JPH02269009A - Cement mixing method and its mixer - Google Patents

Abstract

PURPOSE:To shorten an agitating period of time, by a method wherein a raised agitated matter is moved to the center of a mixing tank, a thrust is given in the direction of the bottom, the agitated matter is circulated and a work is agitated. CONSTITUTION:A thrust is given to only an agitated matter located at almost the center of the agitated matter on the inside of a mixing tank 2 in the direction of the bottom 3 of the central direction of the mixing tank 2, the agitated matter to which the thrust is given is changed in its course by cooling the agitated matter with the bottom 3 and the agitated matter is run along the bottom 3. Then the agitated matter, which has changed its source by running along the bottom 3, is run along a circumferential surface of the mixing tank 2 and raised against gravity. The agitated matter is moved to the center of the mixing tank, the thrust is given to the same in the direction of the bottom 3 similarly, the same is circulated and a work is agitated. With this construction, the agitated matter can be agitated in simple structure, and a short period of time and with a little consumption power and little noise.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a cement mixing method for rapidly stirring and mixing hydraulic powder such as cement and a liquid, and a mixer therefor. In more detail, a convection submersible pump is installed in the stirring tank to produce cement milk, concrete,
This article relates to a cement mixing method for producing mortar, grout, etc., and its mixer.

[Prior art] A liquid made by mixing cement, water, an admixture, an admixture, sand, etc. is called grout, and a dedicated mixer for mixing this grout is called a grout mixer. A propeller is provided in the mixing tank, and the shaft of this propeller is extended and connected to a motor. The grout is made by driving a motor and stirring it with propeller blades. The mixed grout is discharged from the bottom of the mixing tank.

[Problems to be Solved by the Invention] In the propeller blade method of grouting, the propeller blades are attached to fixed positions, so they rotate coaxially and the water flow is in a fixed direction. For this reason, a co-rotation phenomenon occurs in which the stirring blade and the grout rotate around the mixing tank at the same circumferential speed, so the stirring action is weak and the time required for kneading is relatively long. In addition, cement adheres to the walls of the stirring tank, stirring blades, etc. and dries, causing caking. It takes man-hours and time to remove this hardened cement.

In addition, solidification of cement on the walls of the stirring tank, stirring blades, etc.
This impairs the fluidity of the grout, resulting in increased power consumption of the electric motor. In addition, the noise generated from the electric motor, stirring blades, and stirrer is relatively large.The flow of the material to be stirred is also not constant, so the kneading time is not always constant.Furthermore, the material to be stirred is on the transmission shaft that rotates the propeller. Cement solidification occurs and grows in the damp area at the boundary between the part and the outside air. Occasionally, this solidification would flake off and fall and get stuck between the stirring blade and the bottom plate of the stirring tank, stopping the rotation of the stirring blade.

There was also the problem that the solidified cement clogged the discharge hole. This invention was invented to solve the above-mentioned problems, and solves the following problems.

An object of the present invention is to provide a cement mixing method that requires short stirring time and a mixer for the same.

Another object of the present invention is to provide a cement mixing method and a mixer thereof that consume very little power.

Furthermore, another object of the present invention is to provide a cement mixing method and a mixer thereof that have extremely low noise.

[Means for solving the above problems] In order to solve the above problem, the following measures will be taken.

A first means is a cement mixer having a cylindrical mixing tank having a bottom surface, in which only the material to be stirred located approximately at the center of the material in the mixing tank is moved toward the bottom surface in the direction of the center of the mixing tank. A thrust is applied, and the object to be stirred, which has been given this thrust, collides with the bottom surface and changes its direction to follow the bottom surface, and the object to be stirred, which has been changed in direction along the bottom surface, is transferred to the mixing tank. The material to be stirred is raised against gravity along the circumferential surface of the tank, the material to be stirred that has risen is moved to the center of the mixing tank, and the material to be stirred is circulated by applying a thrust toward the bottom surface in the same manner as described above. This cement mixing method is characterized in that the workpiece is stirred by stirring the workpiece.

It is more effective to use a submersible pump having a propeller as the means for applying thrust to the object to be stirred.

The second means includes a cylindrical mixing tank, a bottom surface forming the bottom surface of the mixing tank, a rotating motor fixed at a distance from the bottom surface, and a center of the mixing tank connected to the rotating motor. a propeller provided coaxially so as to coincide with the line and for applying a thrust to the object to be stirred to the bottom surface; and a gap with the bottom surface surrounding the outer periphery of the propeller and allowing the object to be stirred to pass through. A cement mixer comprising a draft ring provided therein.

It is more effective if the bottom surface is tapered toward the center of the mixing tank and protrudes downward in the direction of gravity.

[Function] In a cement mixer having a cylindrical mixing tank with a bottom surface, a submersible pump applies thrust to only the material to be stirred located approximately at the center of the material in the mixing tank in the direction of the bottom surface in the direction of the center of the mixing tank. The material to be stirred, which has been given this thrust, collides with the bottom surface and changes its direction so that it runs along the bottom surface. This is a cement mixing method in which the material to be stirred is raised against gravity, moved to the center of the mixing tank, and similarly thrust is applied toward the bottom to circulate the material and stir the material. .

[Example] Embodiments of the present invention will be described below with reference to the drawings.

The cross-sectional view in FIG. 1 is a cross-sectional view of a mixer 1 of the present invention. The mixing tank 2 has a cylindrical shape with a gently tapered bottom 3 and an obtuse apex 4 at the center. This angle is preferably about 3 to 5 degrees, preferably about 4 degrees.
The top surface of the mixing tank 2 is open, and a disk-shaped insulator 115 is provided in the opening. A cylindrical cement inlet 6 is formed in a part of 115. A specified amount of cement is charged from the cement input port 6. A water input pipe 7 for inputting water is integrally provided in the center of the unit 115.

The bottom surface 3 of the mixing tank 2 is supported by a support stand 8.

A convection submersible pump 10 is provided at the center of the bottom surface 3. This submersible pump 10 has an electric motor and a reduction gear built therein, and its basic structure is a known submersible pump.The submersible pump 10 of this embodiment is a pump manufactured by Fricht. The rotational driving force of the electric motor rotationally drives the propeller 11 via a reduction gear and a propeller shaft. The propeller 11 is a propeller that has three blades at equal angular positions and has a twist angle in the direction of the rotation axis.

The shape of the propeller 11 has a self-cleaning effect and prevents foreign matter from adhering to the surface of the propeller 11.The material of the propeller 11 of this embodiment has improved wear resistance, corrosion resistance, etc. Made of nickel chromium molybdenum steel. An annular draft ring 12 is arranged around the outer periphery of the propeller 11. draft ring 12
The draft ring 12, which has a slightly wider opening in the upper part than in the lower part, increases the efficiency at the outer blade tip of the propeller 11, and also serves as a guide to create a powerful jet swirl flow.

The draft ring 12 is fixed to the pump body 9 and bottom surface 3 of the submersible pump 10 with two stays 13 made of angle material. Furthermore, the pump body 9 and the draft ring 1
The draft ring 12 and the bottom surface 3 are connected to each other for fixation by a connecting member (not shown). After colliding with the bottom surface 3, the flow direction is changed at an acute angle, and a gap is required to allow smooth flow.

It is desirable that the number of stays 13 be as small as possible so as not to interfere with convection.

Normally, two or three water input pipes 7 are required at equiangular positions, and the water input pipes 7 are connected to the water supply pipe 14 . An air pipe 16 is connected to the submersible pump 10, and air is supplied to the submersible pump 10 through this air pipe 16. This air is supplied to the bearing that supports the propeller shaft, cools the bearing, and prevents foreign matter from entering the bearing from the outside. This support structure is a well-known structure and will not be described in detail.The electric wire 15 is for supplying electric power to the electric motor that drives the submersible pump.

Taking cement milling cement milk as an example, the mixing method will be described in detail. Turn on the power, rotate the electric motor, and propeller 11
, and water is supplied into the mixing tank 2 through the water supply pipe 14 and the water input pipe 7. The water input pipe 7 is connected to the main body 9 of the submersible pump lO.
Supply water until it is submerged in water. The supplied water is stirred by the propeller 11 to generate convection as described later to circulate the water. This circulating chilled water is pumped by submersible pump 1.
0 pump body 9, the inner circumferential surface of the mixing tank 2, etc., to clean the previous cement and other deposits.

Inject the required amount of cement from the cement inlet. Since the propeller 11 is rotating, the cement and water circulate as shown in FIG. is guided by the draft ring 12, flies out from the propeller 11, and violently collides with the bottom surface 3. Since the bottom surface 3 is formed into a tapered shape, the flow force of the cement milk tends to head toward the center after collision.

However, since there is no escape in the center, that is, the pressure in the center is high, the cement milk eventually moves outward in the radial direction at an acute angle to the thrust direction of the propeller 11 in a direction that spreads outward all around the circumference. The cement milk that has moved outward in the radial direction spreads along the bottom surface 3 and then rides the jet flow and collides with the inner wall surface of the mixing tank 2 at a certain angle. The collided cement milk repulses and heads toward the center, and even toward the center, cement milk comes out one after another from the bottom, eventually moving to the upper layer along the inner circumferential wall surface of the mixing tank 2.

The cement milk that has moved to the upper layer now moves toward the center because there are no obstacles, that is, since the cement milk is constantly being sent toward the lower layer by the propeller 11, it moves so as to be sucked into the center. The cement milk moves in the axial direction along the outer peripheral surface of the pump body 9.

The moved cement milk is guided by the draft ring 12 and is given a powerful jet thrust to the propeller 11 as described above.

Since the above stirring operation is repeated at high speed,
Cement and water mix rapidly and homogeneously at all locations in the mixing tank 2, making it possible to create cement milk in a short time.
For example, if the diameter of mixing tank 2 is 1.30 m and the height is 1 m,
Blade propeller diameter 0.18m, rotation speed 1,000rpm
m, when stirring with an electric motor with an output capacity of 2 kW, cement milk collides with the bottom surface at approximately 2.0 m/s. Approximately 1
It was possible to stir the mixture homogeneously in about 20 seconds using m5.

By the way, a conventional mixing tank with a similar capacity and cylindrical shape has a diameter of 1.3 m, a height of 1 m, and a three-blade propeller diameter of 2.
It takes 5 minutes to knead using an agitating mixer with a rotation speed of 0 m, a rotation speed of 60 rpm, and an electric motor output capacity of 2 kW. The kneaded cement milk is discharged through a discharge pipe (not shown) connected to the bottom surface 3.
It is discharged by

[Other Examples 1 Although the bottom surface 3 in the above embodiment was conical, it is not limited to this shape. The shapes shown in FIGS. 3 and 4 show other shapes of the bottom surface 3. The bottom of FIG. 3 showing the embodiment is as follows:
This is an example in which a convex spherical surface 20 is formed. Since the convex spherical surface 20 is used, the circulation of the stirred material becomes smooth as described above. FIG. 4(a) is a sectional view, and FIG. 4(b) is a bottom view.

This is an example of a convex striped body 20 whose bottom surface is formed into a polyhedral shape.

The embodiment shown in FIG. 3 is desirable in terms of circulation of the material to be stirred, but it is difficult to manufacture. In the embodiment shown in FIG. 4, a triangular member 27 cut from a plate material and a trapezoidal member 26 can be welded together. It has the advantage that an approximate spherical surface can be produced relatively easily.

Although the above-mentioned example is an example used in the production of cement milk, it is clear from the above description that it may be used in the production of zero mortar, concrete, grout, etc., which is not limited to the production of cement milk. It is. Further, the number of blades of the propeller 11 of the submersible pump 10 is not limited to three, but may be any other number such as two or four.The electric motor is not powered by electric power, but is driven by air, oil pressure, etc. A drive source that powers the motor is sufficient.

[Effects of the Invention] As described in detail above, this cement mixing method and its mixer have a simple structure, can stir the material to be stirred in a short period of time, consumes little power, and makes very little noise. Since each mixing rod can be washed with water, the mixer can be kept clean.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a cement mixer, and Figure 2 is a cross-sectional view of the cement mixer.
-■ sectional view, FIG. 3 is a sectional view showing another embodiment of the mixing tank, FIG. 4(a) is a sectional view showing still another embodiment of the mixing tank, and FIG. It is a bottom view of figure (a). DESCRIPTION OF SYMBOLS 1... Cement mixer, 2... Mixing tank, 3... Bottom, 5... Lid, 6... Cement inlet, 9... Pump body, 10... Submersible pump, 12... ...Draft ring, 14...Water supply pipe

Claims (1)

[Claims] 1. In a cement mixer having a cylindrical mixing tank with a bottom surface, only the material to be stirred located approximately at the center of the material in the mixing tank is mixed with the material in the direction toward the center of the mixing tank. A thrust is applied in the direction of the bottom surface, and the object to be stirred, which has been given this thrust, collides with the bottom surface and changes direction to follow the bottom surface, and the object to be stirred is changed in direction along the bottom surface. The material to be stirred is raised along the circumferential surface of the mixing tank against gravity, and the material to be stirred that has risen is moved to the center of the mixing tank, and a thrust is applied in the direction of the bottom surface in the same manner as described above to stir the material to be stirred. A cement mixing method characterized by stirring the workpiece by circulating a material. 2. The cement mixing method according to claim 1, wherein the means for applying thrust to the material to be stirred is a submersible pump having a propeller. 3. A cylindrical mixing tank, a bottom surface forming the bottom surface of the mixing tank, a rotating motor fixed at a distance from the bottom surface, and a center line of the mixing tank connected to the rotating motor that coincides with the center line of the mixing tank. a propeller provided coaxially to apply a thrust to the agitated material to the bottom surface; and a propeller provided so as to surround the outer periphery of the propeller and to have a gap with the bottom surface so as to allow the agitated material to pass through. A cement mixer comprising a draft ring. 4. The cement mixer according to claim 3, wherein the bottom surface is tapered toward the center of the mixing tank and protrudes downward in the direction of gravity.