JPH10192688A - Horizontal extrusion screw type extrusion granulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold screen strength while increasing a screen area and to inexpensively produce a large amt. of granules having a small particle size. SOLUTION: A horizontal extrusion screw type extrusion granulator 1 is constituted so that a raw material A is transported to an extractor 51 while pressed and compressed by a screw 40 rotated within a screw case 41 and subjected to extrusion molding from an axial direction to a peripheral direction through a screen by slide action and extrusion pressure. In this case, the screen is formed into a semi-annular screen 50 having a semicircular cross-sectional shape by draw processing and the extractor 51 has a material pressing piece 51d formed along the inner surface of the semi-annular screen 50.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion-type screw-type extruder, and more particularly, to a wet-type extruder in the field of handling pharmaceuticals, foods, agriculture, chemicals, fertilizers, feeds and the like. The present invention relates to a screw type extrusion granulator which is widely used for extruding and granulating raw materials.

[0002]

BACKGROUND OF THE INVENTION Methods for obtaining granules having a diameter of about 1 mm or less from wet raw materials such as pharmaceuticals and foods include stirring granulation, fluidized bed granulation, tumbling granulation, and extrusion. There is a grain method. Among these methods, the extrusion granulation method is the most excellent in that the size of the granulated material is uniform and the yield is high, and the extrusion granulation machine for a small particle size employing this extrusion granulation method is preferred. , Basket type, pre-extrusion type screw type, horizontal extrusion type screw type and the like.

[0003] The granulation principle of these extrusion granulators is that an extrusion member such as an extrusion blade or an extract screw is disposed inside a screen having a large number of extrusion molding holes, and is fed between the screen and the extrusion member. The raw material is extruded from an extrusion hole and granulated.

[0004] Therefore, in order to improve the granulation ability, it is only necessary to increase the screen area and increase the number of extrusion holes, and thus, various types of current extrusion granulators also have such a design tendency. However, in the existing screen shapes having such a design tendency, the following problems are separately pointed out.

[0005] First, in the basket type extrusion granulator, the screen is a cylindrical shape fixed vertically, and if the radius of the cylinder is increased to increase the screen area, the strength is reduced and the extrusion pressure is low. Therefore, it is difficult to produce a large amount of granulated material by one unit.

In a pre-extrusion screw type extrusion granulator, a high extrusion pressure can be obtained. However, in order to manufacture a punching plate for forming a flat screen for a small particle size, or to reduce extrusion resistance, a punching granulator is used. It is desirable that the plate thickness be equal to or less than the diameter of the extrusion hole. For this reason, when the screen area is increased, the screen strength is reduced, and problems such as deformation of the screen during granulation occur.

Therefore, in order to solve the problem associated with the increase in the screen area in such a pre-extrusion screw type granulator, Japanese Patent Publication No. Hei 6-22669 "Pre-extrusion type screw type granulator" has been proposed. Spherical screens have been proposed. However, the strength of the spherical screen decreases as the diameter of the sphere increases, so even if the screen area is increased by increasing the diameter, the granulation capacity cannot actually be increased, and the scale-up cannot be performed beyond a certain limit diameter. .

When a spherical screen is formed by drawing from a punched circular plate as shown in FIG. 7 (a), the extruded hole becomes slightly larger at the top of the spherical surface, and the circular plate is formed at the peripheral portion of the spherical surface. Becomes longer in the radial direction and shorter in the circumferential direction. In order to prevent such deformation of the extrusion hole, as a method of reducing the molding distortion which causes the deformation, a molding material provided with a notch as shown in FIG. A method of joining the notch by welding, a method of providing a non-punched part with a fixed width so that the notch of the molding material can be welded, There is a way to change the shape. In each of these methods, it is necessary to take a time-consuming process for producing a spherical screen, and as a result, the production cost is high.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of such a background, and has been made by forming a thin punching plate having a large number of extrusion holes into a semi-annular shape having a semicircular cross section. Novel horizontal extrusion screw-type extrusion granulation that can increase the screen area, maintain the screen strength, and produce a large amount of small-sized granules at low cost by adopting a semi-annular screen This was an attempt to develop a machine.

[0010]

According to a first aspect of the present invention, there is provided a horizontal extrusion type screw extruder, wherein a raw material in a wet state is pressurized and compressed by a screw rotating in a screw case, and the end of the screw is extruded. Lateral extrusion, which is forcibly fed to the extractor provided in the section, and is extruded from the axial direction to the circumferential direction by a screen attached to the side surface of the terminal end of the screw case by the sliding action and extrusion pressure of the extractor In a screw-type extrusion granulator, the screen is formed in a semi-annular shape having a semi-circular cross-sectional shape.
According to the present invention, since a semi-annular screen having a semi-circular cross-sectional shape is employed, the radius of the semi-circular portion of the cross-sectional shape is r, and the radius of the semi-circular portion is R, as shown in FIGS. Then, even if the radius R of the semicircular portion is increased, the radius r of the semicircular portion is
If is not increased, the screen area can be increased without lowering the screen strength. Therefore, it is possible to improve the granulation ability.

A horizontal extrusion type screw extruder according to claim 2 is characterized in that, in addition to the above requirements, the screen is formed by drawing. According to the present invention, since the cross-sectional shape of the screen is drawn into a semi-circular shape having a semi-circular shape, the deformation of the extruded hole due to the forming distortion is reduced as compared with the case where the spherical screen is drawn from a punched circular plate. it can. Therefore, when forming a spherical screen, a notch is provided in the molding material that was used as a measure against molding distortion, and it is time-consuming to weld after molding and to change the hole shape of punching in consideration of molding distortion in advance. Since it is not necessary to take any steps, a semi-annular screen can be manufactured at low cost.

Further, in the horizontal extrusion type screw extrusion granulator according to claim 3, in addition to the above requirements, the extractor includes a material pressing piece formed along an inner surface of a semi-annular portion of the screen. It is characterized by having. According to the present invention, the material pressing piece of the extractor is formed along the inner surface of the semi-annular screen with respect to the semi-annular screen having a semi-circular cross-sectional shape. While being transported in the direction, it can be extruded efficiently by pressing against a semi-annular screen and extruding from an extrusion hole.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a horizontal extrusion screw type extrusion granulator 1 of the present invention will be described based on the illustrated embodiment.
As shown in FIGS. 1 and 2, the horizontal extrusion screw-type extrusion granulator 1 includes a gantry 2 movably fixing the horizontal extrusion screw-type extrusion granulator 1, and a drive for driving a screw 40. Section 3 and transport section 4 for transporting input raw material A
And a granulating unit 5 that substantially performs a granulating action.

Hereinafter, the main components will be described in detail. First, in the drive unit 3, the reduction gear 30, the coupling 3
1. The drive of the motor M is transmitted to the screw 40 via the bearing housing 32 and the screw drive shaft 33.

Next, the transport section 4 will be described. Transport unit 4
A screw case 41 supported by a plate or the like raised from the gantry 2, a screw 40 provided in the screw case 41, and a screw 40.
And a hopper 42 provided at an upper portion of the base end. In the present embodiment, the screw 40 is a single shaft.
Of course, it can be multi-axial.

Next, the granulating section 5 will be described. Granulation unit 5
Comprises a semi-annular screen 50 fixed to the end of the screw case 41 with bolts, screws, etc., and an extractor 51 provided inside the semi-annular screen 50 and fixed to the end of the screw 40. .

As shown in FIGS. 2 and 3, the semi-annular screen 50 is formed by drawing a punched molding material as an example, and has a semicircular cross-sectional shape. It is semi-annular and comprises a flange 50b over the entire outer peripheral edge. Further, a large number of extrusion-molded holes 50a having a diameter of 1 mm or less are formed in the semi-annular portion at an opening ratio of about 20% on the entire surface.

Here, the radius of the semi-circular portion of the cross-sectional shape of the semi-annular screen 50 is defined as r, and the radius of the semi-annular portion is defined as R. Hereinafter, the respective radii will be described as shown in FIGS. , The radius R of the semi-annular part is the radius of the semi-circle in the width center cross section of the semi-annular screen 50, and the radius r of the semi-circular part is
Is the radius of the semicircle in a cross section orthogonal to the width center cross section of the semi-annular screen 50. The semi-annular screen 50, which is a feature of the present invention, can increase the area of the semi-annular screen 50 by increasing the radius R of the semi-annular portion,
At this time, the strength of the semi-annular screen 50 does not decrease unless the radius r of the semi-circular portion that substantially determines the strength of the semi-annular screen 50 is increased. Thus, the granulating ability can be improved.

Next, the extractor 51 will be described. The extractor 51 is, for example, a disk-shaped member formed by shaving a cylindrical metal piece having a radius smaller than the radius R of the semi-annular portion of the semi-annular screen 50 by about 4 mm.

In the extractor 51, a screw mounting portion 51a is formed on the screw 40 side and has a small cylindrical shape and a key groove is formed along the axial direction. In the present embodiment, the screw mounting portion 51a is formed integrally with the extractor 51 by shaving or the like. However, the screw mounting portion 51a may be formed as a separate member from the extractor 51 and fixed by welding or the like.

The entire periphery of the main body of the extractor 51 is rounded to have a semicircular cross section. The radius of this roundness is set to a value smaller by about 4 mm than the radius r of the semicircular portion in the semicircular annular screen 50. Further, a portion from the vicinity of the center of the surface facing the screw 40 to a portion slightly inside from the outer periphery of the surface on the other end side is inclined and cut into a groove shape to form four material transport grooves 51b radially. Specific processing is performed by shaving or casting.

Further, on the peripheral portion of the extractor 51, a pressing piece insertion groove 51c having a constant width and a constant depth, which is parallel to the axial direction, is fixed between the four radially formed material transport grooves 51b. Form. And this pressing piece fitting groove 51c
Is attached with a separate material pressing piece 51d. This material pressing piece 51d has substantially the same shape as the pressing piece insertion groove 51c, and its outer peripheral upper surface is formed by a curved surface having different roundness in the axial direction and in the direction perpendicular to the axis, but the top is fitted. It is a member whose height when inserted is in contact with the inner surface of the semi-annular screen 50. With such a configuration, the material pressing piece 51d has a semi-annular screen 5
It is configured so as to be substantially along the inner surface of the semi-annular part of 0. In the present embodiment, the material transport groove 51b, the pressing piece insertion groove 51c, and the material pressing piece 51d are provided at four positions, respectively, but can be changed according to the granulation conditions. The material pressing piece 51d is formed as a separate member from the extractor 51, but may be formed integrally.

Next, a description will be given of a molding distortion when the punched molding material is drawn on the semi-annular screen 50 of the present embodiment, in comparison with a case where the forming material is drawn on the spherical screen 50 '. FIG. 4A illustrates the radius R of the semi-annular portion of the semi-annular screen 50 as the m direction, and the radius r of the semi-circular portion of the cross-sectional shape as the n direction. The graph of FIG. 4B shows the results of measuring the extrusion hole 50a at points divided into 0 to 80 rows in the n-direction cross section in two directions of m and n. On the other hand, FIG. 5A illustrates the circular plate of the spherical screen 50 ′ before drawing, in which the circumferential direction is the x direction and the radial direction is the y direction. The graph of FIG. 5B shows the extrusion hole 50 at the point where the radius y direction is divided into 0 to 80 rows from the center.
The result of measuring a ′ in two directions of x and y is displayed.

A comparison of these two graphs shows that the semi-annular screen 50 has an extruded hole 5 before drawing.
0a is 0.55 mm;
5 mm, and the sizes of the holes before molding were different. However, comparing the amount of strain with respect to the hole diameter before molding,
It can be seen that the semi-annular screen 50 is smaller. As a result, it is not necessary to take various complicated measures for preventing distortion in the spherical screen 50 '.

Next, a granulation mode using the horizontal extrusion type screw granulator 1 of the present invention will be described. As shown in FIG. 2, the raw material A having been subjected to the pretreatment and having
Put into 2. The input raw material A enters the screw case 41 and is transported while being gradually pressurized and compressed by the rotating screw 40. When the pressure is forcibly fed to the end in the screw case 41, the pressure becomes maximum, and the raw material A reaches the extractor 51. There the extractor 51 is screw 40
As the material transport groove 51b formed in the extractor 51 also rotates, the raw material A is pushed from the axial direction toward the extrusion hole 50a of the semi-annular screen 50 along the inclined surface. . When the material pressing piece 51d rotates here, the raw material A pressed from the axial direction toward the extrusion hole 50a is pressed against the semi-annular screen 50, and is pushed out from the extrusion hole 50a to be continuously. Is extruded.

In this embodiment, the semi-annular screen 50 is drawn from a punching plate.
It is also possible to form an extruded hole 50a by etching or the like after forming a plate having no hole into a semi-annular shape. As shown in FIG. 6, it is also possible to form the screen 52 of the basket-type extrusion granulator in a semi-annular shape.
In that case, the shape of the tip of the inner extrusion blade 53 is also semicircular along the inner surface of the screen 52.

[0027]

According to the horizontal extrusion type screw extruder according to the first aspect, since the semi-annular screen 50 having a semi-circular cross section is formed, the radius R of the semi-annular portion is increased. Even if the granulation area is increased, the strength of the semi-annular screen 50 does not decrease unless the radius r of the semicircular portion of the sectional shape is increased. As a result, the screen strength can be maintained even when the screen area is increased. Capability can be improved.

According to the horizontal extrusion type screw extrusion granulator of the second aspect, since the semi-annular screen 50 having a semi-circular cross-sectional shape is formed by drawing, the punched circular plate is formed into a spherical shape. The deformation of the extrusion hole 50a due to the molding distortion can be reduced as compared with the case where the screen 50 'is drawn. Therefore, it is not necessary to take various complicated steps as a measure against molding distortion, and the semi-annular screen 50 can be manufactured at low cost.

Furthermore, according to the horizontal extrusion type screw extrusion granulator of the third aspect, the inner surface of the semi-annular screen 50 is arranged along the inner surface of the semi-annular screen 50 so as to correspond to the semi-annular screen 50 having a semicircular cross section. Because the material pressing piece 51d is formed,
Raw material A sent to the end of screw case 41
Can be transported from the axial direction to the extrusion molding hole 50a and simultaneously pressed against the inner surface of the semi-annular screen 50 and extruded from the extrusion molding hole 50a to efficiently produce a large amount of small-grained granules at low cost. It is.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a horizontal extrusion type screw granulator according to the present invention.

FIG. 2 is an explanatory diagram of the same.

FIG. 3 is a front view and a side view of a semi-annular screen having a semi-circular cross-sectional shape.

FIG. 4 is an explanatory diagram showing a deformation amount of an extrusion hole of a semi-annular screen.

FIG. 5 is an explanatory diagram showing a deformation amount of an extrusion hole of a spherical screen.

FIG. 6 is a sectional view showing an embodiment in which a screen of a basket-type extrusion granulator is formed in a semi-annular shape.

FIG. 7 is an explanatory diagram showing a problem of the spherical screen.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 horizontal extrusion type screw extrusion granulator 2 gantry 3 drive unit 4 transfer unit 5 granulation unit 30 reduction gear 31 coupling 32 bearing box 33 screw drive shaft 40 screw 41 screw case 42 hopper 50 semi-annular screen 50a extrusion molding Hole 50b Flange 51 Extractor 51a Screw mounting portion 51b Material transport groove 51c Pressing piece insertion groove 51d Material pressing piece 52 Screen of basket type extrusion granulator 53 Extrusion blade A Raw material M Motor

Claims (3)

[Claims] 1. A wet raw material is forcibly fed to an extractor provided at the end of the screw while being pressurized and compressed by a screw rotating in a screw case, and the sliding action of the extractor is improved. In a transverse extrusion screw type extrusion granulator that extrudes from the axial direction to the circumferential direction with a screen attached to the side surface of the terminal end of the screw case by extrusion pressure, the screen has a semicircular cross section. A horizontal extrusion type screw extrusion granulator characterized by being annular. 2. The horizontal extrusion screw type extrusion granulator according to claim 1, wherein the screen is formed by drawing. 3. The horizontal extrusion screw-type extrusion granulation according to claim 1, wherein the extractor has a material pressing piece formed along the inner surface of the semi-annular portion of the screen. Machine.