a glass article that makes bulk density of a mixed raw material fed into a gas melting furnace constant and suppresses the glass article from decreasing in quality.SOLUTION: There is provided a method of manufacturing a glass article that obtains the glass article using a mixed raw material of a glass cullet and a glass raw material, the method of manufacturing the glass article including: a measuring process of measuring bulk density of the mixed raw material; a bulk density adjusting process of adjusting the bulk density so that the mixed raw material including an additional raw material has predetermined bulk density by adding the additional raw material having bulk density different from the bulk density of the mixed raw material to the mixed raw material; and a melting process of melting the mixed raw material having its bulk density adjusted in the bulk density adjusting process.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a glass article such as a glass substrate or glass fiber.

Glass articles are used in various applications. In particular, in the electronics industry and the communication equipment industry, glass products with special functions are very often used. Glass articles for realizing high functions are employed in optical components such as optical fibers, displays such as liquid crystal display devices and plasma displays, and image input devices such as digital cameras. In the automobile industry, a thermoplastic resin reinforced with glass fiber is used as a substitute for metal in order to reduce the weight of the vehicle.
For glass products, mixed raw materials mixed with silica raw materials at a predetermined ratio are put into a glass melting furnace or glass melting pot, heated for a predetermined time to melt the glass raw materials into molten glass, and various homogenization It is manufactured by improving the homogeneity of the molten glass using the means and molding the molten glass into a desired shape by various molding apparatuses.

  There are many factors that determine the homogeneity of the molten glass, and one of the important factors is the characteristics of the mixed raw material charged into the glass melting furnace, such as the particle diameter and composition of the mixed raw material. Besides these, the bulk density of the mixed raw material is also important.

  In order to improve recycling and meltability, glass cullet may be used as a mixed raw material in addition to glass raw materials such as silica and feldspar. In glass melting technology, the bulk density management of mixed raw material (glass raw material + glass cullet) The importance is increasing. If the bulk density of the mixed raw material is too large, the mixed raw material is difficult to melt, and the mixed raw material is deposited near the inlet. Therefore, the temperature of the molten glass in the glass melting furnace becomes non-uniform, the homogeneity of the molten glass is lowered, and the quality of the glass article is lowered. On the other hand, if the bulk density of the mixed raw material is too small, the mixed raw material floats on the liquid surface of the molten glass for a long time, and the mixed raw material becomes insufficiently melted. Therefore, the temperature of the molten glass in the glass melting furnace becomes non-uniform, the homogeneity of the molten glass is lowered, and the quality of the glass article is lowered.

  Patent Document 1 discloses that a bulk material of unknown bulk density is filled by filling a powder body of known bulk density and a mixed raw material mass of unknown bulk density into a container of known volume and mass, and measuring the mass of the filled container. By measuring the bulk density of the glass, it is possible to prevent a consolidated body having an irregular bulk density from being put into the glass melting furnace, and to prevent the occurrence of a heterogeneous state of the molten glass. Is described.

JP 2007-8757 A

  However, even when the method described in Patent Document 1 is adopted, the bulk density may not be within a predetermined range in the actual manufacturing process.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to make the bulk density of a mixed raw material charged into a glass melting furnace constant and to suppress deterioration of the quality of a glass article.

  The method for producing a glass article of the present invention is a method for producing a glass article using a mixed raw material of glass cullet and glass raw material, the measuring step for measuring the bulk density of the mixed raw material, and the mixed raw material A bulk density adjusting step of adding an additional raw material having a bulk density different from the bulk density of the mixed raw material, and adjusting the bulk density so that the mixed raw material containing the additional raw material has a predetermined bulk density, and the bulk density And a melting step of melting the mixed raw material whose bulk density is adjusted by the adjusting step.

  With this configuration, the bulk density of the mixed raw material can be grasped because the bulk density is measured before the mixed raw material is charged into the glass melting furnace. And based on the result, an additional raw material is added to a mixed raw material so that the bulk density of the molten mixed raw material may become in a predetermined range. As a result, the homogeneity of the molten glass is maintained, and the deterioration of the quality of the glass article can be suppressed.

  Further, in the method for producing a glass article of the present invention, the additional raw material is composed of a first additional raw material and a second additional raw material, and the first additional raw material has a bulk density larger than that of the mixed raw material, The second additional raw material preferably has a lower bulk density than the mixed raw material.

  If it is this structure, when the bulk density of a mixed raw material exceeds the upper limit of the predetermined range in a measurement process, the 2nd additional raw material with a small bulk density will be added to a mixed raw material, a bulk density adjustment process will be performed, and mixing When the bulk density of the raw material falls below the lower limit of the predetermined range, the first additional raw material having a large bulk density is added to the mixed raw material to perform the bulk density adjusting step. The bulk density can be easily within a predetermined range.

  In the method for producing a glass article of the present invention, the additional raw material is preferably glass cullet.

  With this configuration, the glass cullet can be used effectively.

  According to the present invention described above, the bulk density of the mixed raw material to be melted can be set within a predetermined range, and the deterioration of the quality of the glass article can be suppressed.

It is a schematic side view of a glass article manufacturing apparatus.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described. However, the present invention is not limited to the following embodiments, and is based on ordinary knowledge of a person skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

  Prior to the description of the glass article manufacturing method of the present embodiment, a glass article manufacturing apparatus will be described with reference to FIG.

  The glass article manufacturing apparatus 1 includes a raw material charging apparatus 2, a glass melting furnace 3, and a glass article forming machine 4 as main components.

  The raw material charging device 2 is a device for charging a mixed raw material (input mixed raw material) containing a glass raw material and glass cullet into the glass melting furnace 3.

  The raw material charging device 2 includes a hopper 21 having a charging port 21a, a discharge port 21b, and a conveyor 22 that conveys the mixed raw material and glass cullet discharged from the hopper 21 to the glass melting furnace 3. A mixed raw material or glass cullet is fed into the hopper 21 through a loading port 21a. The mixed raw material or glass cullet charged into the hopper 21 is discharged downward from the discharge port 21b. The discharge port 21b of the hopper 21 is provided with an opening / closing plate (not shown), and the discharge amount of the mixed raw material or the glass cullet from the discharge port 21b is controlled by opening and closing the opening / closing plate. The opening / closing of the opening / closing plate is controlled by, for example, an opening / closing control device. The raw material charging apparatus 2 includes a first hopper 21A, a second hopper 21B, and a third hopper 21C. The open / close plates of the discharge ports 21b (21Ab, 21Bb, 21Cb) of these hoppers 21 (21A, 21B, 21C) can be controlled independently. As will be described later, a mixed raw material (a hopper mixed raw material) composed of a glass raw material and a glass cullet is input to the first hopper 21A from an inlet 21a (21Aa). The first hopper 21A is provided with a measuring device (not shown) for measuring the bulk density of the hopper mixed raw material in the first hopper 21A. As described later, glass cullet, which is an additional raw material, is input to the second hopper 21B and the third hopper 21C from an input port 21a (21Ba, 21Ca).

  The conveyor 22 is disposed below the discharge port 21 b of the hopper 21, and conveys the mixed raw material and glass cullet discharged from the hopper 21 toward the glass melting furnace 3. As the conveyor 22, for example, a belt conveyor including a sprocket and a heat-resistant endless belt is preferably used.

  The glass melting furnace 3 has a melting tank 31 for melting the input mixed raw material and a clarification tank 32 for clarification of the molten glass G. Here, in this specification, the melting tank 31 side is described as an upstream side, and the clarification tank 32 side is described as a downstream side. A furnace wall, a ceiling part, a bottom part, and the like of the glass melting furnace 3 are made of a refractory material. In addition, the material of a refractory is not specifically limited, A well-known material can be used. Moreover, in order to suppress generation | occurrence | production of the striae and foreign material etc. which arise due to the elution of the refractory component in the molten glass G, you may cover the surface of the refractory in a furnace with platinum.

  The melting tank 31 is provided with a charging port 33 for charging the charged mixed raw material into the melting tank 31 on the upstream furnace wall. The conveyor 22 of the raw material input device 2 conveys the hopper mixed raw material to the input port 33. The conveyed hopper mixed raw material is charged into the melting tank 31 from the charging port 33. The melting tank 31 includes a bottom heater 34 at the bottom and an upper heater 35 at the top in order to heat the inside thereof. As the bottom heater 34, for example, an electric heating device can be used. As the electric heating device, a silicon carbide heating element or the like can be used. As the upper heater 35, for example, a gas burner can be used. The inside of the melting tank 31 is heated by the bottom heater 34 and the upper heater 35 to a temperature (about 800 to 2000 ° C.) according to the composition of the input mixed raw material. The charged mixed raw material charged from the charging port 33 of the melting tank 31 is melted by heating to become a molten glass G.

  In the clarification tank 32, the molten glass G obtained in the melting tank 31 is clarified. The melting tank 31 and the clarification tank 32 are communicated by a throat 36.

  The clarification tank 32 is provided with a gas supply pipe 37 for supplying an inert gas such as helium gas to the clarification tank 32 and a heating device (not shown). As a result, the molten glass G is clarified. Moreover, if the clarifier is mixed with the input mixed raw material, clarification in the clarification tank 32 is further promoted.

  A feeder 38 is connected to the downstream side of the clarification tank 32. The feeder 38 includes a stirrer 39. The molten glass G clarified in the clarification tank 32 is stirred and homogenized by the stirrer 39 of the feeder 38.

  Thereafter, the glass article molding machine 4 continuously molds the glass article. In this embodiment, the glass article molding machine 4 has hundreds to thousands of hollow nozzles (not shown) and is provided at the bottom of the feeder 38. Then, by pulling out the molten glass G from the hollow nozzle of the glass article molding machine 4, a fibrous glass article (glass fiber) is manufactured.

  In the present embodiment, the glass article forming machine 4 is an apparatus for manufacturing glass fibers, but may be an apparatus for manufacturing plate glass, glass bottles, and the like.

  Next, the manufacturing method of the glass article using said glass article manufacturing apparatus 1 is demonstrated.

  First, the hopper mixed raw material is charged into the first hopper 21A. The hopper mixed raw material is obtained by blending a glass raw material composed of a plurality of kinds of raw materials such as a silica raw material and an alumina raw material and a glass cullet composed of crushed glass such as a plate glass at a predetermined ratio. From the viewpoint of keeping the bulk density of the hopper mixed raw material within a predetermined range, the particle size distribution of the glass cullet is preferably narrow.

  The hopper mixed raw material is continuously or intermittently charged into the first hopper 21A from the charging port 21Aa according to production conditions such as the production amount of the glass article.

  The hopper mixed raw material charged into the first hopper 21A is discharged continuously or intermittently from the discharge port 21Ab. A bulk density measuring device is provided in the first hopper 21A, and the bulk density of the hopper mixed raw material in the first hopper 21A is measured by this measuring device (measuring step).

Two types of glass cullet, which are additional raw materials, are charged into the second hopper 21B and the third hopper 21C. The two types of glass cullet have different bulk densities, and the glass cullet thrown into the second hopper 21B has a larger bulk density than the glass cullet thrown into the third hopper 21C.
The bulk density of the glass cullet charged into the second hopper 21B is larger than the upper limit value of the bulk density of the hopper mixed raw material to be described later, and the bulk density of the glass cullet charged into the third hopper 21C is equal to the hopper mixed raw material. It is smaller than the lower limit of the bulk density. Here, the glass cullet thrown into the second hopper 21B is called the first glass cullet (first additional raw material), and the glass cullet thrown into the third hopper 21C is the second glass cullet ( 2nd additional raw material).
The first glass cullet and the second glass cullet are obtained, for example, as follows.
For example, a glass cullet obtained by pulverizing molten glass overflowing from a kiln, or agglomerated glass obtained by water-pulverizing a bottom drain or the like to a predetermined particle size is used as a first glass cullet. The glass cullet obtained by crushing or coarsely pulverizing etc. to a particle size different from that of the first glass cullet is defined as the second glass cullet.
In addition, it is preferable to arrange | equalize the particle size of each glass cullet by classification.

  The open / close control device that controls the open / close plate of the discharge port 21b of each hopper 21 acquires information on the bulk density of the hopper mixed raw material measured from the measurement device of the first hopper 21A, and based on the information, the second Controls the opening and closing plates of the discharge ports 21Bb and 21Cb of the hopper 21B and the third hopper 21C. Specifically, first, the bulk density of the hopper mixed raw material is measured by a measuring device for measuring the bulk density of the hopper mixed raw material in the first hopper 21A. Next, the open / close control device determines whether or not the bulk density of the hopper mixed raw material exceeds an upper limit value within a predetermined range, and whether or not the bulk density of the hopper mixed raw material falls below a lower limit value. When the bulk density of the hopper mixed raw material exceeds the upper limit, the second glass cullet is adjusted so that the bulk density of the hopper mixed raw material is within a predetermined range by controlling the opening / closing plate of the discharge port 21Cb of the third hopper 21C. Discharge a predetermined amount. When the bulk density of the hopper mixed raw material falls below the lower limit value, the opening / closing plate of the discharge port 21Bb of the second hopper 21B is controlled to discharge a predetermined amount so that the bulk density of the hopper mixed raw material falls within a predetermined range. In this way, the bulk density of the charged mixed raw material charged into the glass melting furnace 3 is adjusted to be within a predetermined range (bulk density adjusting step).

  In the bulk density adjusting step, it is preferable to link the opening / closing operation of the opening / closing plate of the discharge port 21b of each hopper 21. That is, when the hopper mixed raw material is intermittently discharged from the discharge port 21Ab of the first hopper 21A, the glass cullet is also intermittently discharged from the discharge ports 21Bb and 21Cb of the second hopper 21B and the third hopper 21C. It is preferable to discharge.

  Further, when the discharge amount of the hopper mixed raw material discharged from the discharge port 21Ab of the first hopper 21A varies, the glass cullet discharged from the discharge ports 21Bb and 21Cb of the second hopper 21B and the third hopper 21C The discharge amount is also preferably linked to the discharge amount of the hopper mixed raw material discharged from the discharge port 21Ab.

  Moreover, the opening degree of the opening / closing plate of the outlet 21Bb of the second hopper 21B and the opening degree of the opening 21Cb of the third hopper 21C according to the amount of deviation from the predetermined range of the bulk density of the hopper mixed raw material By adjusting the above, it is possible to adjust the bulk density of the input mixed raw material with higher accuracy.

(Other embodiments)
In the present embodiment, the bulk density is measured by the measuring device of the first hopper 21A, and the bulk density is adjusted by the glass cullet of the second hopper 21B and the third hopper 21C. The bulk density may be adjusted by measuring the bulk density of the mixture and introducing a glass cullet in an amount corresponding to the bulk density of the mixed raw material and the mixed raw material into the hopper.

DESCRIPTION OF SYMBOLS 1 Glass article manufacturing apparatus 2 Raw material input apparatus 3 Glass melting furnace 4 Glass article molding machine

Claims (3)

A glass article manufacturing method for obtaining a glass article using a mixed raw material of glass cullet and glass raw material,
A measuring step for measuring the bulk density of the mixed raw material;
A bulk density adjusting step of adding an additional raw material having a bulk density different from the bulk density of the mixed raw material to the mixed raw material, and adjusting the bulk density so that the mixed raw material containing the additional raw material has a predetermined bulk density;
A melting step of melting the mixed raw material whose bulk density is adjusted by the bulk density adjusting step;
A method for producing a glass article, comprising: The additional raw material comprises a first additional raw material and a second additional raw material,
The first additional raw material has a larger bulk density than the mixed raw material,
The second additional raw material has a lower bulk density than the mixed raw material,
The method for producing a glass article according to claim 1.   The method for producing a glass article according to claim 1 or 2, wherein the additional raw material is glass cullet.