JP2021147903A - Fiber composition spraying method - Google Patents

Abstract

To provide a technique to allow for estimating that absolute dry bulk density of a fiber layer to be formed is within a predetermined range during construction and a technique to make the absolute dry bulk density of the fiber layer formed by construction fall within a predetermined range in a fiber composition spraying method by a dry construction method or semi-dry construction method.SOLUTION: In a fiber composition spraying method, fiber or fiber dry composition of a predetermined amount is supplied into a fiber pressure feed passage; the fiber or the fiber dry composition is air-pumped by supplying a predetermined amount of air into the fiber pressure feed passage using an air blower and subsequently discharged from a fiber discharge port; a liquid additive is injected from one or a plurality of liquid additive injection ports provided either on an outer periphery or inside of the fiber discharge port or in the fiber pressure feed passage within 1 m from the fiber discharge port so as to spray a merged and mixed material obtained by merging and mixing the fiber or the fiber dry composition and the liquid additive to a coating object. The merged and mixed material is sprayed while checking the pressure in the fiber pressure feed passage during air pumping of the fiber or the fiber dry composition.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for spraying a fiber composition.

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 a coagulant containing water as a main component is often used. As the rock wool spraying method, a wet method, a dry method, and a semi-dry method are known.

The wet method uses a coating material for spraying, which is a mixture of a main material (rock wool granular fiber or cement) and an auxiliary material (surfactant or thickener), and water is added to this and kneaded with a mixer. This is a method of blowing an object from a nozzle with compressed air.

In the dry method, a dry mixture (dry mixture, hereinafter also referred to as "rock wool / cement mixed cotton" or "blended cotton"), which is a dry mixture of rock wool granular fibers and cement, is used as a rock wool sprayer (rock). A rotary feeder, etc., which is put into a cotton-spraying machine called a cotton sprayer) or a cotton-melting machine, is unwound by a built-in rotary cutter, a rotary rod, or the like, and is built in the cotton-melting device. Quantitatively sent into the pumping path, pumped in the hose by a blower (blower), discharged from the spray nozzle, and at the same time, a plurality of fountain ports or / and the center of the spray nozzle arranged on the periphery of the spray nozzle. This is a construction method in which pressure water is injected from one fountain port located near the shaft, and both are merged, mixed and sprayed.

The semi-dry construction method is a construction method in which rock wool granular fibers and cement are not mixed in advance. In the semi-dry method, the rock wool granular fibers are put into the cotton-melting device in the same manner as the mixed cotton in the dry method, and are finely granulated by the built-in rotary cutter, rotary rod, or other unpacking part (finely granular (several mm in diameter ~). It is made into a fiber mass of about several cm), quantitatively sent out into the pumping path by the rotary feeder built in the cotton-melting device, etc., pumped into the hose by a blower (blower), and supplied to the spray nozzle. NS. Cement is mixed with water by a mixer to form a cement slurry, and then a spray nozzle for liquid materials (for cement slurry) placed in a granular fiber spray nozzle through a transport pipe (cement slurry pumping hose) by a slurry pump. Is supplied to. The cement slurry is sprayed from a liquid material (for cement slurry) spray nozzle arranged on the periphery of the granular fiber spray nozzle, or for a liquid material arranged near the central axis of the granular fiber spray nozzle (for liquid material). (For cement slurry) It is sprayed from a spray nozzle and merges and mixes with rock wool to form a fiber layer consisting of rock wool and cement hydrate. According to the semi-dry method, a coating layer having a bulk density close to that of the dry method can be formed with less floating dust. For these reasons, the semi-dry method has become the mainstream of the rock wool spraying method (see, for example, Patent Document 1 (pages 2 and 3), Patent Document 2 (Fig. 4) and Non-Patent Document 1). ).

Since the dry method and the semi-dry method have a longer pumping distance than the wet method, even at a wide construction site or a construction site with multiple floors, the equipment and materials used for mixing such as mixers can be sprayed. There is no need to move it many times and it does not take time. Further, in the dry method and the semi-dry method, the bulk density of the coating layer (sprayed rock wool layer) formed by the rock wool spraying method can be reduced as compared with the wet method. As a result, the dry method and the semi-dry method are generally performed as compared with the wet method.

JP-A-2002-348978 Japanese Unexamined Patent Publication No. 07-166618

"Fireproof coating work" [online], First Built Co., Ltd., [Searched on January 20, 2020], Internet <URL: http://www.firstb.co.jp/fireproofing_01.html>

However, in the dry method and the semi-dry method, the absolute dry bulk density of the formed fiber layer may fluctuate. If the absolute dry bulk density is out of the permissible range, the desired performance such as fire resistance, fire resistance, sound absorption and / or heat insulation may not be obtained. In the worst case, the applied fiber layer may be removed and re-applied.

On the other hand, immediately after the formation of the fiber layer, a large amount of water is contained, and the defect related to the absolute dry bulk density can be known only after the predetermined time has passed and the product has been dried. Therefore, the psychological burden is heavy for the builder during construction.

The present invention solves the above-mentioned problems, and in the method of spraying a fiber composition by a dry method or a semi-dry method, the absolute dry bulk density of the fiber layer to be formed is within a predetermined range during construction. The purpose is to provide a technique that can be estimated.

The present invention solves the above-mentioned problems, and provides a technique in which the absolute dry bulk density of the fiber layer formed by construction is within a predetermined range in a method of spraying a fiber composition by a dry method or a semi-dry method. The purpose is to do.

The present invention that solves the above problems is a method for spraying a fiber composition. A predetermined amount of the fiber or the fiber drying composition is supplied into the fiber pumping path, and a predetermined amount of air is supplied into the fiber pumping path using a blower to pneumatically feed the fiber or the fiber drying composition and then discharged from the fiber discharge port. Then, the liquid additive is injected from the outer circumference or the inside of the fiber discharge port, or from the injection port for one or more liquid additives provided in the fiber pumping path within 1 m from the fiber discharge port. A method for spraying a fiber composition in which a combined mixture of the above-mentioned fiber or fiber drying composition and a liquid additive is sprayed onto a covering object, wherein the fiber or the fiber at the time of pneumatic feeding of the fiber drying composition is used. The above-mentioned confluence mixture is sprayed while checking the pressure in the pumping path. In order to determine whether the absolute dry bulk density of the fiber composition after spraying is appropriate, the above-mentioned confluence mixture may be sprayed while checking the pressure in the fiber pumping path during air pumping of the fiber or the fiber drying composition. preferable.

By confirming that there is no pressure fluctuation, it can be estimated during construction that no trouble has occurred, that is, the absolute dry bulk density of the fiber composition after spraying is appropriate. In addition, the absolute dry bulk density of the fiber composition after spraying is appropriate. The absolute dry bulk density in the present invention is the bulk density when dried in a dryer at 105 ° C. until the volume becomes constant.

In the present invention, preferably, in the test construction, the allowable pressure range in the fiber pumping path at the time of pneumatic feeding of the fiber or the fiber drying composition is set so that the absolute dry bulk density of the fiber composition after spraying is within the allowable range. In this construction, the merging mixture is sprayed while confirming that the pressure in the fiber pumping path at the time of pneumatic feeding of the fiber or the fiber drying composition is within the allowable pressure range.

As a result, it can be estimated during construction that the absolute dry bulk density of the fiber composition after spraying is within the permissible range. In addition, the absolute dry bulk density of the fiber composition after spraying is within the permissible range.

In the present invention, preferably, in the above confirmation, when the pressure in the fiber pumping path deviates from the allowable pressure range, the supply amount of the fiber or the fiber drying composition into the fiber pumping path is adjusted and the fiber pumping is performed. After confirming that the pressure in the path is within the allowable pressure range, continue spraying.

As a result, it is possible to estimate the occurrence of defects during construction, and it is possible to eliminate the defects by adjusting the supply amount. At this time, it is not necessary to interrupt the spraying.

In the present invention, preferably, in the above confirmation, when the pressure in the fiber pumping path deviates from the allowable pressure range, the amount of air blown by the fiber or the fiber drying composition into the fiber pumping path is adjusted and the fiber pumping is performed. After confirming that the pressure in the path is within the allowable pressure range, continue spraying.

As a result, it is possible to estimate the occurrence of a defect during construction, and the defect can be resolved by adjusting the amount of air blown. At this time, it is not necessary to interrupt the spraying.

In the present invention, preferably, in the above adjustment, the pumping amount of the liquid additive per unit time becomes a predetermined ratio with the supply amount of the fiber or the fiber drying composition into the fiber pumping path per unit time. To.

As a result, the quality becomes predetermined.

According to the dry method or the semi-dry method of spraying the fiber composition according to the present invention, it can be estimated during construction that the absolute dry bulk density of the formed fiber layer is within a predetermined range. As a result, the psychological burden on the builder during construction is reduced.

Further, even if a defect occurs, it is easy to estimate the location where the defect occurs. Furthermore, it becomes easy to deal with defects.

According to the dry method or the semi-dry method of spraying the fiber composition according to the present invention, the absolute dry bulk density of the fiber layer formed by the construction is within a predetermined range. As a result, desired performances such as fire resistance, fire resistance, sound absorption and / or heat insulation can be obtained.

This is an example of the spraying system used in this method. It is a figure which shows the relationship between the hose pressure and the absolute dry bulk density when the wind speed is changed. It is a figure which shows the relationship between the hose pressure and the absolute dry bulk density when the supply amount is changed.

~ System outline / basic operation ~
FIG. 1 is an example of a spraying system used in this method. A commonly used spraying system is used. The semi-dry construction method will be explained as an example, and items related to the dry construction method will be inserted as appropriate.

The spraying system 10 includes a cotton removing machine 20, a blower 14, a fiber pressure feeding hose 9, a liquid additive pressure feeding pump 7, a liquid additive pressure feeding hose 6, and a granular fiber spraying nozzle 1.

The cotton-melting machine 20 includes a first cotton-melting unit 21, a second cotton-melting unit 22, a hopper 23, a screw feeder 24, a rotary feeder (quantitative supply device) 25, and a fiber pumping pipe 26.

The pack-shaped fiber 11 is opened and put into the hopper 23. The fiber 11 is supplied to the inside while being crushed by the first thawing part 21, is conveyed by the screw feeder 24, is finely divided by the second thawing part 22, and is a predetermined amount by the rotary feeder 25 based on an external supply amount command. Fibers are supplied to the fiber pumping pipe 26. The fiber pumping pipe 26 is inserted between the blower 14 and the fiber pumping hose 9.

The fibers supplied to the fiber pressure feeding pipe 26 are pressure-fed in the hose 9 by the blower (blower) 14, conveyed to the granular fiber blowing nozzle 1, and discharged from the discharge port. The blower 14 can have a predetermined wind speed based on an external wind speed command.

The granular fiber spray nozzle 1 has one or more injection ports 3 for liquid additives arranged near the center of the discharge port (near the central axis of the spray nozzle) and / or on the periphery of the discharge port.

The liquid additive 4 is stored in the liquid additive storage tank 8. When the liquid additive 4 is in the form of a slurry such as cement slurry, a dispersion medium (for example, water) and a dispersoid (for example, cement) are mixed, and a stirrer is placed in the liquid additive storage tank 8. May be set and stirred. The liquid additive 4 (for example, cement slurry) is injected from the injection port 3 by the liquid additive pump 7 through the liquid additive pump hose 6.

The granular fiber 5 discharged from the granular fiber spray nozzle 1 and the cement slurry 4 ejected from the injection port for the liquid additive are merged and mixed at the tip of the granular fiber spray nozzle 1, and then the surface of the object to be coated 13 is surfaced. A fiber layer 12 is formed by coating and consisting of a confluent mixture. Immediately after spraying, the fiber layer 12 contains a large amount of water and dries after a lapse of a predetermined time.

In the dry method, a fiber drying composition (mixed cotton) in which fibers and cement or the like are mixed is discharged instead of fibers, and water is sprayed instead of cement slurry. A confluence mixture is formed at the tip of the granular fiber spray nozzle 1.

Examples of the fiber include inorganic fiber, organic fiber, and a mixture of inorganic fiber and organic fiber. Examples of the inorganic fiber include metal fiber, rock wool, glass wool, ceramic wool and the like, and examples of the organic fiber include synthetic fiber such as cellulose fiber, jute fiber, polypropylene fiber and polyvinyl alcohol fiber. Cotton-like inorganic fibers selected from rock wool, glass wool, ceramic wool and the like are preferable in terms of durability, sound absorption or heat insulation, and even when rock wool or ceramic wool is exposed to 800 ° C. or higher, the shape is maintained without melting. It is more preferable because it can be formed and is excellent in heat resistance or fire resistance.

Here, 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 produced from a material mainly composed of blast furnace slag is also included.

The rock wool is preferably granular rock wool (granular cotton) obtained by finely dividing raw cotton obtained by collecting fibrous mineral fibers with a decotering machine or the like. When raw cotton is used, it is finely divided by a cotton crusher or the like before transportation. Granular rock wool is obtained through 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, it is difficult for heat to be transferred to the base (covered object) coated with rock wool. As the granular fiber, a dry mixture of granular rock wool and cement (rock wool / cement mixed cotton) can also be used, and in this case as well, it is preferable because the fiber layer to be formed easily obtains fire resistance or nonflammability. As the mineral fiber, glass wool produced from waste glass or the like can also be used in the same manner as rock wool.

The fiber drying composition is a dry mixture of one or more of the above fibers and an inorganic powder and / or an organic powder, or an amount added to the mixture or the above fibers in a range that does not form a slurry or a clay (generally). A liquid of 20% by mass or less) may be added. Examples of the inorganic powder include fly ash, silica fume, blast furnace slag powder, stone powder, expansion material for concrete, admixture for inorganic powdered cement such as quick-setting admixture, cement such as Portoland cement and alumina cement, alkali silicate powder, and slaked lime. One or more selected from hydroxide powders such as sodium hydroxide and sodium hydroxide are preferable examples, and examples of the organic powder include a powdered cement dispersant containing a powdery high-performance water reducing agent and a re-emulsified type. Preferred examples include one or more selected from admixture materials for cement containing powdered organic substances as main components such as powdered resin and cellulose-based thickener, or similar materials. Examples of the liquid that can be contained in the fiber drying composition include a liquid cement dispersant containing a liquid high-performance water reducing agent, a liquid shrinkage reducing agent, an admixture for liquid cement such as a resin emulsion, and a dustproof oil composed of mineral oil. , Water and the like are preferred examples.

Examples of the liquid additive include water, an aqueous solution, an inorganic slurry, a resin emulsion, an inorganic-containing resin emulsion (resin-containing inorganic slurry), and a mixture of two or more of these. More preferable examples include water, aqueous solution, water-hard inorganic powder slurry consisting of water-hard inorganic powder such as cement and blast furnace slag powder and water or aqueous solution, and Al ₂ O ₃ , CaO and / or SiO such as cement and blast furnace slag powder. _{Examples thereof include a slurry containing an inorganic powder containing 2} in the composition, an alkali silicate and water, a resin emulsion (polymer), and a cement-containing resin emulsion (resin-containing cement slurry). Examples of the resin emulsion used for the liquid additive include emulsions of synthetic rubber (for example, styrene / butadiene copolymer, chloroprene rubber, acrylonitrile / butadiene copolymer, methyl methacrylate / butadiene copolymer, etc.), and natural rubber. Emulsion, synthetic resin (eg, polyolefin (eg, polyethylene, polypropylene, etc.), polychloropyrene, polyacrylic acid ester, styrene / acrylic copolymer, all-acrylic copolymer, vinyl acetate resin (eg, polyvinyl acetate, acetate) Vinyl / acrylic copolymer, vinyl acetate / acrylic acid ester copolymer, modified vinyl acetate, ethylene / vinyl acetate copolymer, ethylene / vinyl acetate / vinyl chloride copolymer, vinyl acetate vinyl versate copolymer, acrylic -Emulsion of vinyl acetate, beova (trade name of t-vinyl decanoate) copolymer, etc.), unsaturated polyester resin, polyurethane resin, alkyd resin, epoxy resin, etc., bituminous material (for example, asphalt, rubber asphalt, etc.) ) Emulsion can be mentioned. The liquid additive is expected to play a role as an aggregating material for aggregating granular fibers due to the viscosity of the liquid additive itself. Therefore, in the case of the semi-dry method, a water-hard inorganic powder slurry such as a cement slurry, _{an inorganic powder containing Al 2} O ₃ , Ca O and / or SiO ₂ in the composition, a slurry containing alkali silicate and water, and a resin emulsion (Polymer) and cement-containing resin emulsion (resin-containing cement slurry) are particularly preferred. This is because the granular fibers are more firmly bonded to each other by curing and / or evaporation of the dispersion medium. Further, in the case of the dry method, water or an aqueous solution is particularly preferable.

~ Characteristic composition ~
The spraying system 10 includes a pressure gauge 2 as a characteristic configuration. The pressure gauge 2 is mounted on the fiber pumping path. Here, the fiber pumping path means the distance from the fiber pumping pipe 26 through the fiber pumping hose 9 to the granular fiber spraying nozzle 1. The method of the pressure gauge is not particularly limited as long as the pressure in the fiber pumping path during pneumatic feeding can be measured.

It is preferable that the pressure gauge 2 is provided on the upstream side (closer to the cotton thawing machine 20) of the fiber pumping path as much as possible. As a result, the effect of pressure loss can be almost ignored, and the effect of the occurrence of defects in the fiber pumping path appears as pressure fluctuation.

Specifically, it is preferably within 10 m from the fiber pumping pipe 26 supply point, and more preferably within 5 m from the supply point.

During the spraying work by the spraying system 10, the pressure measurement by the pressure gauge 2 is continued. Other than that, it is the same as the general operation of the spraying system 10.

~Test results~
In the process leading to the invention of the present application, the inventor of the present application conducted the following spray test and obtained the following findings.

Using rock wool granular cotton (trade name "Pacific Mineral Fiber Granular Cotton", manufactured by Taiheiyo Materials Co., Ltd.) as the fiber, and an inorganic slurry mixed with blast furnace slag fine powder, sodium silicate aqueous solution and water as the liquid additive, outline in FIG. Using the spraying system shown in the figure, a spraying test was conducted under the conditions shown in Table 1, and the pressure (hose pressure) in the fiber pumping hose and the discharge time of rock wool granular cotton at that time were measured and sprayed. The absolute dry bulk density of the fiber layer (layer composed of the fiber composition after spraying) formed by the above was measured. Each measurement method was as follows.

-Hose pressure A steel pipe equipped with a pressure gauge was sandwiched between the fiber pressure feeding hose and the fiber pressure feeding pipe of the cotton cutter, and the pressure inside the steel pipe was measured and used as the hose pressure. For the hose pressure, the pressure (N) when only air was sent and the pressure (T) when the rock wool granular cotton was pneumatically fed, that is, during transportation were measured. The position of the pressure gauge was set within 5 m (about 1 m) from the supply point of the rock wool granular cotton into the fiber pumping path.

・ Discharge time of rock wool granular cotton After stopping the rotation of the rotary feeder of the cotton remover, that is, stopping the supply of rock wool granular cotton to the fiber pumping pipe, the discharge of rock wool granular cotton from the fiber pumping path is completed. The time required for the production was measured and used as the discharge time t of rock wool granular cotton. The value obtained by dividing the length (hose length) L of the fiber pumping hose by the discharge time t was defined as the transport speed S.
S = L / t ... (1)

Absolute Dry Bulk Density A part of the formed fiber layer was cut out and dried in a dryer at 105 ° C. until it became constant, and the mass M and volume V at that time were measured, and the absolute dry bulk density ρ was calculated by the following formula.
ρ = M / V ・ ・ ・ ・ ・ (2)

・ Discharge amount of rock wool granular cotton Remove the fiber pumping hose from the spray nozzle, attach a hemp bag to the hose tip of the fiber pumping hose, blow out only rock wool granular cotton for 30 seconds, and the material that entered the hemp bag at that time. Was measured. When only rock wool granular cotton is discharged, the supply amount per hour and the discharge amount per hour shall be substantially the same. The supply amount can be set based on an external supply amount command.

・ Discharge amount of inorganic slurry With the tip of the fiber discharge port of the spray nozzle in the container without removing the hose for pumping the liquid additive from the spray nozzle, that is, the tip of the injection port for the liquid additive The inorganic slurry was discharged for 30 seconds while facing the inside of the container, and the mass of the inorganic slurry accumulated in the container at that time was measured.

・ Wind speed (wind speed when only air is sent)
The spray nozzle was removed from the fiber pumping hose, the mixed cotton was blown without being supplied to the fiber pumping pipe, and the wind speed was measured with an anemometer at the hose tip of the fiber pumping hose. The wind speed can be set based on an external wind speed command. The amount of air blown is the product of the cross-sectional area of the path and the wind speed. The wind speed can be adjusted by adjusting the amount of air blown.

The test results are shown in Table 1 and also in FIGS. 2 and 3. Symbol: RW means rock wool granular cotton, symbol SL means inorganic slurry. In addition, in Table 1, the test No. The same number represents the same test result.

FIG. 2 shows the test No. 3 and test No. This is a comparison with 4. The relationship between the hose pressure T and the absolute dry bulk density ρ when the hose length (80 m) and the discharge amount (2.7 kg / 30 s) are the same and the wind speed is changed is shown.

When the wind speed is increased from 25 m / s to 35 m / s, the hose pressure T increases from 39 kPa to 53 kPa, and the absolute dry bulk density ρ increases ^{from 0.179 g / cm 3} to 0.202 g / cm ³ .

That is, it is considered that as the wind speed increases, the transport speed also increases, the confluent mixture is vigorously sprayed onto the surface of the object to be coated so as to be crushed, and the absolute dry bulk density also increases. At this time, the hose pressure T also fluctuates. A similar tendency is observed in Test No. 1 and test No. It can also be seen in comparison with 2 (hose length 40 m, discharge rate 2.4 kg / 30 s).

FIG. 3 shows the test No. 6 and test No. 4 and test No. This is a comparison with 7. The relationship between the hose pressure T and the absolute dry bulk density ρ when the hose length (80 m) and the wind speed (35 m / s) are the same and the supply amount (discharge amount) is changed is shown.

When the supply amount is increased from 1.4 kg / 30s → 2.7 kg / 30s → 3.5 kg / 30s, the hose pressure T increases from 47 kPa → 53 kPa → 55 kPa, and the absolute dry bulk density ρ increases from 0.214 g / cm ³ → 0. .202 g / cm ³ → Decreases to 0.187 g / cm ³ .

That is, it is considered that as the supply amount increases, the transport speed decreases, the confluent mixture is sprayed on the surface of the object to be coated without momentum and crushing, and the absolute dry bulk density also decreases. At this time, the hose pressure T also fluctuates. A similar tendency is observed in Test No. 2 and test No. It can also be seen in comparison with 5 (hose length 40 m, wind speed 35 m / s).

As a result, if the hose pressure T is within a predetermined range, it is presumed that the absolute dry bulk density ρ is also within a predetermined range. Therefore, if the permissible range of the absolute dry bulk density ρ is set, the permissible range of the hose pressure T can be set.

Further, the hose pressure T can be adjusted by adjusting the wind speed or / the supply amount. If the hose pressure T is out of the permissible range, the hose pressure T can be set within the permissible range by adjusting the wind speed or / the supply amount.

~System operation~
The system operation based on the above knowledge will be described. The system operation consists of test construction and main construction. It is preferable that the spraying system used in the test construction and the spraying system used in the main construction are the same, but a system simulating the spraying system used in the main construction may be used in the test construction. That is, the hose length is the same. If the hose lengths are unavoidably different, find the correction coefficient based on the hose lengths.

-Test construction First, set the allowable range of absolute dry bulk density of the fiber composition after spraying. Then, in the test construction, the allowable pressure range in the fiber pumping path corresponding to the allowable range of the absolute dry bulk density is grasped. For each length of the fiber pumping path, the relationship between the absolute dry bulk density and the pressure in the fiber pumping path is recorded by a conversion table, a relational expression, a graph, or the like.

Also record the wind speed during the test construction. The wind speed in the test construction may be an actually measured value or a set value of the blower.

An example of test construction will be described. The permissible range of absolute dry bulk density is set ^{to 0.20 to 0.21 g / cm 3.} A test construction will be conducted with a hose length of 80 m and a wind speed of 35 m / s. As a result, a graph similar to that in FIG. 3 is created, and it is understood that the allowable pressure range in the path is 50 to 54 kPa.

・ Main construction In this construction, the confluent mixture is sprayed in the same way as general spraying. As described above, the hose length in this construction is the same as the hose length in the test construction. Set the same wind speed as the wind speed during the test construction and the same supply amount as the supply amount during the test construction. Further, during the spraying operation, it is confirmed that the pressure in the fiber pumping path is within the allowable pressure range.

If it is confirmed that the absolute dry bulk density is within the allowable range in the test construction and the main construction is performed under the same conditions as the test construction, the absolute dry bulk density in the main construction is also within the allowable range unless an unexpected problem occurs. It is presumed.

By confirming that the pressure in the fiber pumping path is within the allowable pressure range during the spraying work, it can be inferred that no problem has occurred.

This construction example will be described. The hose length in this construction is 80 m. With reference to the results of the test construction, the wind speed is set to 35 m / s and the supply amount is set to 2.7 kg / 30 s. If this work is carried out under these conditions, it is estimated that ^{the absolute dry bulk density after spraying will be 0.202 g / cm 3 unless a problem occurs.}

By confirming that the pressure in the fiber pumping path is at 50 to 54 kPa during the spraying work, it can be inferred that no problem has occurred.

・ Adjustment As described above, if it is confirmed that the absolute dry bulk density is within the allowable range in the test construction and the main construction is performed under the same conditions as the test construction, the absolute dry bulk density in the main construction will also be as long as no problems occur. It is presumed to be within the permissible range. However, in reality, unexpected problems may occur. In the present application, it is possible to infer the occurrence of a defect by confirming that the pressure in the fiber pumping path is out of the allowable pressure range during the spraying work, and the appropriate absolute dry bulk density can be obtained by the following simple adjustment. Can be maintained.

Adjustment example 1 (wind speed adjustment)
If the pressure in the fiber pumping path is below the permissible pressure range, the wind speed is increased based on the wind speed command from the outside. This increases the pressure in the fiber pumping path. If the pressure in the fiber pumping path exceeds the permissible pressure range, the wind speed is reduced based on the wind speed command from the outside. This reduces the pressure in the fiber pumping path. After adjustment, confirm that it is within the allowable pressure range and continue construction. As a method of lowering the wind speed based on an external wind speed command, for example, a method of adjusting the rotation speed of the motor built in the blower with a setting dial or a setting panel for adjusting the rotation speed of the motor. , Sends an electrical command to lower the rotation speed of the motor built into the blower to the control device that controls the rotation speed of the motor built into the blower, and based on the electrical command, the rotation speed of the motor built into the blower is set. Methods of lowering can be exemplified, and these are preferable.

For example, in the above construction example, when the hose length is 80 m, the wind speed is set to 35 m / s, and the supply amount is set to 2.7 kg / 30 s, but the pressure in the fiber pumping path is 56 kPa, 54 kPa. Decrease the wind speed until it becomes as follows (see Fig. 2).

Adjustment example 2 (Supply amount adjustment)
If the pressure in the fiber pumping path is below the permissible pressure range, the supply amount is increased based on the supply amount command from the outside. This increases the pressure in the fiber pumping path. If the pressure in the fiber pumping path exceeds the permissible pressure range, the supply amount is reduced based on the supply amount command from the outside. This reduces the pressure in the fiber pumping path. After adjustment, confirm that it is within the allowable pressure range and continue construction. As a method of reducing the supply amount based on the supply amount command from the outside, for example, the rotation speed of the rotary feeder rotation motor and / or the screw feeder rotation motor built in the cotton cutter is reduced. How to adjust with the setting dial for adjusting the rotation speed of the motor, the setting panel, etc. The method of adjusting with the setting panel, etc., the rotation of the rotary feeder built into the cotton cutter, the motor for screw feeder rotation, and / or the rotation of the motor to lower the rotation speed of the motor for the cotton remover. A method of sending the number to a control device controlling the number and lowering the number of rotations of the motor based on the electric command thereof can be exemplified, and these are preferable.

For example, in the above construction example, when the hose length is 80 m, the wind speed is set to 35 m / s, and the supply amount is set to 2.7 kg / 30 s, but the pressure in the fiber pumping path is 48 kPa, it is 50 kPa. Increase the supply until the above is reached (see Fig. 3).

Adjustment example 3 (Wind speed and supply amount adjustment)
The wind speed may be adjusted as in Adjustment Example 1, or the supply amount may be adjusted as in Adjustment Example 2. In addition, both wind speed and supply may be adjusted.

Adjustment example 4 (amount of liquid additive)
When the supply amount per unit time changes due to the above adjustment, the amount of liquid additive per unit time is also adjusted in response to the change in the supply amount so that the confluent mixture maintains a predetermined composition ratio. May be good. The amount of pumping of the liquid additive per unit time can be adjusted by adjusting the pump for pumping the liquid additive.

Adjustment example 5 (post-correction)
As described above, in the present application, it is possible to infer the occurrence of a defect by confirming that the pressure in the fiber pumping path is out of the allowable pressure range during the spraying work. On the other hand, the defect is often temporary, and when the pressure in the fiber pumping path returns to the allowable pressure range, the construction is continued without any adjustment.

It is also possible to record the spraying location that was constructed when a defect was suspected and correct only that location after the spraying was completed.

For example, in the above construction example, if the pressure in the fiber pumping path is temporarily 56 kPa, the absolute dry bulk density at the sprayed portion may fall below the permissible range (see FIG. 3). By compacting the fiber layer with a trowel presser, an appropriate absolute dry bulk density can be obtained.

If a simple correction cannot be applied, remove only the fiber layer at the sprayed location and reconstruct. The work load is less than when the entire surface is reconstructed.

Adjustment example 6 (temporary suspension of construction)
If the above simple correction cannot be used, the construction will be suspended when it is estimated that a problem will occur, and after confirming that the supply amount is as specified by the supply amount command and that the wind speed is as specified as the wind speed command, then Resume construction. The work load is less than when the entire surface is reconstructed.

~ System operation modification example 1 ~
Immediately after the formation of the fiber layer, a large amount of water is contained, and the defect related to the absolute dry bulk density can be known only after drying with a dryer so as to have a constant amount at 105 ° C. In addition, the measurement of wind speed and the measurement of the supply amount of rock wool granular fiber (or mixed cotton) cannot be measured during spraying work. On the other hand, in the above, based on the test construction result, the occurrence (non-occurrence) of a defect is estimated by monitoring the pressure in the fiber pumping path during the spraying construction.

However, the basis of the above estimation is the test construction result, and the spraying system in the main construction cannot always be reproduced in exactly the same way in the test construction.

On the other hand, immediately before the main construction, the absolute dry bulk density cannot be confirmed on a trial basis, but the bulk density of the confluent mixture (bulk density before drying) can be confirmed on a trial basis. Therefore, the estimation accuracy may be improved by using the test results immediately before the main construction together. Hereinafter, a modified example will be described.

First, in the test construction, in addition to the relationship between the absolute dry bulk density and the pressure in the fiber pumping path, the relationship with the bulk density of the confluent mixture (bulk density before drying) is also memorized.

Then, immediately before the main construction, the relationship between the bulk density of the confluent mixture (bulk density before drying) and the pressure in the fiber pumping path is confirmed.

The relationship between the bulk density of the merging mixture (bulk density before drying) and the pressure in the fiber pumping path in the test construction is the bulk density of the merging mixture (bulk density before drying) and the pressure in the fiber pumping path immediately before the main construction. If it can be confirmed that the relationship is reproduced as the above, the relationship between the absolute dry bulk density and the pressure in the fiber pumping path in the test construction is reproduced as the relationship between the absolute dry bulk density and the pressure in the fiber pumping path in the main construction. There is a high possibility that

This improves the estimation accuracy of the present application.

~ System operation modification example 2-
In the above system operation, it is essential to grasp the allowable pressure range by test construction. However, if the operation stability can be confirmed by repeating the construction, the test construction can be omitted.

By confirming that the pressure in the fiber pumping path does not fluctuate significantly during the spraying work, it can be inferred that no problems have occurred.

~ Guessing the cause of the problem ~
As described above, if it is confirmed that the absolute dry bulk density is within the allowable range in the test construction and the main construction is performed under the same conditions as the test construction, the absolute dry bulk density in the main construction is also within the allowable range unless a problem occurs. It is presumed to be in. However, in reality, unexpected problems may occur. The inventor of the present application examined the cause of the occurrence of the defect.

In the spraying system, mixed cotton or rock wool granular fibers and liquid additives (water or cement slurry) are merged and mixed. At this time, the liquid additive is discharged more stably than the mixed cotton or rock wool granular fiber. Therefore, it is unlikely that a problem will occur in discharging the liquid additive.

The mixed cotton or rock wool granular fibers are supplied by a decotering machine and transported by a blower. The blower excites the airflow and is relatively stable. Therefore, it is unlikely that the wind speed will fluctuate.

In principle, the cotton remover can supply a predetermined amount of mixed cotton or rock wool granular fibers based on an external supply amount command.

By the way, while the air supplied by the liquid additive or the blower is uniform, the mixed cotton or rock wool granular fibers opened from the pack may not be uniform. For example, it may be partially compressed while being packed and managed.

Further, after the raw material is supplied to the cotton crusher, it undergoes a plurality of steps in the crusher until it is crushed and conveyed to the fiber pumping path. Therefore, the inventor of the present application considered that the supply amount of the mixed cotton or rock wool granular fiber may not be stable.

It is possible to actually measure the supply amount of mixed cotton or rock wool granular fibers at the time of test construction or immediately before the main construction. On the other hand, in this construction, it is difficult to actually measure the supply amount of mixed cotton or rock wool granular fibers. Based on the inventor's hypothesis, even if the supply amount is stable during the test construction or immediately before the main construction, the supply amount may become temporarily unstable during the main construction.

The inventor of the present application also examined to estimate the supply amount by measuring the load of the rotary feeder rotating motor of the cotton cutter and the load applied to the rotary shaft of the rotary feeder. However, the mixed cotton or rock wool granular fiber is light, and it is difficult to detect the difference between the load of the motor and the load applied to the rotating shaft of the rotary feeder. That is, it is difficult to detect fluctuations in the supply amount of fibers (rock wool granular fibers) or fiber drying composition (blended cotton) during the present construction.

Fluctuations in the supply amount cause fluctuations in the absolute dry bulk density of the fiber composition after spraying. The problem of absolute dry bulk density cannot be known until a predetermined time has passed after spraying and the product is dried. That is, it is not known during construction. In the worst case, it may be completely removed and reconstructed.

On the other hand, the inventor of the present application has found that the occurrence (non-occurrence) of a defect can be estimated by paying attention to the pressure in the fiber pumping path. The invention of the present application has been conceived through the above-mentioned thinking process.

1 Granular fiber spray nozzle 2 Pressure gauge 3 Injection port for liquid additive 4 Liquid additive 5 Granular fiber 6 Liquid additive pumping hose 7 Liquid additive pump 8 Liquid additive storage tank 9 Fiber pumping hose 10 Spraying system 11 Fiber or fiber drying composition 12 Fiber layer composed of confluent mixture 13 Covered object 14 Blower (blower)
20 Cotton unraveling machine 21 First unraveling part 22 Second unraveling part 23 Hopper 24 Screw feeder 25 Rotary feeder (quantitative feeder)
26 Fiber pumping pipe

Claims (6)

A predetermined amount of the fiber or the fiber drying composition is supplied into the fiber pumping path, and a predetermined amount of air is supplied into the fiber pumping path using a blower to pneumatically feed the fiber or the fiber drying composition and then discharged from the fiber discharge port. Then, the liquid additive is injected from the outer circumference or the inside of the fiber discharge port, or from the injection port for one or more liquid additives provided in the fiber pumping path within 1 m from the fiber discharge port. A method for spraying a fiber composition, wherein the combined mixture of the fiber or the fiber drying composition and the liquid additive is sprayed onto the object to be coated.
A method for spraying a fiber composition, which comprises spraying the confluent mixture while checking the pressure in the fiber pumping path at the time of pneumatic feeding of the fiber or the fiber drying composition. In order to determine whether the absolute dry bulk density of the fiber composition after spraying is appropriate, it is necessary to spray the confluent mixture while checking the pressure in the fiber pumping path during air pumping of the fiber or the fiber dry composition. The method for spraying a fiber composition according to claim 1. In the test construction, the allowable pressure range in the fiber pumping path during air pumping of the fiber or fiber drying composition, in which the absolute dry bulk density of the fiber composition after spraying is within the permissible range, is grasped.
1. 2. The method for spraying the fiber composition according to 2. In the above confirmation, when the pressure in the fiber pumping path deviates from the allowable pressure range, the supply amount of the fiber or the fiber drying composition into the fiber pumping path is adjusted, and the pressure in the fiber pumping path is the above allowable. The method for spraying a fiber composition according to claim 3, wherein the spraying is continued after confirming that the pressure is within the pressure range. In the above confirmation, when the pressure in the fiber pumping path deviates from the allowable pressure range, the amount of air blown by the fiber or the fiber drying composition into the fiber pumping path is adjusted, and the pressure in the fiber pumping path is adjusted as described above. The method for spraying a fiber composition according to claim 3, wherein the spraying is continued after confirming that the pressure is within the pressure range. The above adjustment is characterized in that the pumping amount of the liquid additive per unit time is set to a predetermined ratio with the supply amount of the fiber or the fiber drying composition into the fiber pumping path per unit time. The method for spraying a fiber composition according to claim 4 or 5.

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