JP2995708B2 - Fiber manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a fiber which is made into a fiber by applying an external force to a raw material melt.

[0002]

2. Description of the Related Art Among fibers, for example, substances used as raw materials for inorganic amorphous fibers include so-called basic rocks such as slag and basalt discharged from various types of glass and blast furnaces, and clay minerals such as kaolin. Also, a mixed raw material of the Bayer method alumina and silica sand and the like are well known.

[0003] These substances are generally melted in a cupola or an electric furnace and then continuously taken out of the furnace as a small stream from a tapping hole.

[0004] The fine stream of the melt is extended into a fibrous form by an external force. There are basically three types of fiberization methods.

(A) Drawing method (Drawing)
Is a method mainly used for producing long glass fibers, and is a method of continuously extending from a base.

(B) Throwing
The method utilizes the centrifugal force of a rotating fiberized disk (spinner) and is also called a spinning method.

(C) The blowing method is a method using a high-speed flow of air or other gas.

In the blowing method, a high-pressure gas, for example, air is injected from a nozzle to obtain a flow velocity close to the speed of sound, and a fine stream of a melt is guided to the jet flow to achieve fiberization by the impact force. The method has several problems.

[0009]

There are three main problems with the blowing method.

First, the energy consumed by the compressor for compressing the air is very large, and the production cost is high. For example, in the case of producing Al ₂ O ₃ —SiO ₂ -based ceramic fiber, when the flow rate of the fine stream of the raw material flowing out of the melting furnace is 400 kg / hr, the pressure is several kgf / cm ² . The capacity of the compressor to obtain the required amount of air for this is approximately 300 horsepower (255 kW). Therefore, the energy consumed for fiberization is 255 kwh / 400 kg = 0.64 kwh /
kg. The energy required to melt the Al ₂ O ₃ —SiO ₂ raw material is approximately 1.8 kwh / kg,
In comparison, the energy required for fiberization cannot be said to be small.

The second problem is a cotton collecting device. The air flow near the sonic velocity attracts environmental air from the surroundings and enters the cotton collecting chamber, so that the exhaust amount is several times the jet air amount. Therefore, if the exhaust capacity is low, the pressure inside the cotton collecting chamber becomes higher than that of the outside air, and the fibers blow out. In order to separate the fine fibers from the exhaust gas from the cotton collection chamber, a huge filtering device is required, and further, a dust collector is required to keep the environmental atmosphere clean. These capital investments are large and their operation consumes a considerable amount of power. For example, the total is 0.5 kwh / kg.

The third problem is that the fiberization rate is low.
It is known that shots exist in rock wool and ceramic fibers. A shot with a large diameter impairs the low thermal conductivity characteristic, which is the function of the ceramic fiber as a heat insulating material, and may impair the function in other uses.

[0013]

SUMMARY OF THE INVENTION The present invention is directed to a method for producing a fiber in which a fiber is formed by applying an external force to a flow of a melt of a raw material. The present invention provides a method for producing a fiber, which comprises converting a raw material into a fiber.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a liquid jet is directly injected into a flow of a raw material melt, and the raw material melt is fiberized by utilizing the impact force of the liquid jet.

Liquid is easier to pressurize than gas (air) and has a higher density, so that kinetic energy can be applied efficiently. The energy consumption for pressurization is also very small. The size of the compressor is also small. The jet of high-pressure liquid does not attract the air around it, and the resulting fibers enter the aquarium with the liquid, so that no fine fiber dust is generated.
Therefore, no special cotton collecting room, no exhaust air filtering device and no dust collector are required. The fiber is dewatered and dried as it is or via a paper machine. In a water tank, shots can be separated. The fibers can also be stored temporarily with the liquid.

The strong impact force of the liquid jet makes it possible to atomize (finely atomize) the melt of the raw material, so that the amount of shots can be reduced and the shot particles can be reduced.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention has been made to solve the above-mentioned problem of the blowing method, and is a method in which the impact force of a high-pressure liquid jet is used instead of high-pressure gas or air. The liquid here includes, for example, water, an aqueous solution in which another substance is dissolved in water, and a suspension in which another substance is suspended in water.

The compressor engine that produces the high pressure liquid preferably has 20 to 150 horsepower. Working pressure is 55-4
000 kgf / cm ² is preferred. The capacity (discharge amount) of the compressor is preferably from 10 to 390 l / min.

The output of the engine during operation of the compressor is preferably 50% or less, and at this time, the average pressure of the liquid is 100 to 20%.
00 kgf / cm ² , average flow rate is 15-100 l / mi
It is preferably n.

By performing fiberization with the above configuration,
Energy required for fiberization is 0.05 to 0.5 kwh /
Desirably kg.

The ejection of the liquid jet may be performed by one nozzle, but it is usually preferable to perform the jet by using at least two nozzles. When the number of nozzles is one, it is preferable that the liquid jet is jetted at an angle of 10 to 90 degrees with respect to the fine stream of the raw material. It is also preferred that the liquid jets from a plurality of nozzles are arranged in a vertical blow such that they intersect. For example, it is preferable that two liquid jets are jetted at an angle of 30 to 65 degrees with respect to each other. It is preferable that the fine stream of the raw material melt is caused to flow at a flow rate of 75 to 500 kg / hr and substantially at the center of the intersection line of the intersecting liquid jets.

By injecting a liquid jet into the melt of the raw material under the above-described configuration, the melt of the raw material is turned into fibers and falls downward. At this time, not only the fiber shape is formed, but also the cooling is performed at the same time.

In order to collect the produced fibers, it is preferable to provide a water tank below the jet portion of the liquid jet. In this water tank, fibers coming down with the liquid of the liquid jet can be collected.

The recovered fibers are then dehydrated and dried. If necessary, the paper is passed through a paper machine before dewatering / drying, and other processing steps are performed before and after dewatering / drying.

EXPERIMENTAL EXAMPLES 1 AND 2 First, Experimental Examples 1 and 2 using the fiber production method of the present invention will be described.

First, a mixed raw material of Bayer alumina and silica sand in an equal amount by weight is melted in a 300 KVA arc furnace, and a boron nitride (BN) wafer having a hole having a diameter of 4 or 3 mm and placed on the bottom of a spout portion of the furnace is prepared. The melt was drained vertically as an orifice. In Experimental Example 1, the diameter of the hole was 4 mm
The flow rate at this time was about 150 kg / hr on average. In Experimental Example 2, the diameter of the hole was 3 mm, and the flow rate at this time was about 75 kg / hr on average.

Water was used for the liquid jet. Sugino Machine Jet Cleaner equipped with a 150 hp engine as a compressor for generating high-pressure water, JCE-7008
Type 5 was used. The normal pressure of the compressor is 700kgf / cm
^{2. The} capacity is 72 l / min.

During the operation of the compressor, in the case of Experimental Example 1, the engine output was 16%, the average pressure was 500 kgf / cm ² , and the average flow rate of water was 27 l / min. The energy required for fiberization was 24 horsepower, that is, 18 kWh, and 18 kWh / 1
50 kg, ie 0.12 kwh / kg. In the case of Experimental Example 2, the engine output was 4% and the average pressure was 200 kgf /
cm ² , the average flow rate of water is 17 l / min. The energy required for fiberization is 6.1 horsepower, that is, 4.6 kW
h, 4.6 kwh / 75 kg or 0.06 k
wh / kg. The nozzle used was a direct injection nozzle JNF-1 for a gun manufactured by the same company in both Experimental Examples 1 and 2.
There are two 021 types. The nozzles were arranged longitudinally so that the liquid jets from the nozzles intersected. At this time, in Experimental Example 1, the liquid jets are jetted at an angle of 60 degrees with each other. In Experimental Example 2, the liquid jets are jetted at an angle of 30 degrees to each other. A trickle of the raw material melt was allowed to flow down to approximately the center of the intersecting liquid jets. This will be described below with reference to the drawings. FIG.
FIG. 2 is a view showing a liquid jet injection method of Experimental Examples 1 and 2 of the present invention. A small stream 4 of the melt of the raw material that has flowed down from the vertical upper part flows down substantially at the center of the intersection line 3 where the liquid jets 2 ejected from the two nozzles 1 intersect. The rivulet 4 of the raw material melt is fiberized by the liquid jet 2 and falls downward.

The produced fibers were recovered by a box-shaped cotton collector provided below. There is a water tank at the bottom of the box type cotton collecting machine,
The fibers enter the aquarium with the liquid jet liquid.

Next, the fibers in the water tank were dewatered and dried.

Next, the characteristics of the produced fiber (bulk) were measured. Table 1 shows the experimental conditions and Table 2 shows the measurement results.

Experimental Example 3 A mixed raw material of Bayer alumina and silica sand was melted in an arc furnace in the same manner as in the methods of Experimental Examples 1 and 2, and the melt was passed through an orifice having a hole having a diameter of 4 mm to 150 kg / hr.
Vertically. Experimental examples 1 and 2
The one with the same specification as that used was used. The conditions during the operation of the compressor are as follows: the engine output is 27%, the average pressure is 700 kgh / cm ² , and the average flow rate of water is 29.6 l / min. The energy required for fiberization is 40 horsepower, that is, 30 kWh, and 30 kWh.
kwh / 150 kg, that is, 0.2 kwh / kg. The nozzle used was a gun-shot flat nozzle and one was used. The nozzle is configured such that a liquid jet from the nozzle is ejected at an angle of 70 degrees with the trickle of the melt. FIG. 2 is a view showing a method of ejecting a liquid jet of Experimental Example 3. The produced fiber was collected in a water tank, then dehydrated and dried, and its properties were measured. Table 1 shows the experimental conditions and Table 2 shows the measurement results.

Comparative Example Next, a comparative example using a conventional blowing method will be described.

The raw materials were prepared in the same manner as in Experimental Examples 1 and 2.
It was drained out in a molten state.

As a compressor for generating high-pressure air, 1
A portable compressor equipped with a 90 hp diesel engine was used. The normal pressure of the compressor is 7kgf / cm
^{2. The} capacity is 19 m ³ / min.

When the compressor is operating, the engine output is 75% (1
43 horsepower), an average pressure of 5.2 kgf / cm ² , and an average air flow rate of 19 m ³ / min. The energy required for fiberization is 107 kwh / 150 kg, that is, 0.71 k
wh / kg.

The air nozzle used is disclosed in US Pat.
6,324. Air nozzle is 1
They were used individually and arranged so as to blow sideways. When the melt of the raw material flows down toward the air stream, the melt is fiberized. At this time, the air stream is ejected at an angle of about 90 degrees with respect to the fine stream of the raw material melt.

The produced fibers were collected by a box type cotton collecting machine.
A wire mesh was stretched on the lower surface of the box type cotton collecting machine, and suction was performed at 100 m ³ / min with an exhaust fan below the wire mesh. The fibers are filtered by wire mesh and separated from the air. The exhaust contains dust. In order to maintain a clean environmental atmosphere, it was necessary to guide the exhaust gas to a bag filter type dust collector operating with a power of 10 kwh to separate dust.

Next, the characteristics of the produced fiber (bulk) were measured. Table 1 shows the experimental conditions and Table 2 shows the measurement results.

Next, the results of comparison between Experimental Examples 1, 2, and 3 and Comparative Examples will be described with reference to Tables 1 and 2.

Comparing the flow rate of the liquid jet of Experimental Example 1 with the flow rate of the air flow of Comparative Example, it can be seen that Experimental Example 1 requires an extremely low flow rate. Similarly, Experimental Examples 2 and 3
Comparing the flow rates of Comparative Examples 1 and 2, it can be seen that the flow rates of Experimental Examples 2 and 3 are also extremely small.

The energy required for fiberization is about 1/6 of the comparative example in Experimental Example 1, and about 1/10 of the comparative example in Experimental Example 2. In Experimental Example 3, it is about 1/4 of Comparative Example.

Generated ceramic fiber (bulk)
, Mean diameters of Experimental Examples 1, 2, and 3 are almost the same as those of Comparative Example. Further, the shot contents (shots of 65 mesh or more) were also measured in Experimental Examples 1, 2, and 3.
In both cases, it was about 1/2 that of Comparative Example 1, and it was confirmed that the value was greatly reduced. Also, the shots smaller than 65 mesh were smaller in Experimental Examples 1, 2, and 3 than in Comparative Example. That is, the comparative example is 39.7%,
Experimental Example 1 was 33.5%, Experimental Example 2 was 34.3%, and Experimental Example 3 was 36.1%. From the above, it was confirmed that all of the experimental examples 1, 2, and 3 had a smaller amount of the entire shot than the comparative example, and a reduced amount of the shot having a large particle size.

As a result of the experiment, since fine fiber dust was not generated in Experimental Examples 1 and 2, there was no need to provide an exhaust device, and the equipment scale was small. On the other hand, a large amount of dust was generated in the comparative example. This confirmed that the fiber production method of the present invention did not adversely affect environmental air.

[0045]

According to the method of the present invention, the amount of shot in the formed ceramic fiber bulk is extremely small despite the extremely small amount of liquid used. Therefore, the yield of fiber from the same amount of raw material is greater than before.
Further, since the shot has a small particle size, even if the shot is mixed with the fiber, the feel is good.

In addition, the energy consumption for increasing the pressure of the liquid is small, and the amount of liquid necessary for fiberization is also small.
Therefore, the energy efficiency of fiberization is good.

Further, since the liquid to be used is a small amount of liquid, it does not attract a large amount of ambient air at the time of blowing. Therefore, it is not necessary to provide a large-capacity dust collecting device in the cotton collecting machine. Furthermore, since there is no generation of dust, the surrounding environmental air is not deteriorated.

Further, since the fibers can be temporarily stored together with the liquid, processing such as separation of shots, dehydration / drying of fibers, etc. is not performed immediately, but is performed collectively later.
Before and after that, other necessary processing steps can be passed.

[0049]

[Table 1]

[0050]

[Table 2]

[Brief description of the drawings]

FIG. 1 is a diagram showing a liquid jet injection method of Experimental Examples 1 and 2 of the present invention.

FIG. 2 is a diagram showing a method of ejecting a liquid jet according to Experimental Example 3 of the present invention.

[Description of Signs] 1 Nozzle 2 Liquid jet 3 Crossing line of liquid jet 4 Fine stream of raw material melt 5 Fiber

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kimio Hirata 4-4 Nihonbashi Hisamatsucho, Chuo-ku, Tokyo Itoishi Building Inside Toshiba Monoflux Co., Ltd. (72) Inventor Yasuo Misu 4th Nihonbashi Hisamatsucho, Chuo-ku, Tokyo No. 4 In Itushige Building Toshiba Monoflux Co., Ltd. (72) Inventor Akira Ito 4-4 Nihonbashi Hisamatsucho, Chuo-ku, Tokyo In Itoshige Building Toshiba Monoflux Co., Ltd. (56) References JP-A-61-194222 ( JP, A)

Claims (1)

(57) [Claims] 1. A fiberization by applying an external force to a flow of a raw material melt.
In the method of producing fibers, the liquid
A method for producing fibers, comprising jetting a jet and fibrillating a raw material melt by the liquid jet .