JPH0450258B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an apparatus for producing fibers made of heat-softening substances such as glass fibers.

[Prior Art] In an apparatus for producing a heat softening substance such as glass fiber, a nozzle is installed at the bottom of a tank holding molten glass, and the heat softening substance is discharged from an outlet provided in the nozzle. I am trying to make it flow out. In the glass filament manufacturing apparatus, the poured glass is stretched and wound up to produce glass filaments. In addition, in a short glass fiber manufacturing apparatus, glass is made into short fibers by spraying gas or water vapor onto the glass flowed out of a nozzle, or by using the centrifugal force of a high-speed rotating body. Therefore, in such a glass fiber manufacturing apparatus, it is important to heat the glass to a predetermined temperature range and to flow the glass at a predetermined viscosity. Methods for heating glass include embedding a heater in the side wall of a tank that holds the glass, or installing a silicon carbide heating element above the molten glass material.

In addition, the nozzle at the bottom of the tank is usually made of platinum or platinum alloy, which has high corrosion resistance against molten glass, but it is also possible to make this nozzle in a shape that allows electricity to be passed through it and generate heat by passing a large current at a low voltage. ing.

Furthermore, in recent years, a rotary gas jet method has been known, such as in Japanese Patent Application Laid-Open No. 52-25113. In this rotary gas jet method, a swirling gas jet is blown onto an outflow of a heat-softening material such as glass to elongate it into short fibers. It has become clear that this rotary gas jet method is extremely advantageous in terms of production efficiency, product quality, etc. compared to conventional manufacturing methods such as the so-called flame method and centrifugal method. In this rotary gas jet method as well, the nozzle is made of platinum or a platinum alloy, and is configured to heat the glass by generating electricity.

[Problems to be solved by the invention] In heating methods in which a heater is embedded in the side wall of the tank body or a heating element is installed above the molten glass base, the glass base receives heat from its side or top surface. , the heating efficiency is poor, and it is difficult to uniformly heat the entire substrate.

A nozzle that generates heat by energizing the nozzle is preferable in that it can prevent the temperature from dropping by heating the glass to be flowed out, but the nozzle will become hot and will be oxidized by oxygen in the air and deteriorate It becomes more likely to occur.

In particular, in the rotary gas jet method, compared to conventional short fiber manufacturing methods such as the flame method, the temperature of the glass is usually raised to lower its viscosity before it flows out from the nozzle. If the temperature of the glass is increased by increasing the temperature of the glass, the deterioration of the nozzle is likely to progress.

Note that these problems are common not only to equipment for manufacturing glass fibers, but also to equipment for manufacturing slag wool and rock wool.

[Means for Solving the Problems] The apparatus for producing fibers of a heat-softening material according to the present invention is such that a resistance heating element is installed in a portion above a nozzle inside a tank body.

[Function] In the apparatus for producing fibers of a thermosoftening material of the present invention, glass can be heated by supplying electricity to a resistance heating element provided above the nozzle. This resistance heating element has high heat transfer efficiency because it is immersed in the glass base. Furthermore, since heating is performed by this resistance heating element, the amount of current applied to the nozzle can be reduced, and it is also possible to prevent deterioration of the nozzle.

[Example] Examples will be described below with reference to the drawings.

FIG. 1 is a longitudinal cross-sectional view of a main part of a glass fiber manufacturing apparatus according to an embodiment of the present invention, and this embodiment relates to a glass fiber manufacturing apparatus using a rotary gas jet method. Note that Figures 2 and 3 are from Figure 1.
4 is a sectional view taken along lines - and - in the figure, and FIG. 4 is a perspective view of the main part of FIG. 1.

In the figure, reference numeral 1 denotes a tank holding molten glass 2, the side wall of which is made of refractory bricks 3, and the bottom of which is provided with a nozzle 4 made of platinum or platinum alloy. This nozzle 4 has a long shape in one direction (the left-right direction in FIG. 1), and as shown in FIGS. 2 and 3, a molten glass outlet 5 and a molten glass flowing out from the outlet 5 A gas guide hole 6 and a spout 7 are provided to jet the gas toward the flow. In addition, the gas outlet 7
are installed around the outlet 5 to be oriented in the swirling direction in order to bring the swirling gas into contact with the glass flow flowing out from the outlet 5.

A resistive heating element 8 is provided above the nozzle 4. In this embodiment, this resistance heating element 8 is made of platinum or a platinum alloy,
It has a plate shape and extends in the longitudinal direction of the nozzle 4. This plate-shaped resistance heating element 8
is erected so that its plate surface is vertical, and is spaced apart from the top surface of the nozzle 4 by a predetermined distance. In this embodiment, the resistance heating element has reinforcing ribs 8a and 8b formed on its upper and lower sides so as to have a hook-shaped cross section.

Both longitudinal ends of the resistance heating element 8 are connected to the nozzle 4 by end plates 9 made of platinum or platinum alloy, and the longitudinal center portion of the resistance heating element 8 is connected to the nozzle 4 by a central reinforcing plate 10. It is supported by the nozzle 4.

Both ends in the longitudinal direction of the resistance heating element 8 are cut diagonally, and end plates 9 are attached to both ends.
is fixed. As shown in FIG. 4, this end plate 9 has a trapezoidal shape, and is configured so that the heat generation distribution due to resistance is uniform by changing the wall thickness from the proximal end toward the distal end. There is.

When installing the resistance heating element 8 and the end plate 9, it is preferable to install them so that they do not come into contact with the firebrick 3. Although not shown, a heater is embedded in the firebrick 3 and is configured to heat the molten glass.

In the glass fiber manufacturing apparatus configured in this way, the molten glass 2 in the tank body 1 is flowed out from the outlet 5 in a thin cylindrical shape, and a swirling gas jet is ejected through the gas guide hole 6 and the spout 7. The fibers are drawn to become short glass fibers. Since the resistive heating element 8 is installed, it is possible to maintain the molten glass 2 at a predetermined temperature even if the amount of electricity supplied to the nozzle 4 is reduced. It is possible to suppress deterioration.

In this example, since the resistance heating element 8 is plate-shaped, the contact area with the molten glass 2 is large, and the molten glass 2 can be heated more efficiently. Furthermore, since the plate-shaped resistance heating element 8 is provided with reinforcing ribs 8a and 8b and the central reinforcing plate 10 is installed, deformation of the resistance heating element 8 can be reliably prevented. The glass supplied into the tank 1 may be supplied as marble or cullet, or may be supplied as a molten glass stream.

Although the apparatus of the above-mentioned embodiments is related to an apparatus employing a rotary gas jet method, the present invention can also be applied to a manufacturing apparatus using a flame method, a centrifugal method, or the like.

FIG. 5 shows an embodiment in which the present invention is applied to an apparatus for producing short glass fibers using a flame method, in which a nozzle 13 is installed at the bottom of a tank 12 surrounded by a refractory 11.
is installed. A heating element 14 made of silicon carbide is installed in the tank body 12 and melts the glass raw material 16 introduced from the input port 15 to form molten glass 2 . This molten glass 2 is drawn out as thin fibers from a nozzle 13, stretched by rollers 17 and 18, and then converted into short fibers by a flame 20 emitted from a burner 19. A resistance heating element 21 is installed in the tank body 12 above the nozzle 13 to heat the molten glass 2. In the apparatus of the embodiment shown in FIG. 5 as well, the molten glass 2 can be efficiently heated by the resistance heating element 21.

Although the apparatus of the above embodiment relates to an apparatus for producing short glass fibers, the present invention can also be applied to an apparatus for producing long glass fibers. It is also clear that the present invention can be applied to an apparatus for producing fibers of heat-softening substances such as rock wool and slag wool.

〔Effect of the invention〕

As is clear from the above explanation, in the present invention, the resistance heating element is installed in the upper part of the nozzle, and the heat softening substance can be efficiently heated, so the temperature of the heat softening substance can be easily raised. It is possible to efficiently produce fibers. In addition, when the present invention is applied to an apparatus for manufacturing fibers of a thermosoftening substance, in which the nozzle is made of platinum or a platinum alloy and the nozzle is energized to generate heat, the amount of energization to the nozzle is reduced, It is also possible to suppress deterioration due to oxidation.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of an embodiment of the device of the present invention;
3 and 3 are sectional views taken along lines - and -, respectively, in FIG. 1, and FIG. 4 is a perspective view of the main part of the apparatus shown in FIG. 1. FIG. 5 is a sectional view of an apparatus according to another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Tank body, 2... Molten glass, 4... Nozzle, 5... Outlet, 8... Resistance heating element, 9... End plate.

Claims (1)

[Claims] 1. Production of fibers of a heat-softening substance, comprising a nozzle with an outlet for the heat-softening substance at the bottom of a tank housing the heat-softening substance in a softened state. 1. An apparatus for producing fibers of a heat-softening substance, characterized in that a resistance heating element is installed in a portion above a nozzle inside the tank. 2. The apparatus for producing fibers of a heat-softening material according to claim 1, wherein the nozzle and the resistance heating element are made of platinum or a platinum alloy. 3. The apparatus for manufacturing fibers of a heat-softening material according to claim 1, wherein the nozzle has a long shape in one direction, and the resistance heating element extends in the one direction. 4. The apparatus for producing fibers of a heat-softening material according to claim 2, wherein the nozzle has a long shape in one direction, and the resistance heating element extends in the one direction. 5. Claim 4, characterized in that the resistance heating element is connected to a nozzle at both ends thereof.
An apparatus for producing fibers made of a heat-softening substance according to item 1. 6. Any one of claims 1 to 5, wherein the nozzle is provided with a gas guide hole and an ejection port for ejecting gas for stretching the thermoplastic material from the vicinity of the outlet. An apparatus for producing fibers made of a heat-softening substance according to item 1. 7. The apparatus for producing fibers of a heat-softening material according to claim 6, wherein the gas jet port is oriented in a direction that rotates with respect to the outflow flow of the heat-softening material. 8. The apparatus for producing fibers of a heat-softening material according to any one of claims 1 to 7, wherein the resistance heating element has a plate shape. 9. The apparatus for producing fibers of a heat-softening material according to claim 8, wherein the resistance heating element is provided with reinforcing ribs.