JPS591373B2 - Granulation equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coal slurry granulation apparatus that is applied to granulate coal particles in a coal slurry.

Generally, when transporting coal from its production area to a port, the transport distance is long, so coal is
Coal slurry is produced by pulverizing coal into particles on the order of mm or less and dispersing them in water, and this coal slurry is increasingly transported by pipe line.

The coal concentration of coal slurry suitable for transportation is, for example, 50
~60% by weight, but the transportation power and transport are better when the coal particles in the slurry have a relatively wide particle size distribution, for example, from pulverized coal with a diameter of about 5 yen or less to pulverized coal on the micron scale. This is convenient in terms of quantity, etc.

However, after transportation, it is necessary to perform dewatering, drying, etc. to remove the coal particles from the slurry.
If the coal slurry contains pulverized coal, it will clog the filter during dewatering, significantly reducing the dewatering efficiency, taking a long time to dry, and causing bridging phenomenon when taking out the slurry after storage. There were problems such as the generation of dust and the scattering of dust.

This invention was made in order to solve the above problem, and it is possible to effectively granulate coal particles in coal slurry after transportation, and it also greatly simplifies the work of extracting coal particles from coal slurry. It is an object of the present invention to provide a coal slurry granulation device that allows smooth granulation of coal slurry.

This invention will be explained below based on embodiments shown in the drawings.

FIG. 1 schematically shows a method for granulating coal slurry.

As shown in the figure, first, a binder is added to a coal slurry or lee containing coal particles with a particle size of about 500 mm or less, and then this slurry is mixed with a stirring device such as a homomixer or a homogenizer to a coal particle size of about 2,000 mm or less. 9000r
The binder is dispersed by stirring at a high rotation speed of pm, and the binder is attached to the surface of the coal particles to perform temporary granulation.

Note that oil is used as the binder.

Specifically, heavy oil, dissolved oil, light oil, distilled oil, vegetable oil, etc. are used.

Coal slurry, for example, has a coal concentration of 5 to 30% by weight and is suitable for transportation and diluted to be suitable for granulation. It is added at a ratio of 10 to 25 parts of baking soda based on the amount of coal.

In this case, coal particles and oil generally have an affinity for each other, so in a slurry in which coal particles are dispersed in water,
Coal particles and oil are bonded by affinity, and the oil is attached to the surface of the coal particles.

Next, the coal slurry after the primary granulation is gently stirred by the granulation device according to the present invention to perform secondary granulation,
A coal slurry containing granules having a relatively large particle size in the form of oil-impregnated pellets is obtained.

This slurry of granules contains granules of a size suitable for subsequent removal operations of coal particles such as dehydration and drying.

FIGS. 2 and 3 show a coal slurry granulation apparatus according to the present invention.

In the figure, a coal slurry granulation device 1 is equipped with a rotating shaft 3 in a stirring tank 2 that accommodates coal slurry after primary granulation to which a binder has been added. First stirring blades 4 made of mesh are attached at right angles to the coaxial shaft 3 and spaced apart from each other by a predetermined distance, and between each of these first stirring blades 4 there are three mesh-made stirring blades each. The second stirring blade 5 is attached parallel to the coaxial shaft 3.

Here, the three first stirring blades 4 have a circular shape, are each attached to the rotating shaft 3 by a mounting bracket 6, and are spaced apart from each other by a distance corresponding to two-fifths of the blade diameter. It's open.

Note that each first stirring blade 4 has a diameter corresponding to about four-fifths of the inner diameter of the cylindrical stirring tank 2.

Each of the second stirring blades 5 has a rectangular shape when viewed from the side, and three of these are arranged between the circular first stirring blades 4 at an angle of 120 degrees from each other. Second
A gap 7 is provided between the inner edge of the stirring blade 5 and the rotating shaft 3, and the outer edge of each blade 5 and the outer peripheral edge of the circular first stirring blade 4 are aligned with each other.

More specifically, the first and second stirring blades 4 and 5 have a diameter of 3
It is made of stainless steel wire mesh made of 20μ wire wires woven at intervals of 590μ.

In addition, 8 is a motor, which rotates the rotating shaft 3 by, for example, 150 mm.
It is rotated at a relatively slow speed of ~300 rpm.

9 is a lid of the stirring tank 2. When the coal slurry after primary granulation is gently stirred by the granulation device 1, the stirring tank 2
first and second stirring blades 4, 5 made of inner walls and wire mesh;
The transfer of the coal particles to the upper part 8 is improved, and the coal particles move through the wire mesh of the first and second stirring blades 4 and 5, thereby reducing the movement of water and the entrainment of air. It is possible to stir the coal particles by reducing the amount and improving the movement of the coal particles.This allows the coal particles to which the binder is attached to adhere well to each other, and the granulation effect is very large.

In the above embodiment, three first stirring blades 4 made of wire mesh are attached to the rotating shaft 3, but at least two first stirring blades 4 may be attached.

Further, the first stirring blade 4 is attached perpendicularly to the rotating shaft 3, but may be attached at a slight angle.

On the other hand, the second stirring blade 5 is arranged parallel to the rotating shaft 3, but it may be arranged slightly obliquely to the rotating shaft 3, and the second stirring blade 5 and the rotating shaft 3 In some cases, the gap 7 cannot be provided between them.

Further, the outer edge of each second stirring blade 5 may be arranged to protrude outward from the outer peripheral edge of the first stirring blade 4, or may be arranged to extend inward from the outer peripheral edge. .

The shape, size, mesh size, etc. of the first and second stirring blades 4 and 5 made of these wire meshes can be appropriately selected depending on the size of the coal particles.

Further, the number of second stirring blades 5 used and the arrangement interval are arbitrary.

Further, in the above embodiment, the second stirring blade 5 is made of the same kind of wire mesh as the first stirring blade 4, but it may be made of a different kind of wire mesh.

Although the rotating shaft 3 is arranged in the vertical direction, it may also be arranged in the horizontal direction.

As mentioned above, the coal slurry granulation device according to the present invention is equipped with a rotating shaft 3 in the stirring tank 2 that accommodates the coal slurry to which a binder has been added, and a plurality of sheets are attached to the rotating shaft 3. A first stirring blade 4 made of all-mesh is attached at right angles to the coaxial shaft 3 and spaced apart from each other by a predetermined distance, and a second stirring blade made of all-mesh is installed between these first stirring blades 4. Since the stirring blades 5 are mounted parallel to the coaxial shaft 3, the transfer of coal particles on the inner wall of the stirring tank 2 and the first and second stirring blades 4 and 5 made of wire mesh is prevented. The granulation effect is very good, and the coal particles move through the wire mesh of the stirring blades 4 and 5, resulting in a very large granulation effect.

Therefore, the coal particles in the coal slurry after being transported through the pi-to-line can be granulated into oil-containing pellets with a large particle size and a narrow particle size distribution range, and this allows for dehydration and removal of the coal particles from the slurry. Operations such as drying can be carried out very smoothly, and coal particles can be recovered from the slurry with a high yield. Therefore, the transport efficiency of coal can be greatly increased, and the effective use of coal can be achieved. This has the effect of being extremely economical.

Next, this invention will be explained in detail.

Experimental Example (I) Preparation of Coal Slurry Coal pulverized into powder particles with a particle size of 3 mm or less was dispersed in tap water using a stirrer to prepare a coal slurry.

The coal concentration in the slurry was 7.5% by weight. Incidentally, the measurement results of the particle size distribution of the coal raw material having a particle size of 311L1rt or less are shown in FIG.

As shown in curve A in the same figure, the coal raw material has a particle size of 3m11L.
The following powdered coal and pulverized coal are mixed on average and have a wide range of particle sizes, and this can be used as coal slurry for pipes and
It is suitable for line transportation.

(II) Primary granulation Next, a binder made of heavy oil (coplanar C heavy oil) was added to the above coal slurry, and the mixture was granulated at 200 Orpm with a homogenizer.
The slurry was stirred for 10 minutes at a rotational speed of 1, to disperse the heavy oil into the slurry and perform primary granulation.

The amount of heavy oil added is calculated as heavy oil amount/coal amount x 100,
It was 155% by weight.

(1) Secondary granulation Next, using the coal slurry granulation apparatus 1 of the present invention shown in FIG. 3, the coal slurry after the primary granulation is passed through three first stirring blades 4 made of wire mesh Stirring was carried out for 2 hours at a rotational speed of 300 rpm using three second stirring blades 5 made of wire mesh placed between each of these.

(IV) Granules in the slurry Next, the granules after secondary granulation are classified underwater using a sieve with 149μ holes, and the adhering water is removed in a constant humidity tank at 50°C. Then, the recovery rate of coal granules in the form of oil-impregnated pellets was measured.

The recovery rate was calculated according to the following formula.

In this experimental example, the recovery rate of the oil-impregnated coal granules was 91.2% by weight.

The measurement results of the particle size distribution of the obtained granules are shown at the curved line in FIG.

As can be seen from this curved line, according to the coal slurry granulation apparatus 1 of the present invention, oil-impregnated coal granules having a large particle size and a narrow particle size distribution range can be obtained. It is clear that the apparatus 1 has a significantly superior granulation effect on coal slurry.

Note that the coal slurry granulation device 1 of the present invention is also applicable to coke slurry.

[Brief explanation of drawings]

Fig. 1 is a block diagram illustrating a coal slurry granulation method, Figs. 2 and 3 show examples of the present invention, and Fig. 2 is a perspective view of a wire mesh stirring blade attached to a rotating shaft. figure,
FIG. 3 is a cross-sectional view of the coal slurry granulation device, and FIG. 4 is a curve diagram showing the measurement results of the particle size distribution of coal. 1... Coal slurry granulation device, 2...
- Stirring tank, 3... Rotating shaft, 4... First stirring blade made of wire mesh, 5... Second stirring blade made of wire mesh, i.
... Particle size distribution curve of coal raw material, mouth ... Particle size distribution curve of oil-impregnated coal granules.

Claims (1)

[Claims] 1 A rotating shaft 3 is installed in a stirring tank 2 containing a coal slurry to which a binder has been added, and a plurality of first stirring blades 4 made of all-mesh are attached to this rotating shaft 3 at right angles to the coaxial shaft 3. A second stirring blade 5 made of a full mesh is installed in the middle of these first stirring blades 4 at a predetermined distance from each other in a shape parallel to the coaxial shaft 3. Coal slurry granulation equipment.