JP2000015621A - Device and method for continuous mixing method for concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuous kneading method and a device thereof of particularly superior 'kneading properties' for the purpose of eliminating the insufficient kneading in a continuous mixer. SOLUTION: When cement, materials similar to cement, water, clay or various kinds of powder and grain materials are mixed continuously in a mixing tank in a continuous mixing method, concrete is manufactured through a first process of pressure filling an introduced mixed material 1 into a mixing tank 3 and a second process of shearing and compression mixing the mixed material 1 introduced into the mixing tank 3. A continuous mixing device is provided with a mixing tank 3 having mixing plates, the peripheries of which are closed, and also provided with a filling means for transferring the mixed material 1 into the mixing tank 3, and compressing the same in the mixing tank 3, mixing plates for sealing and compression mixing the mixed material 1 in the state of being compressed by the filling means and a pressure control means for controlling the compression ratio of the mixed material 1 in the mixing tank 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous mixing method and apparatus for continuously mixing cement, cement analogs, water, and various powders.

[0002]

2. Description of the Related Art When a cement mixture is obtained by mixing cement and cement-like materials, water, clay or fly ash, etc., a predetermined slump cannot be obtained due to insufficient kneading in a conventional continuous mixer, and pumping is performed by pumping. However, it is impossible to mix the slump 7 more than the slump 13 required for pumping in a short time. For this reason, recently, an attempt has been made to tilt the continuous mixer from the horizontal state to reduce the moving speed of the mixture and to increase the residence time in the mixing tank (Japanese Utility Model Laid-Open No. 3-98933).

[0003]

However, the cement mixture (concrete) cannot be sufficiently mixed simply by extending the residence time in the mixing tank.
Conventionally known three mixing elements, shear and
It is necessary to perform compression mixing, convection mixing and diffusion mixing.

[0004] The continuous mixer is equipped with a screw blade or a paddle and mixes while convection, diffusion and shearing / compression. However, the above problem is caused by the lack of generally known "kneading". it seems to do.

Accordingly, the present invention has been made in view of the above, and in order to improve the shortage of kneading in the continuous mixer, the "kneading"
It is an object of the present invention to provide a continuous kneading method and apparatus excellent in the above.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method for continuously mixing cement and a cement analog, water, clay or various powders and granules in a mixing tank. A continuous mixing method for producing concrete through a first step of pressure-filling the mixed material and a second step of shearing and compression-mixing the mixed material pressure-filled in the mixing tank.

This method is used for mixing concretes.
Focusing on the point that water is strongly binding the surface of powder particles such as cement by surface tension, and a large shear force is required to crush the powder particles and their agglomerates,
Through the step of compressing the mixed material and the step of shearing the compressed mixed material, sufficient “kneading” is enabled. That is, the mixed materials in the mixing tank are brought into close contact with each other in the first step, in other words, the mixed material is filled and sealed in the mixing tank, and mixed by the mixing blade as in the conventional case. Rather than simply moving the material, the compressed mixed material is reliably sheared and ground by the mixing blades.

In a second aspect, a first step of pressure-filling the mixed material into the mixing tank and a step of shearing the mixed material under pressure are provided.
The method of continuously mixing concretes according to claim 1, wherein the second step of compression mixing is repeated a plurality of times.

A third aspect of the present invention is a continuous mixing apparatus having a mixing tank and mixing blades in the mixing tank and continuously producing concrete, wherein the mixing tank has a closed periphery around the mixing blade. Filling means for transferring the mixed material into the mixing tank and compressing the mixed material into the mixing tank; mixing blades for shearing and compressing the mixed material in a state compressed by the filling means; It is characterized by comprising pressure adjusting means for adjusting the compression ratio. This device adjusts the compression ratio of the mixed material in the mixing tank particularly by the filling means and the pressure adjusting means, and performs the same operation as the above-mentioned claim 1.

According to a fourth aspect of the present invention, there is provided the continuous concrete mixing apparatus according to the third aspect, wherein the filling means includes a rotating screw blade.

A fifth aspect of the present invention is the continuous mixing apparatus for concretes according to the fourth aspect, wherein the lead angle of the screw blade gradually decreases as the distance from the inlet increases.

According to a sixth aspect of the present invention, the discharge gate for discharging the mixture in the mixing tank to the outside of the mixing tank is disposed at a position higher than the mixing tank. It is a mixing device.

According to a seventh aspect of the present invention, there is provided the continuous mixing apparatus for concretes according to the third aspect, wherein the pressure adjusting means includes a discharge gate for adjusting a discharge amount of the mixture.

According to an eighth aspect of the present invention, the pressure adjusting means adjusts the pressure by a difference between a filling amount by the filling means and a discharge amount of the mixture in the mixing tank.
It is a continuous mixing apparatus of the concretes described.

A ninth aspect of the present invention is the concrete mixing apparatus according to the third aspect, wherein the pressure adjusting means has a variable wall for adjusting a volume in the mixing tank.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the structure of a continuous mixing apparatus of the present invention will be described with reference to FIGS. 1, 2 and 3 by taking an example having two rotating shafts as an example. FIG. 1 is a plan view showing only a section of the mixing tank 3 of the continuous mixing apparatus of the present invention, and FIG.
2 is a side view showing only the mixing tank 3 in FIG. 1 in cross section, and FIG. 3 is a cross-sectional view taken along the line AA in FIG.

The mixing tank 3 is configured so that all surfaces thereof are covered with walls so that a space is formed therein.
Only the inlet 6 and the discharge gate 8 have openings.

Inside the mixing tank 3, two parallel rotating shafts 4 penetrating the two walls facing each other in the longitudinal direction of the mixing tank 3 are connected to the mixing tank 3 via bearings 5 at both ends of the rotating shaft 4. It is mounted horizontally, and is rotatable around the rotation axis center line.

The screw blade 7 is connected to the input port 6 of the rotating shaft 4.
Is provided with an appropriate section length on the side close to. The mixing blade 9 is formed in a plate shape, and a plurality of spiral blades are provided on the rotating shaft 4 at intervals from the terminal end of the screw blade 7 toward the discharge gate 8.

The screw blade 7 and the mixing blade 9 are oriented so that the mixed material 1 proceeds from the inlet 6 toward the discharge gate 8 in accordance with the direction of rotation of the rotary shaft 4. The rotating shaft 4 is provided with a return blade 16 near the side wall of the mixing tank 3 on the side of the discharge gate 8.
Are screw-shaped blades in such a direction as to advance from the discharge gate 8 to the inlet 6.

The mixing tank 3 has a wall around the mixing blade 9 so that the tip of the mixing blade 9 does not come into contact with the blade and keeps a constant clearance when the mixing blade 9 rotates. The side wall of the mixing tank 3 on the discharge gate side in the axial direction of
Similarly, on the screw blade side, the periphery of the mixing blade 9 is configured to be hermetically closed by a configuration called an end surface of the screw blade 7.

The inlet 6 into which the mixed material 1 is supplied is located above the screw blade 7 so that the upper wall of the mixing tank 3 is opened, and a chute shaped wall is formed so as to spread upward so as to be easily supplied. It has been made.

A discharge gate 8 serving as a pressure adjusting means
Opens a part of the lower wall of the mixing tank 3 below the mixing blade 9,
The opening is provided with a slide gate or a door that can be opened and closed, and the opening and closing is performed by using the expansion and contraction of the cylinder 10 driven by electric power, hydraulic pressure, pneumatic pressure, or the like.

The rotation of the rotary shaft 4 is performed by connecting a sprocket 11 attached to one end of the rotary shaft 4 to a sprocket 13 of a motor 12 by a chain 14. A gear 15 mounted outside the sprocket 11 is provided to synchronize the rotation speeds of the two rotating shafts 4.

Next, a process of supplying a mixed material 1 (cement and cement analog, water, clay or various powders / granules) and discharging the same as a cement mixture 2 using the continuous mixing apparatus will be described.

First, in the first step, the mixed material 1 continuously supplied from the charging port 6 is mixed while being convected and diffused by the rotation of the screw blade 7 provided in the filling portion 17 of the mixing tank 3. At the same time, it is continuously transferred in the direction of the mixing blade 9.

At this time, the discharge gate 8 is completely closed until the mixed material 1 is sufficiently filled in the kneading section 18 of the mixing tank 3, and the mixed material 1 is continuously transferred by the screw blade 7. Then, the kneading part 18 of the mixing tank 3 is pressure-filled until there is no space around the mixing blade 9.

Next, in the second step, the mixed material 1 pressure-filled in the first step is sheared by the rotation of the mixing blade 9 and, at the same time, is transferred in the direction of the discharge gate 8. At this time, since the transfer amount of the screw blade 7 is set to be larger than the transfer amount of the mixing blade 9, the mixed material 1 is always pressure-filled around the mixing blade 9. The mixed material 1 that has been sufficiently sheared is discharged out of the mixing tank by opening the discharge gate 8, and the discharge amount of the cement mixture 2 is adjusted by the opening degree of the discharge gate 8, and at the same time, the mixing tank 3 is opened. The compression ratio of the pressure filling of the mixed material 1 inside is adjusted.

The return blades 16 return the cement mixture 2 so that the pressure-filled mixed material 1 does not leak from the clearance between the rotating shaft 4 and the side wall of the mixing tank 3 and damage the bearing of the bearing 5. , And serves to apply pressure to the mixing section 18.

In this step, the powder particles and the agglomerates thereof in a state in which water strongly binds the surfaces of the powder particles such as cement by the surface tension of the water are applied to the mixed material 1 around the mixing blade 9. Is pressure-filled, so that the mixing blade 9 is rotated to surely apply a shearing force and pulverize.

As described above, through the first step and the second step, it is possible to mix and discharge a slump 13 or more required in a case of sufficiently kneading and pumping in a short time. it can.

In the above embodiment, the rotating shaft 4 is
Although the number of rotation axes may be one or three or more, in such a case, in the cross section perpendicular to the axis of the mixing tank, the mixing tank keeps a constant clearance without contact when the screw blade and the mixing blade rotate. As long as it is formed in
As for the arrangement of the rotating shafts, for example, if there are three rotating shafts, three rotating shafts may be arranged in parallel or a triangle (or inverted triangle) may be formed. In this case, when the supply amount is small in accordance with the supply amount of the mixed material, the number of rotation shafts can be easily reduced by using one rotary shaft and the apparatus can be reduced.

As an example of the other filling means, any means may be used as long as it transfers the mixed material into the mixing tank and compresses the mixed material into the mixing tank. For example, a hose is provided between the charging port and the mixing tank, and the hose in the hose is provided. The mixed material may be extruded while being squeezed into the mixing tank.

When the screw blade is provided as another filling means and the lead angle gradually decreases as the distance from the inlet increases, the lead angle of the screw blade decreases as the mixed material approaches the mixing blade. Therefore, it is possible to perform pressure filling with a larger force, and a greater effect of shear / compression mixing by the mixing blade can be expected.

As another example of the filling means, although not shown, the outlet of the discharge pipe through which the mixture is discharged using the discharge gate 8 as a tubular discharge pipe is higher than the upper surface of the mixed material 1 inside the mixing tank 3. By setting the position, it is possible to generate a resistance at the time of discharging by the weight of the cement mixture 2 in the discharge pipe due to its own weight, and to constantly generate pressure inside the mixing tank 3. It is not necessary to provide the cylinder 10, and the maintenance part for maintaining the performance of the machine can be reduced.

FIG. 4 is a plan view showing a cross section of only a mixing tank 3 showing another embodiment, and FIG. 5 is a side view thereof. Figure 1
When compared with the apparatus of FIG. 3, the rotary shaft 4 is divided at the boundary between the screw blade 7 and the mixing blade 9, a bearing 20 is provided in the divided portion, and a motor for rotating the rotary shaft on the mixing blade side is added. is there.

This is characterized in that the screw shaft 21 and the mixing shaft 22 are independently rotated by separate motors, respectively, and the screw shaft 21 and the mixing shaft 22 are arranged around the mixing blade 9 which is the kneading section 18 of the mixing tank 3. The pressure adjustment for pressure-filling the mixed material 1 adjusts the rotation speed of the screw shaft 21 and the mixing shaft 22, for example, by increasing the rotation speed of the screw shaft 21 to be higher than the rotation speed of the mixing shaft 22 to increase the compression ratio of the kneading unit. This is performed by increasing the pressure, so that the continuously supplied mixed material 1 can be pressure-filled with a larger force, and the shearing force by the mixing blade 9 is more effectively applied. Further, this apparatus can select the number of revolutions of the rotating shaft in accordance with the optimum peripheral speed of the mixing blade that varies depending on the properties (for example, viscosity, particle size, water content, etc.) of the supplied mixed material 1, This makes it possible to obtain a cement mixture with better kneading. In this case, the number of the rotating shafts can be easily adjusted by setting the number of the rotating shaft to an arbitrary number according to the supply amount of the mixed material.

As another example of the pressure adjusting means, as shown in FIG. 6, a part of the wall around the mixing blades of the mixing tank 3 is slidable by the cylinder 24 toward the kneading section 18 of the mixing tank.
3, the volume of the kneading section 18 is reduced, and the kneading section 18 is maintained while the discharge amount from the discharge gate 8 is kept substantially constant.
Pressure adjustment alone can be performed,
Since the discharge amount and the pressure inside the mixing tank can be adjusted independently of each other, a better cement mixture can be produced.

[0039]

According to the method and apparatus of the present invention, since the mixed material in the mixing tank is pressure-filled until there is no space around the mixing blade, the powder particles in the mixed material and agglomerates thereof are reduced. Since they are formed in a state where they come into close contact with each other and receive a force, the shearing force of the mixing blade is effectively given, and the shear efficiency is greatly improved, and an excellent mixture can be obtained.

In addition, since the kneading is sufficiently performed, the length of the mixing tank is shorter than that of a device having only a screw blade and a paddle exhibiting the same mixing ability, and it is possible to provide a smaller device.

[Brief description of the drawings]

FIG. 1 is a plan view showing only a cross section of a mixing tank 3 of the continuous mixing apparatus of the present invention.

FIG. 2 is a side view showing only a mixing tank 3 in FIG. 1 in cross section.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a plan view partially showing a cross section of another embodiment.

FIG. 5 is a side view showing a part of FIG. 4 in section;

FIG. 6 is a partially enlarged sectional view of another embodiment of the pressure adjusting means.

[Explanation of symbols]

 1 Mixed material (concrete) 2 Cement mixture 3 Mixing tank 4 Rotary shaft 6 Input port 7 Screw blade 8 Discharge gate 9 Mixing blade 10 Cylinder 16 Return blade 17 Filling part 18 Kneading part 20 Bearing 21 Screw shaft 22 Mixing shaft 23 Variable wall

Continued on the front page F-term (reference) 4G056 AA06 CC07 CC09 CC10 CC37 CC39 CD01 CD11 CD31 CD36 CD55

Claims (9)

[Claims] 1. A first step of pressure-filling a charged mixed material into a mixing tank when continuously mixing cement and a cement analog, water, clay or various powders / granules in the mixing tank. And a second method of shearing and compression-mixing the mixed material pressure-filled in the mixing tank to produce concretes. 2. The continuous concrete according to claim 1, wherein the first step of pressure-mixing the mixed material into the mixing tank and the second step of shearing / compressing and mixing the mixture under pressure are repeated a plurality of times. Mixing method. 3. A mixing tank, comprising: a mixing tank; and a mixing blade in the mixing tank.
A continuous mixing apparatus for continuously producing concrete, comprising: a mixing tank in which a periphery of the mixing blade is sealed; a filling means for transferring a mixed material into the mixing tank and compressing the mixed material into the mixing tank; A continuous mixing apparatus for concrete, comprising: a mixing blade for shearing and compressing a mixed material in a state compressed by a filling means; and a pressure adjusting means for adjusting a compression ratio of the mixed material in the mixing tank. 4. The continuous mixing apparatus for concretes according to claim 3, wherein said filling means includes a rotating screw blade. 5. The continuous concrete mixing apparatus according to claim 4, wherein the lead angle of the screw blade gradually decreases as the distance from the inlet increases. 6. The continuous concrete mixing apparatus according to claim 3, wherein a discharge gate for discharging the mixture in the mixing tank to the outside of the mixing tank is provided at a position higher than the mixing tank. 7. The continuous concrete mixing apparatus according to claim 3, wherein the pressure adjusting means includes a discharge gate for adjusting a discharge amount of the mixture. 8. The continuous concrete mixing apparatus according to claim 3, wherein the pressure adjusting means adjusts the pressure by a difference between a filling amount by the filling means and a discharge amount of the mixture in the mixing tank. 9. The apparatus according to claim 1, wherein said pressure adjusting means has a variable wall for adjusting a volume in said mixing tank.
3. A continuous mixing device for concretes according to 3.