JPH0567872B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a powder drying device used for evaporating and removing moisture contained in powder and granules.

[Background technology]

A powder drying device is used to remove moisture contained in the powder. A powder drying device supplies powder into a container and dries the powder by blowing hot air through it. However, in conventional powder drying apparatuses, the powder often adheres to the inner surface of the container during drying. Some powder and granular materials burn explosively at low temperatures, and if adhesion occurs,
Adhering materials may heat up due to heat transfer from the inner surface of the container and burn, or they may block the hot air inlet, raising the temperature of the hot air and causing combustion. In order to prevent this, it is necessary to occasionally clean the inside of the container to remove deposits, which is very troublesome.

[Purpose of the invention]

In view of the above points, it is an object of the present invention to provide a powder drying device that causes less adhesion of powder and granules and does not require cleaning work inside the container.

[Disclosure of the invention]

In order to achieve the above object, the present invention includes a cylindrical container arranged vertically and open at both upper and lower ends, and a supply means for supplying powder or granular material into the container from the side, and hot air blows into the lower end of the container. In the powder drying device, the powder and granules flow into the container and flow out together with the powder from the upper end. A crusher for crushing powder and granules is installed below the position and above the hot air inflow position. Although there are fine irregularities, the crusher is smooth with no fuzz, and the crusher includes a perforated disc that rotates in a horizontal plane and has a large number of holes that allow hot air to flow into the container, and The gist of the present invention is a powder drying device characterized by comprising a stirring arm fixed on a disk. This will be explained in detail below based on the drawings showing one embodiment thereof.

As shown in Figure 1, this powder drying device is
The apparatus includes a cylindrical container 1 with both ends open, a supply means 3 for supplying granular material 2 into the container, and a crusher 4 for crushing the granular material 2 supplied into the container. The supply means 3 consists of a hopper 5 and a screw conveyor 6. The screw conveyor 6 is connected to a powder supply port 7 provided in the container 1 . The screw 8 of the screw conveyor 6 is rotated by a motor 9, so that the powder 2 in the hopper 5 is supplied into the container from the powder supply port 7. The lower end 10 of the container is connected via a duct 11 to a heating device such as a heat exchanger. The upper end 12 of the container is connected via a duct 13 to a product collection device and a suction device. The lower end 10 of the container serves as an inlet for hot air, and the upper end 12 serves as an outlet for hot air and powder. The crusher 4 is built in the lower part of the container 1, and as shown in FIG. The stirring arm 15 is fixed to the stirring arm 15. The perforated disk 14 allows hot air to pass through. The stirring arm 15 is made of steel bent in a U-shape. The power of the motor 17 is transmitted through a belt 18 to rotate the crusher 4. In the figure, 19 is a bearing section. As the crusher 4 rotates, the agitation arm 15 disperses or loosens the aggregates of the granular material 2 supplied from the supply means 3 into the container 1.

A cloth 20 is stretched inside the container 1 along the inner surface. In the figure, the cross section of the cloth is shown in a waveform to make it clear where the cloth is stretched. This cloth 20 is fixed in places with bolts from inside the container. The cloth 20 is woven with threads made of long fibers with a diameter of 0.01 to 1 mm, and has a smooth surface with no fuzz, although there are fine irregularities due to the texture, and is breathable. .
An air outlet 21 is provided on the wall of the container, to which a compressed air supply pump 22 and a valve 23 are connected.
are connected. Compressed air from the compressed air supply pump 22 is intermittently blown out from the air outlet 21 by opening and closing the valve 23. Compressed air blown out from the air outlet 21 is sent between the cloth 20 and the inner surface of the container 1, momentarily vibrates the cloth 20, and escapes into the container 1 through the weave of the cloth 20. . In this embodiment, the air outlet 21 is provided at one location, but it may be provided at multiple locations.

The granular material 3 supplied into the container is crushed by a crusher 4, transported through the container with hot air and dried, and sent out from the upper end 12 of the container as a dry granular material. There is.

In the conventional powder drying apparatus, as mentioned above, the powder often adheres to the inner surface of the container. This was because the inner surface of the container was flat, so the contact area between the powder and the inner surface of the container was large, and the adhesion force was large. In the powder drying device according to the present invention,
A cloth woven from long fibers with a diameter of 0.01 to 1 mm is attached along the inner surface of the container. Since the surface of such a cloth has fine irregularities due to the texture, the contact area between the cloth surface and the powder is small, and the adhesion force is small. Furthermore, since the surface of the cloth is smooth and free of fuzz, the powder particles will not get caught on the surface of the cloth. Therefore, adhesion of powder particles becomes less likely to occur. Moreover, even if a small amount of it adheres to the cloth, the cloth prevents heat transfer from the container to the powder and granules, so the temperature of the powder and granules do not rise and burn.

Further, in the above embodiment, the flexibility of the cloth is used to vibrate the cloth with compressed air to shake off the powder particles adhering to the cloth. Therefore, adhesion of powder and granules can be completely prevented.

However, blowing air is not essential;
It is sufficient if the cloth is attached along the inner surface of the container. That is, in the above embodiment, it is only necessary that the cloth be fixed with bolts or the like from the inside of the container in places and stretched along the inner surface of the container. Also,
A cloth may be attached so as to be in close contact with the inner surface of the container.

The cloth used in this invention must be woven from yarns made by spinning extremely long continuous fibers, generally called long fibers. On the other hand, cloths woven from felt and short fibers are unfavorable because they have a lot of fuzz on the cloth surface and powder particles get caught on the cloth surface. In particular, it is preferable that the cloth used in this invention be heat resistant, since the inside of the container may reach a high temperature. Furthermore, when blowing air into the fabric, the fabric needs to be breathable.

Note that the powder drying apparatus according to the present invention is not limited to the above embodiment. As the supply means, a belt conveyor may be used instead of the screw conveyor, or a means using gravity such as a chute may be used. The cloth does not have to be attached to the entire inner surface of the container, but if it is attached partially, the powder tends to adhere to the inner surface of the container near the powder supply port, so it is recommended to attach it to that part. It is better to

〔Effect of the invention〕

As seen above, the powder drying device according to the present invention has a diameter inside the container for drying the powder.
The cloth is woven with threads consisting of long fibers of 0.01 to 1 mm, and the surface has small irregularities due to the texture, but is smooth and free of fluff.The cloth is attached along its inner surface, so that the contact between the cloth surface and the powder and granules is smooth. The contact area is small and the adhesion force is small. Further, the powder particles will not get caught on the cloth surface. Therefore, adhesion of powder and granules can be reduced. Moreover, even if a small amount adheres to the cloth, the cloth prevents heat transfer from the container to the powder and granules, so the powder will not heat up and burn, making it highly safe. . Since there is less adhesion of powder and granules and the adhering powder and granules do not burn, cleaning inside the container, which was conventionally necessary, is no longer necessary. The powder drying device according to the present invention is equipped with a crusher equipped with a perforated disc rotating in a horizontal plane and an agitation arm fixed on the perforated disc, so that the powder is supplied into a cylindrical container. Even if there are aggregates in the powder or granules, they can be dispersed or loosened. Since the porous disk is installed at a position through which the hot air in the cylindrical container passes, the dispersion and loosening are performed extremely efficiently by the stirring force of the arm and the blowing force of the hot air.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of a powder drying apparatus according to the present invention, and FIG. 2 is an enlarged perspective view showing the same crusher. 1... Container, 2... Powder, 3... Supply means,
4... Disintegrator, 10... Lower end of container, 12... Upper end of container, 17... Cloth, 19... Compressed air supply pump.

Claims (1)

[Claims] 1. A cylindrical container arranged vertically and open at both upper and lower ends, and a supply means for supplying powder or granules into the container from the side, wherein hot air flows in from the lower end of the container and from the upper end. In the powder drying device, the powder and granular material is discharged from the container, and a cloth is attached along the inner surface of the container, and
A crusher for crushing the powder is installed below the powder supply position in the container and above the hot air inflow position, and the cloth is made of yarn made of long fibers of 0.01 to 1 mm in diameter. The crusher rotates in a horizontal plane and has a large number of holes that allow the passage of hot air flowing into the container. What is claimed is: 1. A powder drying device comprising: a porous disk; and a stirring arm fixed on the porous disk. 2. The granular material drying apparatus according to claim 1, wherein the cloth has air permeability and means for feeding compressed air between the cloth and the inner surface of the container is provided.