JP3389946B2 - Powder mixing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder / granular mixing apparatus, and more particularly, to a horizontal rotating cylindrical mixing apparatus suitable for mixing fragile particles. The present invention relates to a powder and granular material mixing device capable of efficient and efficient mixing.

[0002]

2. Description of the Related Art A container rotation type mixing device is a device for mixing an object to be processed in a container by rotating the processing container itself and utilizing the drop around the container and its own weight. For example, Japanese Patent Laid-Open No. 8-229380 describes a "rotating cylindrical container type continuous mixer" as a container rotating type mixing device for the purpose of uniform mixing.

In the mixing device described in the above publication, a rotary cylindrical container having an axis of a horizontal axis, a supply port and a discharge port for the object to be treated provided at each end of the rotary cylindrical container, and a rotary cylindrical container It is composed of a plurality of spiral partition plates (spiral blades) attached to the peripheral surface with a length of about half a circumference. In such a mixing device, by a plurality of pairs of a pair of spiral partition plates attached corresponding to substantially the same position of the axis, the inside of the rotating cylindrical container is divided into a plurality of mixing chambers along the axial direction, further, The spiral directions of the pair of spiral partition plates are set to be opposite to each other,
Then, the objects to be treated are mixed by repeating the normal rotation and the reverse rotation of the rotating cylindrical container.

The container rotary type mixing device having a horizontal rotation axis as described above, a so-called horizontal rotary cylindrical type mixing device, can easily supply and discharge the powdery particles from the supply port and the discharge port at each end of the container. As compared with the V-type mixing device and the double-cone mixing device of the same container rotation system, there is no need to attach and detach the pipes due to the supply and discharge of the powder and granules, and it is excellent in that dust generation can be prevented. Moreover, since the stirring operation is gentle, it is suitable for a mixing operation of a powdery or granular material such as a granular material formed by molding magnetic powder as a raw material for manufacturing a magnetic recording medium, which is fragile like agglomerated fine particles.

[0005]

However, the above horizontal rotary cylindrical type mixing device is slower than the V type and double cone type mixing devices in terms of uniformity of mixing and mixing speed because the stirring operation is gentle. Is inferior. The present invention has been made as a result of various studies in order to realize an efficient mixing operation while making use of the above advantages in the horizontal rotary cylindrical mixing device, and the object thereof is to provide a fragile powder or granular material. A horizontal rotating cylindrical type mixing device suitable for mixing,
It is an object of the present invention to provide a powdery or granular material mixing apparatus capable of more uniform and efficient mixing.

[0006]

In order to solve the above-mentioned problems, a powdery-particle mixing apparatus according to the present invention is a rotary cylinder type mixing apparatus for agitating and mixing powdery particles, the axis of which is substantially horizontal. , Which can be rotated forward and backward, a supply port and a discharge port for the granular material provided at each end of the cylindrical container, and a first spiral attached to the inner peripheral surface of the cylindrical container. The blade includes a blade and a second spiral blade attached to the inside of the first spiral blade. Direction, the second spiral blade has a spiral structure for moving the internal granular material in the direction of the supply port by the forward rotation of the cylindrical container, and the second spiral blade The spiral pitch of the blades is larger than the spiral pitch of the first spiral blades. It is set, and, on the supply port
Is a supply spiral whose spiral direction is the same as that of the second spiral blade.
A blade is attached, and the outlet has a spiral direction.
A discharge spiral blade identical to the first spiral blade is attached
It is characterized by

In the above-mentioned mixing apparatus, when the cylindrical container is rotated in the reverse direction to perform the mixing operation, the inner peripheral surface of the cylindrical container lifts the powdery particles upward and drops them into an avalanche. At that time, the first spiral blade that rotates in accordance with the reverse rotation of the cylindrical container applies a force relatively to the falling powder and granular material in the direction of the supply port, and the second spiral blade drops. A force is applied relatively to the granular material in the direction of the discharge port, and as a result, a folding movement along the first spiral blade and the second spiral blade is generated in the granular material inside the cylindrical container. . And the first
The structure in which the spiral pitch of the second spiral blade and the spiral pitch of the second spiral blade are set to a specific ratio causes a left-right interchange movement when the scraped powder particles fall.
Also, in the mixing operation, the supply spiral blade of the supply port,
Prevents backflow from the supply port, discharge spiral blade at the discharge port
Prevents the granular material from overflowing from the outlet.

In the mixing device of the above aspect,
Especially, the spiral pitch of the second spiral blade is equal to that of the first spiral blade.
It is preferable that the spiral pitch is set to 1.5 to 2.5 times.
Good Further, the width of the second spiral blade is set to 30 to 70% of the width of the first spiral blade in order to prevent uneven distribution of the powdery particles in the cylindrical container and to mix them more efficiently. Is preferred. That is, in the structure in which the widths of the first spiral blade and the second spiral blade are set to a specific ratio, the pressure applied by the first spiral blade and the pressure applied by the second spiral blade to the granular material are Equilibrate and allow the agitated powder to be distributed approximately uniformly in the cylindrical container.

[0009] In each embodiment described above, in order to smoothly discharged at the discharge operation the pre-mixed powdery grains, the end portion of the cylindrical container outlet side was gradually reduced in diameter toward the distal cone Preferably a section is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a mixing apparatus for powder particles according to the present invention will be described with reference to the drawings. FIG. 1 is a partially cutaway perspective view showing the main structure of a powder / granular mixing apparatus according to the present invention. FIG. 2 is a cross-sectional view schematically showing the stirring function of each spiral blade in the mixing device of FIG. In the following description of the embodiments, the powder / granular mixing device is abbreviated as “mixing device”.

The mixing apparatus of the present invention is a batch-type rotary cylinder type mixing apparatus for stirring and mixing powder particles. Examples of the powder and granules include granular materials in a fragile form obtained by molding submicron particles such as iron powder and iron oxide powder for magnetic recording media into pellets. Usually, the particle size of such pellets is 3
The length is about 4 mm and the length is about 5 to 10 mm. When the pellets are used as a material at the time of manufacturing a magnetic recording medium, they are sufficiently mixed and prepared in order to compensate for differences in magnetic characteristics between individual pellets and to homogenize in a lot. However, when fine powder is generated during mixing, the homogeneity as a raw material lot is impaired, and a problem in handling such as transportation and weighing occurs. Therefore, in the case of mixing powders or granules such as the above-mentioned pellets, it is necessary to maintain a uniform shape as a raw material product and to disintegrate as much as possible, and to mix them efficiently.

As shown in FIG. 1, the mixing apparatus of the present invention is mainly provided in a cylindrical container (1) whose axes are arranged substantially horizontally and which can rotate in the forward and reverse directions, and at each end of the cylindrical container. And a discharge port (4) for the granular material, a first spiral blade (5) concentrically attached to the inner peripheral surface of the cylindrical container (1), and the first spiral blade. And a second spiral blade (6) attached to the inside of the.

The cylindrical container (1) can be formed in an appropriate shape as long as it has a circular cross section orthogonal to the axis and has an internal volume capable of sufficiently containing the powder or granular material as the object to be treated.
The illustrated cylindrical container (1) is a container provided with a conical portion (2) whose diameter is gradually reduced toward the tip at one end side. The dimensional specifications of the cylindrical container (1) are set according to the amount of powder and granular material to be processed, the equipment cost, and the like. For example, the cylindrical container (1)
The maximum inner diameter is about 1000 to 2000 mm, and the axial length of the cylindrical container (1) is about 1000 to 4000 mm.

Although not shown, the cylindrical container (1) has a support mechanism for supporting the body by four rollers, or
In addition to the above-mentioned four rollers, the supply port (3) and the discharge port (4) are rotatably supported by using a support mechanism that supports the support by bearings. As a driving mechanism of the cylindrical container (1), a mechanism for driving one of the rollers by a motor, a chain is wound around a sprocket provided along the outer periphery of the cylindrical container (1), and the chain is driven by a motor. There is a mechanism for doing so. Further, in the above drive mechanism, a motor capable of forward / reverse rotation or a transmission capable of reverse rotation is used in order to rotate the cylindrical container (1) normally and reversely.

As shown in FIG. 1, the supply port (3) is provided on the flat end face side of the cylindrical container (1). A supply spiral blade (7) having the same spiral direction as the second spiral blade (6) is attached inside the supply port (3) formed in a cylindrical shape. The supply spiral blade (7) in the spiral direction as described above has a function of smoothly carrying the powdery particles into the cylindrical container (1) in the supply operation and preventing a backflow from the supply port (3) in the mixing operation. Demonstrate. Then, although not shown, a transfer pipe line extended from a hopper or the like of the powder or granular material is connected to the supply port (3).

The outlet (4) is provided at the tip of the conical portion (2). Inside the discharge port (4) formed in a cylindrical shape, a discharge spiral blade (8) having the same spiral direction as the first spiral blade (5) is attached. The discharge spiral blade (8) in the spiral direction as described above has a function of preventing the granular material from overflowing from the discharge port (4) in the mixing operation and smoothly discharging the granular material in the discharge operation. . Then, although not shown, a transfer pipe line for transferring the mixed powder or granular material to a storage tank or the like in the next step is connected to the discharge port (4).
In addition, each of the transfer pipelines is connected to the supply port (3) and the discharge port (4) via a mechanical seal or the like in order to prevent generation of dust.

The first attached to the inner peripheral surface of the cylindrical container (1)
Of the first spiral blade (5) has a function of stirring and discharging the granular material, and the second spiral blade (6) attached to the inside of the first spiral blade (5) is the granular material. It has the function of promoting the stirring of. That is, in the mixing apparatus of the present invention,
The first spiral blade (5) has a spiral structure for moving the internal granular material toward the discharge port (4) by the forward rotation of the cylindrical container (1), and the second spiral blade (6) is Cylindrical container (1)
It is provided with a spiral structure for moving the powder particles inside in the direction of the supply port (3) by the normal rotation of. As a result, by rotating the cylindrical container (1) in one direction, the powder and granules can be sufficiently mixed without crushing, and by rotating the cylindrical container (1) in the other direction, the powder and granules can be smoothly discharged.

Further, in the mixing apparatus of the present invention, during the mixing operation, the powder particles that are temporarily lifted in the circumferential direction with the rotation of the cylindrical container (1) are prevented from interfering by the first spiral blade (5) with the axis line. It is important that the spiral pitch of the second spiral blade (6) is set to be larger than the spiral pitch of the first spiral blade (5) in order to make the second spiral blade (6) fall to a different position. Preferably, the spiral pitch of the second spiral blade (6) is 1.5 to 2.5 times the spiral pitch of the first spiral blade (5), specifically the second spiral blade (6). When the spiral pitch of the first spiral blade (5) is about 500 to 1000 mm, the spiral pitch of the first spiral blade (5) is about 200 to 7
It is set to 00 mm.

In the mixing operation, as will be described later, the cylindrical container (1) is reversely rotated, but the second spiral blade (6) is set by the reverse rotation and the above-mentioned setting of the spiral pitch.
The function of conveying the powder or granular material to the discharge port (4) side is promoted. Therefore, in the mixing device of the present invention, the conveying function of the second spiral blade (6) is suppressed to some extent, and the first spiral blade (5) and the second spiral blade (6) are agitated during the mixing operation. It is preferable to adjust the balance of functions.

That is, the first spiral blade (5) and the second spiral blade (5)
The spiral blades (6) are also continuous spiral plates, and from the above viewpoint, the width of the second spiral blade (6) (the height in the radial direction of the cylindrical container (1)) is the first. The width of the spiral blade (5) (height in the radial direction of the cylindrical container (1)) is about 30 to 70%. Specifically, the width of the first spiral blade (5) is designed to be about 100 to 300 mm, and the width of the second spiral blade (6) is designed to be about 50 to 150 mm.

The mixing process by the mixing device of the present invention is as follows. First, in the supply operation, the cylindrical container (1)
While rotating in reverse, powder particles are introduced into the supply port (3). The supply spiral blade (7) attached to the supply port (3) is
When this rotates in the reverse direction, the powder or granular material at the supply port (3) is fed into the cylindrical container (1). The supply amount of the powdery particles to the cylindrical container (1) is usually about 50% or less of the inner volume of the cylindrical container (1) in order to prevent deterioration of the stirring function.

Next, as shown in FIG. 2, the cylindrical container (1)
In the mixing operation of the powder or granular material supplied to the cylindrical container (1), the cylindrical container (1) is rotated in the reverse direction as in the supplying operation. In such rotation of the cylindrical container (1), the inner peripheral surface of the cylindrical container (1) lifts up the internal granular material and drops it into an avalanche. Moreover, the first spiral blade (5) rotates in accordance with the reverse rotation of the cylindrical container (1), and exerts a relative force on the falling granular material in the direction of the supply port (3), On the other hand, the second spiral blade (6) rotates in accordance with the reverse rotation of the cylindrical container (1), and exerts a relative force on the falling granular material in the direction of the discharge port (4). As a result, in the granular material inside the cylindrical container (1), a folding motion occurs along the first spiral blade (5) and the second spiral blade (6).

Further, in the above mixing operation, the spiral pitch of the first spiral blade (5) and the spiral pitch of the second spiral blade (6) are set to a specific ratio, and the second spiral blade is (6) is a position different in the axial direction when the granular material once lifted by the rotation of the cylindrical container (1) and the first spiral blade (5) is dropped, specifically, the discharge port (4) Move some to the side. That is, the first spiral blade (5) moves the scraped powder particles to the supply port (3) side, and the falling powder particles are moved to the discharge port (4) side by the second spiral blade (6). Let As a result, in the inside of the cylindrical container (1), the particles are exchanged along the axial direction.

In other words, in the mixing apparatus of the present invention, the first spiral blade (5) having a different spiral direction and spiral pitch when falling due to its own weight is applied to the powder or granular material contained in the cylindrical container (1). Since the second spiral blade (6) causes the folding motion in the left-right direction and the alternating movement in the left-right direction, the powder particles can be uniformly and efficiently mixed without crushing the powder particles.

Further, in the above mixing operation, the width of the first spiral blade (5) and the width of the second spiral blade (6) are set to the above specific ratio, It is possible to prevent uneven movement of the granular material toward the discharge port (4) due to the difference in spiral pitch. That is, the first spiral blade (5)
In the structure in which the widths of the second spiral blade (6) and the width of the second spiral blade (6) are set to a specific ratio, the pressure applied by the first spiral blade (5) to the powder particles due to the reverse rotation and the second spiral blade (6). ) And the pressure applied by the method (1) are balanced, and the powdery particles under stirring are distributed substantially uniformly in the cylindrical container (1). Therefore, in the mixing apparatus of the present invention, the cylindrical container (1) and the first spiral blade (5) and the second spiral blade (6) attached inside the cylindrical container (1) can sufficiently function, and the efficiency is further improved. The powder and granules can be mixed together.

Further, in the stirring operation by the reverse rotation, the supply spiral blade (7) of the supply port (3) rotates so as to move the powdery particles toward the discharge port (4), and the discharge port (4) Since the spiral blade (8) for discharge of) rotates so as to move the powder particles toward the supply port (3), in the stirring operation,
Granules do not overflow from both the supply port (3) and the discharge port (4).

Next, after the above-described mixing operation for a predetermined time, the cylindrical container (1) is rotated in the forward direction to perform the discharging operation. In the discharging operation, when the cylindrical container (1) is normally rotated, the first spiral blade (5) moves the powder particles toward the discharging port (4) contrary to the above mixing operation. Working, second
The spiral blade (6) acts to move the powder particles toward the supply port (3).

At this time, the conical portion (2) formed on the discharge port (4) side of the cylindrical container (1) cooperates with the first spiral blade (5) projecting on the peripheral surface thereof. It functions and sends out the granular material in the vicinity of the discharge port (4) to the discharge port sequentially. Then, the discharge spiral blade (8) attached to the discharge port (4) is
As this rotates forward with the cylindrical container (1),
The powder and granules at the discharge port (4) are discharged to a transfer pipe. Then, when the amount of the granular material in the cylindrical container (1) gradually decreases, the function of the second spiral blade (6) further deteriorates, and the peripheral surface of the cylindrical container (1) and the first spiral blade (5). Since the carrying-out function by (1) is enhanced, the particles are sequentially discharged at a high speed, and finally, all the granular materials in the cylindrical container (1) are discharged from the discharge port (4).

As described above, in the mixing apparatus of the present invention, the fragile granular material as described above is provided by the first spiral blade (5) and the second spiral blade (6) having different spiral directions and pitches. The powder and granules can be mixed uniformly and efficiently without crushing. Then, since the supply and discharge conduits can be airtightly connected to the supply port (3) and the discharge port (4) projecting at both ends along the axis with a mechanical seal or the like in advance, the series of operations described above is performed. It is possible to reliably prevent the generation of dust.

[0030]

As described above, according to the mixing apparatus for powder particles of the present invention, the powder particles contained in the cylindrical container are different in the spiral direction and the spiral pitch when falling due to their own weight. Since the spiral blade and the second spiral blade cause the folding motion in the left-right direction and the alternating movement in the left-right direction, the powder particles can be uniformly and efficiently mixed without crushing the powder particles , and , To the inlet and outlet
Each attached supply spiral blade and discharge spiral blade
Allows the powder from the supply port and the discharge port in the stirring operation to be
It can prevent the overflow of granules. Further, since the width of the first spiral blade and the width of the second spiral blade are set to a specific ratio, it is possible to prevent the uneven movement of the powder particles toward the discharge port due to the difference in the spiral pitch. Therefore, the powder and granules can be mixed more efficiently.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing the main structure of a powder / granular mixing apparatus according to the present invention.

2 is a cross-sectional view schematically showing the stirring function of each spiral blade in the mixing device of FIG.

[Explanation of symbols]

1: Cylindrical container 2: Conical part 3: Supply port 4: outlet 5: First spiral blade 6: Second spiral blade 7: Supply spiral blade 8: Spiral blade for discharge

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B01F 3/18 B01F 9/16

Claims (5)

(57) [Claims] 1. A rotating cylinder type mixing device for stirring and mixing powders and granules, comprising a cylindrical container having an axis arranged substantially horizontally, and rotatable forward and backward, and provided at each end of the cylindrical container. It is composed of a supply port and a discharge port for the granular material, a first spiral blade attached to the inner peripheral surface of the cylindrical container, and a second spiral blade attached to the inside of the first spiral blade. , The first
The spiral blade of No. 2 has a spiral structure for moving the internal granular material toward the discharge port by the normal rotation of the cylindrical container, and the second spiral blade of the second internal blade is formed by the normal rotation of the cylindrical container. comprising a helical structure for moving the body in the direction of the supply port, moreover, the helical pitch of the second helical blade is set to a larger pitch than the helical pitch of the first spiral blade, and the supply port The spiral direction is the second
The same supply spiral blade as the spiral blade is attached, and
The discharge port has the same spiral direction as the first spiral blade.
A mixing device for powder and granular material, which is equipped with a spiral blade for output . 2. The mixing device according to claim 1, wherein the spiral pitch of the second spiral blade is set to 1.5 to 2.5 times the spiral pitch of the first spiral blade. 3. The mixing device according to claim 1, wherein the width of the second spiral blade is set to 30 to 70% of the width of the first spiral blade. 4. The end of the cylindrical container on the side of the outlet is provided with a tip.
A contract that is equipped with a conical portion that gradually reduces in diameter as it goes
The mixing apparatus according to any one of claims 1 to 3. 5. A powder or granular material is obtained by molding magnetic powder into pellets.
The mixture according to any one of claims 1 to 4, wherein the mixture is a powder or granule.
apparatus.