JPH0131448Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a mixer for cement paste that can produce good cement hydrate.

When cement, water and aggregates are mixed at the same time,
It is already known that concrete of sufficient strength cannot be obtained.

The reason is said to be that complete cement hydrate in a highly dispersed state cannot be obtained in fresh concrete.

Therefore, mortar is mixed by putting cement, sand, and water into the upper mixer.

When the above-mentioned mortar kneading is completed, the mortar flows from the upper mixer to the lower mixer, and the lower mixer mixes the aggregate and the mortar.

However, in the above-mentioned upper mixer, since the cement is simply kneaded while being transferred by the mixing blades, it does not work to increase the degree of dispersion of cement particles in the fluidized mortar during kneading.

For this reason, the cement particles are properly hydrated (absorbing the water necessary to chemically react with the cement)
There was a drawback that I couldn't do anything about it.

Therefore, cement is charged together with water into both ends of a cylindrical mixing drum, and the cement is pumped to the center using a mixing shaft penetrating through the mixing drum, the thrust direction of which is opposite to each other. The paste is fed into a pressure chamber that communicates with the center of the paste, and the compression and shearing effects that occur in this pressure chamber are used as the primary dispersion effect.Furthermore, this pressure effect increases the flow rate of the paste in the narrowed part whose opening can be adjusted, and its discharge. There is a mixer for cement paste in which force is applied to impact plates to give a secondary dispersion effect, and the paste that has passed through these plates is refluxed into a mixing drum to obtain a high degree of dispersion of cement particles in a short time. .

In this type of mixer, cement is pumped from both ends of a single mixing shaft to the center using screws whose thrust directions are opposite to each other. The cement simply collides and is forced into the constriction.

For this reason, there was a problem in that the shearing effect on the cement paste was small between the opposing ends of the screw, making it impossible to provide a good dispersion effect to the paste.

This invention aims to solve the above-mentioned problem by effectively shearing the cement paste toward the narrowed passage.

This idea involves inserting drive shafts driven in opposite directions by motors into each end of the mixing drum in a mixer for cement paste, and inserting drive shafts inward from both ends of the mixing drum into each drive shaft. To provide a mixer for cement paste, which is provided with a screw for transferring the paste, collides the paste between opposite ends of the screw, and shears the paste.

In the figure, reference numeral 1 denotes a horizontal cylindrical mixing drum, and a discharge port 2 that can be opened and closed is provided on the bottom surface of the center portion between both ends of the mixing drum 1.

In the illustrated case, the outlet portion 2 is opened and closed by operating a butterfly valve 4 using a handle 3.

5 and 5' are drive shafts inserted from both ends of the mixing drum 1.

The above drive shafts 5, 5' are connected to the mixing drum 1.
The drive shafts 5, 5' are supported by bearings 8 provided on the outside of both end plates 7, and motors 9, 9' are mounted at the outer ends of the drive shafts 5, 5' to drive the drive shafts 5, 5' in mutually opposite directions. is connected.

Further, the drive shafts 5, 5' are provided with screws 6, 6' that generate a thrust for transporting the mixing drum 1 inwardly from both ends thereof.

Furthermore, a container 10 is provided on the mixing drum 1, and the cement charged into the container 10 is configured to flow down into openings 11 provided in the top wall at both ends of the mixing drum 1.

Further, an opening 12 is provided in the top wall at the center between both ends of the mixing drum 1, and a narrow passage 13 whose opening degree can be adjusted is provided directly above the opening 12 so that the cement paste can flow therein.

A pair of left and right sliders 14, 14 are arranged on both sides of the opening in the case of the narrowed passage 13 shown in the figure, and tapered surface portions are provided on the opposing surfaces of the sliders 14, 14, with the opposing distance becoming smaller as they go upward; Further, a rod 15 extending from the outer ends of the sliders 14, 14 is passed through the flange 16 and end plate 7 of the mixing drum 1 from the container 10, and the rod 15 is inserted so as to sandwich the flange 16 and end plate 7.
Screw in the pair of nuts 17, and slide the slider 14 by loosening the nut 17 and rotating the rod 15.
4 and 14 can be freely adjusted.

Further, directly above the narrowed passage 13, there is a collision plate 18 that causes the mortar to collide and flow down into the openings 11, 11.
is provided.

In the illustrated case, the collision plate 18 is constructed by installing a triangular cylinder 19 whose bottom wall serves as the collision plate 18 between both end walls of the container 10, and supplying water to the cylinder 19 through a pipe 20. The supplied water flows down from through holes 21 provided on both side edges of the cylindrical body 19.

In the figure, 22 is a lid that closes the upper edge opening of the container 10;
23 is a metal fitting for fixing the lid 22 to the container 10.
24 is a support frame.

The mixer for cement paste according to this invention has the above-mentioned structure, and its operation will be explained next.Cement and water are supplied to the container 10 and flowed down from the opening 11 into both ends of the mixing drum 1. .

The cement and water that have flowed down to both ends of the mixing drum 1 are removed by the screws 6 of the drive shafts 5, 5'.
6' to transfer them inwardly and knead them.

At this time, the cement is pressurized by the thrust, and a large pressure is applied to the cement hydrate in the central pressurizing chamber a of the mixing drum 1 to cause the cement to collide, and the colliding cement is rotated in opposite directions, so that the cement paste is sheared, and the degree of dispersion of cement particles in the cement hydrate increases.

Therefore, the cement hydrate in the pressurized chamber a is pushed into the narrowed passage 13 and pressure is applied to it, and
The dispersion effect is further affected by the speed change.

Then, it is dispersed left and right from the narrowed passage 13 toward the collision plate 18, and is caused to flow down from the opening 11 to both ends of the mixing drum 1.

When the mortar collides with the collision plate 18, the mortar is again subjected to a dispersion effect.

By repeating the above steps, a high degree of dispersion of cement particles can be obtained in a short time.

As described above, according to the cement paste mixer of this invention, cement is fed and kneaded into the center of the mixing drum by the screws with mutually opposing thrust forces, and the cement is compressed and kneaded by the feeding pressure. The shearing effect is used as a primary dispersion effect, and further, a secondary dispersion effect is given by feeding this into a narrowing passage and changing speed and collision by a collision plate, and then by repeatedly returning it to a mixing drum, a cement paste is obtained. In this mixer, drive shafts that drive in opposite directions are inserted from both ends of the mixing drum, and screws are installed on both drive shafts to transfer cement to the center of the mixing drum. A large pressure is applied to the cement hydrates in the central pressurized chamber to cause them to collide, and the colliding cements are rotated in opposite directions.

Therefore, the cement paste is effectively sheared and the degree of dispersion of the cement particles in the cement hydrate is increased.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of a mixer according to this invention, and FIG. 2 is a longitudinal sectional side view of the same. 1... Mixing drum, 2... Discharge port, 3... Handle, 4... Butterfly valve, 5, 5'... Drive shaft, 6, 6'... Screw, 7... End plate, 8... Bearing,
9, 9'...Motor, 10...Container, 11...Opening, 1
2...Opening, 13...Narrowed passage, 14...Slider,
15...rod, 16...flange, 17...nut,
18... Collision plate, 19... Cylindrical body, 20... Pipe, 21
...through hole.

Claims (1)

[Scope of utility model registration request] A horizontal mixing drum has a discharge port that can be opened and closed, a screw is installed on a drive shaft passing through the drum so as to generate an inward thrust from both ends, and cement and water are placed at both ends of the mixing drum. The flow is returned to openings at both ends of the mixing drum through an input opening provided to supply the mixture, an opening provided in the top wall of the center of the mixing drum, and a narrow passageway that communicates with these openings and is provided so that the degree of opening can be adjusted. In a cement paste mixer, a mixer for cement paste is comprised of a collision plate that is branched to allow cement hydrate to collide with each other, and drive shafts that drive in opposite directions are inserted from both ends of the mixing drum. A mixer for cement paste characterized by having a drive shaft equipped with a screw for transferring cement toward the center of a mixing drum.