JPH067171Y2 - Admixture addition mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention mainly relates to an admixture adding mechanism used for wet spraying.

[Conventional technology and its technical problem]

As a wet spraying method for hydraulic materials such as concrete, mortar, and furnace materials, a wet material is densely conveyed by a pump for a predetermined distance, and then compressed air is blown to transfer it to an air stream, and the spray nozzle or its The method of adding and spraying a quick-setting agent at a nearby position is known from JP-A-61-28670 proposed by the present applicant.

This method conveys wet material densely to the spray nozzle with pump discharge pressure, and compared to the conventional spraying method in which compressed air is added and blown at the position of the spray nozzle, relatively low-slump material is transported over a long distance. Although it has the excellent advantage of being able to do so, it is still not sufficient in terms of the mixing of the quick-setting agent.

That is, in this prior art, the quick-setting agent adding mechanism had a simple Y-tube structure in which a straight pipe was interposed between the hoses and a blowing thin pipe was obliquely connected to the straight pipe. However, in this structure, the dispersed wet material passes through the inlet passage and the outlet passage on the same axis at a high speed, and the quick-setting admixture is blown in a chasing manner. Moreover, when the wet material is concrete, its apparent specific gravity is much larger than that of the quick-setting agent (generally 16: 1). Therefore, even if the added air pressure to the blow-in narrow tube is set higher than the added air pressure for starting the air flow conveyance, the quick-setting admixture cannot be mixed quickly and reliably, and a sufficient quick-setting admixture effect is obtained. I couldn't get it.
Therefore, in view of this, the amount of the quick-setting admixture that is considerably larger than the required set amount is added, and as a result, the generation of dust becomes large and the problem of increased rebound loss cannot be avoided. Another method is to move the addition position of the quick-setting agent to the upstream side, but this method is not practical because it causes the coagulation reaction to proceed too much and causes a big trouble such as clogging of the hose and the spray nozzle.

The present invention was devised to solve the above-mentioned problems, and its purpose is to reliably and extremely efficiently use an admixture represented by a quick-setting admixture in the wet material during air flow conveyance. It is an object of the present invention to provide an admixture adding mechanism for a wet spraying device that can mix and spray.

[Means for Solving the Problems]

In order to achieve the above object, the present invention provides a mechanism for adding an admixture to a wet material during air flow conveyance by adding air, wherein the admixture adding mechanism includes a nozzle-shaped main body and a blowing pipe, and the nozzle-shaped main body is The inlet passage and the outlet passage have a phase shift, and the inlet passage and the outlet passage are connected by a mixing barrel having a diameter larger than those diameters, and blown into the enlarged mixing barrel. The pipes are connected diagonally.

It is preferable that an angle formed by the axis of the blow pipe and the axis of the inlet passage is in the range of 36 to 45 °.

The admixture is mainly a quick-setting admixture, and there are various admixtures necessary for construction such as a retarder.

The present invention is suitable for hand-held or robotic spraying.

〔Example〕

 An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a wet spray system using an admixture adding mechanism according to the present invention.

In FIG. 1, reference numeral 1 denotes a pump, and in the figure, a piston pump, but a squeeze type, a screw type and the like are optional. 2 is the discharge port 1 of the pump 1
It is a rigid transport line connected to a and is formed by connecting a plurality of metal pipes in series. Reference numeral 3 denotes a flexible conveyance pipe line, which is made of rubber hoses and has a spray nozzle 5 at its tip.

Reference numeral 4 denotes an air blowing mechanism interposed at an upstream part of the flexible transfer conduit 3 or at an end part of the rigid transfer conduit 2, and is a straight pipe or a tapered nozzle body 4a (not shown).
And an annular pipe 4b surrounding the same, and a plurality of oblique blow pipes 4c connected from the annular pipe 4b into the nozzle body 4a. The oblique blow pipe 4c includes the air pipe 40 Is guided to the compressed air supply source A by the pressure gauge 41 and the control valve 4
It is possible to control the air pressure and flow rate with 2. Of course, the air blowing mechanism 4 is not limited to the above mechanism.

Reference numeral 6 denotes an admixture adding mechanism, which is a feature of the present invention, and is located at a position immediately adjacent to the spray nozzle 5 or at a proper position, for example, 2-3.
m It is interveningly connected to the flexible transport line 3 on the upstream side.

The admixture adding mechanism 6 is shown in detail in FIGS. 2 to 4. That is, the admixture adding mechanism 6 comprises a nozzle-shaped main body 7 and a blow pipe 8, and the blow pipe 8 is the hose 1
It is connected via 0 to a supply means 9 of any type.

The nozzle-shaped main body 7 has an inlet-side tubular portion 7a and an outlet-side tubular portion 7b whose axes C ₁ and C ₂ are substantially parallel to each other, and has the inlet-side tubular portion 7a and the outlet-side tubular portion 7b. Are connected to each other through a large-diameter mixing body 7c. Specifically, when viewed from the side, the mixing body portion 7c is a straight lower half wall of the inlet side tubular portion 7a and the outlet side tubular portion 7b at a short distance from the inlet 70.
The front widening wall 72 connected to the straight tubular lower half wall and the inlet side tubular portion 7
It has a straight tubular lower half wall a long distance from the inlet 70 of a and a tapered wall 73 connecting the upper half wall close to the outlet 71 of the tubular portion 7b.

Sealing grooves are provided on the outer circumferences of the ends of the inlet-side tubular portion 7a and the outlet-side tubular portion 7b, and are connected to the flexible conveying pipeline 3 via an O-ring (not shown) fitted therein. ing. The inner diameter D _{1 of the} inlet 70 and the inner diameter D _{2 of the} outlet 71 are the same or D ₂ is slightly larger than D ₁ , and the maximum inner diameter D ₃ of the mixing body 7c is D ₁ or D ₂ . On the other hand, it is about 1.4 to 2 times.

The diameter of the blow pipe 8 is smaller than D ₁ and D ₂ , and the mixing body 7
It is obliquely inserted into the front widening wall 72 of c. Although the method of insertion is a screw type in the embodiment, it is needless to say that welding, press fitting or the like may be performed, and the insertion angle α, that is, the axis C ₁ of the inlet side tube portion 7a and the axis C ₃ of the blow-in pipe 8 may be used. According to an experiment conducted by the present inventor, the mixing efficiency was highest in the range of 36 to 45 ° (more preferably 40 to 43 °). Needless to say, the blow-in pipe 8 may be inserted in the tangential direction instead of being centripetal.

The nozzle-shaped main body 7 does not necessarily have to be an integral body. For example, the front half and the rear half may be separately formed and joined by welding or the like, but in any case, wear-resistant metal or ceramics is used. It is preferable to make. The tapered wall 73 is a region where the wet material is squeezed, so that it may be thickened as shown in FIG.
The anti-wear agent 730 is lined as shown.

The admixture may be either powder or liquid, but in the examples, powder is used, which is cut out quantitatively by a rotary feeder,
I try to carry it by compressed air. That is, the powder is contained in the tank 90, cut out by a fixed amount by the rotation of the rotor 91 at the bottom of the tank, and discharged to the machine side nozzle 93 by the air sent from the compressor or the receiver tank A ′ to the air blowing nozzle 92. Air flow is carried to the blow-in pipe 8 via a hose 10. In the case of liquid, a compressed air supply system may be connected to the discharge side of the suction pump.

[Operation of Example]

The moist material is discharged from the pump 1 to the rigid transport pipe line 2 and is pressure-fed in a dense state through this pipe line. At this time, compressed air is being supplied to the air blowing mechanism 4, and the compressed air is blown from the annular pipe 4b into the nozzle main body 4a through the oblique blowing pipes 4c, so that the wet material encounters this air flow. By doing so, buoyancy is given and the air is conveyed through the flexible conveying pipe 3, and the dispersed wet material reaches the admixture adding mechanism 6 at an increased speed.

In the admixture adding mechanism 6, the admixture quantitatively cut out from the supply means 9 is conveyed by compressed air as an air stream and is blown from the oblique blow pipe 8 into the expanded diameter mixing body 7c. . The mixing body portion 7c communicates with the inlet side passage 70a and the outlet side passage 70b each having a smaller diameter,
Moreover, the inlet side passage 70a and the outlet side passage 70b have the axis C
₁ and C ₂ are misaligned. Therefore, at the moment when the dispersed wet material passes through the inlet-side passage 70a, the flow velocity is temporarily reduced due to the expansion of the opening area, and then the flow velocity is recovered by being reduced by the reduction of the opening area, and during that time. Further, the direction of the flow is changed by the flared wall 72 and the tapered wall 73.

As a result, as shown schematically in FIG. 5, the mixing body 7c
The turbulent flow E is created therein, and the region F along the divergent wall 72 forming the lower half of the mixing body 7c has a coarser material density as the flow velocity decreases. Therefore, the blow pipe 8
Even if the specific gravity of the admixture blown from is small, the admixture mixes well with the material in the region F, reaches the center of the mixing body 7c, is entrained in the turbulent flow E, and is vigorously stirred. Therefore, the mixing efficiency is significantly improved, and the admixture can be uniformly dispersed in the wet material.

Cement 380kg / m ² , s / a: 60%, w / c: 53%, A
d: 0.9%, Sl: 8 ± 2 cm, maximum aggregate 15 mm, FM: 2.85 Wet material is pressure-fed by a double piston pump at 6 m ³ / h, discharge pressure 35 kg / cm ² , and from the air blowing mechanism on the way. 1.8kg /
cm ^2, flow rate 10 Nm ³ / min of compressed air blowing, the air 5% powdered quick-setting admixture to cement content from this invention admixture adding mechanism connected from the spray nozzle to the position of 2m upstream pressure 3.0 kg/
I tried blowing it in cm ² .

The admixture adding mechanism had an inner diameter of 65 mmφ at the inlet and the outlet, a body diameter of 105 mmφ for mixing, an axial misalignment amount of the inlet-side passage and the outlet-side passage of 37 mm, and a blowing pipe insertion angle of 40 °. as a result,
The amount of dust is extremely small at 1.5 to 2.5 mg / m ^{2 in the} immediate vicinity of the face,
The amount of rebound is about 18% at the arch and about 10% at the side wall.
Very few and excellent early strength was obtained.

On the other hand, when a Y-shaped tube was used as an admixture addition mechanism, the amount of quick-setting agent required was 7-10% to obtain the same early strength, and the amount of dust was 4-6 mg / m ² near the face. The rebound amount is about 25-27% at the arch and about 14-16% at the side wall.
Met.

[Effect of the present invention]

According to the present invention described above, an admixture typified by a quick-setting admixture can be extremely efficiently and uniformly applied to a wet material that is conveyed by airflow at a speed increased while being dispersed by blowing compressed air from a dense conveyance state. Since they can be mixed, therefore, good construction with less dust and rebound can be performed, and the consumption amount of expensive admixture can be reduced, so that an excellent effect such as a reduction in construction unit price can be obtained.

[Brief description of drawings]

FIG. 1 is an explanatory view showing the outline of a wet spray system to which the present invention is applied, FIG. 2 is a vertical side view of an admixture adding mechanism according to the present invention, and FIGS. 2a and 2b are other embodiments. FIG. 3 is a partial sectional view showing the same, FIG. 3 is a front view thereof, and FIG.
Fig. 5 is a sectional view taken along the line IV-IV, and Fig. 5 is a sectional view schematically showing the flow of materials in the present invention. 1 ... Pump, 2 ... Rigid carrier line, 3 ... Flexible carrier line, 4 ... Air blowing mechanism, 5 ... Spray nozzle, 6
…… Admixture addition mechanism, 7a …… Inlet side cylinder part, 7b …… Outlet side cylinder part, 7c …… Mixing body part

Claims (2)

[Scope of utility model registration request] 1. A mechanism for adding an admixture represented by a quick-setting admixture to a moist material being conveyed by air by adding air, wherein the admixture adding mechanism comprises a nozzle-shaped main body and a blowing pipe, The main body has a phase shift on the axis of the inlet passage and the outlet passage, and the inlet passage and the outlet passage are connected by a mixing barrel having a diameter larger than those diameters, and An admixture adding mechanism characterized in that the blow pipes are connected obliquely. 2. The admixture adding mechanism according to claim 1, wherein the angle formed by the axis of the blow pipe and the axis of the inlet passage is in the range of 36 to 45 °.