JP2981504B2 - Manufacturing method of lightweight sound absorbing plate - 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 manufacturing a lightweight sound absorbing plate using slag wool.

[0002]

2. Description of the Related Art With the spread of sewage facilities, the amount of sludge such as earth and sand and fresh materials in sewage is increasing year by year. Traditionally, most of the sludge is burned to ash and disposed of by dumping on land or in the sea. However,
With the progress of urbanization, it has become increasingly difficult to secure a place suitable for dumping. In addition, it is necessary to carry out a treatment for insolubilizing harmful heavy metals contained in sludge. in this way,
Sludge treatment is a major social problem. Therefore, effective use of sludge as a resource is being studied.

[0003] Under such circumstances, the inventors have developed slag wool obtained from sludge. This slag wool separates sludge from sewage, burns the separated sludge to obtain ash, melts the obtained ash to obtain liquid sludge slag, and scatters liquid sludge slag. And slag wool. The slag wool obtained from the sludge has a composition similar to that of a conventionally known fiber forming slag wool (hereinafter referred to as "rock wool") obtained by scattering a liquid blast furnace slag, although the composition is substantially the same as that of the fiber. Of different fibers. That is, sludge slag wool has a feature that the content of silica (SiO ₂ ) is larger and the fiber diameter is larger than rock wool.

[0004] On the other hand, conventionally, rock wool is dispersed in a large amount of water together with an additive to form a slurry, which is formed by a paper machine to obtain a plate having a predetermined thickness. There is an inorganic sound absorbing plate that is appropriately processed. This sound absorbing plate has various designs on its surface and is used for many purposes such as ceiling plates and wall plates. And, in the sound absorbing plate, reduction in weight and improvement in bending strength are major issues.

[0005]

OBJECTS OF THE INVENTION It is an object of this invention can be effectively utilized sludge contained in the wastewater, using a slag wool obtainable from the sludge, lightweight acoustical excellent in lightweight and flexural strength An object of the present invention is to provide a method for manufacturing a plate .

[0006]

Means for Solving the Problems The inventors have conducted intensive studies to solve the above-mentioned problems. As a result, a predetermined amount of slag wool obtained from sludge and a predetermined amount of rock wool were used as raw materials for the sound absorbing plate, and these were dispersed together with additives in a large amount of water to form a slurry, which was then converted into a paper machine. If a sheet having a predetermined thickness is formed by papermaking and subjected to perforation processing and other appropriate processing, a sound absorbing plate that is lighter and more excellent in bending strength than a conventional sound absorbing plate made of rock wool as a raw material. Was found to be obtained.

The present invention has been made based on the above findings. The method for producing a sound-absorbing plate according to the present invention provides a method for producing a sound-absorbing plate having a fiber diameter of not less than 7 μm and not more than 20 to 100 wt. % Of slag wool and the remaining amount of rock woofer having a fiber diameter of 3-4 μm.
Using the Le as the raw material, the raw material was mixed with water and certain additives, and <br/> stirring to maintain good entanglement between fibers 0.4～0.8Wt. %, And the slurry mixture is guided to a paper machine, formed into a plate having a predetermined thickness by the paper machine, and subjected to appropriate processing on the plate. is there.

Next, slag wool and rock wool used in the present invention will be described. First, a process of obtaining slag wool from sludge will be described with reference to the drawings. That is, sludge is separated from sewage, and the separated sludge is concentrated in a concentration facility. The concentrated sludge is dewatered in a dewatering facility. Next, the dewatered sludge is further dried to form a cake.

Next, slag wool is prepared by a melting furnace 1 and a slag wool manufacturing apparatus 2 shown in FIG. That is, in the melting furnace 1, 3 is a burner, and 4 is a burner.
Is a sludge supply port. A mixture of the dried sludge and a calcium component modifier described later is supplied into the melting furnace 1 through a sludge supply port 4, and a high-temperature combustion gas is blown into the melting furnace 1 through a burner 3, and the mixture is mixed. To make it sludge ash.

[0010] The sludge ash obtained in this way is burner 3
The molten sludge 5 is melted by the high-temperature combustion gas from the sludge. Liquid sludge slag 5 thus obtained
Once accumulates in the sludge slag sump 6 and is then discharged from the sludge slag discharge port 7 in the form of a falling flow.

In addition, the dried sludge is incinerated in an incinerator other than the melting furnace 1 described above, a calcium component modifier is added to the obtained sludge ash, and these are mixed to form a mixture. The obtained mixture may be melted in the melting furnace 1 by the same method as described above to obtain a liquid sludge slag.

The slag wool is produced from the liquid sludge slag 5 discharged from the sludge slag discharge port 7 by the slag wool production apparatus 2 as follows. That is, the liquid sludge slag 5 discharged from the melting furnace 1 falls on the outer peripheral surface of the disk-shaped spinning wheel 8a having a predetermined thickness and rotating at a high speed in the direction of the arrow in FIG. Then, it collides with the outer peripheral surface of another spinning wheel 8b that rotates at a high speed in the direction of the arrow in FIG. 2 and further scatters.

The scattered sludge slag 5 is blown off by the air flow jetted from a plurality of air jet nozzles 9 provided near the spinning wheels 8a and 8b.
The slag wool 10 is obtained by coagulation into a fibrous form. The obtained slag wool 10 is collected by a collection belt conveyor 11
It falls down and is then collected in the trolley 12.
Thus, slag wool having a fiber diameter of 7 μm or more is manufactured.

The sound absorbing plate of the present invention uses sludge slag wool (hereinafter referred to as "slag wool") obtained as described above as a raw material. Then, rock wool is used as a raw material. The mixing ratio of slag wool and rock wool is slag wool: less than 20 to 100 wt.%, The rest being rock wool. If the content of slag wool is less than 20 wt.%, Desired effects cannot be obtained for the effect of improving strength and reducing weight. On the other hand, when the content is less than 20 wt.%, It is against the object of the present invention to use sludge effectively. Therefore, the mixing ratio of slag wool should be limited to a range of less than 20 to 100 wt.%.

Since the slag wool used in the present invention has a high silica content, it has a high viscosity upon melting and it is difficult to obtain fibers having a diameter of 7 μm or more. On the other hand, if the fiber diameter of the slag wool is less than 7 μm, the desired effect on the bending strength improving effect cannot be obtained. Furthermore, the larger the fiber diameter is, the smaller the bulk specific gravity is, and the weight can be reduced. The higher the slag wool mixing ratio with the rock wool having a fiber diameter of 3 to 4 μm, the more the weight can be reduced.

As the rock wool, a well-known rock wool conventionally obtained as a raw material of a sound absorbing plate obtained by scattering a liquid blast furnace slag is used. By adding rock wool having a fiber diameter smaller than that of slag wool (3 to 4 μm), slag wool and rock wool are mixed, the entanglement action of the wool fibers is improved, and the bending strength is improved.

Next, an embodiment of a process for manufacturing a sound absorbing plate of the present invention will be described with reference to the drawings. FIG. 1 is a systematic process diagram showing the manufacturing process of the present invention.

Slag wool, rock wool, and additives as raw materials are respectively supplied in predetermined amounts to a stirrer, and are stirred and mixed in the presence of water to form a slurry.

Next, the slurry mixture mixed in the stirrer is supplied to a papermaking machine. In a papermaking machine, a plate is formed from the slurry-like mixture.

After the plate is formed, it is dehydrated with a dehydrator. Next, cutting is performed by a cutter in accordance with the scale of the dryer. Further, the cut plate is continuously dried by a dryer.

The slurry concentration at the time of papermaking in the papermaking machine is 0.1.
It should be limited to the range of 4 to 0.8 wt.%. In the case where conventional rock wool is used as a raw material, the slurry concentration during papermaking is about 1.0 to 3.0 wt.%, Which is higher than that of the present invention. The reason is that the average fiber diameter of rock wool is 3-4μ.
m, which is a numerical value sufficient to maintain good entanglement between fibers. However, the fiber diameter of slag wool is 7 μm or more, which is larger than rock wool, as described above. Therefore, in the present invention using slag wool, the slurry concentration of the papermaking machine is made lower than before in order to maintain good entanglement between fibers. However,
If the slurry concentration is less than 0.4 wt.%, The mechanical load increases and the productivity decreases. That is, inconveniences such as an increase in the diameter of the pipe for transporting the slurry, an increase in the capacity of the pump, and an increase in the capacity of the head box of the paper machine occur. On the other hand, if the slurry concentration exceeds 0.8 wt.%, The entanglement between the fibers becomes insufficient, and the strength of the plate becomes difficult to appear. Therefore, the slurry concentration should be limited to the range of 0.4-0.8 wt.%.

After the plate is manufactured in this way, the plate is cut into a desired size for a product by a cutting machine. Next, a hole is formed in the plate body by a press machine, an emboss machine or the like. The perforation is performed to impart sound absorbing properties to the plate. The perforation is performed to apply a design to the surface of the plate. Further, the surface of the plate body is coated or the like, and thus is commercialized as a sound absorbing plate.

[0023]

( Reference example)

Using the raw materials and additives shown in Table 1 below, a sound absorbing plate was prepared by the steps shown in FIG. That is, slag wool, an additive and water shown in Table 1 were supplied to a stirrer, and the mixture was stirred and mixed to form a slurry. The slurry concentration at this time was 0.4
-0.8 wt.%. Next, the slurry-like mixture was supplied to a paper machine, and a plate was formed by the paper machine. Then
The plate was dehydrated with a dehydrator and then cut with a cutter. Further, the cut plate is continuously dried by a drier, and then cut into a predetermined size. Then, a hole is formed in the plate, and a sound absorbing plate sample (hereinafter referred to as a “ reference sample”). "
Was prepared.

[0024]

[Table 1]

Example A sound absorbing plate was prepared according to the process shown in FIG. 1 using the raw materials and additives shown in Table 2 below. That is, slag wool, rock wool, an additive, and water were supplied to the stirrer in the amounts shown in Table 2, and the mixture was stirred and mixed to form a slurry. The slurry concentration at this time was in the range of 0.4 to 0.8 wt.%. Next, the slurry-like mixture was supplied to a paper machine, and a plate was formed by the paper machine. Next, the plate is dehydrated with a dehydrator, and then
It was cut by a cutting machine. Further, the cut plate is continuously dried by a drier, and then cut into a predetermined size. No. 1 (referred to as “the specimen of the present invention”)
2 was prepared.

[0026]

[Table 2]

COMPARATIVE EXAMPLE For comparison, a rock wool was used, a slurry concentration of a paper machine was set to 1.0 to 3.0 wt. Specimen (hereinafter referred to as "comparative specimen")
Was prepared. Table 3 below shows raw materials and additives used in Comparative Examples.

[0028]

[Table 3]

Then, the density and flexural strength of each of the test specimen of the present invention, the reference test specimen and the comparative test specimen were examined.
Table 4 shows the results. The density of each specimen was measured according to JIS A-6307, and the bending strength test was performed according to the test method specified in JIS A-1408.

[0030]

[Table 4]

As apparent from Table 4, the specimens of the present invention
Nos. 1 and 2 have lower densities than the comparative specimens,
Also, the bending strength was excellent.

[0032]

As described above, according to the present invention, slag wool obtained from sludge contained in sewage can be effectively used, and is lighter in weight and bending strength than a conventional sound absorbing plate made of rock wool. This makes it possible to obtain a sound absorbing plate using slag wool which is excellent in industrial properties, and thus has an industrially useful effect.

[Brief description of the drawings]

FIG. 1 is a systematic process diagram showing a manufacturing process of the present invention.

FIG. 2 is a partially cutaway perspective view showing an apparatus for manufacturing slag wool used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Melting furnace 2 Slag wool manufacturing apparatus 3 Burner 4 Sludge supply port 5 Sludge slag 6 Sludge slag accumulation 7 Sludge slag discharge port 8a, 8b Spinning wheel 9 Air injection nozzle 10 Slag wool 11 Recovery belt conveyor 12 truck.

Continued on the front page (73) Patentee 000004123 Nippon Kokan Co., Ltd. 1-2-1, Marunouchi, Chiyoda-ku, Tokyo (72) Inventor Noriharu Kaneko 189 Iwasakicho, Hodogaya-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Atsushi Mori Kanagawa (72) Inventor Takashi Shindo 1-2-503, Nagata Minamidai, Minami-ku, Yokohama-shi, Kanagawa Prefecture, Japan (72) Inventor Shuro Inogawa 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan Nippon Kokan Co., Ltd. (72) Inventor Nobuyuki Sugiyama 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Tetsuo Akashi 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor, Ning Hoshino 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor, Takashi Mayahara 1-1-1, Inami-cho, Inami-cho, Higashi-Tonami-gun, Toyama Pref. 72) The inventor, Tadao Yamama, 1 Inaba, Inami-cho, Higashi-Tonami-gun, Toyama (72) Inventor Keiji Shuto 1 in Iba, Inami-cho, Higashi-Tonami-gun, Toyama Prefecture Daiken Kogyo Co., Ltd. (72) Inventor Takao Takaki 1 in Inami-cho, Inami-cho, Higashi Tonami-gun, Toyama (56) References JP-A-63-285179 (JP, A) JP-A-61-183150 (JP, A) JP-A-52-1977 (JP, A)

Claims (1)

(57) [Claims] (1) obtained from sludge contained in sewage;
20-100 Wt. Having a fiber diameter of 7 μm or more. % Of slag wool and the remaining amount of 3-4 μm fiber diameter
Using rock wool having the following characteristics as a raw material, mixing water and a predetermined additive with the raw material, and obtaining good entanglement between fibers.
Stirring to maintain 0.4-0.8 wt. %, Wherein the slurry-like mixture is introduced into a paper-making machine, formed into a plate having a predetermined thickness by the paper-making machine, and subjected to appropriate processing on the plate. Plate manufacturing method.