JPH06167108A - Spraying process of cement mortar - Google Patents

Abstract

PURPOSE:To provide a spray method of cement mortar by which cement mortar previously kneaded in a wet process is pumped under pressure over a long distance and sprayed and also the inside of hose can be easily cleaned. CONSTITUTION:While continuously extruding cement mortar previously kneaded in a wet process by a mortar pump 3 into a pressure hose 4, the compressed air toward extrusive direction into the pressure hose 4 is ejected at a plurality of spots of the full length of hose 4 and cement mortar is dispersed and pumped under pressure to spray from a nozzle to a wall face. In this way, since the compressed air is ejected toward the extrusive direction at a plurality of spots of the full length of the pressure hose, cement mortar can be conveyed under pressure over a long distance and since the mortar in the hose is dispersed by the compressed air and forcibly conveyed, it does not stay during discontinuing operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for spraying cement mortar onto the wall surface of civil engineering structures, buildings and the like.

[0002]

2. Description of the Related Art In a conventional cement mortar spraying method, as shown in FIG. 3, cement, aggregate and the like are wet kneaded by a mortar mixer A at a constant water cement ratio,
There is known a so-called wet spraying method in which a mortar pump B is used to pressurize a hose C and a spray nozzle D supplies compressed air E to form a cement mortar layer G on a wall surface F.

Further, as shown in FIG. 4, cement, aggregate and the like are dry-mixed by a cement mixer H, compressed air I is supplied and pneumatically fed into an air feeding pipe J, and water is sprayed at a spray nozzle K portion. A so-called dry spraying method in which L is supplied by a pipe M and kneaded in a spray nozzle K to a predetermined water-cement ratio to form a cement mortar layer G on the wall surface F is also used.

However, in the wet spraying method, the water-cement ratio is easily controlled, the quality of the cement mortar is stabilized, and the rebound loss during the work is small, but the cement mortar filling the pressure-feeding hose C is pressure-fed. Therefore, long-distance pressure feeding is not possible, and when work is interrupted, it is necessary to remove the cement mortar in the pressure feeding hose and wash the inside of the hose to avoid hardening of the cement mortar in the hose, resulting in material loss and significant cleaning. There is a problem that it takes time.

Further, in the dry spraying method, dry cement, aggregate and the like are pneumatically fed, and long-distance pressure feeding is possible, and hardening of cement mortar does not occur in the pneumatic pipe when work is interrupted. Although the inside of the pneumatic hose is easy to clean, since the water L is supplied and kneaded at the spray nozzle K portion, the control of the water-cement ratio is left to the operator's judgment, and the quality of the obtained cement mortar is unsatisfactory. It has problems that it tends to be uniform and rebound loss tends to increase.

[0006]

In view of the problems of the above conventional method, the present invention enables the long-distance cement mortar to be pumped in spite of adopting the wet kneading in which the water-cement ratio is easily controlled. Therefore, it is an object of the present invention to provide a method for spraying cement mortar in which the cement mortar in the pressure-feeding hose can be easily removed and the hose can be easily cleaned even when the work is interrupted, and the rebound loss is small.

[0007]

In order to solve the above problems, in the present invention, cement mortar that has been wet-kneaded in advance is pushed into a pressure feeding hose by a mortar pump while being pushed at a plurality of locations along the entire length of the pressure feeding hose. In this configuration, compressed air is jetted into the hose in a certain direction, cement mortar is placed on the air flow in the pressure feed hose, dispersed and pressure-fed, and then sprayed from the nozzle at the tip of the pressure feed hose.

[0008]

In the present invention, the compressed air is ejected into the hose at a plurality of locations along the entire length of the pressure-feeding hose in the pushing direction of the cement mortar. Therefore, the cement mortar is dispersed in a small lump by the ejected compressed air. Along with the flow, it is made to flow at a high speed in the direction of the tip of the pressure-feeding hose, and negative pressure acts on the upstream side of the compressed air jetting site to suction the cement mortar, enabling the cement mortar to be pushed for a long distance. Becomes

When the pushing of cement mortar by the mortar pump is stopped and only the compressed air is jetted, the cement mortar in the pressure-feeding hose downstream from the most upstream compressed air jetting portion is jetted out from the nozzle, and the hose is jetted out. Since it does not remain inside, it is easy to clean the inside of the pressure-feeding hose downstream from the jetting site of the most upstream compressed air.

Therefore, the cement mortar remaining in the pressure-feeding hose may be removed inside the pressure-feeding hose between the mortar pump and the most upstream compressed air jetting portion,
Mortar removal work is completed in a short time.

[0011]

1 and 2 show an example of an embodiment of the present invention, which is a cement composed of a cement, an aggregate, a quick-setting admixture, water, etc. kneaded in a mortar mixer 1 at a predetermined water-cement ratio. The mortar 2 is put into the hopper of the mortar pump 3, and is continuously pushed into the pressure-feeding hose 4 by the mortar pump 3.

The pressure-feeding hose 4 is provided with jetting devices 5, 6, 7 for injecting compressed air into the hose at a plurality of positions along its entire length.

As shown in FIG. 2, the compressed air jetting devices 5, 6 and 7 have an air receiving ring 9 fixed to the tip of an upstream pressure feeding hose 8 and a downstream pressure feeding hose 10.
The air ejection ring 11 fixed to the rear end is integrally fixed.

At the air receiving ring 9 of each of the jetting devices 5, 6, 7 are attached air hoses 13, 14, 15 branched from the air compressor 12 shown in FIG.
6, the air passage 17 of the joint portion 16 communicates with the annular air reservoir 18 of the air ejection ring 11.

In the air reservoir 18 of the air jet ring 11,
The air ejection passages 20 are formed in the pressure feeding hose 4 of the cement mortar 2 so as to be inclined in the pushing direction X, and are provided at equal intervals over the entire circumference of the communication port 21 between the pressure feeding hose 10 and the air ejection ring 11. The opening 22 is opened on the inner peripheral surface of the air ejection ring 11.

Therefore, the compressed air sent from the air compressor 12 is ejected as a convergent wind from the opening 22 toward the center of the pressure-feeding hose 10 and in the pushing direction X,
Immediately, the flow is rectified in the feeding hose 10 in the pushing direction X.

As described above, the cement mortar 2 continuously pushed into the pressure-feeding hose 4 by the mortar pump 3 reaches the position of the most upstream compressed air ejecting device, that is, the ejecting device 5 in FIG. , Is dispersed by the action of the compressed air ejected from the opening 22, is carried on the compressed air flow in the pushing direction X, and is fed under pressure.

When the compressed air is jetted from the opening 22, a negative pressure area is generated in the immediate upstream side of the opening 22, and this negative pressure causes the cement mortar 2 to be in the immediate upstream area of the opening 22.
The suction action of the cement mortar 2 occurs, and the cement mortar 2 is pushed at a higher speed.

Suction, dispersion, and pressure feeding to the cement mortar 2 by the compressed air are repeated in the same manner in the compressed air jetting devices 6 and 7, and the cement mortar 2 is distributed over the entire length of the pressure feeding hose 4. It is pumped with the same kinetic energy and sprayed onto the wall surface 24 from the nozzle 23 at the end of the hose.

The nozzle 23 at the end of the hose is fixed to the air ejection ring 11 instead of the pressure feeding hose 10 on the downstream side of the compressed air ejection device shown in FIG.

The apparatus used for carrying out the present invention is not limited to the structure shown in FIGS. 1 and 2, and it is needless to say that the structure can be changed to another structure having substantially the same operation.

[0022]

EFFECTS OF THE INVENTION In the present invention, cement mortar, which has been wet-kneaded in advance, is placed on an air flow of compressed air and pressure-fed, so that it is possible to spray cement mortar of uniform quality.

The cement mortar is dispersed and pushed by the jetting of compressed air and the suction action due to the negative pressure immediately upstream of the jetting, and this action is repeated at a plurality of locations over the entire length of the pumping hose. It also has the effect of pumping cement mortar at high speed over a long distance at a substantially uniform flow rate.

At the time of work interruption such as pipe arrangement or break, only the mortar pump is stopped and the compressed air is jetted for a predetermined time, and the entire amount of cement mortar in the pressure-feeding hose can be sprayed, so that the waste of materials is minimized. However, the amount of cement mortar remaining in the pressure-feeding hose is only a small amount that adheres to the inner wall of the hose, cleaning is sufficient in a short time, and cement mortar remaining in the pressure-feeding hose can be removed with a mortar pump. Since only the pressure-feeding hose portion between the most upstream compressed air jetting portion is sufficient, labor-saving cleaning can be achieved.

As in the case of the dry spraying operation, the compressed mortar, which has been wet-kneaded in advance, is pumped by compressed air regardless of the use of compressed air as a carrier medium. Since there is almost no cement mortar remaining in the hose, there is an effect that waste of materials can be saved.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of the present invention.

FIG. 2 is a schematic vertical cross-sectional view of an example of a compressed air ejection device.

FIG. 3 is a schematic side view of an example of a conventional wet spraying method.

FIG. 4 is a schematic side view of an example of a conventional dry spraying method.

[Explanation of symbols]

 2 Cement mortar 3 Mortar pump 4 Pressure feed hose

Claims (1)

[Claims] 1. Cement mortar, which has been wet-kneaded in advance, is pushed into a hose by a mortar pump, and compressed air is jetted into the hose at a plurality of locations along the entire length of the hose to push the hose in the hose. A method for spraying cement mortar, characterized in that the cement mortar is placed on an air flow, dispersed, pressure-fed, and sprayed from a nozzle at the tip of the pressure-feeding hose.