JP7092464B2 - Granular fiber spraying device and granular fiber spraying method - Google Patents

Description

The present invention relates to a granular fiber spraying device. More specifically, the present invention relates to a granular fiber spraying device capable of suppressing dust generated during spraying of granular fibers. The present invention also relates to a method for spraying granular fibers. More specifically, the present invention relates to a method for spraying granular fibers in which the amount of dust generated during spraying the granular fibers is small.

It is widely practiced to provide a fiber layer made of rock wool on the surface of a structure for the purpose of imparting fire resistance, fire resistance, sound absorption and / or heat insulation. For the formation of the fiber layer, a spraying method using granular fibers (fiber lumps having a diameter of several mm to several cm) and an agglomerate containing water as a main component is often used. As the rock wool spraying method, a dry method, a wet method, and a semi-dry method are known. In the dry method, a dry mixture (dry mixture, hereinafter sometimes referred to as "rock wool / cement mixed cotton"), which is a dry mixture of rock wool granular fibers and cement, is discharged from the nozzle, and at the same time, on the periphery of the nozzle. This is a construction method in which pressure water is sprayed from a plurality of arranged fountain ports and both are mixed and sprayed. This dry method can form a lightweight covering layer with a bulk specific density of 0.2 to 0.3, but it has been pointed out that there is an environmental problem due to significant dust generation due to cement and rock wool during construction. The wet method is used to improve the defects of the dry method. This wet method uses a coating material for spraying, which is a mixture of rock wool granular fibers and cement, which are the main materials, with a surfactant and a thickener, and a paste containing water is sprayed from a nozzle using compressed air. The method. Although the problem of suspended dust has been improved in this wet method, it has been pointed out that the bulk specific density of the formed coating layer is as heavy as 0.4 to 0.6, and the cost is higher than that of the dry method. ..

The semi-dry method is a method in which rock wool granular fibers and cement are not mixed in advance. In the semi-dry method, rock wool granular fibers are defibrated (cotton) and crushed (finely granulated (fiber lumps with a diameter of several mm to several cm)) using a defibrator (cotton defibrator), and rotary valves, etc. It is quantitatively sent out by the air blower, is pumped in the hose by the air blower, and is supplied to the spray nozzle. Cement is mixed with water in a slurry tank to form a cement slurry, and then supplied to a spray nozzle through a transport pipe by a slurry pump. The cement slurry is sprayed from the peripheral edge of the spray nozzle or sprayed from the vicinity of the central axis of the spray nozzle to merge and mix with rock wool to form a fiber layer composed of rock wool and cement hydrate. According to the semi-dry method, floating dust is reduced, and a coating layer having a bulk specific density close to that of the dry method can be formed. For this reason, the semi-dry method has become the mainstream of the rock wool spray method. The semi-dry method can reduce the amount of dust generated during spraying compared to the dry method, but has the problem that it is difficult to make the spraying device compact. It is a dry method using rock wool / cement mixed cotton that makes it easy to make the spraying device compact. In addition, even if a foamed resin-based heat insulating material such as polystyrene foam or hard urethane foam is covered with a fiber layer made of rock wool and cement hydrate with a thickness of 30 mm by a semi-dry method, the nonflammability is insufficient, and the semi-dry method is used. It has been found by the present inventors that sufficient nonflammability can be obtained in a fiber layer formed to a thickness of 30 mm by replacing granular fibers consisting only of rock wool pumped by the method with rock wool / cement mixed cotton (for example). See Patent Document 1). Therefore, even with the rock wool spraying method that transports rock wool / cement mixed cotton to the spray nozzle, that is, the rock wool spraying method that uses mixed cotton or the semi-dry method, it is a technique that can suppress dust generated during spraying. Was desired.

A method has been proposed in which a spray nozzle having a plurality of injection holes for injecting air and water at one time is used on the outer periphery of the tip of a conduit through which a material containing a fiber or the like and a water-hard inorganic adhesive is passed (for example, Patent Document 2). Or see 3.). In addition, there is a technique to arrange a plurality of water supply nozzles on the front side of the spray nozzle in a ring shape so that the axis of the jet of pressurized water discharged from the water supply nozzle intersects on the axis of the jet of mixed cotton discharged from the spray nozzle. It has been proposed (see, for example, Patent Document 4).

Japanese Unexamined Patent Publication No. 2014-141868 Jikkensho 55-011961 Gazette Utility Model Registration No. 2582028 Gazette Jitsukosho 49-0000053 Gazette

In the present invention, a dry mixture (dry mixture, hereinafter sometimes referred to as "blended cotton"), which is a dry mixture of granular fibers and cement, is transported to a spray nozzle and sprayed from the discharge port of the spray nozzle into the dry mixture. Provided is a granular fiber spraying device that generates less dust when used in a spraying method in which a coagulant whose main component is water discharged (sprayed) from a coagulant injection nozzle arranged at the outer edge of the discharge port is merged and mixed. The purpose is to do.

Further, the present invention is a granular fiber spraying method capable of suppressing the amount of dust generated during spraying of granular fibers, that is, a dry mixture of granular fibers and cement is transported to a spray nozzle and sprayed from the discharge port of the spray nozzle. Dust generated in the granular fiber spraying method in which a coagulant containing water discharged (sprayed) from the coagulant spray nozzle arranged at the outer edge of the discharge port is merged and mixed with the dry mixture (blended cotton). It is an object of the present invention to provide a method of spraying a small amount of granular fibers.

As a result of diligent studies for solving the above-mentioned problems, the present inventor has found that the above-mentioned problems can be solved by using a nozzle for spraying granular fibers under specific conditions, and completed the present invention. That is, the present invention is the granular fiber spraying device represented by the following (1) or (2 ), and the granular fiber spraying method represented by ( 3 ).
(1) Equipped with a granular fiber spray nozzle, a granular fiber transport device, a coagulant transport device and a pneumatic feed device.
The granular fiber spraying nozzle is provided with a plurality of coagulant injection nozzles around the granular fiber pumping pipe and the discharge port of the granular fiber pumping pipe, and is discharged from the coagulant injection nozzle with respect to the central axis of the granular fiber pumping pipe. The angle θ formed by the central axis of the aggregate is within the range of 4 to 10 °.
The pressure of the compressed air that the agglomerate injection nozzle communicates with the agglomerate transport device and the air pressure feeding device and is pressure-fed from the air pressure feeding device to the agglomerating material injection nozzle is 0.2 to 1 MPa.
The granular fibers transported by the granular fiber transport device and discharged from the granular fiber spray nozzle are a dry mixture with cement.
A granular fiber spraying device in which a granular fiber transport device and a granular fiber pumping pipe communicate with each other.
(2) The fiber spraying device according to (1) above, wherein the angle θ is within the range of 6 to 10 °.
(3) The granular fiber discharged from the discharge port of the granular fiber pumping pipe by the granular fiber spraying device of the above (1) or (2) and the compressed air of 0.1 to 1 MPa are discharged from the agglomerate injection nozzle. A method for spraying granular fibers in which the above-mentioned granular fibers are a dry mixture with cement, which is characterized by merging and mixing with the aggregated materials and spraying them onto a structure .

According to the present invention, it is possible to obtain a granular fiber spraying apparatus in which the amount of dust generated during the spraying of granular fibers is small. According to the present invention, the main component is water discharged (sprayed) from the agglomerate injection nozzle arranged on the outer edge of the discharge port to the dry mixture transported to the spray nozzle and sprayed from the discharge port of the spray nozzle. A granular fiber spraying device with less dust generated when used in a spraying method in which agglomerates to be mixed and mixed can be obtained.

Further, according to the present invention, it is possible to obtain a granular fiber spraying method capable of suppressing the amount of dust generated when the granular fiber is sprayed. According to the present invention, a dry mixture of granular fibers and cement is transported to a spray nozzle, and the dry mixture (blended cotton) sprayed from the discharge port of the spray nozzle is provided with a flocculant spray nozzle arranged on the outer edge of the discharge port. In the granular fiber spraying method in which agglomerates containing more discharged (sprayed) water as a main component are merged and mixed, a granular fiber spraying method with less generated dust can be obtained.

According to the present invention, since the amount of dust generated when spraying granular fibers can be suppressed, the work of spraying granular fibers can be easily performed, the protective equipment can be simplified, the cleaning work can be reduced or omitted, and the construction efficiency can be improved. You can also hope.

It is a schematic diagram of an example of the granular fiber spraying apparatus of this invention. It is a schematic vertical sectional view of an example of a granular fiber spraying nozzle.

The granular fiber spraying device of the present invention includes a granular fiber spraying nozzle, a granular fiber transport device, a flocculant transport device, and an air pressure feed device.
The granular fiber spraying nozzle is provided with a plurality of coagulant spray nozzles around the granular fiber pumping pipe and the discharge port of the granular fiber pumping pipe, and is discharged from the coagulant injection nozzle with respect to the central axis of the granular fiber pumping pipe. The angle θ formed by the central axis of the aggregate is within the range of 1 to 30 °.
The pressure of the compressed air that the coagulant spray nozzle communicates with the agglomerate transport device and the air pressure feeding device and is pressure-fed from the air pressure feeding device to the coagulant spray nozzle is 0.1 to 2 MPa.
It is characterized in that the granular fiber transport device and the granular fiber pumping pipe communicate with each other.

In the present invention, the granular fiber is a fiber mass having a diameter of several mm to several cm, preferably a fiber mass having a diameter of 5 mm to 5 cm, and the material thereof may be an inorganic fiber, an organic fiber, or a mixture of an inorganic fiber and an organic fiber. It is often, preferably an inorganic fiber because it is easy to obtain fire resistance or nonflammability, and more preferably a mineral fiber. Most preferably rock wool. In the present invention, rock wool is a material (mineral fiber) in which a material mainly composed of rock or blast furnace slag melted in a melting furnace is rapidly cooled and fiberized. For example, slag wool manufactured from a material mainly composed of blast furnace slag is also included. As the rock wool, granular rock wool obtained by finely pulverizing raw cotton obtained by collecting fibrous mineral fibers with a decotching machine or the like can be preferably used. When raw cotton is used, it is finely divided with a cotton crusher or the like before transportation. Granular rock wool is obtained by one or a combination of two or more steps such as crushing, crushing, cutting, classifying (for example, sieving), and granulating raw cotton of rock wool. When such rock wool is used, heat is difficult to transfer to the base covering the rock wool. As the granular fiber of the present invention, a dry mixture with cement is preferable because the fiber layer to be formed easily obtains fire resistance or nonflammability.

Suitable examples of the flocculant in the present invention include water, an aqueous solution, an inorganic slurry and a resin emulsion, and an inorganic-containing resin emulsion (resin-containing inorganic slurry), and more preferable examples are water, an aqueous solution, a cement slurry and a synthetic resin. Examples thereof include emulsions (polymers) and cement-containing resin emulsions (resin-containing cement slurrys). The cement used in the present invention includes various Portland cements such as ordinary Portland cement, early-strength Portland cement, and white Portland cement, eco-cement, alumina cement, mixed cement such as fly ash cement and blast furnace cement, and rapid hardness such as ultrafast hard cement. Examples thereof include water-hard cement such as cement. The resin emulsion used for the flocculant of the present invention includes synthetic rubber such as styrene / butadiene copolymer, chloroprene rubber, acrylonitrile / butadiene copolymer or methyl methacrylate / butadiene copolymer, natural rubber, polyethylene, polypropylene and the like. Polyolefin, polychloropyrene, polyacrylic acid ester, styrene / acrylic copolymer, all acrylic copolymer, polyvinyl acetate, vinyl acetate / acrylic copolymer, vinyl acetate / acrylic acid ester copolymer, modified vinyl acetate, Acetic acid such as ethylene / vinyl acetate copolymer, ethylene / vinyl acetate / vinyl chloride copolymer, vinyl acetate vinyl versatate copolymer, acrylic / vinyl acetate / beova (trade name of t-vinyl decanoate) copolymer, etc. Examples thereof include synthetic resins such as vinyl resins, unsaturated polyester resins, polyurethane resins, alkyd resins and epoxy resins, and bituminous emulsions such as asphalt and rubber asphalt.

In the present invention, the granular fiber spraying nozzle is provided with a plurality of coagulant injection nozzles around (outer edge) the granular fiber pumping pipe and the discharge port of the granular fiber pumping pipe. The granular fiber pumping pipe communicates with the granular fiber transport device. This granular fiber transport device includes a fixed quantity supply device for granular fibers, a blower (blower), and a material pressure feeding hose (material hose), and a cotton crusher can also be used as the fixed quantity supply device for granular fibers. In this case, the unpacking machine quantitatively supplies the granular fibers compressed by packing into the pumping path of the granular fibers while unraveling them. The blower (blower), the fixed quantity supply device for granular fibers, the material pressure feeding hose (material hose), and the granular fiber pressure feeding pipe of the granular fiber blowing nozzle communicate with each other. The granular fibers quantitatively supplied in the pumping path are sent to the granular fiber pumping pipe of the granular fiber blowing nozzle through the material pumping hose by the air sent from the blower (blower), and the tip of the granular fiber pumping pipe. It is ejected from the discharge port of the part.

The agglomerate injection nozzle is arranged around (outer edge) the discharge port of the granular fiber pumping pipe. The distance between the center of the ejection hole of the coagulant injection nozzle and the granular fiber pumping pipe is preferably within the diameter of the granular fiber pumping pipe. The number of the agglomerate injection nozzles is preferably 2 to 20, more preferably 3 to 8. The agglomerate injection nozzle has an injection hole for injecting the agglomerate, which communicates with the aggregating material transport device and the air pressure feeding device, and the agglomerating material pumped from the agglomerating material transporting device is an air pressure feeding device. Together with the more pressure-fed compressed air, it is injected from the injection hole of the coagulant injection nozzle. The angle θ formed by the central axis of the agglomerating material discharged from the agglomerating material injection nozzle with respect to the central axis of the granular fiber pumping pipe needs to be within the range of 1 to 30 °. The central axis of the flow of granular fibers ejected from the discharge port at the tip of the shaped fiber pumping tube coincides with the central axis of the granular fiber pumping tube. When the injection hole of the agglutinating material injection nozzle is a straight hole, the central axis of the injection hole coincides with the central axis of the agglomerating material discharged from the agglutinating material injection nozzle. When the angle θ is in the range of 1 to 30 °, the dust generated by the injected granular fibers can be merged and mixed with the granular fibers together with the agglomerating material by the jet of the agglomerating material, and the dust is reduced. It seems to be. When the angle θ is less than 1 °, it is considered that the merging and mixing with the granular fibers is insufficient and the dust is not reduced. Further, even when the angle θ exceeds 30 °, dust is not sufficiently reduced. The more preferable angle θ is 4 to 15 °, and more preferably 6 to 10 °.

Further, if the pressure of the compressed air pressure-fed from the air pressure feeding device to the flocculant injection nozzle is in the range of 0.1 to 2 MPa, the generation of dust can be suppressed, but if it is out of the range, the dust is not sufficiently reduced. The pressure of the compressed air pressure-fed from the air pressure feeding device to the flocculant injection nozzle is preferably 0.1 to 1.5 MPa, more preferably 0.2 to 1.0 MPa. The air pressure feeding device is preferable because the compressor can continuously pump compressed air at a stable pressure.

In the granular fiber spraying method of the present invention, the granular fiber sprayed from the discharge port of the granular fiber pumping pipe and the compressed air of 0.1 to 2 MPa from the coagulant spray nozzle are sprayed by the above-mentioned granular fiber spraying device. It is characterized by merging and mixing with an agglomerating material and spraying it onto a structure.

FIG. 1 shows a schematic diagram of an example of the granular fiber spraying device of the present invention. The mixed cotton 11 is put into the thawing machine 10, thawing, and quantitatively supplied into the pumping path of the granular fibers. The granular fibers that have entered the pumping path pass through the material hose 9 by the air sent into the path from the blower 12, are sent into the granular fiber pumping pipe 2 of the granular fiber blowing nozzle 1, and are ejected from the discharge port 3 ( Discharge). The agglomerate 13 is pumped through the pressure-resistant hose for the agglomerate by a pump 7 communicating with the agglomerate storage tank 8 containing the agglomerate 13 and a suction hose to the granular fiber spray nozzle 1. Further, compressed air is pressure-fed to the flocculant injection nozzle 14 by the compressor 6 (pneumatic feeding device). The compressed air and the agglutinating material merge inside the granular fiber spraying nozzle 1 and are ejected from the linear ejection hole 15 of the agglutinating material injection nozzle 14. The jet 4 of the injected agglomerate and the jet 5 of the granular fibers ejected from the discharge port 3 merge and mix at the tip of the discharge port 3 and are sprayed onto the surface of the structure to form a fiber layer.

[Example 1]
The central axis 16 of the agglomerate discharged from the aggregating material injection nozzle with respect to the central axis 17 of the granular fiber pumping pipe, that is, the central axis of the granular fiber pumping pipe and the linear ejection hole 15 of the agglomerating material injection nozzle 14 Using a granular fiber spraying nozzle with an angle θ of 10 ° (No. 4 spraying nozzle, number of coagulant injection nozzles 14: 8), 60% by mass of granular rock wool (rock wool granular cotton) is used as the granular fiber. With 100 parts by mass of rock wool / cement mixed cotton consisting of 40% by mass of ordinary Portoland cement, 180 parts by mass of cement slurry with a water cement ratio of 200% as a coagulant is merged and mixed at a constant speed (1 m) at a substantially perpendicular angle to a vertical wall. / Second), spray while moving the granular fiber spray nozzle 1 with an amplitude of 1 m to the left and right, and operate the dust measuring instrument placed 1.5 m from the spray surface for 1 minute from 10 seconds after the spray start time to dust. The amount generated (relative concentration) was measured. At this time, the air pressure of the compressed air was 0.2 MPa, and the pressure of the agglomerating material was 0.2 MPa.

Table 1 shows the materials used, the pressure of the granular fiber spraying nozzle, and the compressed air, and the evaluation of the amount of dust generated 20 seconds and 60 seconds after the start of spraying (evaluation of the dust suppressing effect).

[Example 2]
Spraying was performed in the same manner as in Example 1 except that the air pressure of the compressed air was 1.0 MPa, and the amount of dust generated was measured. The results are shown in Table 1.

[Example 3]
The angle θ formed by the central axis of the agglomerating material discharged from the agglomerating material injection nozzle with respect to the central axis of the granular fiber pumping pipe, that is, the linear ejection of the central axis of the granular fiber pumping pipe and the agglomerating material injection nozzle 14. Spraying was performed in the same manner as in Example 1 except that a granular fiber spraying nozzle (No. 3 spraying nozzle, number of agglomerating material spraying nozzles 14: 8) having an angle θ formed by the holes 15 of 6 ° was used. , The amount of dust generated was measured. The results are shown in Table 1.

[Example 4]
The angle θ formed by the central axis of the agglomerating material discharged from the agglomerating material injection nozzle with respect to the central axis of the granular fiber pumping pipe, that is, the linear ejection of the central axis of the granular fiber pumping pipe and the agglomerating material injection nozzle 14. Spraying was performed in the same manner as in Example 1 except that a granular fiber spraying nozzle (No. 2 spraying nozzle, number of agglomerating material spraying nozzles 14: 8) having an angle θ formed by the holes 15 of 4 ° was used. , The amount of dust generated was measured. The results are shown in Table 1.

[Example 5]
The amount of dust generated was measured by spraying 100 parts by mass of rock wool / cement mixed cotton in the same manner as in Example 1 except that 80 parts by mass of water was mixed and mixed as a coagulant. The results are shown in Table 1.

[Comparative Example 1]
The angle θ formed by the central axis of the agglomerating material discharged from the agglomerating material injection nozzle with respect to the central axis of the granular fiber pumping pipe, that is, the linear ejection of the central axis of the granular fiber pumping pipe and the agglomerating material injection nozzle 14. Spraying was performed in the same manner as in Example 1 except that a granular fiber spraying nozzle (No. 1 spraying nozzle, number of agglomerating material spraying nozzles 14: 8) having an angle θ formed by the holes 15 was used. , The amount of dust generated was measured. The results are shown in Table 1.

[Comparative Example 2]
The air pressure of the compressed air was 0.0 MPa, that is, spraying was performed in the same manner as in Example 1 except that the compressed air was not used, and the amount of dust generated was measured. The results are shown in Table 1.

[Comparative Example 3]
The angle θ formed by the central axis of the agglomerating material discharged from the agglomerating material injection nozzle with respect to the central axis of the granular fiber pumping pipe, that is, the linear ejection of the central axis of the granular fiber pumping pipe and the agglomerating material injection nozzle 14. Spraying was performed in the same manner as in Example 1 except that a granular fiber spraying nozzle (No. 5 spraying nozzle, number of agglomerating material spraying nozzles 14: 8) having an angle θ formed by the holes 15 of 40 ° was used. , The amount of dust generated was measured. The results are shown in Table 1.

[Comparative Example 4]
Spraying was performed in the same manner as in Example 1 except that the air pressure of the compressed air was set to 3.0 MPa, and the amount of dust generated was measured. The results are shown in Table 1.

In all of the test-level products according to the examples of the present invention, the generation of dust was sufficiently suppressed and the amount of dust was small. In particular, the angle θ formed by the central axis of the aggregate material ejected and discharged from the aggregate material injection nozzle with respect to the central axis of the granular fiber pressure feed pipe, that is, the central axis of the granular fiber pressure feed pipe and the aggregate material injection nozzle 14. Using a granular fiber blowing nozzle with an angle θ formed by the linear ejection holes 15 of 6 ° to 10 ° and setting the air pressure of the compressed air to 0.2 to 1.0 MPa, the generation of dust is particularly small, and comparison is made. The amount of dust was suppressed to 60% or less as compared with Example 2.

INDUSTRIAL APPLICABILITY The present invention can be suitably used for sprayed rock wool and the like, and can be constructed while suppressing dust generated in a fiber layer composed of granular fibers and cement hydrate, and is a fire-resistant coated structure and a non-combustible structure. Alternatively, it can be suitably used for constructing a heat insulating structure.

1 Granular fiber spray nozzle 2 Granular fiber pressure feeder 3 Discharge port 4 Aggregate jet 5 Granular fiber jet 6 Compressor (pneumatic feeder)
7 Pump 8 Coagulant storage tank 9 Material hose 10 Cotton crusher 11 Blended cotton 12 Blower 13 Coagulant 14 Coagulant injection nozzle 15 Ejection hole 16 Aggregate material ejected from the agglomerate injection nozzle Central axis 17 Center of granular fiber pumping pipe Shaft 18 Angle θ between the central axis of the granular fiber pumping pipe and the central axis of the agglomerating material discharged from the agglomerating material injection nozzle.
19 Pressure-resistant hose attachment part for compressed air 20 Granular fiber spraying device 21 Pressure-resistant hose attachment part for agglomerating material 22 Intersection

Claims (3)

Equipped with a granular fiber spray nozzle, a granular fiber transport device, a flocculant transport device, and a pneumatic feed device.
The granular fiber spraying nozzle is provided with a plurality of coagulant injection nozzles around the granular fiber pumping pipe and the discharge port of the granular fiber pumping pipe, and is discharged from the coagulant injection nozzle with respect to the central axis of the granular fiber pumping pipe. The angle θ formed by the central axis of the aggregate is within the range of 4 to 10 °.
The pressure of the compressed air that the agglomerate injection nozzle communicates with the agglomerate transport device and the air pressure feeding device and is pressure-fed from the air pressure feeding device to the agglomerating material injection nozzle is 0.2 to 1 MPa.
The granular fibers transported by the granular fiber transport device and discharged from the granular fiber spray nozzle are a dry mixture with cement.
A granular fiber spraying device in which a granular fiber transport device and a granular fiber pumping pipe communicate with each other. The granular fiber spraying apparatus according to claim 1, wherein the angle θ is in the range of 6 to 10 °. The granular fiber discharged from the discharge port of the granular fiber pumping pipe by the granular fiber spraying device according to claim 1 or 2, and the aggregate discharged with compressed air of 0.1 to 1 MPa from the aggregate injection nozzle. A method for spraying granular fibers, wherein the granular fibers are a dry mixture with cement, which is characterized by merging and mixing and spraying the fibers onto a structure .

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