JPS5934876Y2 - Granule scattering device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a raw material supply device for a vertical sintering furnace or the like.

There are many examples in which granular or powdered raw materials are granulated using a granulator and then subjected to treatments such as drying, sintering, and roasting (hereinafter referred to as sintering, etc.).

Among these, granular raw materials are fed into a vertical filling tank from the top and discharged from the bottom to form a packed bed, and high temperature gas etc. is blown into this packed bed from a port provided on the inner circumference of the filling tank to fill the tank. In most cases, a device (hereinafter referred to as a vertical sintering furnace, etc.) that performs sintering or the like on materials is used.

In this vertical furnace sintering furnace, etc., the air flow distribution in each part of the packed bed is mainly influenced by the length of the flow path from the port to the free space above the packed bed and the porosity of each flow path.

In order to obtain good sintering results, it is necessary to achieve a uniform airflow distribution in the circumferential direction and an appropriate airflow distribution in the radial direction.

When gas is blown into a packed bed from a port provided on the outer circumferential surface of the packed bed, the porosity is relatively large on the outer periphery of the packed bed.The gas blown through the port is especially close to the center of a large-diameter packed bed! Therefore, the radial airflow distribution increases with radius.

! In the example of heating, the raw material grains descending on the outer periphery of the packed bed descend through the port and are blown in from the port! On the other hand, the raw material grains descending from the center exchange heat with the raw material grains descending from the outer periphery and are heated by the lower temperature gas, resulting in low-temperature heating.

For this reason, the heating becomes non-uniform in the radial direction of the packed bed, and therefore the effects of sintering etc. become non-uniform.

To compensate for this, various methods have been devised to increase the amount of ventilation in the center.

One of the methods is to maintain the shape of the stock line, which is the boundary between the packed bed and the free space above it, into an inverted conical shape.

In other words, among the ventilation paths that reach each part of the stock line from the port, by making the ventilation path that reaches near the center of the stock line shorter than the ventilation path that reaches the outer periphery of the stock line, the ventilation near the center, especially in the upper part of the packed bed. The amount is increased to compensate for the lack of heating.

A conventional method for making a stock line into an inverted conical shape is to spread granular raw materials along the inner periphery of a filling tank, thereby making the stock line into an inverted conical shape with an inclination that follows the angle of repose of the raw material.

However, the angle of repose is determined by the raw material itself, and the inverted conical stock line shape determined by this angle does not necessarily guarantee an appropriate air flow distribution.

The purpose of the present invention is to obtain an appropriate airflow distribution by arbitrarily controlling the shape of the stock line.

The present invention consists of a ring-shaped disk that rotates in a horizontal plane and has an auxiliary plate attached to the inner circumference with a downward slope; This is a granular material dispersing device characterized by comprising a scraper that scrapes the granular material and causes the granular material to fall toward the inner diameter side.

Next, the present invention will be explained with reference to drawings of embodiments.

FIG. 1 is a plan view of an embodiment in which the present invention is applied to a sintering furnace, and FIG. 2 is a side view of its branch.

The furnace body 1, which is a filling tank, has a large number of ports 2 on the central furnace wall at its height for blowing out high-temperature combustion gas from the combustion chamber, and is filled with granular raw materials up to the stock line 3. The filling is discharged by a discharge device (not shown) installed at the bottom of the furnace body 1, and the entire cross section is! The stock line 3 is maintained by descending at a uniform descending speed and by dispersing granular raw materials by a dispersing device 4 provided at the top.

The spraying device has the following configuration.

A plurality of driven shafts 10 are rotatably supported by bearings 7 provided on a base 6 installed on the furnace body 1, and rollers 8 and 9 having ribs are fixed thereto, and rotationally driven from a drive source (not shown) via a sprocket 12. In addition to the rollers 8.9, a drive shaft 13 to which bevel gears 11 and 11' are fixed is rotatably supported by a bearing I.

A table ring gear 16 that is attached to the upper surface of the table 15, which is a ring-shaped disc, and a scraper ring gear 19 that drives the scraper 17 that scrapes on the table 15 via an arm 18 are supported by rollers 8 and 9, respectively. and are guided by their respective flanges, and are driven to rotate within a horizontal plane in the directions of arrows 16' and 19', respectively, in mesh with bevel gears 11' and 11, respectively.

The number of rotations per unit time indicated by arrow 19' is set higher than that indicated by arrow 16', and an auxiliary plate 20 is attached to the inner diameter of table 15 with a downward slope toward the center.

The granular raw material granulated by a granulator (not shown) is transported to a conveyor 21.
is continuously fed onto the rotating table 15 at arrow 1.
The table moves around the circumference by 150 rotations, which is the same rotation as 6'.

The scraper 17 that rotates in the same direction as the arrow 19' is the table 1.
Since the rotation speed is higher than 50 rotation speed, the granular raw material is scraped on the table 15 and evenly distributed over the entire circumference on the inner diameter side of the table 15.
drop the amount.

A part of the falling granular raw material falls directly from the table 15 onto the outer periphery of the stock line 3', and another part rolls on the auxiliary plate 20 and falls onto a part other than the outer periphery of the stock line 3', thereby being stocked. It is spread over the entire surface on line 3 at a uniform areal density.

If there is no auxiliary plate 20, all the raw materials on the table 15 will fall from the inner diameter of the table 15 directly onto the inner circumference of the furnace, and the shape of the stock line at this time will be as shown in 3 according to the angle of repose of the raw materials.

That is, by providing the auxiliary plate 20 and adjusting its shape and number, the shape of the stock line can be freely controlled within the angle of repose.

High-temperature combustion gas blown into the packed bed from a large number of ports 2 provided on the inner wall of the furnace body 1 heats and dries the granular raw materials falling one after another, causing them to undergo a sintering action.

Before installing the auxiliary plate 20 in the sintering furnace to which the present invention was applied, ventilation was concentrated in the center above the packed bed, as shown by the broken line 30, especially when the stock line was operated at a low position 13''.

For this reason, the dispersed cold raw material grains are easily heated and disintegrated in this area, and the temperature decreases at the outer periphery of the 3" stock line. The cold raw material grains, which tend to stick to each other, increase their moisture content due to condensation of water in the gas, increasing the adhesion effect.On the other hand, the particles that are not completely dried fall under pressure due to the new raw material sprinkled on top of them. As a result, they tended to adhere to each other and form clumps.

According to the present invention, the following effects can be achieved by installing the auxiliary plate 20 and controlling the stock line shape as shown in 3' to obtain an optimal radial ventilation distribution.

(1) Reduced fuel consumption rate by 21.7%, (2) Reduced product sieving rate by 0.73% (relative to total product weight), (3) Improved product porosity by an average of 2.52%. The variation range was reduced by 13.5% compared to the conventional variation.

(This porosity strongly influences the post-processing of this product.

) (4) Reduce the furnace pressure by 33.5 times.

As explained above, the present invention is a dispersion device consisting of a ring-shaped disk and a scraper, and by providing an auxiliary plate 20, the shape of the stock line when introducing granular raw materials can be arbitrarily controlled within the angle of repose. The purpose is to make the ventilation distribution appropriate, and it is not limited to the type of raw material or its treatment such as sintering.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 1 is a plan view of its branch. Fig. 2 1: Furnace body, 2: Port, 3.3', 3' varnish line, 4: Granule scattering device, 15: Table, 17: Scraper, 20: Auxiliary plate.

Claims (1)

[Scope of utility model registration request] In an apparatus for supplying and filling a granular material into a vertical filling tank with a granular material supply device to form a packed bed, and processing the granular material by blowing gas into the packed bed from a port provided in the filling tank, The granular material supply device includes a ring-shaped disk that rotates in a horizontal plane and has an auxiliary plate attached to the inner circumference with a downward slope, and rotates on this ring-shaped disk at high speed in the same direction as this ring-shaped disk. A granular material dispersing device comprising a scraper that scrapes the granular material and causes the granular material to fall toward the inner diameter side.