JPH07106325B2 - Wet atomizer for cement grout - Google Patents

Description

TECHNICAL FIELD The present invention relates to a grout material atomizer, and more specifically, to a cement-based grout material used at a construction site for waterproofing in civil works and improvement of foundation ground. The present invention relates to a wet atomizer.

[Conventional technology]

Dam construction for water stoppage and water use is increasing rapidly with industrial development. Recently, however, most of the sites that have suitable bedrock for dam construction have been developed and damned, and it has been unavoidable to install a dam on the foundation ground that is geologically disadvantageous for dam construction, such as gravel, clay, and soft rock. Generally, this kind of foundation ground contains many fine gaps and arc racks, and there are many problems in design and construction for dam construction.

Various methods such as a chemical injection method have been developed for such stable treatment of the foundation ground. However, since the chemical injection method is a pollution problem due to chemicals, its use has been restricted since 1974 except for water glass. In consideration of such an environment, the cement-based grout material injection method is now becoming the mainstream of the foundation ground stabilization method instead of the chemical injection method.

The average particle size D ₅₀ of ordinary Portland cement used in the grout material injection method is about 20 μm, and it cannot be used because there is an injection limit in particle size for filling fine gaps and hair cracks in the foundation ground.

Therefore, cement particles having an average particle diameter D ₅₀ of 6 to 8 μm are used by using a dry atomizer such as a ball mill, but they are not sufficient to inject into the above-mentioned ground gap. Moreover, the cost of dry atomization is 5 to 10 times that of ordinary cement due to the large number of man-hours, and because the cement and water are mixed and used at the time of injection at the construction site, the particles are aggregated (multiple individual particles are collected. And becomes particles with a large volume) and the apparent grout particle size becomes large, so that the injection effect is reduced. Further, since the cement particles are minute, the particles are deteriorated quickly, and long-term storage is difficult.

In view of the above circumstances, the present inventors have proposed a grout injection method according to JP-A-57-33613 and a grout agent wet adjustment mechanism according to JP-A-59-88526.

The method disclosed in JP-A-57-33613 focuses on the fact that cement grout is used in the form of a slurry, and by changing the conventional atomization method of cement from wet type to improve the efficiency of crushing and the cement grout performance. After making improvements, wet atomization is performed at the construction site and this is immediately injected into the foundation ground. By this method, the property of the dry fine powder cement that tends to absorb moisture was removed, and by further dispersing the cement particles in water, effective injection became possible.

Further, the adjusting mechanism disclosed in JP-A-59-88526 is an apparatus for carrying out the above-mentioned construction method, in which a rotary shaft having a plurality of disks arranged horizontally in a horizontal processing cylinder, An inlet for cement grout material and an inlet for beads are provided at the upper end of the processing cylinder, and an overflow port for discharging the treated cement grout material is provided at the upper end of the processing cylinder at the bottom of the processing cylinder. Provide an outlet for beads. Further, the disk is provided with a through hole having a taper, and the disks having the tapered through holes whose opening directions are opposite to each other are arranged in combination so as to improve the crushing effect by the beads in the processing cylinder. Thus, the beads are packed in the treatment cylinder, the beads are subjected to a high-speed rotary motion by the disk, and the cement-based grout material is continuously passed through the beads to atomize the cement particles.

[Problems to be solved by the invention]

In the adjusting mechanism of JP-A-59-88526 described above, the beads are supplied manually through the charging port at regular time intervals. As a result, the operating efficiency was low, and a leveled cement product (fine-grained cement-based grout material) could not be obtained. Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks of the adjusting mechanism disclosed in JP-A-59-88526.

[Means for solving problems]

The above-mentioned purpose is a cylindrical processing cylinder arranged in a substantially horizontal shape,
A rotary shaft that is disposed in the processing cylinder in the axial direction and is driven to rotate by a motor, and a plurality of disks that are fixed to the rotary shaft at a predetermined interval and that are substantially orthogonal to the axis. Each disk has a plurality of tapered through holes in the axial direction, and the through holes of each disk have a direction in which each tapered through hole expands with a substantially central portion in the longitudinal direction of the processing cylinder as a boundary. They are formed opposite to each other and toward the end of the processing cylinder, and an inlet for the cement-based grout material to be atomized and a bead inlet are provided at the upper end of one end of the processing cylinder, and the beads are discharged at the bottom of the processing cylinder. In an apparatus provided with an outlet and an overflow port of the cement-based grout material that has been subjected to atomization treatment through an excess member at the upper end of the other end of the processing cylinder, the bead charging port is provided above the central portion in the longitudinal direction of the processing cylinder. , The bottom of the bead input port A vertical bead loading hopper opened vertically in the processing cylinder is erected, an ammeter for detecting the load current value of the motor, a switch for receiving a detection signal from the ammeter and disconnecting the motor circuit, and a motor. This is achieved by a wet atomization device for cement-based grout material, which is characterized in that an electric control device including a timer for restarting the motor after a lapse of a certain time has been attached to the motor.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to embodiments with reference to the accompanying drawings.

A horizontally cylindrical processing cylinder 2 is provided on the machine base 1, and a plurality of disks 3 are fixedly mounted in the processing cylinder 2 at predetermined intervals and substantially orthogonal to the axis of the processing cylinder. A shaft 4 is rotatably mounted horizontally via gland packings 5 provided at both ends of the processing cylinder 2. The rotating shaft 4 is rotated at high speed by a motor 9 fixed to the machine base 1 via pulleys 7 and 8 around which a belt 6 is wound. A cement-based grout material inlet 10 is provided at one upper end of the processing cylinder 2, and a cement-based grout material in which ordinary cement is mixed with water is continuously fed into the processing cylinder 2 through a pump P from a mixer (not shown). To be supplied to. A bead charging hopper 11 made of hard particles such as steel balls, steel pellets, ceramics or porcelain is provided at the center of the processing cylinder 2 in the longitudinal direction. The charging hopper 11 is a vertical cylinder, and the lower part is opened inside the processing cylinder 2. Further, the overflow port 12 is provided on the other end of the processing cylinder 2.
Is provided, and a wedge-shaped screen bar-shaped excess member 13 is disposed at the bottom thereof. The wedge-shaped screen bar is arranged in the axial direction, and the wedge is expanded outward to facilitate cleaning with the wire brush. In addition, the overflow port 12 itself has a double structure, which is removable for cleaning. Reference numeral 14 denotes an atomized grout material take-out pipe provided on the upper member 13. A bead outlet 15 having a bottom lid 15A is provided at the center bottom of the processing cylinder 2, and a tray 16 and an outlet 17 from the tray 16 are provided below the bead outlet 15.

The above-mentioned disks 3 are fixed to the rotating shaft 4 at right angles to each other. The beads supplied into the processing cylinder 2 are stirred to grind the grout material, and the beads at the center of the processing cylinder 2 are directed toward both ends. Make a contract to move. For this reason disk 3
As shown in FIG. 2, there are a plurality of tapered through holes 3A.
Are formed in the axial direction. This through hole 3A is the processing cylinder 2
The left side disk 3 is provided with a taper that expands toward the left side, and the right side disk 3 is provided with a taper that expands toward the right side with the center part of the boundary as a boundary. Since the beads move in the direction in which the taper of the through hole 3A expands, the beads move rhythmically inside the processing cylinder 2 due to the rotational movement of the disk 3,
This improves the effect of crushing the grout material into fine particles.

The processing cylinder 2 is surrounded by a water cooling jacket 18. Reference numeral 19 is a control device including an ammeter 20, a switch 21 and a timer 22, which are connected to the motor 9 and the pump P, respectively.

Next, an operation example of the apparatus of the present invention will be described.

The inner volume of the processing cylinder used was 50, and the rotation speed of the rotating shaft was 700.
It was ~ 800 rpm. About 300 kg of beads having a particle size of 0.6 to 2.0 mm are charged into this treatment cylinder 2, and grout material in which ordinary Portland cement is mixed at a cement water ratio (C / W) = 1: 3 is used at a speed of 7 to 10 l / min. A pump P was continuously fed through the feed port 10 to carry out atomization treatment. By this treatment, ordinary Portland cement having an average particle size D ₅₀ = 20 μm was refined to have an average particle size D ₅₀ = 2 to 3 μm. The take-out speed of the finely-ground grout material obtained from the overflow port 12 is 8.5 l / min on average.

During the above-mentioned refining treatment, the beads are worn by friction with the disk 3 and the grout material, and when the average particle diameter becomes 0.1 to 0.2 mm, the cement particles cannot be effectively ground. 5 kg of beads that can be used in this way per hour
Decrease. However, in order to produce a good quality grout material, it is necessary to maintain a certain amount of usable beads in the processing cylinder 2.

According to the apparatus of the present invention, a predetermined amount of beads is contained in the bottomless charging hopper 11. During the operation of the apparatus, centrifugal force acts on the beads and grout material filled in the processing cylinder 2, so that the beads in the charging hopper 11 are in equilibrium with the filling and do not fall into the processing cylinder 2. Maintained in the incoming hopper. As described above, when the number of usable beads, that is, the beads having a large diameter, is reduced, the filling rate of the beads in the processing cylinder 2 is reduced, so that the load of the motor 9 is reduced and the ampere value of the current is reduced. The control device 19 is configured to detect the ampere value of the current flowing through the motor 9 with the ammeter 20 and stop the operation of the motor 9 and the pump P by the switch 21 that receives the signal.

When the operation of the motor 9 is stopped, the centrifugal force of the packing becomes 0, and the charging hopper is placed in the surface slurry part 23 of the packing below the charging hopper 11 (slurry does not appear in this part during operation).
The beads at the bottom of 11 fall. When the time set in the timer 22 has passed, the motor 9 and the pump P are restarted and the operation is started. The pump P does not have to be stopped when the above stop time is short. In the case of the present embodiment, the amount of beads reduced is 5 kg / hr, so if the operating time per day is 6 hours, the capacity of the charging hopper 11 will be 30 kg.

Next, the relationship between the load current value of the motor 9 and the bead replenishment amount
3 and 4 and [Table] will be described.

The lower limit current value of the load current of the motor was set to 170A, and the stop time of the motor was set to 8 seconds. As shown in FIG. 3 and the table, when the motor 9 is stopped, an average drop difference of 7.6 cm occurs between the lower surface of the beads in the charging hopper 11 and the surface of the slurry portion 23, and an average of 2.5 kg of beads becomes the slurry portion. Drops to the surface of 23. When the motor is restarted, the load current value averages 182A. The average driving cycle is 30 minutes.

FIG. 4 is a diagram showing the cumulative replenishment amount of beads, and as can be seen from the table, the corresponding amount of beads is replenished from the charging hopper 11 according to the decrease of the beads in the processing cylinder 2.

When operating for a long time, the amount of worn beads in the processing cylinder 2 increases and the atomization efficiency decreases. Therefore, the operation of the apparatus is periodically stopped, the discharge port 15 is opened, and the packing material is taken out and sieved. At this time, beads with a particle size larger than 0.6 mm are reused, and other beads are discarded.

〔The invention's effect〕

The present invention is configured as described above, and when the load current of the motor reaches the set value, the operation of the apparatus is stopped and the beads from the bottomless charging hopper drop by a certain amount into the processing cylinder due to their own weight. The replenishment amount is replenished, and during operation, the replenishing beads are kept in a state of not falling due to the centrifugal force of the packing in the processing cylinder and friction with the charging hopper. The entry effect is obtained.

[Brief description of drawings]

FIG. 1 is a partially cutaway sectional view of the device of the present invention, FIG. 2 is an enlarged sectional view of its rotary shaft and disk portion, and FIG.
FIG. 4 is a diagram showing changes in load current with time, and FIG. 4 is a diagram showing cumulative replenishment amount of beads. 2 ... Processing cylinder, 3 ... Disc, 3A ... Tapered through hole, 4 ... Rotary shaft, 9 ... Motor, 10 ... Grout material inlet before atomization, 11 ... Bead loading hopper, 12 …… Overflow port of atomized grout material, 13 …… Over-material,
15 …… Bead outlet, 19 …… Electric control device, 20 ……
Ammeter, 21 …… switch, 22 …… timer.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Hayaya 2-4-1-3, Shiki-shi, Saitama

Claims (1)

[Claims] 1. A cylindrical processing cylinder (2) arranged substantially horizontally.
A rotary shaft (4) arranged in the processing cylinder in the axial direction and driven to rotate by a motor (9); and a rotary shaft (4) at a predetermined interval from the rotary shaft so as to be substantially orthogonal to the rotary shaft. A plurality of fixed discs (3), each disc has a plurality of tapered through holes (3A) in the axial direction, and the through holes of each disc bound the substantially central portion in the longitudinal direction of the processing cylinder. Then, the expansion directions of the respective tapered through holes are formed so as to be opposite to each other and toward the end of the processing cylinder, and the inlet (1) of the cement-based grout material to be atomized is formed at the upper end of one end of the processing cylinder.
0) and a bead input port, a bead discharge port (15) at the bottom of the processing cylinder, and an excess member (13) at the upper end of the other end of the processing cylinder.
In an apparatus provided with an overflow port (12) for a cement-based grout material that has been subjected to atomization treatment, the bead charging port is provided at the upper part of the central part in the longitudinal direction of the processing cylinder, and the bead charging port is provided with a bottom part. A vertical bead loading hopper (11) having an opening in the processing cylinder is provided upright, and an ammeter (20) for detecting a load current value of the motor (9) and a motor receiving a detection signal from the ammeter. The electric control device (19) including a switch (21) for disconnecting the circuit of (1) and a timer (22) for restarting the motor after a lapse of a certain time after stopping the motor is attached to the motor. Wet atomizer for cement-based grout material.