Shaftless screw conveyor

Abstract

To provide a shaftless screw conveying device with which objects-to-be-conveyed can be conveyed appropriately obliquely upward at more than 30 degrees and less than 75 degrees from the horizontal line.SOLUTION: A shaftless screw conveying device 1 includes a shaftless screw blade 10, a flange 20 fixed to one end of the shaftless screw blade 10, a prismatic casing 30 having a (regular) n-polygon cross-section that accommodates the shaftless screw blade 10 therein and driving means 50 connected with the shaftless screw blade 10. The distance (d) between the (regular) polygon inner surface of the prismatic casing 30 and the outer diameter of the shaftless screw blade 10 is 8 mm or more and 12 mm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vertical shaftless screw conveying device for conveying an object at an angle above 30 degrees but not exceeding 75 degrees from the horizontal. [Background technology]

[0002] Conventional commercially available shaftless screw conveying devices are guaranteed to convey materials at an upward angle of 30 degrees from the horizontal. Due to the structure of the shaftless screw blade, the inner surface of the casing is generally cylindrical with a circular cross section.

[0003] Meanwhile, the applicant created a device capable of vertical conveyance by changing the inner shape of the casing from a cylindrical shape to a rectangular prism with a regular octagonal cross section. Specifically, the vertical screw conveyors in Patent Documents 1 and 2 are mechanisms for vertically conveying powder, and disclose a configuration comprising a shaftless screw blade and a casing with a regular octagonal cross section that houses the shaftless screw blade. Patent Document 2 provides an example in which the blade is equipped with a scraping portion and an inner bar, and conveyance is possible with the conveying axis at an angle of 60 to 90 degrees relative to the horizontal. The applicant also created Patent Document 3, a conveying device for conveying materials to high places. Patent Document 3 discloses a screw-type conveying device suitable for conveying chips and the like discharged from machine tools, etc., which includes a vertical conveyor equipped with a vertical conveying shaftless screw arranged in a trough with its rotation axis extending vertically, and a horizontal conveyor equipped with a horizontal conveying shaftless screw arranged in the trough with its rotation axis extending horizontally, and supplies objects to be conveyed by the horizontal conveyor to the bottom of the vertical conveyor, thereby conveying the objects to a high place. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6697665 (Claim 9) [Patent Document 2] Patent No. 6733980 [Patent Document 3] Japanese Patent Application Publication No. 2019-182629 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a shaftless screw conveying device that can suitably convey conveyed objects obliquely upward at an angle of more than 30 degrees and up to 45 degrees from the horizontal without providing a scraping section and an inner bar. [Means for solving the problem]

[0006] While commercially available cylindrical shaftless screw conveying devices are guaranteed to convey materials at an inclination of up to 30 degrees, the applicant has conducted extensive research and created a structure that allows for conveyance at a wide range of inclined upward angles, from over 30 degrees (over 35 degrees) to 75 degrees. Horizontal conveyance is also possible from below 30 degrees.

[0007] The shaftless screw conveying device (1) of the present invention is A shaftless screw blade (10); a flange (20) fixed to one end (base of the blade) of the shaftless screw blade (10); a rectangular columnar casing (30) having an inner circumferential cross section of a (regular) n-polygon (n=6 to 24) and accommodating the shaftless screw blade (10) therein; a drive means (50) connected to the shaftless screw blade (10) (the flange (20) thereof); Equipped with The distance (d) between the inner surface (side surface 31) of the (regular) cross section of the prismatic casing (30) and the outer diameter (outermost periphery) of the shaftless screw blade (10) is 8 mm to 12 mm. The interval (d) is set according to the physical properties of the transported object and / or the transport amount per unit time (screw outer diameter, inner diameter, pitch, total length, and screw rotation speed).

[0008] The prismatic casing (30) has an n-sided or regular n-sided cross section. n may be an even number, and the casing may be a regular hexagonal prism, a regular octagonal prism, a regular decagonal prism, a regular dodecagonal prism, or a regular icosagonal prism. The cross-sectional shape of the shaftless screw conveying device (1) may be set to a (regular) n-sided polygon (n = 6 to 24) according to the inclination angle (α) from the horizontal. The more horizontal the device, the larger n may be, and the more circular the cross-section may be. As the inclination angle (α) increases beyond 30 degrees, it is preferable to decrease n to 12, 10, 8, etc. The inclination angle (α) can be set to an angle between 30 degrees and 40 degrees, between 30 degrees and 50 degrees, between 30 degrees and 60 degrees, between 30 degrees and 70 degrees, or between 30 degrees and 75 degrees. The maximum inclination angle may be set depending on the physical properties of the transported object.

[0009] The prismatic casing (30) may be made of, for example, reinforced plastic or metal, and is preferably made of, for example, stainless steel. The prismatic casing (30) may be configured to have a first part and a second part along the longitudinal direction. The prismatic casing (30) may have an input section (71) into which the transported object is input and an output section (72) from which the transported object is output.

[0010] A trough 240 may be provided on the entire inner surface of the prismatic casing 30. The trough is configured to match the shape of the inner surface of the prismatic casing 30. The trough may be made of, for example, reinforced plastic or metal, and is preferably made of, for example, stainless steel.

[0011] The driving means (50) is composed of a motor, a speed change gear, a connecting means, a control device, a power supply, etc. The driving means preferably rotates the shaftless screw blade at a rotation speed of, for example, 3 rpm to 15 rpm. When the motor of the drive means and the like are installed above the shaftless screw blade (10), there is no need to provide a bearing below as in the case of a shafted screw conveyor, so there is no need to worry about the bearing being damaged. Also, even if the motor of the drive means (50) and the like are installed below, there is no need to worry about the conveyed object getting in because of the high level of sealing (sealed structure). The driving means (50) preferably rotates the shaftless screw blade (10) at a rotation speed of 5 to 17 rpm, more preferably 8 to 12 rpm. Within the above rotation speed range, it is preferable that the rotation speed be decreased as the outer diameter (80 mm to 600 mm) of the shaftless screw blade (10) increases, and that the rotation speed be increased as the outer diameter decreases.

[0012] The transported material has a plurality of components, and examples thereof include powder, chips, household waste, industrial waste, sludge, etc. The transported material may contain water.

[0013] 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 flight 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 Figures 1 and 2.)

[0014] The sum of the inner diameter (r2) and the blade width (w) is the outer diameter (r1). Alternatively, (r2 + w ≒ r1), where r1 is smaller when 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 when w is inclined and not extending perpendicularly from the radial direction. Two blades may be configured as one blade, with the outer width surface of the second blade having a smaller outer diameter fixed to the inner width surface of the first blade having a larger outer diameter.

[0015] 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 more preferably 1 / 2 to 2 / 3 of the pitch relative to the outer diameter (r1).

[0016] 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) are 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 conveyed material and / or the conveyance amount per unit time (screw rotation speed) and the degree of mixing.

[0017] (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.), and TMCP-type high-tensile steel plates (SM570TMC, SMA570WTMC, etc.).

[0018] The steel material used as the raw material for the shaftless screw blade 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 shrinks by about 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, such as wear-resistant steel plates (HARDOX (registered trademark) from Swedish Steel Corporation and EVERHARD (registered trademark) from JFE Steel Corporation), shrink to an extremely small extent. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a schematic diagram of a shaftless screw conveying device. [Figure 2] FIG. 2 is a diagram for explaining a casing and a shaftless screw blade. DETAILED DESCRIPTION OF THE INVENTION

[0020] (Embodiment 1) The inclined vertical shaftless screw conveying device 1 of this embodiment will be described with reference to the drawings. The inclined shaftless screw conveying device 1 in Fig. 1 includes a shaftless screw blade 10, a regular octagonal prism casing 30 that houses the shaftless screw blade 10 therein, an inlet section 71 for conveyed material provided at the bottom of the prism casing 30, a discharge section 72 provided at the top of the prism casing 30, a flange 20 connected to the blade base of the shaftless screw blade 10, and a drive means 50 connected to the flange 20 and for rotating the shaftless screw blade 10. The driving means 50 has a drive shaft 51 connected to the flange 20 and a motor-equipped reducer connected to the drive shaft 51 .

[0021] In this embodiment, the casing 30 has a regular octagonal prism shape. That is, the cross section is a regular octagon. The distance d between the outer diameter (end) of the shaftless screw blade 12 of the casing 30 and the inner surface 31 of the casing 30 is 10 mm.

[0022] The inclination angle α of the shaftless screw conveying device 1 from the horizontal is greater than 30 degrees and is 75 degrees. In this embodiment, the inclination angle α is 35 degrees to 75 degrees.

[0023] FIG. 1 shows a horizontal shaftless screw conveying device 200 connected to an inclined vertical shaftless screw conveying device 1. The horizontal shaftless screw conveying device 200 includes a shaftless screw blade 210, a cylindrical casing 230 that houses the shaftless screw blade 210, an input section 271 for conveyed materials provided at the top of the cylindrical casing 230, a discharge section 272 provided on the cylindrical casing 230, a flange 220 connected to the blade base of the shaftless screw blade 210, and a driving means 250 connected to the flange 220 and rotating the shaftless screw blade 210. The conveyed materials discharged from the discharge section 272 are sent from the input section 71 to the inclined vertical shaftless screw conveying device 1. A U-shaped trough 240 is provided on the inner surface of the cylindrical casing 230.

[0024] (Another embodiment) (1) Figure 2 shows examples of casings with regular hexagonal, octagonal, decagonal, and dodecagonal shapes. The distance d2 from the edge of the outer diameter of the blade to the side edge is longer than the distance d as n is smaller, and shorter as n is larger. (2) The drive means 50 is connected to the base of the blade of the shaftless screw blade 10, but the drive means 50 may also be connected to the tip side of the shaftless screw blade. In such a case, it is preferable that the drive shaft 51 penetrates the casing 30 with a seal unit (not shown) installed therebetween to improve the airtightness between the drive shaft 51 and the casing.

[0025] <Example> Using the inclined shaftless screw conveyor device 1 of embodiment 1, it was confirmed that sand and incineration ash could be conveyed at inclinations of 32 degrees, 40 degrees, 45 degrees, 50 degrees, 60 degrees, 70 degrees, and 75 degrees. The "single" in the inner diameter (r2) refers to a single blade, and "double" refers to a double blade (a screw blade with single blades connected in the radial direction). The rotation speed was confirmed in the range of 7 rpm to 14 rpm. The total length (L) of the shaftless screw blade was confirmed to be between 2 m and 9 m. The thickness t of the shaftless screw blade was 25 mm. [Table 1]

[0026] In another example, when the distance d was set to 9 mm and 11 mm, it was confirmed that transport was possible. In addition to a regular octagonal prism, it was also confirmed that transport was possible with a regular hexagonal prism, a regular decagonal prism, and a regular dodecagonal prism. [Explanation of symbols]

[0027] 1. Shaftless screw conveyor 10. Shaftless screw blade 20 flange 30 Casing 50 Driving means

Claims

[Claim 1] A shaftless screw conveying device that is installed with an inclination angle (α) relative to the horizontal of 75 degrees or less, A shaftless screw blade; a flange fixed to one end (base of the blade) of the shaftless screw blade; A cross section of a regular n-sided polygon (n = 6 to 24) that houses the shaftless screw blade inside. a prismatic casing; a driving means connected to the shaftless screw blade; a distance (d) between a center portion of a side of the inner surface (side surface of the rectangular column) of the rectangular column casing having a regular n-gon cross section and an outer diameter (outermost periphery) of the shaftless screw blade is 8 mm or more and 12 mm or less; However, the present invention does not include a plurality of scraping portions protruding in the blade radial direction of the shaftless screw blade, and inner bars provided on the inner surfaces of the rectangular casing along the longitudinal direction of the inner surfaces, and the inner bars do not have a width shorter than the sides of a regular n-gon when the center line along the longitudinal direction of the inner surfaces is aligned with the center line along the longitudinal direction of the inner bars. Shaftless screw conveying device.

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