JPH10129827A - Screw conveyer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive simple screw conveyer which can surely prevent the occurrence of locking state when a thing is transferred irrespective of the quality of the thing. SOLUTION: A screw 7 having a screw blade 7b on the outer peripheral surface of a rotation shaft 7a is disposed in a cylindrical easing 1. A thing M to be transferred dumped in the casing 1 is transferred in the direction of length of the casing 1 by the action of screw feed of the screw blade 7b produced by the rotation of the screw 7. A projection 12 for increasing friction force between the thing M to be transferred and the inner peripheral surface is made on the inner peripheral surface of the easing body 2 of the casing 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw conveyor for transporting an object loaded into a cylindrical casing in a longitudinal direction of the casing by a screw feed action of a screw blade accompanying rotation of a screw. In particular, the present invention relates to a screw conveyor used for transporting residue and the like in a water treatment facility, a sludge treatment facility, and the like.

[0002]

2. Description of the Related Art In a conventional screw conveyor, a screw having screw blades provided on the outer peripheral surface of a rotating shaft is disposed inside a cylindrical casing having a loading port and a discharging port at both ends. Of structure. Both ends of the rotary shaft of the screw are supported by both ends of the casing, and a rotary drive device such as a motor is connected to one end of the rotary shaft.

[0003] When the screw is rotated by the rotary drive device, the conveyed object input from the input port is conveyed in the lengthwise direction of the inside of the casing by the screw feeding action of the screw blade, and is discharged from the output port. When the transported object is screw-fed by the screw blade, the transported object is transported while sliding relatively to the propulsion surface of the screw blade.

[0004] Such a screw conveyor has an advantage that its structure is relatively simple, and it is easy to adopt a sealed structure in taking measures to prevent the transported objects from scattering and deodorizing. For transporting waste and scum together with sediment with a particle size of about 5 mm that has been lifted up and separated from a sand basin to a predetermined storage facility, or for transporting a dewatered cake after dewatering sludge to a predetermined storage facility. It is being used effectively.

[0005]

However, when a conveyed object is conveyed by this kind of screw conveyor, depending on the properties of the conveyed object, the circumferential direction between the propulsion surface of the screw blades and the conveyed object may vary. The frictional force is increased, and the transferred object is less likely to slide relative to the propulsion surface. If the conveyed object has a granular and fluid property such as sedimentation, the conveyed object slides relatively to the propulsion surface of the screw blade without being affected by the frictional force, and is conveyed. The operation is performed relatively smoothly.

However, when the transported object is extremely poor in fluidity such as waste and sludge-like and viscous such as scum or dewatered cake, the circumference between the propulsion surface of the screw blade and the transported object is reduced. The frictional force in the direction becomes larger than the frictional force in the circumferential direction between the inner peripheral surface of the casing and the transferred object.
As a result, the conveyed object is entangled in a bridge shape with the screw blade, adheres in a lump and does not slide relatively to the propulsion surface, and the conveyed object rotates with the screw blade and cannot be conveyed, There is a problem of causing a so-called locked state.

In order to solve the above-mentioned problem, a screw conveyor having a structure in which two screws are arranged in parallel inside a casing has been proposed. In this screw conveyor, even if the conveyed object is stuck to the screw blades, the conveyed object is scraped off between the screw blades of the two screws, thereby preventing the occurrence of the locked state beforehand. Is done.

[0008] However, such a screw conveyor requires two screws, so that the entire equipment including the rotary driving device becomes large and the production cost is greatly increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problem, and has a simple and inexpensive screw conveyor which can reliably prevent the occurrence of a locked state during transport regardless of the properties of the transported object. The purpose is to provide.

[0010]

According to the present invention, a screw provided with a screw blade on an outer peripheral surface of a rotating shaft is disposed inside a cylindrical casing, and a conveyed object put into the casing is provided. In the screw conveyor that conveys in the longitudinal direction of the casing by the screw feed action of the screw blades accompanying the rotation of the screw, the inner peripheral surface of the casing has a projection for increasing the frictional force with the conveyed object. It was formed.

[0011] In the screw conveyor according to the second aspect of the present invention, the protrusions are ridges extending in the longitudinal direction of the casing, and a plurality of the protrusions are equally arranged in the circumferential direction.

[0012]

[Function] By the protrusion formed on the inner peripheral surface of the casing,
Since the circumferential frictional force between the inner peripheral surface of the casing and the conveyed object is larger than the circumferential frictional force between the screw blade of the screw and the conveyed object, even if the conveyed object is on the screw blade. Even if they are easily adhered, the transported object slides relatively to the propulsion surface of the screw blade, and as a result, the occurrence of a locked state during transport is prevented.

[0013] In the screw conveyor according to the second aspect of the present invention, since the protrusion is provided with a ridge extending in the length direction as the protrusion, the conveyed object is conveyed in the casing while being guided by the ridge.

[0014]

1 and 2 show the construction of a screw conveyor according to an embodiment of the present invention. In the illustrated screw conveyor, reference numeral 1 denotes a cylindrical casing which is supported by legs 13 and 14 in an inclined posture. The casing 1 includes a casing body 2 having an open upper surface and a U-shaped cross section, and a casing An upper plate 3 for closing an open upper surface of the main body 2 and end plates 4 and 4 for closing both open end surfaces of the casing main body 2 are formed in a closed structure. The casing 1 is provided with a loading port 5 for the transported object M on the upper surface side of the inclined lower end portion, and a discharge port 6 for the transported object M on the lower surface side of the inclined upper end portion. Note that the casing 1 may be a cylindrical body instead of the coupling structure between the casing body 2 and the upper plate 3.

A rotary shaft 7a is provided inside the casing 1.
A screw 7 having a screw blade 7b provided on the outer peripheral surface of the screw 7 is provided.
Both ends are rotatably supported on the end plates 4 and 4 of the casing 1 by bearings 8 and 8, respectively.

A rotary drive unit 9 composed of a geared motor is mounted on the upper surface of the inclined upper end of the casing 1, and the rotary drive unit 9 and the rotary shaft 7a of the screw 7 are mounted.
Between the rotating shaft 9a and the rotating shaft 7a.
A chain transmission mechanism 10 for transmitting power to the vehicle is interposed. The screw 7 includes a screw blade 7b extending between the input port 5 and the discharge port 6, and a surface facing the inclined upper end of the screw blade 7b forms a propulsion surface 11 for propelling the conveyed object M.

A plurality of projections 12 are formed on the inner peripheral surface of the casing main body 2 to increase a frictional force between the casing main body 2 and the object M. The projecting portion 12 generates a circumferential frictional force between the transferred object M and the inner peripheral surface of the casing main body 2 and a circumferential friction between the transferred object M and the propulsion surface 11 of the screw blade 7b. In this embodiment, as shown in FIG. 3, the protrusion 12 is formed by a protrusion extending in the length direction of the casing 1. Projection 12
In this embodiment, a plurality of square steels having a length substantially equal to the entire length of the casing 1 are welded or bolted to the inner peripheral surface of the casing main body 2 in this embodiment. Is formed by being fixed.

The magnitude of the frictional force with the object M can be arbitrarily set by adjusting the thickness t and the width w of the projection 12 in addition to the number of the projections 12. In the case of a normal-scale screw conveyor applied to a sewage treatment facility, a sludge treatment facility, or the like, the projecting portion
If the thickness t is about 3 to 5 mm and the width w is about 25 mm,
Appropriate friction force can be set.

The protrusion 12 is not limited to a protrusion using a square steel, but may be a protrusion using a round steel, as shown in FIG. 4, or an edge, as shown in FIG. A ridge using a triangular steel having a large effect may be used, and the cross-sectional shape of the ridge is not limited. Further, as shown in FIG. 6, the protrusion 12 may be formed with a protrusion having an appropriate angle with respect to the circumferential direction of the casing 1, and the arrangement thereof is also arbitrary. Furthermore, the projection 12 is not limited to the above-described projection, and may be a projection as shown in FIGS. 7 and 8. FIG.
In FIG. 8, a plurality of flat quadrangular prism-shaped protrusions 12 are arranged in a staggered arrangement over substantially the entire length of the casing 1. In FIG. Absent. Furthermore, the protrusion 12 of each of the above embodiments is used.
Is formed by fixing a steel material to the inner peripheral surface of the casing main body 2 by welding or the like, but may be formed integrally with the inner peripheral surface of the casing main body 2. Furthermore, if the casing 1 is formed of a cylindrical body, the protrusion 12 may be formed over the entire peripheral surface of the casing 1.

Next, the operation of the screw conveyor shown in FIGS. 1 to 3 will be described. Now, when the rotary drive device 9 is driven to rotate the screw 7, the conveyed object M introduced into the casing 1 from the introduction port 5 is subjected to the screw feeding action by the screw blade 7 b and moves in the casing 1 in the longitudinal direction. And is discharged from the discharge port 6. When the transported object M is screw-fed by the screw blade 7b, a circumferential frictional force is generated between the transported object M and the propulsion surface 11 of the screw blade 7b, and the transported object M and the inner periphery of the casing body 2 are formed. A circumferential frictional force is also generated between the surface and the surface.

Depending on the properties of the transferred object M, the transferred object M
And a large frictional force is generated between the screw blade 7b and
The transferred object M is less likely to slide relatively to the propulsion surface 11 of the screw blade 7b. However, a protrusion 12 is provided on the inner peripheral surface of the casing main body 2 so that the transferred object M and the casing main body 2
Is set larger than the frictional force between the transferred object M and the screw blade 7b, the difference between the frictional forces causes the propulsion surface 11 of the screw blade 7b to move.
Relative to the transfer object M is reliably performed.
As a result, even if the transported object M is a residue such as sewage, scum, or dehydrated cake, there is no possibility that these are entangled with the screw blade 7b or adhered to the screw blade 7b, and the transport operation is performed. It is performed smoothly.

[0022]

As described above, according to the present invention, a projecting portion for increasing a frictional force with an object to be conveyed is formed on an inner peripheral surface of a casing in which a screw is disposed, and a conveyed object is formed. The frictional force in the circumferential direction between the transferred object and the inner peripheral surface of the casing is set to be larger than the frictional force in the circumferential direction between the screw blade and the screw blade. Even if it is easy to carry, the object to be conveyed slides relatively to the propulsion surface of the screw blade, and as a result, it is possible to prevent the occurrence of a locked state during conveyance. Moreover, since only the protrusion is provided on the inner surface of the casing, the structure can be manufactured simply and inexpensively, and as in the conventional example using two screws, there is a possibility that the equipment becomes large and the manufacturing cost rises. Absent.

According to the second aspect of the present invention, since the protrusion is formed by the protrusion extending in the longitudinal direction of the casing, there is an effect that the protrusion serves as a guide so that the object can be smoothly transferred.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a configuration of a screw conveyor according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view partially showing a casing body provided with a protrusion.

FIG. 4 is a perspective view partially showing a casing body provided with a protrusion according to another embodiment.

FIG. 5 is a perspective view partially showing a casing body provided with a protrusion according to another embodiment.

FIG. 6 is a perspective view partially showing a casing body provided with a protrusion according to another embodiment.

FIG. 7 is a perspective view partially showing a casing body provided with a protrusion according to another embodiment.

FIG. 8 is a perspective view partially showing a casing body provided with a protrusion according to another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 7 Screw 7a Rotating shaft 7b Screw blade 11 Propulsion surface 12 Projection

Claims (2)

[Claims] 1. A screw provided with a screw blade provided on an outer peripheral surface of a rotary shaft inside a cylindrical casing, and a conveyed object charged into the casing is rotated by the screw blade as the screw rotates. A screw conveyor for conveying in the longitudinal direction of a casing by a screw feeding action of the above, wherein a protrusion for increasing a frictional force with an object to be conveyed is formed on an inner peripheral surface of the casing. 2. The screw conveyor according to claim 1, wherein the protrusions are protrusions extending in a longitudinal direction of the casing, and a plurality of protrusions are equally arranged in a circumferential direction.