JPH0721447Y2 - Screw conveyor for conveying high temperature powders - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a screw conveyor that conveys powder and granules.

(Prior Art) In general, screw conveyors are often used for conveying powder and granules because of environmental measures such as closed conveyance of powder and granules and quantitative conveyance of powder and granules.

As a typical example of this, as shown in Japanese Utility Model Application Laid-Open No. 50-27585, screw blades rotated by the rotation of a rotation shaft provided in the transfer tube and the rotation direction of the screw blades are in the same direction. , A screw conveyor having a spiral groove on the inner peripheral wall of the transfer tube, or a plate material having a rectangular cross-section with spiral blades, as in Japanese Utility Model Laid-Open No. Sho 53-149390, which has a heat-resistant and wear-resistant material spray-coated on its outer peripheral surface. Have been proposed,
Some of them have been put to practical use and have been quite effective.

(Problems to be solved by the invention) However, while these screw conveyors are advantageous in closed transfer and quantitative cutout, when transferring high-temperature powder or granules, the rotary shaft is deformed or the spiral fixed to the rotary shaft is fixed. The blades are distorted by thermal stress and cannot rotate due to deformation competition in the transfer tube.

Even if the non-rotatable state due to this competition is avoided, the blades, the transfer tube (casing), and the like are damaged and worn, and the life of the screw conveyor is greatly reduced.

On the other hand, as another means for avoiding this thermal distortion, it is possible to increase the gap between the blade and the inner surface of the casing.
Increasing this gap causes a problem such as deteriorating the original effect of the powder conveyer on the screw conveyor.

The present invention solves the above-mentioned disadvantages of the conventional conveying device when conveying high-temperature powder or granular material, which eliminates the local wear and tear caused by thermal deformation such as inability to rotate or deformation, and does not impair the conveying efficiency of powder or granular material. It is to provide a granular material conveying screw conveyor.

(Means for Solving the Problems) FIG. 1 is a schematic sectional view of a screw conveyor for conveying high-temperature powder and granules according to the present invention, FIG. 2 is a partial detailed sectional view of FIG. 1, and FIG. 2 is a sectional view taken along the line AA ′ of FIG. In the figure, reference numeral 1 denotes an inner casing made of a metal plate such as steel or stainless steel, and a cooling medium passage 3 for passing water or air as a cooling medium is provided by the outer casing 2.

A rotatable shaft 4 is provided in the inner casing 1, and the shaft 4 is supported by bearings 5A and 5B provided outside the outer casing 2. One end of the shaft 4 is connected to a drive source (not shown). The drive transmission unit such as the chain wheel 6 is integrally provided. Further, the shaft 4 is provided with a cooling medium flow path 3a utilizing a space such as a double pipe or a pipe, and the cooling medium flow path 3a is provided at both ends with rotatable rotary joints 7a and 7b, for example. It is in communication with a cooling medium source (not shown) in communication with the other end being the discharge side.

Next, a spiral blade (hereinafter referred to as a screw blade) is attached to the shaft 4.
8 is provided integrally with the shaft 4. 9 is a cover plate. The screw blade 8 is provided with at least one kerf 10 having an arcuate bottom with a pitch of 1 in FIG. The number of the cut grooves 10 is set to 2 to 3 per pitch, and if the depth of cut is too deep, the blade strength decreases and the thermal deformation is promoted, which lowers the transportation efficiency of the powder and granules themselves. Leave 1/3 to 1/4 of h) in Figure 3.

FIG. 3 shows a case where three cutting grooves 10 are provided per pitch, and it is important that the bottom of each groove is an arcuate bottom 11 with a rounded shape.

Further, it is preferable that the kerfs 10 have a groove number and a groove width that satisfy the conditions of Table 1 in consideration of the state of the powder and granules.

Further, it is preferable to determine the shaft 4 within the range of 1/3 to 3/5 of the diameter of the screw blade 8 because the mutual thermal strain dispersibility with the shaft 4 and the screw blade 8 is enhanced.

Further, according to the present invention, in order to solve the above-mentioned problem, the screw blade 8 may be divided into at least three portions per pitch as shown in FIG. 4, and the end portions of the divided blades may be overlapped with the adjacent divided blades. .

That is, the screw blade 8 is composed of divided blades 8a to 8c, and the divided blades 8a to 8c are integrally fixed to the shaft 4, and the end portion 12 simply overlaps with the adjacent divided blades 8a to 8b. It is in a state of being a free end, and is provided so that it can freely slide against expansion and contraction.

(Operation) With the above configuration, the kerf 10 absorbs the maximum thermal stress strain concentrated at the tip of the screw blade 8 while ensuring the rigidity of the shaft 4 and the screw blade 8.

Moreover, since the cut groove 10 is provided with the arcuate bottom portion 11, the clutch of the screw blade 8 due to the thermal strain of the cut groove 10 can be prevented.

The kerf 10 is a high temperature powder or granular material, for example, slag, red hot coal, coke, sinter or incinerator ash, boiler residual ash, etc. during transport, the gap is reduced due to thermal expansion, so the screw conveyor should be used for the original transport. There is no hindrance to efficiency. Further, when the blades are piled up, thermal distortion is eliminated by sliding of the respective end portions 12.

As a result, it was not possible to convey high-temperature substances by the conventional screw conveyor, but the present invention enables the conveyance of high-temperature powder particles for the first time.

(Effect of the Invention) As described above, by using the screw conveyor according to the present invention, it is possible to convey high-temperature powder particles, which has been impossible in the past, and the screw conveyor itself has a long service life and the conveyance efficiency is high. It was possible to realize an extremely excellent screw conveyor without any damage.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a screw conveyor for conveying high-temperature powder and granules according to the present invention, FIG. 2 is a partial detailed sectional view of FIG. 1, and FIG. 3 is a sectional view taken along line AA 'of FIG. The arrow view is shown. FIG. 4 is a schematic view of a blade portion of another example of the present invention. 1 is an inner casing 2 is an outer casing 3, 3a is a cooling medium flow path 4 is a shaft 5A, 5B is a bearing 8 is a screw blade 10 is a kerf 11 is an arc bottom

Claims (2)

[Scope of utility model registration request] 1. A screw conveyor in which a spiral blade is integrally fixed to a casing and a freely rotatable shaft inserted in the casing, and a cooling medium flow path is provided in the casing and the shaft, and the spiral blade is provided to the spiral blade. A screw conveyor for conveying high-temperature powdery or granular material, characterized in that at least 1/3 to 1/4 of the height of the spiral blade is left and at least one groove having an arcuate bottom is provided per pitch. 2. A screw conveyer in which a spiral blade is integrally fixed to a casing and a freely rotatable shaft inserted in the casing, a cooling medium passage is provided in the casing and the shaft, and a spiral blade Pitch at least 2
A screw conveyor for conveying high-temperature powder or granular material, characterized in that the end portions of the divided blades are overlapped with each other and the end portions of the adjacent divided blades are free ends.