JPH03164443A - Method and apparatus for producing fiber of thermally softening material - Google Patents

Abstract

PURPOSE:To prevent the oxidation consumption of a platinum alloy nozzle block by the atm. air by coating the surface of the nozzle block with high-temp. gases of a low oxygen content at the time of producing glass fibers by allowing fused glass to flow out of the orifice of the platinum alloy nozzle block and ejecting the high-temp. gas from plural nozzles. CONSTITUTION:The fused glass 2 is put into the platinum alloy nozzle block 1. The fused glass is allowed to flow down as a circular conical flowing down body 4 from the bottom orifice 3. At least 3 pieces of the nozzles 6 are symmetrically disposed around this orifice 3 and the gaseous flow 7 of a high temp. and high velocity is blown to the circular conical flowing down body 4 of the fused glass to blow off the fused glass as the glass fibers 12. The glass fibers are thus produced. The high temp. gases 11, 11' of the oxygen content as low as 0 to 2vol.% and 800 to 1600 deg.C are injected at 2 to 60m/sec injection rates from a 2nd nozzles 8, 8' at the rate of 10 to 150% of the above-mentioned gaseous flow 7 in this case. The inflow of the atm. air near to the orifice 3 of the nozzle block 1 is prevented by such high-temp. gases 11 and the oxidation consumption of the platinum alloy nozzle block by the atm. air is prevented.

Description

[Detailed Description of the Invention] [Field of Application of Industry] The present invention relates to a method for producing fibers from a heat-softening substance, and in particular, a method for producing fibers from a heat-softening substance, in particular heating and melting a heat-softenable substance! A high-temperature viscous substance consisting of 7 is flowed out from an outflow orifice, and a heated high-speed gas flow is blown out from a gas jet nozzle to turn the high-temperature viscous substance into a fibrous form}
2. A method and apparatus for producing fibers made of the material by applying a swirling gas jet to the material. [Conventional Extraction Technique] A method for efficiently producing fibers, especially short fibers, from heat-softening materials such as glass} The present applicant has proposed the so-called whirling gas jet method (hereinafter referred to as rR.GJ method J). (Japanese Patent Publication No. 58 No. 57374) This method involves passing a gas flow having a tangential component to the outer periphery of a molten columnar flow of a thermally softened material in a direction in which the molten material is displaced in the lateral direction. This is a method for producing fibers of a heat-softening material, in which the material is rotated at high speed while being in contact with each other so as to prevent the material from flowing, and the thinned filamentous material is drawn out by centrifugal force. (hereinafter referred to as a first high-speed gas flow)
Here, each q of the gas flow has a tangential component H along the outer periphery of a cross section that crosses the central axis of the substance, and a component H in the tangential direction along the outer circumference of the cross section that intersects the central axis of the substance, and a component H that gradually approaches the central axis of the substance toward the outflow direction of the substance. and then gradually move away from the central axis, so that the gas flow extends from the beginning of the outflow of the substance to the part where the gas flow is closest to the central axis of the substance. In a certain first zone, the material is caused to rotate around its central axis and to form a substantially conical shape whose cross section gradually decreases in the direction of its outflow; In the region of !, the substance is forced into fibers E from the conical tip and spirals out in the outflow direction and radially outward, and then in this ! The substance on the a-fiber is brought into contact with the gas flow that gradually moves away from the central axis to further stretch it. This RGJ method blows a high-temperature, high-pressure gas flow in a spiral shape along the glass flow flowing out of an orifice to make the glass into fine fibers, so it is a fiberization method with excellent thermal efficiency and efficiently produces small-diameter m-fibers. [Problem to be solved by the invention 1] This RGJ method has the following improvement problems.
was recognized. In other words, if glass fibers are manufactured continuously by the RGJ method, the shape of the bottom surface of the nozzle block will gradually change, and this change will disrupt the stability of fiberization, making it difficult to continuously manufacture high-quality fibers over a long period of time. The present invention aims to overcome such problems and to enable short fibers to be produced efficiently at low cost. [Means and effects for solving the problem] The present inventors,
In the RGJ method, we conducted a more detailed study on the cause of the above-mentioned change in the shape of the bottom surface of the nozzle block that disrupts the stability of fiberization.As a result, we found that the air around the nozzle is It moves with the gas flow, and air (atmosphere) flows into the area below the orifice from the outer periphery to supplement the moved air (this moving air is called wake), and this flow (air)
It was found that oxidation and evaporation of platinum on the bottom surface of the nozzle block due to oxygen inside the nozzle block caused the change in the shape of the bottom surface of the nozzle block. Furthermore, the present inventor has proposed that as the first gas flow (swirling gas flow), the surrounding air moves with the gas flow, and air (atmosphere) flows into the lower surface of the nozzle block and the area below the orifice from the outer periphery. A flow occurs and the speed reaches 2 to 60 m/s.When manufacturing fibers such as glass fibers that require high temperatures to form, it is necessary to heat the nozzle to a high temperature, which causes a considerable amount of heat. When the wake with a flow velocity is ambient air, oxidation and evaporation of the lower surface of the nozzle due to oxygen in the air is promoted and increases compared to when in still air.Also, when the wake is present in the region below the orifice, oxidation and evaporation of the lower surface of the nozzle is accelerated. By cooling the glass, the viscosity of the glass increases, reducing the drawing efficiency and requiring a higher temperature glass in order to obtain the required small fiber diameter. Based on the knowledge of a method for ejecting a high-speed jet stream of high-temperature pressurized gas, we discovered that such wear on the platinum wall can be prevented by reducing the oxygen content of the gas that passes through it. For convenience, we will explain the conventional method for the equipment. Figure 3 shows a glass wool manufacturing equipment using the conventional RGJ method, in which molten glass is supplied to a platinum alloy bot (nozzle block) 1 by a supply device (not shown). The molten glass 2 in the pot is maintained at a temperature of 1,000 to 1,500°C.The molten glass passes through the nozzle part of the pot 1 and is blown in a line at a pitch P (for example, 3 mm pitch) to the lower end.
It flows down from zero or more heat softening substance outflow orifices, that is, glass outflow orifices 3. A high-speed gas jet stream 7 is ejected from a swirling gas jet ejection nozzle 6 provided around each orifice 3, whereby the glass is finely divided into glass wool 12. Due to the high-speed gas jet flow 7 (velocity 600 to 850 m/s) from the swirling gas jet ejection nozzle 6 for fiberization, the surrounding atmosphere moves with the high-speed gas jet flow, and in order to supplement the flow, the surrounding atmosphere moves. An atmospheric flow (referred to as a wake) 10 at a speed of 2 to 60 m/s is generated along the lower surface of the nozzle block, and the platinum alloy on the lower surface of the nozzle block comes into contact with oxygen in the wake, causing oxidation and evaporation of the platinum alloy. This causes a change in the shape of the lower surface, disrupting the stability of fiber formation, and making it difficult to continuously produce high-quality fibers over a long period of time.In addition, expensive platinum group metals are also lost, and the viscosity of the glass decreases due to cooling of the cone by the wake. As the temperature rises, the fiberization efficiency also deteriorates. The present invention has been made based on this knowledge. That is, in the present invention, an outflow orifice and a gas ejection nozzle are bored in close proximity to each other in a nozzle block made of platinum group metal material, a high temperature viscous substance flows out from the outflow orifice, and a high-temperature viscous substance flows out from the gas ejection nozzle. In the method for manufacturing fibers, in which the high-temperature viscous substance is made into a fiber and drawn by blowing out a heated high-speed gas flow, by supplying high-temperature gas with a low oxygen content so as to cover the surface of the nozzle block, This method of manufacturing fibers is characterized in that the air which tends to flow from the outer periphery of the outflow orifice into the lower region of the outflow orifice due to the high-speed gas flow is prevented from coming into contact with the nozzle block surface. In the present invention, a high-temperature gas with a low oxygen concentration and an inert gas such as nitrogen gas can also be used, but the residual oxygen concentration is controlled to 0-2%. A car that uses combustion gas is preferable.
By reducing the oxygen concentration on the lower surface of the orifice nozzle and lowering the temperature of the nozzle block, the amount of oxidation and evaporation is reduced, and the wear and deformation of the platinum alloy-containing wall is prevented. 8. By preventing heat dissipation from the molten glass, the fiberization efficiency can be increased and the temperature of the bottom surface of the nozzle blower and sink can be lowered as a result.

In other words, the present invention is based on high-temperature feeding.
Nozzle I made of platinum group metal material maintained at a temperature below ℃
On the cock r side. Cleaning of the lower surface by a swirling gas jet and a high-speed gas jet from the jet nozzle 6 1.
The dispensing alloy on the face of the nozzle F is replaced by a gas having an oxygen content of 0-2% by volume, preferably 0"-0.5% by volume, through the second blower nozzle 8 at least a part of O. 9F Embodiment] The present invention will be explained in more detail below with reference to the embodiments shown in FIGS. 1 and 2.
The figure is a schematic partial bottom view of one embodiment of the fiberizing device of the present invention. Figure 2 is a schematic partial cross-sectional view taken along line I-X in Figure 1. In the R G J swirling gas jet device shown in FIGS. 1 and 2, a platinum bot 1 has a glass outflow orifice 3 and a gas jet I/spout nozzle 6.6'. The molten glass 2 heated to 1.300-1450'C flows out of the glass outflow orifice 3 of the platinum pot, forms a molten cone 4, and then jets out from the gas jet jet nozzles 6, 6'. First gas flow7.
7' to form fiber 12. The gas jet nozzles 6, 6° connected to the manibolds 5, 5° for swirling gas jet jets are located 1000 to 15° from their jet ports.
A high-speed gas jet flow at 00℃. The tangential component along the outer periphery of the cross section that crosses the center line Illll of the molten glass 2 flowing out from the orifice 3, and the component 1 that approaches the central axis of the outflow flow toward the outflow direction of the molten glass 2.
~,next,? ffi flow skew flow l], and a component gradually moving away from the central axis of the flow direction. Note that in Figure 1, the gas ejection nozzle marked with ] is 4.
Although the number is not limited, it is preferable that there be at least three. Further, in the glass fiber bag holder of the present invention, it is preferable that the first gas jet nozzles 6, 6° are arranged approximately symmetrically around the molten glass outflow orifice 3. Furthermore, although not shown in the figure, a plurality of auxiliary gas jetting nozzles may be provided outside the first gas jetting nozzle, and the central axis of the auxiliary gas jetting nozzle is parallel to the central axis of the first gas jetting nozzle. A point closest to the central axis of the outflow orifice 3, that is, a point further below the first convergence point A and the center Ia of the molten glass outflow orifice 3
8.8 in Figure 1.2, having a second point of convergence that is substantially or completely convergent in a line, or may be parallel to the central axis of the molten glass outflow orifice; is a second nozzle for replacing a part of the wake of the first gas flow with a second gas flow in a region below the orifice 3, and is disposed opposite to the orifice 3 with the orifice 3 in between. In addition. In this embodiment, the nozzle 8.8' is a gas spanner nozzle, and is used to produce a mixed gas 9 of a fuel gas such as butane and a gas containing oxygen such as air.
, 9゛ (equivalent ratio 0.9-1.1>) is introduced into the mixing chambers 13, 13, passes through the premixed gas nozzle screens 8a, 8a' and burns inside the nozzles 8, 8゜. Approximately 1350℃
The resulting combustion gas is the second gas flow]! ．． , ll'h, and is installed in a horizontal position so that it flows along the bottom surface (or outer wall surface) of the nozzle block toward the center axis of the orifice. By supplying the gas from the periphery along the lower surface of the nozzle block, it is taken into the lower region as part of the wake of the first gas flow. The mixing ratio of fuel gas such as butane and air in the mixed gas is adjusted to produce the second gas flow 1], 1.
1" is controlled to a residual oxygen concentration of 0 to 1% by volume, and the lower surface of the nozzle block is covered with a second gas flow. Oxygen supply to the lower surface, that is, the wake of the atmosphere].0.10" is blocked from the lower surface of the nozzle block. Or it can be decreased. This also has the effect of preventing platinum oxidation and evaporation on the bottom surface of the nozzle block. In addition. The required amount of the second gas stream 11 is 10 to 150%, in particular 30 to 100%, of the first gas stream per unit fiberizing device (0.3 to 10% per unit length of the row of glass outlet orifices). It is preferable to set it to about 2.0Nm3/H.cm). The preferred positional relationship of the second nozzle 8 is that the slit width S3=
2 to 10 mm and does not inhibit cone formation (spacing S2 = 10 to 30 m)
m). The distance S2 and the slit width S3 are preferably 10 times or less than the slit width S3 in order to ensure the thickness of the second gas flow covering the bottom surface of the nozzle5.In addition, if the distance S2 is too large, the required amount of the second gas flow will be reduced. becomes large, so the distance between the central axes on the opening surface of the swirling gas jet nozzle should be set at 81, which is a range that does not inhibit the formation of a cone in the glass.
The interval S2 must be at least twice that of S1, and it must be made smaller (
For example, it is preferable that S2 be 2 times to 2.5 times that of 81). Next, Tables 1, 2, and 3 show examples in which combustion gas is used as the second gas flow. However, the gas amount of the first gas flow is a value per unit length of the glass outflow orifices arranged in a row. Examples 1 to 3, Comparative Example 1 First gas flow Pressure 3 kg/cm2 Gas amount
3Nm3/H. cm Temperature (inside the jetting manifold) 1400°C Second gas flow outlet slit @ S3 = 4mm interval S2 = 28mm Temperature (inside the screen for premixed gas jetting) 20-50°C Temperature (internal combustion of the second gas flow nozzle temperature")
The results at 1200-1450°C are shown in Table 1. Table 1: Second gas flow rate and platinum depletion Table 2: Second gas flow rate and platinum depletion Examples 4 to 6, Comparative Example 2 First gas flow pressure (inside the jetting manifold) 3 kg/ cm2 Gas amount 3Nm3/H. cm Temperature (inside the blowout manifold) 1350℃ Second gas outlet slit width S3 = 2mm interval
S2 = 14mm Temperature (inside the screen for ejecting mixed gas) 20 to 50°C Temperature (internal combustion temperature of the second gas flow nozzle)
The results at 1150-1400°C are shown in Table 2. Comparative Example 3, Example 6 The results are shown in Table 3. Chapter: 3 Table 2 v)' Temperature of AK (fl')

[Brief explanation of the drawing]

FIG. 1 is a schematic partial bottom view of an embodiment of the fiberizing apparatus of the present invention, FIG. 2 is a schematic partial cross-sectional view taken along line I-I in FIG. 1, and FIG. 4 is a schematic partial bottom view illustrating the mold apparatus, and FIG. 4 is a schematic partial sectional view taken along the line II-IX in FIG. 3. FIG. 5 shows an example of mounting the second gas jet nozzle of the present invention. 1 Platinum alloy nozzle block 1 Bot casing 2 Molten glass 3 Glass outflow orifice 4 Melt cone flow (cone) 5,5' swirling gas jet 1 - Manifold for ejection 6.6
'D-time gas jet ejection nozzle 7.7' High-speed gas jet 1/flow 8, 8' Second gas ejection nozzle 8a, 8a' Mixed gas ejection screen 9.9' Flammable premixed gas 10.10' Atmospheric wake around the nozzle block 11.
11' Second gas flow 12 Fiber I1t flow S1 Distance between the central axes of the opening surface of the swirling gas jet nozzle S2 Spacing between the second nozzles

Claims (7)

[Claims] (1) An outflow orifice and a gas jet nozzle are bored in close proximity to each other in a nozzle block made of a platinum group metal material, and a high-temperature viscous substance made by heating and melting a thermosoftening substance flows out from the outflow orifice. In the method for producing fibers of a heat-softening substance, the high-temperature viscous substance is made into a fiber and drawn by blowing out a heated high-speed gas stream from the gas injection nozzle, the high-temperature gas having a low oxygen content is ejected from the nozzle. By supplying the nozzle block so as to cover the surface of the block, the air which tends to flow into the region below the outflow orifice from the outer periphery along with the high-speed gas flow is prevented from coming into contact with the surface of the nozzle block. A method for producing fibers of a thermosoftening substance. (2) Production of fibers of thermosoftening material according to claim 1, wherein the high temperature gas with a low oxygen content is an inert gas or a combustion gas with an oxygen content of 0 to 2% by volume. Method. (3) The high temperature gas with a low oxygen content is supplied toward the surface portion of the nozzle block so that the oxygen concentration near the bottom surface or outer wall surface of the nozzle block is maintained at 0 to 5% by volume. A method for producing fibers of a heat-softening substance according to claim 1. (4) The high temperature gas with low oxygen content is 800 to 16
The method for producing fibers of a heat-softening material according to claim 1, wherein the gas is heated at a high temperature of 00°C, preferably 1000 to 1400°C. (5) The flow rate of the high temperature gas with a low oxygen content is 10 to 150% of the flow rate of the heated high speed gas flow, preferably 30 to 150%.
100% and the gas nozzle exit velocity of the high temperature gas with low oxygen content is in the range 2 to 60 m/s, preferably in the range 10 to 40 m/s. Method for producing fibers of softenable substances. (6) The gas ejection nozzle is at least three nozzles arranged at intervals in the circumferential direction around the outflow orifice, from which a heated high-velocity gas stream is blown out in a straight line, where the gas stream is a tangential component along the outer periphery of a cross section that crosses the central axis of the substance;
The outflow flow of the substance has a component that first gradually approaches the central axis of the substance and then gradually moves away from the central axis, so that the outflow flow of the substance is directed toward the central axis of the substance. While rotating on its own axis, the fiber is formed into a substantially conical shape whose cross section gradually decreases in the direction of its outflow, and from the tip of the conical shape, it is formed into a fiber-like shape, which spirals outward in the radial direction and protrudes into a spiral shape to prevent stretching. A method for producing fibers of a heat-softening material according to claims 1 to 5. (7) A nozzle block made of a platinum group metal material, in which an outflow orifice and a gas ejection nozzle are bored close to each other, and the nozzle block on the side where the outflow orifice and the gas ejection nozzle are open. at a position facing the surface of the outflow orifice and not interfering with the flow of the high-temperature viscous material formed by heating and melting the heat-softening material flowing out from the outflow orifice and the flow of the heated high-speed gas blown out from the gas jetting nozzle. 1. An apparatus for producing fibers of a thermosoftening material, comprising: a shielding wall provided in the shielding wall; and means for supplying high-temperature gas with a low oxygen content into a space between the shielding wall and the nozzle block surface.