JPH1122391A - Method for spraying fresh concrete and its spray nozzle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve function by pumping fresh concrete to a discharge opening from an L-shaped pipe introduction through a curvature, and atomizing a chemical from the curvature to the discharge opening. SOLUTION: Fresh mortar or fresh concrete FC is pumped to the introduction part 3 of an L-shaped pipe 1, direction-changed by a curvature 2, and directed to a discharge opening 5. Next, high speed compressed air PA is supplied to a chemical spraying pipe 10 from the concrete FC, and mixed with a set accelerating agent CR supplied from a chemical supply opening 13 to be sprayed from a spray opening 11. When a chemical CR is sprayed at the center 2C of the curvature 2, the chemical CR is mixed with the concrete FC while it is diffused from the center of a discharge part toward a pipe inner wall face 4P. In addition, at need the central axis 11C of the spraying opening 11 and the central axis 5C of the discharge opening 5 are shifted to improve mixing efficiency and the like. As a result, adherence and solidification on the pipe inner wall can be prevented, clogging is prevented to continuously perform execution, and average quickly solidifying strength can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for spraying fresh concrete and a spray nozzle device used when spraying fresh concrete or fresh mortar material on a ceiling or a wall of a tunnel.

[0002] When the ceiling or wall of a tunnel is solidified with concrete or mortar, fast-setting fresh concrete or fresh mortar material is used. The fresh concrete and the fresh mortar material are in a state immediately after kneading cement, bone and water, but fresh concrete is generally called ready-mixed concrete. In the following, description will be made mainly on the case where fresh concrete is used as a spraying material, but it goes without saying that the fresh mortar material is included in this fresh concrete.

Conventionally, when fresh concrete is sprayed on a wall surface or the like, a spray nozzle device has been used.
This device includes a fresh concrete pumping passage and a drug supply passage intersecting the pumping passage, and mixes fresh concrete and quick-setting agent without the pumping passage and sprays the mixture on a wall surface or the like.

[0004]

The conventional spray nozzle device has the following problems. (1) Since the chemical is supplied to the inner wall side of the fresh concrete pumping passage and mixed with the fresh concrete, the mixing with the fresh concrete flowing through the central portion of the passage is not sufficiently performed. For this reason, quick setting of fresh concrete cannot be averaged, and it is difficult to obtain concrete having uniform strength over the entire surface.

(2) In the vicinity of the intersection of the Y-pipe between the pressure-feeding passage and the chemical supply passage, fresh concrete in direct contact with the quick-setting agent starts to solidify, so-called quick-setting concrete is formed, and the concrete grows. Nozzle clogging. Therefore, frequently, for example, 3
The spraying operation must be interrupted once every 5 minutes, and the nozzle device must be removed, replaced and disassembled, inspected, repaired, etc., so that the working time becomes longer and the spraying operation is not efficient. .

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to prevent nozzle clogging. Another object is to ensure that the mixing of the drug and fresh concrete is sufficient.

[0007]

SUMMARY OF THE INVENTION According to the present invention, fresh concrete or fresh mortar material is pressure-fed to an introduction portion of an L-shaped pipe, the direction is changed by a curved portion, and the direction is changed to a radiation port of a radiation portion. And spraying a chemical toward a central portion of the emission port.

According to the present invention, there is provided an L-shaped tube provided with an introducing portion and a radiating portion continuous through a curved portion; a tip portion protruding into the curved portion, and a spray port thereof faces a radiating port of the radiating section. And a spray nozzle for fresh concrete.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A spray nozzle device comprises an L-shaped tube and a medicine ejection tube. This L-shaped tube has an introduction portion and a radiation portion that are continuous via a curved portion. When fresh concrete or fresh mortar material (hereinafter, simply referred to as fresh concrete) is pumped into the introduction portion, the fresh concrete enters the radiation portion while changing the direction at the curved portion, and heads toward the radiation port. The drug spray tube is provided with a compressed air port and a drug supply port, and the tip end protrudes into the curved portion of the L-shaped tube. When the compressed air and the medicine are supplied to the medicine spray tube, the medicine is mixed with the compressed air and sprayed into the curved portion from the spray port at the distal end. The supply rate of the compressed air is designed to be faster than the supply rate of the fresh concrete.

At this time, a negative pressure is generated in the vicinity of the spray port in the curved portion due to the Venturi effect, and the fresh concrete heads toward the radiation port while being pulled by the compressed air.
Further, fresh concrete passing through the inside of the curved portion is in a turbulent state. Therefore, when the compressed air containing the medicine is sprayed toward the center of the emission port, the medicine is sufficiently mixed with the fresh concrete, and is emitted from the emission port in the mixed state.

When the medicine supply port is connected to the medicine ejection pipe via the medicine storage chamber, the medicine in the medicine storage chamber is sucked by the compressed air passing through the spray pipe, so that the supply of the medicine is not interrupted. Further, the medicine spraying tube or the holder of the medicine spraying tube may be rotatable to improve operability.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. The spray nozzle device includes an L-shaped tube 1 and a chemical spray tube 10. The L-shaped tube 1 is composed of an introducing portion 3 and a radiating portion 4 which are continuous via a curved portion 2.

The tip 10a of the chemical spray tube 10 is squeezed,
The tip portion 10a projects into the curved portion 2 of the L-shaped tube 1. The position and amount of protrusion are appropriately selected as needed.

For example, in order to improve the mixing efficiency and the suction efficiency in the pipe, the center axis 11C of the spray port 11 and the center axis 5C of the discharge port 5 of the radiation section 4 are shifted by an interval T, and the protrusion amount is set to L. The spray port 11 is located at a substantially central portion 2C of the curved portion 2. The chemical spray tube 10 has a compressed air port 1
2 and a medicine supply port 13 are provided. This medicine spray tube 10 is housed in a holder 15.

Next, the operation of this embodiment will be described. When fresh concrete FC made of kneaded cement, aggregate and water is fed under pressure to the introduction portion 3 of the L-shaped tube 1, the fresh concrete FC is guided by the curved portion 2 and changes its direction to the radiating portion 4, and the radiating port is formed. Go to 5. When compressed air PA, which is faster than the fresh concrete FC, is supplied to the compressed air port 12 of the chemical spray tube 10 and a liquid quick-setting agent CR is sent from the chemical supply port 13, the quick-setting agent CR is mixed with the compressed air PA. It flows down while being mixed, and is discharged as a mist from the spray port 11.

When the chemical CR is sprayed at the central portion 2C in the curved portion 2, the chemical CR is spread by the compressed air PA from the central portion 4C of the cross section of the radiating portion 4 toward the inner wall surface 4P of the fresh concrete FC. Mixed in. Then, the fresh concrete FC is radiated from the radiating port 5 toward the wall surface or the like in a state where the medicine CR is sufficiently mixed.

When cleaning the spray nozzle device, compressed air PA is supplied from the compressed air port and cleaning water is supplied from the chemical supply port 13.

A second embodiment of the present invention will be described with reference to FIG. The difference between this embodiment and the first embodiment is as follows. (1) The medicine supply port 13 communicates with the medicine spray pipe 10 via the medicine storage chamber 20. When the compressed air PA flows through the medicine spray tube 10, the medicine CR in the medicine storage chamber 20 is sucked and mixed with the compressed air PA by the principle of atomization of the Venturi tube, so that instantaneous liquid shortage is eliminated. Can be. It should be noted that even when the suction force of the medicine spray tube 10 is weak, the medicine in the medicine storage chamber is sucked, and the medicine CR is pressure-fed by a metering pump to prevent the liquid from running out.

(2) The holder of the chemical spray tube 10 is rotatably supported. The holder for accommodating the chemical spray tube 10 is separated into a first holder part 21 and a second holder part 22, and bolt holes 23, 24 are provided in both holder parts 21, 22.
Is provided. Ring-shaped bolt receiving grooves 25 and 26 are formed on both ends of the chemical spray tube 10. The fixing bolts 27 and 28 are screwed into the bolt holes 23 and 24, and the ends thereof are located in the bolt receiving grooves 25 and 26. Thus, the second holder 22 is rotatable, so that troubles such as the hose connected to the connection fitting 13A of the medicine supply port 13 are entangled are eliminated. A similar effect can be obtained even if the medicine spray tube itself is rotatably supported.

(3) The chemical spray tube is detachably provided on the curved portion of the L-shaped tube. When replacing the drug spray tube 10, the fixing bolts 27 and 28 are loosened and removed, and the second holder 22 is pulled to the rear end side of the drug spray tube 10, and the drug spray tube 10 is removed from the L-shaped tube 1. Easy to come off. When installing the chemical spray tube, a process reverse to the above process is performed. In addition, since the connection fitting 13A of the medicine supply port 13 is screwed to the second holder 22, it can be easily removed.

A third embodiment of the present invention will be described with reference to FIG. The difference between this embodiment and the above embodiment is that the L-shaped tube 1
The attachment preventing cylinder 30 is provided at the tip 4a of the radiating section 4. The anti-adhesion cylinder 30 is, for example,
And is fixed to the distal end portion 4a by a bolt 35. This adhesion prevention cylinder 30 is
Vibration is caused by the operation of the spray nozzle device to prevent adhesion of fresh concrete and the like.

The embodiment of the present invention is not limited to the above, and can be used not only for spraying fresh concrete but also for spraying fresh mortar material. Therefore, the concept of fresh concrete includes this fresh mortar material.

[0023]

As described above, the present invention has the following remarkable effects. (1) The fresh concrete and the chemical are sufficiently mixed, so that they do not adhere to the inner wall of the pipe and solidify. Therefore, since no clogging occurs, the spraying operation can be continuously performed for a long time. (2) Since the agent is sufficiently mixed with the fresh concrete, each part of the concrete can have an average quick-setting strength.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view taken along line II-II of FIG.

FIG. 3 is a longitudinal sectional view showing a second embodiment of the present invention.

FIG. 4 is a partial sectional view showing a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 L-shaped pipe 2 Bending part 3 Introduction part 4 Radiation part 5 Radiation port 10 Drug spray tube 12 Compressed air port 13 Drug supply port 15 Holder 20 Drug storage room 30 Adhesion prevention cylinder

Claims (8)

[Claims] 1. A fresh concrete or fresh mortar material is pressure-fed to an introduction portion of an L-shaped tube, and the direction is changed by a curved portion to be directed to a radiation port of a radiation portion, and from the curved portion to a central portion of the radiation port. A method of spraying fresh concrete, characterized by spraying a chemical toward the fresh concrete. 2. An L-shaped tube having an introduction portion and a radiating portion continuous through a curved portion; a tip portion protruding into the curved portion, and a spray port thereof faces the radiating port of the radiating portion. And a spray nozzle for spraying fresh concrete. 3. The spray nozzle device for fresh concrete according to claim 2, wherein the central axis of the radiation port is shifted from the central axis of the spray port. 4. The spray nozzle device for fresh concrete according to claim 2, wherein the chemical spray pipe communicates with the compressed air port and the chemical supply port. 5. The spray nozzle device for fresh concrete according to claim 4, wherein the medicine supply port communicates with the medicine spray pipe through a medicine storage chamber. 6. The spray nozzle device for fresh concrete according to claim 2, wherein the chemical spray tube is rotatably supported. 7. The spray nozzle device for fresh concrete according to claim 2, wherein an adhesion preventing cylinder is provided at a tip end of the radiating portion. 8. The spray nozzle device for fresh concrete according to claim 7, wherein the adhesion preventing cylinder is formed by tapering natural rubber.