JP7790701B2 - Shaftless screw blade for conveying and mixing and shaftless screw conveying and mixing device equipped with same - Google Patents

Description

The present invention relates to a shaftless screw conveying and mixing blade that mixes (stirs) materials while conveying them, and a shaftless screw conveying and mixing device equipped with the same.

The solid content separation device of Patent Document 1 uses a shaftless helical screw as a solid-liquid separation means. However, this technology simply sends a suspension to the shaftless helical screw and separates the solid content and liquid content while stirring them, and is not a technology for mixing the transported material (including multiple components) while transporting it.
The dewatered sludge transport system in Patent Document 2 describes a kneading device equipped with a shaftless screw as an example of a kneading device. However, this is merely an example and does not disclose a specific structure, and the kneading device is not a technology for mixing transported materials (including multiple components) while transporting them.
Patent Document 3 discloses a shaftless screw conveying device that conveys an object (peeled vegetable skins). However, the purpose of the shaftless screw conveying device is conveyance, and the structural design is not intended to mix the object (including multiple components) while conveying it.

JP 2013-52334 A JP 2017-148767 A Japanese Patent Application Laid-Open No. 2019-177989

The object of the present invention is to provide a shaftless screw blade for conveying and mixing that can mix conveyed materials (including multiple components) while conveying them, and a shaftless screw conveying and mixing device equipped with the same.

The non-axial screw blade (1) for conveying and mixing of the present invention is
A blade body (10),
a flange (20) fixed to one end (base) of the blade body (10) (for connection to the driving side);
At least one mixing protrusion is provided per pitch (p) of the blade body (10) on the first main surface (10a) and/or the second main surface (10b) of the blade body (10);
Equipped with.

The "first main surface" refers to the surface facing the main surface of the flange (20) when the device is stopped. The mixing protrusions erected on the first main surface are called first mixing protrusions (there is one or more per pitch).
The "second main surface" refers to the surface opposite to the first main surface. The mixing protrusions erected on the second main surface are called second mixing protrusions (there is one or more per pitch).

When a plurality of first mixing protrusions per pitch of the blade body (10) are erected on the first main surface (10a), they may be arranged at equal or substantially equal intervals in the spiral shape of the blade body (10).
When a plurality of second mixing protrusions per pitch of the blade body (10) are erected on the second main surface (10b), they may be arranged at equal or substantially equal intervals in the spiral shape of the blade body (10).
If there are three mixing protrusions, they may be arranged at intervals of 120° on the first main surface (second main surface) of the spiral shape around the blade rotation axis (a0).
If there are four mixing protrusions, they may be arranged at intervals of 90° on the first main surface (second main surface) of the spiral shape around the blade rotation axis (a0).
In the case of six mixing protrusions, they may be arranged at intervals of 60° on the first main surface (second main surface) of the spiral shape around the blade rotation axis (a0).

The position of the first mixing protrusion provided on the first main surface (10a) and the position of the second mixing protrusion provided on the second main surface (10b) may be the same or substantially the same across the blade body (thickness t) (see FIG. 1D(a)).
The position of the first mixing protrusion provided on the first main surface (10a) and the position of the mixing protrusion provided on the second main surface (10b) may be different with the blade body (thickness t) sandwiched therebetween. When they are different positions, the second mixing protrusion may be provided on the second main surface (10b) between adjacent first mixing protrusions provided on the first main surface (10a) (for example, at a slightly shifted position (see FIG. 1D(b)), an intermediate position, etc.).

The mixing protrusion may be erected in the perpendicular direction to the first main surface (10a) or the second main surface (10b), or may be erected at a predetermined angle α (for example, ±1 degree to ±45 degrees) with respect to the perpendicular direction.
It may be inclined at an angle α (1 to 45 degrees) in the rotational direction from a vertical imaginary line (F2) extending perpendicularly from the first main surface (10a) (see another example in FIG. 1C).

The shape of the mixing protrusion may be, for example, a triangular plate, a rectangular plate, a polygonal plate, a rod (cylinder, square pillar), or a branched shape.
The plurality of first mixing protrusions erected on the first main surface (10a) and the plurality of second mixing protrusions erected on the second main surface (10b) may all be standardized to the same shape and size, or may all be different, or may be partially standardized.

When the shape of the mixing protrusion is plate-like, the plate-like main surface may be erected on the first main surface (10a) or the second main surface (10b) parallel to the blade radial direction (a1), or may be erected at a predetermined angle (for example, ±1 degree to ±45 degrees) with respect to the blade radial direction (a1).
When the screw blade is viewed parallel to the blade rotation shaft center (a0) (see FIG. 1B ), for example, the inclination at the predetermined angle may be an angle β (1 to 45 degrees) in the rotation direction, starting from an imaginary line (F0) in the blade radial direction (a1) extending from the blade rotation shaft center (a0) and an inner blade point (a2) on the imaginary line (F0).
The mixing protrusion may have a length equal to or shorter than the blade width (w) parallel to the blade radial direction (a1).

The "main surface when the mixing protrusion is plate-shaped" may be a flat surface or a curved surface. The main surface has a larger surface area than the side surfaces.
The "mixing protrusions" come into contact with the conveyed material as the blades rotate. The mixing action occurs due to the difference between the action of the mixing protrusions sending the conveyed material toward the central space of the blades (the shaftless space) and the action of the conveyed material hitting the main surface of the blade without hitting the mixing protrusions and sending it in the conveying direction.

The total length (L) of the shaftless screw blade is, for example, 2 m to 20 m.
The outer diameter (r1) of the shaftless screw blade is, for example, 80 mm to 600 mm.
The pitch (p) of the shaftless screw blade is, for example, 27 mm to 600 mm.
The inner diameter (r2) of the shaftless screw blade is, for example, 30 mm to 500 mm.
The thickness (t) of the shaftless screw blade is, for example, 10 mm to 35 mm.
The blade width (w) of the shaftless screw blade is, for example, 30 mm to 80 mm.
(See Figure 1A for each.)

The outer diameter (r1) is the sum of the inner diameter (r2) and the blade width (w). Alternatively, (r2 + w ≒ r1), where r1 is smaller if w is inclined and not extending perpendicularly from the radial direction. In another embodiment, the outer diameter (r1) is the sum of the inner diameter (r2) and twice the blade width (w). Alternatively, (r2 + w × 2 ≒ r1), where r1 is smaller if w is inclined and not extending perpendicularly from the radial direction. Two blades may be configured as one blade, with the outer surface of the second blade with a smaller outer diameter fixed to the inner surface of the first blade with a larger outer diameter.

The relationship between the outer diameter (r1) of the shaftless screw blade and the pitch (p) of the shaftless screw blade is 1/3 to 2/3 of the pitch relative to the outer diameter (r1), and a pitch of 1/2 to 2/3 of the pitch relative to the outer diameter (r1) is more preferable.

The shaftless screw blade may have a rectangular cross section, for example. The larger the outer diameter (r1) of the screw blade, the larger the blade width (w) and blade thickness (t) should be set. The total length (L), screw blade outer diameter (r1), pitch (p), blade inner diameter (r2), and blade width (w) are set according to the physical properties of the material being conveyed and/or the amount conveyed per unit time (screw rotation speed) and the degree of mixing.

(Material for shaftless screw blades)
Examples of steel materials that can be used as raw materials for shaftless screw blades include general structural rolled steel materials (SS330, SS400, SS490, SS540, etc.), cold-rolled steel plates (SPCC, SPCD, SPCE, SPCF, SPCG, etc.), carbon steel materials (S25C, S30C, S35C, S45C, S50C, S55C, etc.), hot- or cold-rolled stainless steel plates (SUS304 , SUS316, SUS430, SUS410, etc.), wear-resistant steel plates (HARDOX (registered trademark) from Swedish Steel Corporation, EVERHARD (registered trademark) from JFE Steel Corporation, etc.), high-tensile steel plates (SM570, SMA570W, etc.), TMCP type high-tensile steel plates (SM570TMC, SMA570WTMC, etc.).

The steel material used as the raw material for shaftless screw blades is preferably a steel material with higher strength (higher tensile strength) than general structural rolled steel (SS400). This is preferable from the standpoint of wear resistance and durability. In the case of SS400, the overall length of the screw blade will shrink by approximately 10% to 15% compared to its initial value after long-term use (for example, 6 months, 7 hours/day). However, stainless steel plates with higher strength (higher tensile strength) than SS400, and wear-resistant steel plates (such as HARDOX (registered trademark) from Swedish Steel and EVERHARD (registered trademark) from JFE Steel), show extremely little shrinkage.

Another non-axial screw conveying mixer (100) of the present invention is
The above-mentioned conveying and mixing non-axial screw blade (1),
a casing (110) for accommodating the shaftless screw blade (1);
a trough (120) disposed on the inner surface of the casing;
a driving means (130) connected to the flange of the shaftless screw flight;
Equipped with.

The casing (110) may have a circular, regular n-sided or U-shaped cross section.
The casing (110) may be made of, for example, reinforced plastic or metal, and is preferably made of, for example, stainless steel.
The casing (110) may be configured to have a first part having a U-shaped cross section along the longitudinal direction and a second part that covers the open upper part of the U. When the casing (110) is cylindrical, it may be configured to have a cylindrical lower part and a cylindrical upper part.

The trough (120) may be, for example, U-shaped.
The trough may be made of, for example, reinforced plastic or metal, and is preferably made of, for example, stainless steel.

The driving means (130) is composed of a motor, a speed change gear, a connecting means, a control device, a power supply, etc. It is preferable that the driving means rotate the shaftless screw blade at a rotation speed of, for example, 3 to 15 rpm.

The transported material contains multiple components, such as household waste, industrial waste, and sludge. The transported material may also contain moisture.

The materials are mixed while being transported, and the mixing rate increases as they are sent to the tip of the blade.
The mixing ratio is controlled by, for example, the total length, outer diameter, inner diameter, pitch, conveyance amount per unit time, rotation speed, and mixing projection of the shaftless screw.
For example, the total length can be 7 m to 12 m, the outer diameter 400 mm to 500 mm, the inner diameter 150 to 420 mm, the pitch 400 to 500 mm, the conveying amount 2 t/hour to 3 t/hour, the rotation speed 5 to 12 rpm, there are 4 to 6 rectangular plate-shaped mixing protrusions on the first main surface and 4 to 6 on the second main surface, and when the material is conveyed up to 60% of the total length, it is possible to achieve a mixing level of 50 to 70%, and when the material is conveyed up to 80 to 90% of the total length, it is possible to achieve a mixing level of 90 to 100%.

FIG. 1 is a diagram showing an outline of a shaftless screw blade. 10 is a diagram illustrating the mounting position and inclination angle β of the mixing protrusion portion. FIG. FIG. 10 is a diagram illustrating the inclination angle α of the mixing protrusion portion. 10A and 10B are diagrams showing examples of the arrangement of mixing protrusions attached to the first and second main surfaces. 10A and 10B are diagrams showing an example of a planar shape of a mixing protrusion portion. FIG. 1 is a diagram showing an outline of a shaftless screw conveying mixer.

(Embodiment 1)
1A shows a shaftless screw blade 1 for conveying and mixing. The shaftless screw blade 1 includes a blade body 10, a flange 20 fixed to the blade base of the blade body 10, four first mixing protrusions 41, 42 provided on the first main surface 10a of the blade body 10, and four second mixing protrusions 53, 54 provided on the second main surface 10b. One part of a reinforcing plate 30 is welded to the first main surface 10a at a position 180 degrees spirally rotated from the blade base, and the other part is welded and fixed to the flange 20.

Four first mixing protrusions 41, 42 are provided per pitch p of the impeller body 10, although only two are shown in Figure 1A. Four second mixing protrusions 53, 54 are provided per pitch p of the impeller body 10, although only two are shown in Figure 1A. In this embodiment, the screw blade in Figure 1A is a double blade, with two screw blades with different outer and inner diameters connected radially. The inner diameter of the radially outer screw blade matches (or nearly matches) the outer diameter of the radially inner screw blade, and they are joined together by welding. The first and second mixing protrusions are angle plates with L-shaped cross sections, and are welded to the main surfaces of the blades.

In FIG. 1A, four first mixing protrusions per pitch of the blade body 10 are erected on the first main surface 10a, and are arranged at equal or substantially equal intervals in the spiral shape of the blade body 10. Furthermore, four second mixing protrusions per pitch of the blade body 10 are erected on the second main surface 10b, and are arranged at equal or substantially equal intervals in the spiral shape of the blade body 10. In other words, since there are four mixing protrusions, they are arranged at 90° intervals on the spiral-shaped first main surface 10a or second main surface 10b around the blade rotation axis a0.

The mounting position and inclination angle β of the mixing protrusion 41 will be explained using Figure 1B. When the mixing protrusion 41 is plate-shaped, the plate-shaped main surface is erected on the first main surface 10a parallel to the blade radial direction a1. In another embodiment, the protrusion may be erected at a predetermined angle (e.g., ±1 to ±45 degrees) relative to the blade radial direction a1. In Figure 1B, when the screw blade is viewed parallel to the blade rotation axis center a0, the predetermined angle of inclination is determined by an imaginary line F0 extending from the blade rotation axis center a0 in the blade radial direction a1, and the dashed mixing protrusion 41 is inclined at an angle β (in the range of 1 to 45 degrees) in the rotational direction starting from a blade inner point a2 on that imaginary line F0.

The inclination angle α of the mixing protrusion 41 will be explained using Figure 1C. The first plate portion 411, which has an L-shaped cross section, of the mixing protrusion 41 is welded and fixed to the first main surface 10a, and the second plate portion 412 stands upright in the perpendicular direction to the first main surface 10a. In another embodiment, the second plate portion 412 may be inclined at a predetermined angle α (e.g., ±1 degree to ±45 degrees) relative to the perpendicular direction. The second plate portion 412 may also be inclined by angle α (1 degree to 45 degrees) in the rotational direction from a vertical imaginary line F2 extending perpendicularly from the first main surface 10a.

Figure 1D shows an example of the arrangement of the mixing protrusions attached to the first and second main surfaces. In Figure 1D(a), the position of the first mixing protrusion 41 erected on the first main surface 10a and the position of the second mixing protrusion 51 erected on the second main surface 10b are the same, with the blade body (thickness t) in between. In Figure 1D(b), the position of the first mixing protrusion 41 erected on the first main surface 10a and the position of the second mixing protrusion 51 erected on the second main surface 10b are slightly offset, with the blade body (thickness t) in between.

Figure 1E shows an example of the planar shape of the mixing protrusion. Examples include (a) rectangular, (b) cylindrical (rod-shaped), (c) comb-shaped (branched at the tip), (d) trapezoidal, and (e) triangular, but other shapes are also acceptable. Mixing protrusions of one or more different planar shapes may be used, or a single type of planar shape may be used.

Figure 2 shows a shaftless screw conveying and mixing device 100. The shaftless screw conveying and mixing device 100 comprises a shaftless screw blade 1 for conveying and mixing, a casing 110 that houses the shaftless screw blade 1, a U-shaped trough 120 arranged on the inner surface of the casing 110, and a drive means 130 connected to a flange 20 fixed to the base of the blade body 10 of the shaftless screw blade 1.

The driving means 130 is composed of a motor, a speed change gear, a connecting means, a control device, a power supply, etc. The driving means 130 rotates the shaftless screw blade at a rotation speed of, for example, 5 to 12 rpm. The driving shaft 131 passes through the casing 110 with a seal unit (not shown) installed therebetween to improve the airtightness between the driving shaft 131 and the casing.
The casing 110 includes an input section (not shown) for the transported materials and a discharge section for discharging the mixed transported materials.

(Example)
The total length (L) was 9 m, the outer diameter (r1) was 477 mm, the inner diameter (r2) was 177 mm, the pitch (p) was 477 mm, the conveying rate was 2.5 t/h, the rotation speed was 7 rpm, and four L-shaped cross-section protruding portions for mixing were provided on the first main surface and four on the second main surface. The second plate portion 412 was a square measuring 70 mm in length and 70 mm in width. The inclination angle α was 0 degrees (i.e., vertically erected), and the inclination angle β was 45 degrees.
Two types of sand with different average particle sizes were prepared as transported materials, and one of the sands was made white. The materials were transported and mixed. Visual inspection confirmed that the mixture was 60% to 70% when transported up to 60% of the total length, and 90% to 100% when transported up to 80% to 90% of the total length.

(Comparative Example)
The same as in Example 1 was used except that the L-shaped cross section mixing protrusions were not provided on the first and second main surfaces.
As a result, it was visually confirmed that the mixture was about 40% to 50% when the material was transported to 60% of the total length, and that the mixture was about 50% to 60% when the material was transported to 80% to 90% of the total length.
Since the materials being transported were sands that mix easily with each other, about half of the materials were mixed in the comparative example, but the mixing was poor at the front and rear ends of the transport, and there was a noticeable tendency for only one type of sand to be transported and discharged without being mixed.

DESCRIPTION OF SYMBOLS 1 Shaftless screw blade 10 Blade body 20 Flange 30 Reinforcing plates 41, 42 First mixing protrusions 51, 52 Second mixing protrusions 100 Shaftless screw conveying and mixing device 110 Casing 120 Trough 130 Drive unit

Claims (4)

A non-axial screw blade for conveying and mixing,
A blade body;
a flange fixed to one end of the blade base body;
At least one mixing protrusion is erected per pitch of the blade base body on the first main surface and/or the second main surface of the blade base body , and does not extend outside the blade outer diameter ;
A shaftless screw blade. The shaftless screw blade according to claim 1, wherein the mixing protrusion is erected perpendicular to the first or second main surface or at a predetermined angle relative to the perpendicular direction. The shaftless screw blade described in claim 1 or 2, wherein the mixing protrusions are erected on the first or second main surface parallel to the blade radial direction, or inclined at a predetermined angle relative to the blade radial direction. The shaftless screw blade for conveying and mixing according to any one of claims 1 to 3;
a casing that houses the shaftless screw blade therein;
a trough disposed on the inner surface of the casing;
a driving means coupled to the flange of the shaftless screw blade;
A shaftless screw conveying and mixing device comprising: