Spray nozzle and spray system

Abstract

To provide a spray nozzle capable of reducing rebound and having high spray workability.SOLUTION: A spray nozzle includes: a hose attachment portion to which a hose to which first spray material is supplied can be attached, where the hose attachment portion includes a spray material introduction port having substantially the same diameter as an inner diameter of the hose, and where a spray material flow path is formed from the spray material introduction port to a spray material discharge port of a nozzle tip portion, and in the spray nozzle, ratio (B / A) of an inner diameter (B) of the spray material discharge port to an inner diameter (A) of the spray material introduction port is 0.1 to 0.6.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a spray nozzle and a spray system using the spray nozzle. [Background technology]

[0002] Mortar is mainly used for surface finishing and cross-section repair of existing concrete. Mortar is usually produced by mixing cement, aggregate, and water in a mortar mixer. In the past, the most common application method was to apply the mortar with a trowel, but this required skill, was difficult to apply thickly, and involved a lot of labor. For this reason, the method of spraying the mortar by pumping it is now widely used.

[0003] However, spraying construction can cause rebound of the sprayed mortar, which can reduce workability. Therefore, Patent Document 1 proposes a sprayable cement composition containing a specific blended mortar and emulsion, and a spraying method thereof. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-47755 A Summary of the Invention [Problem to be solved by the invention]

[0005] According to the sprayable cement composition and spraying method described in Patent Document 1, it is possible to prevent the cement mortar from peeling or dripping immediately after spraying, it is possible to increase the thickness of the sprayed cement mortar, it improves the strength development and pumpability, it is possible to significantly reduce rebound and the amount of dust, it shortens the working time, and it is possible to perform a spraying construction for concrete surface finishing and cross-section repair with good workability.

[0006] However, Patent Document 1 achieves rebound reduction and the like by blending a cement composition for spraying, and does not pay particular attention to devices such as spray nozzles. In addition, no evaluation was made under conditions where application is difficult, such as spraying onto a ceiling surface, and where rebound reduction is difficult.

[0007] In view of the above, an object of the present invention is to provide a spray nozzle that can reduce rebound and has high spray workability. [Means for solving the problem]

[0008] As a result of intensive research aimed at solving the above problems, the present inventors have come up with the following invention and found that the above problems can be solved.

[0009] [1] A spray nozzle having a hose attachment portion to which a hose through which a first spray material can be attached, the hose attachment portion having a spray material inlet having approximately the same diameter as the inner diameter of the hose, a spray material flow path formed from the spray material inlet to a spray material outlet at the tip of the nozzle, and a ratio (B / A) of the inner diameter (A) of the spray material inlet to the inner diameter (B) of the spray material outlet is 0.1 to 0.6. [2] The spray nozzle according to [1], wherein at least a portion of the nozzle tip is made of rubber. [3] A spray nozzle as described in [1] or [2], in which a hard tube is provided on the spray material outlet side of the spray material flow path so that the inner diameter of the spray material outlet is reduced. [4] The spray nozzle according to any one of [1] to [3], wherein a mixing section is provided in a spray material flow path to supply a second spray material and mix it with the first spray material. [5] A spraying system including a first conveying means for conveying a first spray material and a spray nozzle for spraying the first spray material onto a part to be sprayed, wherein the spray nozzle is a spray nozzle described in any one of [1] to [3]. [6] A spraying system including a first conveying means for conveying a first spraying material, a second conveying means for conveying a second spraying material, and a spraying nozzle for spraying a mixed spraying material, which is a mixture of the first spraying material conveyed from the first conveying means and the second spraying material conveyed from the second conveying means, onto a part to be sprayed, wherein the spraying nozzle is the spraying nozzle described in [4]. Effect of the Invention

[0010] According to the present invention, it is possible to provide a spray nozzle that can reduce rebound and has high spray workability. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is a diagram showing an example of a spray nozzle according to the present embodiment. [Diagram 2] 6A and 6B are diagrams illustrating another example of a spray nozzle according to the present embodiment. [Diagram 3] FIG. 13 is a diagram showing an example in which a hard tube is provided in the spray nozzle according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, one embodiment of the present invention (hereinafter, may be referred to as "this embodiment") will be described. In this specification, "parts" and "%" are based on mass unless otherwise specified.

[0013] [Spray nozzle] As shown in Figure 1, the spray nozzle 10 of this embodiment has a hose attachment portion 11 to which a hose 20 through which a first spray material is supplied can be attached, and the hose attachment portion 11 has a spray material inlet 12 of approximately the same diameter as the inner diameter Hd of the hose 20, and a spray material flow path 14 is formed from the spray material inlet 12 to a spray material outlet 13 at the tip of the nozzle.

[0014] In this embodiment, the ratio (B / A) of the inner diameter (B) of the spray material discharge port to the inner diameter (A) of the spray material inlet is 0.1 to 0.6, preferably 0.12 to 0.55, and more preferably 0.15 to 0.4.

[0015] If the ratio (B / A) is less than 0.1, blockage of the mortar and a reduction in the amount of discharge will occur, and if it exceeds 0.6, increased rebound of the mortar and dripping of the mortar will occur, resulting in a reduction in adhesive strength.

[0016] At least a part of the nozzle tip of the spray nozzle 10 is preferably made of rubber, and the outer periphery of the tip is preferably made of rubber. By using rubber, the tip can be made flexible and malleable.

[0017] As shown in Fig. 2, the spray nozzle 10 according to this embodiment preferably has a mixing section 15 in the spray material flow path 14, where the second spray material is supplied and mixed with the first spray material. This allows a so-called 1.5 shot to be achieved. The second spray material is usually transported to the mixing section 15 through the material transport pipe 30 together with compressed air supplied from the air supply pipe 40.

[0018] The length from the inlet for the spraying material to the outlet for the spraying material is preferably 150 to 350 mm, and more preferably 180 to 300 mm.

[0019] In addition, the spray nozzle 10 preferably has a tapered portion at its tip end, the cross-sectional area of ​​which gradually decreases overall or in part toward the spray material discharge port 13 . Here, "having a tapered portion that is gradually tapered in part" means that the cross-sectional area gradually decreases from the spray material inlet side and then becomes a straight pipe midway toward the spray material outlet side. 3, it is preferable that a hard pipe 16 is provided on the spray material flow path on the spray material discharge port 13 side so as to reduce the inner diameter of the spray material discharge port 13. By providing a hard pipe, it is possible to discharge mortar in a straight line, and dripping from the discharge port can be minimized.

[0020] Here, the hard pipe 16 is a pipe having a hardness that is not easily deformed by human hands, and examples thereof include metal pipes such as iron, stainless steel, and aluminum, and hard resin pipes such as hard polyvinyl chloride, acrylic resin, AS resin, and ABS resin. Among these, stainless steel, which has excellent strength and corrosion resistance, is preferable.

[0021] The inner diameter of the hard pipe on the side of the spraying material outlet is smaller than the inner diameter of the spraying material outlet, and is preferably 8 to 14 mm, more preferably 10 to 12 mm. The axial length of the hard pipe is preferably 15 to 40 mm, more preferably 18 to 30 mm.

[0022] The shape of the rigid pipe is not particularly limited and may be a straight pipe, but it is preferable to use a shape that takes into consideration the dischargeability of the spray material. For example, it is preferable that the tip side of the rigid pipe 16 in Fig. 3 has a tapered shape in which the cross-sectional area gradually decreases toward the spray material discharge port 13, or a tapered portion in which the cross-sectional area gradually decreases in part, as in the case of the rigid pipe 16 in Fig. 3.

[0023] As long as the structure allows the inside diameter of the spray material discharge port 13 to be small, the shape of the rigid tube is not particularly limited, and shapes other than those mentioned above are also possible.

[0024] [Spray system] The first spraying system of this embodiment includes a first conveying means for conveying a first spraying material, and a spraying nozzle for spraying the first spraying material onto a part to be sprayed, the spraying nozzle being the spraying nozzle of the present invention described above. The first spray system is a so-called one-shot spray system using a nozzle with only one type of spray material.

[0025] In addition, the second spraying system of this embodiment is a spraying system including a first conveying means for conveying a first spraying material, a second conveying means for conveying a second spraying material, and a spraying nozzle for spraying a mixed spraying material, which is a mixture of the first spraying material conveyed from the first conveying means and the second spraying material conveyed from the second conveying means, onto the part to be sprayed, and the spraying nozzle is the spraying nozzle of the present invention described above. The second spray system will be a spray system using a 1.5 shot nozzle.

[0026] Here, the first spraying material may be a mortar composition or a concrete composition containing cement and aggregate. These may contain admixtures such as hardening accelerators, setting retarders, shrinkage reducing agents, short fibers, and fluidizing agents as appropriate. The mortar composition or the concrete composition is mixed with water to become the first spraying material.

[0027] As mixers to be used for mixing, a mortar mixer having a ball with a spherically curved bottom, an omni mixer, a pan-type mixer, a Damacut mixer having a pan-type blade that rotates on its own axis, and a twin-shaft mixer used for mixing concrete can be used.

[0028] The aforementioned cement is not particularly limited, but ordinary cement can be used. Specifically, various Portland cements such as ordinary, early strength, and extra early strength, and various mixed cements in which silica fume, fly ash, blast furnace slag, etc. are mixed with these Portland cements are listed. From the viewpoint of ease of use, ordinary Portland cement is preferred.

[0029] The aggregate has a bone dry specific gravity of 2.0 g / cm 3 The aggregates mentioned above have a maximum particle size of 4 mm or less, and include naturally occurring river sand, crushed stone, and silica sand. The aggregates may be mixed with cement in advance, or may be mixed when mixing the materials on-site. When mixing with cement in advance, dried aggregates are used. The amount of aggregate used is 100 to 300 parts, preferably 150 to 250 parts, per 100 parts of cement.

[0030] The hardening agent is not particularly limited, but calcium aluminate, a material containing calcium aluminate and gypsum, alumina cement, etc. can be used, and among these, a material containing calcium aluminate and gypsum is preferred.

[0031] Calcium aluminate is available in crystalline and amorphous (formless) forms, with the use of amorphous forms being preferred from the standpoint of rapid hardening. Specific examples of calcium aluminate include those having a composition ratio expressed as 3CaO·Al2O3, CaO·Al2O3, and 12CaO·7Al2O3, and those having a composition ratio expressed as 11CaO·7Al2O3·CaF2, 11CaO·7Al2O3·CaCl2, and 3CaO·3Al2O3·CaF2, which are solid solutions of these with halogens. Of these, those having a composition ratio expressed as 12CaO·7Al2O3 are preferred.

[0032] Gypsum includes anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum, which can be used alone or in combination, but anhydrous gypsum, especially type II anhydrous gypsum, is preferred in terms of strength development. When calcium aluminate is used, gypsum normalizes the setting of cement to enhance strength development, and produces a large amount of ettringite to enhance the mechanical strength. The mixing ratio of calcium aluminate and gypsum is usually preferably 50 to 300 parts of gypsum to 100 parts of calcium aluminate.

[0033] The fineness of calcium aluminate and gypsum is 1,000 cm2 in terms of Blaine specific surface area (hereinafter referred to as Blaine value). 2 / g or more is preferable, and 4,000 to 6,000 cm 2 / g is more preferred.

[0034] The amount of the hardening agent made of calcium aluminate and gypsum used is preferably 1 to 15 parts, more preferably 5 to 10 parts, per 100 parts of cement. By using 1 to 15 parts, it becomes easier to develop strength in a short time and ensure an appropriate working time.

[0035] The setting retarder is not particularly limited, but examples thereof include oxycarboxylic acid setting retarders such as citric acid and tartaric acid. By adjusting the amount of the set retarder used, the time until the initial setting of the mortar composition or concrete composition can be adjusted to a desired range. The amount of the set retarder used is preferably 0.1 to 1.0 part per 100 parts of cement.

[0036] The shrinkage reducing agent is not particularly limited, but can be an alkylene oxide adduct or a polyoxyalkylene compound. The amount of shrinkage reducing agent used is preferably 0.1 to 8.0 parts, more preferably 0.5 to 5.0 parts, per 100 parts of cement. By using 0.1 to 8.0 parts, it is easy to obtain a good shrinkage reducing effect and strength.

[0037] Types of short fibers include polymer fibers such as vinylon fibers, polypropylene fibers, and nylon fibers, and inorganic fibers such as steel fibers, glass fibers, and carbon fibers. The length of the short fibers is preferably 12 mm or less, which helps prevent the mortar from clogging the spray nozzle. The amount of short fibers used is preferably 0.05 to 2.0 parts, and more preferably 0.1 to 1.0 parts, based on 100 parts of cement. When the amount is 0.05 to 2.0 parts, good durability is easily obtained.

[0038] The fluidizing agent is not particularly limited, but examples thereof include melamine-based fluidizing agents, naphthalene-based fluidizing agents, lignin-based fluidizing agents, and polycarboxylic acid-based fluidizing agents, and are used to adjust the fluidity of mortar. The amount of the fluidizing agent used is preferably 0.02 to 1.0 part, and more preferably 0.05 to 0.5 part, relative to 100 parts of cement. When the amount is 0.02 to 1.0 part, the effect of improving fluidity is easily exhibited.

[0039] In the mortar composition and concrete composition, the water / cement ratio is preferably 30 to 55%, and more preferably 35 to 45%. By having a ratio of 30 to 55%, sufficient fluidity for pumping can be easily obtained, and material separation is less likely to occur in the hose during pumping.

[0040] In the first spraying system according to this embodiment, the first conveying means includes a known pump and a pressure delivery pipe (e.g., a hose or the like) through which the first spraying material is pressure-delivered. The first spraying material supplied from the first conveying means is sprayed onto the target area from the spray nozzle of the present invention.

[0041] In addition, the second spraying system of this embodiment includes the first conveying means described above and a second conveying means for conveying a second spraying material, and this second spraying material can be a liquid quick-setting agent such as an aqueous aluminum sulfate solution.

[0042] For example, when the liquid quick-setting admixture is an aluminum sulfate aqueous solution, the aluminum sulfate concentration is preferably 15% or more. By having the aluminum sulfate concentration of 15% or more, it is possible to reduce the sagging of the spray material after spraying. As the aluminum sulfate aqueous solution, there is a commercially available product with an aluminum sulfate [Al2(SO4)3] concentration of 26.8 to 27.4%, which can be used well.

[0043] In this embodiment, by further mixing a setting retarder into the aqueous aluminum sulfate solution, it is possible to ensure a workable time after spraying. The setting retarder is not particularly limited, but examples thereof include oxycarboxylic acids such as citric acid and tartaric acid. The mixing ratio of the setting retarder to the aqueous aluminum sulfate solution is preferably 0.1 to 1.0 part per 100 parts of aluminum sulfate from the viewpoints of ensuring workable time and short-time strength development.

[0044] The second conveying means includes a known pump and a pressure delivery pipe (for example, a hose or an air supply pipe) by which the second spray material is pressure-delivered. The first spray material transported from the first conveying means and the second spray material transported from the second conveying means are mixed in the mixing section of the spray nozzle of the present invention to become a mixed spray material, which is sprayed onto the area to be sprayed.

[0045] As the pressure pipe for pressure-feeding the material, a chemical hose, a hose containing a pressure-resistant metal mesh (pressure-resistant hose), or a metal pipe can be used. Usually, a chemical hose or a pressure-resistant hose is used, and it is preferable to use metal pipes before and after it.

[0046] There is no particular limit to the length of the pressure pipe, and the length used varies depending on the construction conditions, but typically a length of 5 to 30 m is used. The diameter of the pressure pipe is usually 1 to 2 inches, taking into consideration the pumping ability and ease of handling the pressure hose.

[0047] In the first and second spraying systems of this embodiment, various locations can be applied as the sprayed area, but since the spray nozzle of the present invention makes it possible to reduce rebound and provides high spraying workability, it can be suitably used in locations including ceiling surfaces, etc. EXAMPLES

[0048] The mortar composition, in which all ingredients except water have been measured, is poured into the mixer, and the measured water is poured in (water / cement ratio: 45%). The mixture is mixed for 2 minutes to prepare the first spray material, which is then dropped into a hopper and sprayed at a rate of 1 m per hour. 3The mixed mortar was pumped by a mortar pump adjusted to discharge the amount of the mixed mortar. The flow value of the first spraying material (mixed mortar) was 190 mm. The mixed mortar was pumped by a mortar pumping pipe, which was a pressure-resistant hose with a diameter of 40 mm and a length of 50 m, to a spray nozzle connected to the mortar pumping pipe.

[0049] Separate air compressor: pressure 4MPa, flow rate 0.8m 3 Compressed air was introduced at a rate of 1 / min, and a 20% concentration aluminum sulfate aqueous solution (special reagent grade aluminum sulfate was dissolved in pure water and adjusted to a concentration of 20%) was pumped using the liquid pump of a plunger pump adjusted to a mixing ratio of 1 part aluminum sulfate per 100 parts of mixed mortar. The aluminum sulfate aqueous solution was pumped into the connected spray nozzle.

[0050] In the mixing section of the spray nozzle, the mixed mortar was mixed with an aqueous aluminum sulfate solution to create a mixed spray material, which was then sprayed onto the ceiling surface of a mock tunnel. The time required from mixing the cement mortar to spraying was five minutes.

[0051] The spray nozzle ratio (B / A) used was as shown in Table 1 (Examples 1 to 3, Comparative Examples 1 and 2). Furthermore, Example 4 was the same as Example 2, except that a hard pipe was provided on the spray material discharge port side of the spray material flow path. The hard pipe was made of stainless steel, the inside diameter of the hard pipe on the spray material outlet side was 10 mm, and its axial length was 20 mm.

[0052] <Materials used> Cement: Ordinary Portland cement, commercially available, Blaine value 2,500 cm 2 / g Aggregate: Limestone aggregate with a maximum particle size of 1.2 mm Rapid hardening material: 100 parts of 12CaO 7Al2O3 (a compound synthesized by mixing reagent grade calcium carbonate and aluminum oxide in a molar ratio of 12:7 and baking at 1,350℃ for 3 hours twice) and 100 parts of type II anhydrous gypsum are mixed and ground, with a Blaine value of 5,000 cm 2 / g Shrinkage reducing agent: Polyoxyalkylene compound, special nonionic powder shrinkage reducing agent, product name "ADEKA SEMSURF", manufactured by ADEKA Corporation Short fiber A: Vinylon fiber, product name "RECS7×6mm", length 6mm, manufactured by Kuraray Co., Ltd. Superplasticizer: Powder type polycarboxylic acid water reducing agent, product name "MELFLUX AP101", manufactured by BASF Set retarder: Reagent grade tartaric acid Water: Tap water

[0053] <Spray test> The following spray tests (1) and (2) were carried out, and the results are shown in Table 1. (1) Rebound rate: The weight sprayed onto the ceiling surface was kept constant, and the rebound weight was measured. (2) Adhesion: The mixed spray material was sprayed onto the ceiling surface with a diameter of 10 cm, and the thickness of the sprayed material when it peeled off was measured. (3) Discharge capacity Discharge volume per hour from the spray nozzle (m 3 ) was calculated as the discharge capacity.

[0054] [Table 1] [Industrial Applicability]

[0055] The spray nozzle of the present invention can be suitably used in the fields of civil engineering and construction for surface finishing of concrete, cross-section repair, and the like. [Explanation of symbols]

[0056] 10 Spray nozzle 11 Hose attachment part 12 Spraying material inlet 13 Spray material outlet 14 Spray material flow path 15 Mixing section 16 Hard tube 20 Horse 30 Material transport pipe 40 Air supply pipe

Claims

1. A spray nozzle having a hose attachment portion to which a hose through which a first spray material is supplied can be attached, the hose attachment portion having a spray material inlet having a diameter substantially the same as an inner diameter of the hose, and a spray material flow path formed from the spray material inlet to a spray material outlet at a tip of the nozzle, A spray nozzle in which the ratio (B / A) of the inner diameter (B) of the spray material discharge port to the inner diameter (A) of the spray material inlet is 0.1 to 0.

6.

2. 2. The spray nozzle of claim 1, wherein at least a portion of said nozzle tip is made of rubber.

3. 3. The spray nozzle according to claim 1, wherein a hard pipe is provided on the spray material flow path on the side of the spray material outlet so that the inside diameter of the spray material outlet is reduced.

4. 3. The spray nozzle according to claim 1 or 2, further comprising a mixing section provided in the spray material flow path for supplying the second spray material and mixing it with the first spray material.

5. A spraying system comprising a first conveying means for conveying a first spray material and a spray nozzle for spraying the first spray material onto a part to be sprayed, wherein the spray nozzle is a spray nozzle as described in claim 1 or 2.

6. A spraying system including a first conveying means for conveying a first spraying material, a second conveying means for conveying a second spraying material, and a spraying nozzle for spraying a mixed spraying material, which is a mixture of the first spraying material conveyed from the first conveying means and the second spraying material conveyed from the second conveying means, onto a part to be sprayed, wherein the spraying nozzle is the spraying nozzle described in claim 4.

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