JP2000185315A - Mixing device for lightweight aggregate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize efficient manufacturing of the mixture of lightweight aggregates such as rice hulls, wood chips further stumped matters or the like. SOLUTION: This device has a bottomed cylindrical container, a rotating shaft 3 provided along the center line shaft of the cylindrical container 2 and one sheet of a mixing blade 4 attached to the rotating shaft 3 so as to locate the neighborhood of the bottom part of the cylindrical container. Even when lightweight and irregular-shaped aggregates such as rice hulls, wood chips and further stumped matters or the like are employed, neither agglomeration nor bridging develops, thus allowing efficient mixing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixing apparatus for lightweight aggregates, and more particularly, to a method for mixing lightweight aggregates such as rice hulls, wood chips and root extraction materials with binders such as bituminous materials and hydraulic inorganic materials. The present invention relates to a light-weight aggregate mixing apparatus that can mix well.

[0002]

2. Description of the Related Art Rice husks, wood chips, and root removal materials have recently been in the spotlight as aggregates for pavement mixtures, and these aggregates are conventionally used crushed stones, cobblestones, and gravel. Unlike aggregates such as sand and the like, the density is low, the weight is small, and the shape is irregular and complicated. Therefore, it has been difficult to efficiently produce a mixture using an existing general-purpose mixing device. Above all, the root extraction material is a material obtained by extracting the root of the tree remaining after cutting down the tree and cleaving and / or crushing it with a cleaver or crusher, and usually has a length of about 10 to 150 mm and a width of about 10 to 150 mm. Is about 3 to 60 mm, has a complicated shape such as a rod shape or a curved shape, and
Since whisker-like projections such as hair roots are also present, they are entangled with each other at the time of mixing, and it is extremely difficult to sufficiently mix them with the binder.

[0003] That is, as a general-purpose small mixing device, for example, a mortar mixer as shown in FIG. 7 has been conventionally used, and this mortar mixer stands at the center of a cylindrical mixing vessel 2. The arm 1 is attached to the rotating shaft 3
A plurality of mixing blades 4, 4 are attached via 1. Using such a mortar mixer, for example, when trying to mix a root extraction material and a binder such as asphalt emulsion, the root extraction materials are not only entangled with each other and aggregated, but also insufficiently mixed with the binder. Mixing vessel in which the root extraction material is gradually lifted by the rotating plurality of mixing blades 4 and 4 to cause a cross-linking phenomenon, so that the upper portion of the rotation range of the mixing blades 4 and 4 and neither the arm 11 nor the mixing blades 4 and 4 pass. There occurs a phenomenon in which the so-called shelves stay at the so-called blind spots in FIG. The retained root extraction material may remain without being mixed, or may be eventually pushed out of the mixing vessel 2 by the root extraction material that is pushed up one after another.

[0004] A similar phenomenon is observed in the case of rice hulls and wood chips. Light-weight aggregates such as rice hulls and wood chips that have caused a bridging phenomenon to form shelves above the mixing blades and fall by their own weights. Unless it is dropped again by human power, it is present outside the rotating mixing area of the mixing blade during the mixing period, and sometimes it is released out of the mixing container by crosslinked rice hulls or wood chips that are lifted one after another. Become. For this reason, in a conventional mixing device such as a mortar mixer, even if the mixing device itself has a large capacity, the amount of the mixture that can be actually mixed must be small.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and efficiently produces a mixture of lightweight aggregates such as rice hulls, wood chips, and root extraction materials. It is an object of the present invention to provide a general-purpose, small-sized mixing apparatus that can perform the above-described operations.

[0006]

Means for Solving the Problems As a result of repeated studies to solve the above problems, the inventors of the present invention have come up with the idea of a conventional mixing device that the mixing efficiency is proportional to the number of mixing blades.
Surprisingly, by attaching only one mixing blade to the rotating shaft at the center of the mixing container, it is possible to efficiently produce a uniform mixture even if the aggregate is lightweight, surprisingly. And completed the present invention.

That is, the present invention provides a cylindrical container having a bottom, a rotating shaft provided along a central axis of the cylindrical container, and a rotating shaft provided near the bottom of the cylindrical container. The object is achieved by providing a mixing device for a lightweight aggregate having one attached mixing blade. Note that to be located near the bottom of the cylindrical container here means that the mixing blades are attached so as to substantially rotate the bottom of the cylindrical container,
The specific mounting position is not particularly limited as long as the mixing blade can substantially stir and mix the mixture present at the bottom of the cylindrical container, but, for example, the lower end of the mixing blade is A distance of about 5 to 30 mm, preferably about 10 to 20 mm from the bottom is desirable from the viewpoint of achieving efficient mixing without biting the aggregate.

In the mixing device for a lightweight aggregate of the present invention,
The angle formed between the mixing blade attached to the rotating shaft and the bottom of the cylindrical container is in the range of 30 to 50 degrees, especially 35 to 45 degrees.
It is preferably in the range of degrees, more preferably around 40 degrees. Even if the angle between the mixing blade and the bottom of the cylindrical container exceeds 50 degrees, mixing does not necessarily become impossible, but the resulting mixture tends to have poor uniformity. Conversely, if the angle between the mixing blade and the bottom of the cylindrical container is less than 30 degrees, mixing is not impossible, but the time required to obtain a uniform mixture tends to be long.

Further, in the mixing device for a lightweight aggregate of the present invention, when the length L of the installed mixing blade in the cylindrical radial direction from the center of the rotation axis is R, the radius of the cylindrical container is R. , L / R = 0.75 to 0.95,
It is preferably in the range of 0.85 to 0.95. L / R
Is less than 0.75, it does not mean that mixing becomes impossible, but the mixing efficiency tends to decrease. Also, L / R
Even if the value exceeds 0.95, mixing is not impossible, but the aggregate is caught between the tip of the mixing blade and the inner wall surface of the cylindrical container, which hinders rotation of the mixing blade. May be caused.

On the other hand, the width B of the mixing blade in the direction orthogonal to the length L measured in the cylinder radial direction of the mixing blade is B / R = 0.40 to 0.4, where R is the radius of the cylindrical container. It is preferably in the range of 65, especially in the range of 0.45 to 0.55. If the value of B / R is less than 0.40, mixing does not necessarily become impossible, but the mixing efficiency tends to decrease. Conversely, if the value of B / R exceeds 0.65, the mixture to be mixed is deteriorated. Tends to be pushed upward, and the uniformity of the mixture tends to decrease.

In the mixing apparatus for a lightweight aggregate according to the present invention, an auxiliary blade made of a material softer than the mixing blade is attached to the mixing blade, and the mixing blade and the inner wall of the cylindrical container and / or the bottom of the cylindrical container are attached to the mixing blade. It is desirable to close the gap. Since the auxiliary blade is made of a soft material, there is no danger of the aggregate being caught between the inner wall of the cylindrical container and / or the bottom of the cylindrical container, and the mixing efficiency can be further improved. In addition, the auxiliary blade only needs to at least partially close the gap between the mixing blade and the inner wall of the cylindrical container and / or the bottom of the cylindrical container, and the gap between the mixing blade and the inner wall of the cylindrical container and / or the bottom of the cylindrical container can be reduced. , It is not necessary to completely close.

When the height of the cylindrical container is H and the radius of the cylindrical container is R, the ratio H / R is 1.5 to 1.8. Is preferably in the range. If the value of H / R is less than 1.5, the amount of the mixture that can be put into the cylindrical container is small, and the mixture may jump out of the container, which may make it impossible to mix efficiently. On the other hand, when the value of H / R exceeds 1.8, it is difficult to take out the mixture.

In the mixing device for a lightweight aggregate of the present invention,
The cylindrical container is supported so as to be tiltable with respect to the apparatus main body, and can be tilted at an appropriate angle at the time of discharging the mixture to facilitate discharge of the mixture. In addition, it is also possible to discharge the mixture by opening the bottom of the cylindrical container. The mixing device for a lightweight aggregate of the present invention usually performs mixing in a state in which a cylindrical container is upright, that is, in a state in which a rotation axis is vertical. You may use it in the state that it was.

The lightweight aggregate targeted by the mixing device for lightweight aggregate of the present invention is not limited to the above-described rice hulls, wood chips and root extraction materials, but also includes straw, fiber materials, rubber particles, plastic particles, cork particles. Of course, other aggregates such as sand and screenings may be mixed with these lightweight aggregates. The binder mixed with the aggregate is not limited to ordinary asphalt and modified asphalt, asphalt emulsion and modified asphalt emulsion, but also includes hydraulic inorganic materials such as cement, resins, and polymer substances. The use of the mixture to be produced is not limited to paving.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a light weight aggregate mixing apparatus of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a light-weight aggregate mixing apparatus 1 according to the present invention.
FIG. 1 is a view showing an example, and in the figure, a mixing device for lightweight aggregate indicated by reference numeral 1 includes a cylindrical container 2, a rotating shaft 3 provided along a cylindrical axis of the cylindrical container 2, And one mixing blade 4 attached to the shaft 3. In the present invention, it is important that only one mixing blade 4 is attached to the rotating shaft 3. The mixing blade 4 is rotated in the direction of the arrow by a driving source such as an electric motor indicated by 5 and is a material to be mixed. The lightweight aggregate and the binder are mixed efficiently. Reference numeral 6 denotes a gantry, which supports the cylindrical container 2 in a tiltable manner by rotating shafts 7, 7. The tilting of the cylindrical container 2 may be performed manually or using mechanical force such as hydraulic pressure. In addition, the mixture that has been mixed is usually discharged from the inside of the cylindrical container 2 to the outside by tilting the cylindrical container 2 by a required angle. Of course, an openable and closable opening for discharging the mixture may be provided.

The light-weight aggregate mixing apparatus of the present invention may be provided with an elevating means (not shown) to make the vertical position of the cylindrical container 2 variable, and further, by providing a not-shown moving wheel. It is also possible to arbitrarily perform the steps described above or to provide a position fixing means to prevent the mixing apparatus from becoming unstable during the mixing operation.

FIGS. 2 and 3 are diagrams for explaining the relationship between the cylindrical container 2, the rotating shaft 3 and the mixing blade 4 in more detail. The same components as those in FIG. is there. As shown in FIGS. 2 and 3, the mixing blade 4 is attached to the rotating shaft 3 so as to be located near the bottom of the cylindrical container 2. It is preferable that a small gap S is left between the lower end of the mixing blade 4 and the bottom of the cylindrical container 2 from the viewpoint of preventing scraping of the aggregate, usually about 5 to 30 mm,
Preferably, they are separated by about 10 to 20 mm. It is desirable that the gap S be adjustable depending on the type of aggregate that is the mixture to be mixed. For example, in the case of a root extraction material generally having a length of about 10 to 150 mm and a width of about 3 to 60 mm, It is relatively large, and it is desirable to make it small for rice husks with a small length and width.

The mixing blade 4 includes the mixing blade 4 and the cylindrical container 2.
Is 30 to 50 as described later.
In the range of degrees, especially in the range of 35 to 45 degrees,
It is preferably in the vicinity of degrees. That is, since the mixing blade 4 is inclined at a predetermined angle, as the mixing blade 4 rotates, the material to be mixed is jumped upward along the inclination of the mixing blade 4 and falls behind the mixing blade 4 when falling. It is considered that the material to be mixed at the upper portion is entangled and falls, and the mixing proceeds at the portion behind the mixing blade 4. Even if the angle α between the mixing blade 4 and the bottom of the cylindrical container 2 exceeds 50 degrees, mixing is not impossible, but
There is a disadvantage that the mixture is agglomerated, and simply moves in the cylindrical container 2 as the mixing blade 4 rotates, so that it is difficult to obtain a uniform mixture. Also, conversely,
Even if the angle α is less than 30 degrees, mixing is not impossible, but the time required to obtain a uniform mixture becomes longer,
Efficiency tends to decrease.

The width B of the mixing blade 4 is set to be B / R = 0.0, where R is the radius of the cylindrical container 2 as described later.
It is preferably in the range of 40 to 0.65, and especially in the range of 0.45 to 0.55. Even if the value of B / R is less than 0.40, mixing is not impossible, but the area of the mixing blade 4 tends to be too small, and the mixing efficiency tends to decrease.
Conversely, if the value of B / R exceeds 0.65, the mixture tends to be pushed upward, and the uniformity of the mixture tends to decrease.

On the other hand, as shown in FIG. 3, the length L of the mixing blade 4 measured in the cylindrical radial direction from the center of the rotating shaft 3 is, as described later, L / R = 0.75 to 0.95. It is preferably in the range, especially in the range of 0.85 to 0.95. L
If the value of / R is less than 0.75, mixing does not necessarily become impossible, but the area of the mixing blade 4 becomes too small, and the mixing efficiency tends to decrease. Further, when the value of L / R is 0.
Even if the mixing ratio exceeds 95, mixing is not impossible, but the aggregate may be caught between the tip of the mixing blade 4 and the inner wall surface of the cylindrical container 2, which may hinder the rotation of the mixing blade 4. There is.

The shape and size of the cylindrical container 2 are not particularly limited. When the height of the cylindrical container is H and the radius of the cylindrical container is R, H / R = 1.5 to 1 .8 is preferred. When the value of H / R is less than 1.5, the amount of the mixture that can be charged at one time is small, and there is a possibility that efficient mixing may not be performed. When the value of H / R exceeds 1.8, the amount of the mixture may be reduced. Extraction becomes difficult.

The mixing blade 4 is usually plate-shaped, and is formed of, for example, a tough material such as steel, stainless steel, or hard plastic. The mounting of the mixing blade 4 to the rotating shaft 3 is performed, for example, by welding. Means may be used, but it is desirable that the mixing blade 4 is detachably attached to the rotating shaft 3 and that the position thereof can be adjusted. For this purpose, for example, means such as screws, screws, pins, and fittings are used. It is desirable.

The shape of the mixing blade 4 is usually the shape shown in FIGS.
Is a rectangular shape as shown in FIG. 4, but may be a shape having an uneven width B as shown in FIGS. 4 and 5, for example. In the case where the width B has a non-uniform shape as described above, the determination as to whether or not the B / R is in a suitable range can be made based on the value of the width B when converted into a rectangle having the same area.

FIG. 6 is a view showing an example in which the auxiliary blade 8 is attached to the mixing blade 4. As shown in FIG. 6, the auxiliary blade 8 is provided with an oval slit 9 in the mixing blade 4.
Is mounted so as to be adjustable in position by a bolt and nut 10. The space between the mixing blade 4 and the bottom surface of the cylindrical container 2 is almost completely closed by the auxiliary blade 8, and the space between the mixing blade 4 and the inner wall surface of the cylindrical container 2 is similarly set by the auxiliary blade 8. It is closed. Bolt and nut 10
By loosening the auxiliary blade 8 and adjusting the mounting position of the auxiliary blade 8 so that a gap is left between the lower end of the auxiliary blade 8 and the bottom surface of the cylindrical container 2. It is also possible to appropriately close the gap between the mixing blade 4 and the inner wall surface of the cylindrical container 2 in place of the above.

As a material of the auxiliary blade 8, any material that is softer than the mixing blade 4 can be used, but rubber such as styrene butadiene rubber, butadiene rubber, isoprene rubber, and natural rubber can be used. Is desirable,
A hard band cloth, a band brush made of metal or the like can also be used.

Hereinafter, the present invention will be further described with reference to Experimental Examples and Examples.

[0028]

[Experiment 1] <Effect of mounting angle of mixing blade> Radius 38
A rotary shaft is attached to the center of the bottom of a cylindrical container having a height of 0 mm and a height of 630 mm, and one rectangular plate-shaped mixing blade having a length from the axis of the rotary shaft to the tip of 350 mm and a width of 265 mm is attached to the rotary shaft. A light-weight aggregate mixing device as shown in FIG. 1 was prepared by mounting the mixing blade so that the gap between the lower end of the mixing blade and the bottom of the cylindrical container was 10 mm. Using this mixing device for lightweight aggregates, the quality of the mixing property when the angle α between the mixing blade and the bottom surface of the cylindrical container, that is, the mounting angle of the mixing blade, was variously tested. The quality of the mixing property was determined by asking the six experienced workers whether or not a cross-linking phenomenon had occurred due to the mixture during the mixing operation, whether or not the mixture had agglomerated, whether the properties of the obtained mixture were good or not, and We asked them to judge comprehensively from the viewpoint of the presence or absence of overflow of the mixture during work.
Those judged good by three or more out of six persons were judged as △, and those judged as poor were judged as ×. The mixing time was 2 minutes, and the rotation speed of the mixing blade was 60 times / minute. Table 1 shows the composition of the mixture used, and Table 2 shows the results.

[0029]

[Table 1]

[0030]

[Table 2]

As is apparent from the results in Table 2, relatively good results were obtained when the mounting angle α of the mixing blade was 30 to 50 degrees, and in particular, when the angle α was 35 to 45 degrees, six judges made the judgment. Were judged to have good mixing properties. Also, the angle α
At 40 ° C., the properties of the kneaded mixture were uniform and particularly excellent.

[0032]

[Experiment 2] <Effect of width of mixing blade> Experiment 1 was performed using the same lightweight aggregate mixing apparatus as in Experiment 1 except that the mounting angle α of the mixing blade was fixed at 40 degrees and the width of the mixing blade was variously changed. In the same manner as in the above, the quality of the mixing property when the width of the mixing blade was variously changed was tested. Table 3 shows the results.

[0033]

[Table 3]

As is clear from the results in Table 3, the width B of the mixing blade is B / R = 0.0 with respect to the radius R of the cylindrical container.
Relatively good results are obtained when the value is 4 to 0.65.
When / R was 0.45 to 0.55, all the six judges judged that the mixing property was good. The properties of the mixture were uniform and particularly excellent.

[0035]

[Experiment 3] <Effect of length of mixing blade> Using the same lightweight aggregate mixing device as in Experiment 1, except that the mounting angle α of the mixing blade was fixed at 40 degrees and the length of the mixing blade was variously changed. In the same manner as in Experiment 1, the quality of the mixing property when the length of the mixing blade was variously changed was tested. Table 4 shows the results.

[0036]

[Table 4]

As is evident from the results in Table 4, the length L from the rotation axis of the mixing blade to the tip is L / R = 0.75 to 0.95 with respect to the radius R of the cylindrical container. Sometimes relatively good results are obtained, especially when L / R is between 0.85 and 0.95
At the time of, all of the six judges judged that the mixing property was good.

[0038]

Example 1 Using the light-weight aggregate mixing apparatus used in Experiment 1, the mounting angle α of the mixing blade was set to 40 degrees, and the length was set to 35 degrees.
A mixing operation of a mixture having the same composition as in Experiment 1 was performed in the same manner as in Experiment 1, except that auxiliary blades made of styrene butadiene rubber having a thickness of 0 mm, a width of 250 mm, and a thickness of 10 mm were attached to the mixing blades as shown in FIG. went. The total weight of the mixture was about 96 kg. During the mixing operation, no agglomeration or cross-linking of the mixture occurred, and a uniform mixture was obtained 2 minutes after the start of mixing.

[0039]

COMPARATIVE EXAMPLE 1 Using a mortar mixer shown in FIG. 7, the number of revolutions was set to 60 times / min in the same manner as in Example 1, and a mixture having the same composition as in Example 1 was mixed. The size of the cylindrical mixing container of the mortar mixer is the same as that of the cylindrical container used in Example 1, and the same weight of the mixture is charged to start mixing. A phenomenon of popping out of the container was observed. A crosslinking phenomenon occurred during the mixing operation, and each time, it was necessary to stop the rotation of the mixing blade and destroy the crosslinked portion using a scoop or the like. Mixing time of 2 minutes was still insufficient, and a satisfactory mixture was finally obtained with a mixing time of 6 minutes. Mixing with a conventional mortar mixer, compared with the case of using the lightweight aggregate mixing apparatus of the present invention, is the amount of the mixture that can be processed per batch, even though the size of the cylindrical mixing container is the same. The mixing time required was about 1/3, and the mixing time required was about three times as long without including the time during which the rotation of the mixing blade was stopped.

[0040]

Example 2 A mixing operation was performed in the same manner as in Example 1 except that the root extraction material in the mixture was changed to wood chips having the same volume. As in Example 1, no cross-linking phenomenon or agglomeration was observed, and a mixture of uniform and excellent properties could be obtained in about 2 minutes after the start of mixing.

[0041]

Example 3 A mixing operation was carried out in the same manner as in Example 1 except that the root extraction material in the mixture was changed to rice hulls having the same volume. As in Example 1, no cross-linking phenomenon or aggregation was observed.
About 2 minutes after the start of mixing, a uniform mixture having excellent properties could be obtained.

[0042]

As described above, the light-weight aggregate mixing apparatus of the present invention can be used for agglomeration, even for light-weight and irregularly-shaped aggregates such as rice husks, wood chips, and root extraction materials. Mixing can be performed efficiently without causing a crosslinking phenomenon. Moreover, the lightweight aggregate mixing apparatus of the present invention is small, can be easily mounted on a work vehicle or the like, and can be easily carried to a construction site. It makes it possible to manufacture. The mixing device for a lightweight aggregate of the present invention can be easily manufactured by modifying an existing mortar mixer or the like, and is extremely convenient and useful.

[Brief description of the drawings]

FIG. 1 is a view showing an example of a lightweight aggregate mixing apparatus of the present invention.

FIG. 2 is a diagram showing an attached state of a mixing blade.

FIG. 3 is a view showing an attached state of a mixing blade.

FIG. 4 is a diagram showing another example of the mixing blade.

FIG. 5 is a view showing still another example of the mixing blade.

FIG. 6 is a diagram showing an example of a mixing blade having auxiliary blades.

FIG. 7 is a diagram showing an example of a conventional mortar mixer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mixing device for lightweight aggregates 2 Cylindrical container 3 Rotating shaft 4 Mixing blade 5 Drive unit 6 Mounting stand 7 Rotating shaft 8 Auxiliary blade 9 Slit 10 Bolt nut 11 Arm α Mounting angle of mixing blade L Length of mixing blade B Mixing Blade width R Radius of cylindrical container H Height of cylindrical container

Continuation of the front page (72) Inventor Iwao Sugawara 2-8, 4-8 Mijigaoka, Kiyota-ku, Sapporo-shi, Hokkaido F-term (reference) 2D052 AA00 AA08 AA09 BA06 BA15 4G056 AA08 CC12 CD01 CD11 4G078 AA03 AB01 AB05 BA05 DA03

Claims (6)

[Claims] 1. A cylindrical container having a bottom, a rotating shaft provided along a cylindrical central axis of the cylindrical container, and a rotating shaft attached to the rotating shaft so as to be located near a bottom of the cylindrical container.
A mixing device for a lightweight aggregate having two mixing blades. 2. The lightweight aggregate mixing apparatus according to claim 1, wherein an angle formed between the mixing blade and the bottom of the cylindrical container is in a range of 30 to 50 degrees. 3. The length L of the mixing blade in the mounted state measured in the radial direction of the cylinder from the center of the rotation axis is R / R = 0.75 to 0.95, where R is the radius of the cylindrical container. And the width B of the mixing blade in the direction orthogonal to L is B / R =
The mixing device for a lightweight aggregate according to claim 1 or 2, wherein the mixing ratio is in the range of 0.40 to 0.65. 4. The mixing device for a lightweight aggregate according to claim 1, further comprising an auxiliary blade softer than the mixing blade for closing a gap between the mixing blade and the inner wall of the cylindrical container and / or the bottom of the cylindrical container. . 5. When the height of the cylindrical container is H and the radius of the cylindrical container is R, the ratio H / R is in the range of 1.5 to 1.8. A mixing device for a lightweight aggregate as described in the above. 6. The mixing device for a lightweight aggregate according to claim 1, wherein the cylindrical container is tiltably supported.