JPS5939332A - Granulator - Google Patents

Abstract

PURPOSE:To prevent the formation of non-granulated coal, by a method wherein a pair of rotary shafts rotating to opposed directions are provided in a container and stirring blades are attached to the rotary shafts while mountain shaped guides are provided to the middle parts of said rotary shafts. CONSTITUTION:A granulator 1 consists of a cylindrical container 3 and a pair of rotary shafts 4, 5 provided in said container 3 and rotating to opposed directions. Stirring blades 6, 8, 10 are attached to the rotary shaft 4 while stirring blades 7, 9 are attached to the rotary shaft 5 and mountain shaped guides 11, 13...19 and 12, 14...20 are respectively attached to the middle parts of the rotary shafts 4, 5 along the rotary peripheral flanges of stirring blades in upper and lower relationship in pair in order to transfer an object to be granulated to the peripheries of the stirring blades of one rotary shaft 5 from the peripheries of the stirring blades of the other rotary shaft 4. By this structure, a stay time can be shortened to a large extent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wet granulator, and particularly to a granulator suitable for producing coal granules from coal/water slurry and a binder.

Conventionally, when deashing coal, petroleum fuel oil is added as a binder to a water slurry of pulverized coal, and this is stirred in a granulator to remove combustible components from the coal through the binder and turn it into granules. A method is known in which noncombustible components such as ash are left in water as a suspension, and this suspension is used as waste liquid.

By the way, the granulators used for such deashing operations are generally equipped with stirring blades in the container or tank, and when such a granulator is used, the recovery rate of combustible components in coal is determined by the amount of binder. It is determined by the residence time of coal particles in the granulator.

Generally, the recovery rate of combustible components in coal in a granulator is expressed by the amount of combustible components in the net souvenirs after granulation using a wet vibrating screen or the like.

Normally, the opening of the vibrating screen is about 0.5, but if the granulation operation in the granulator is incomplete, a large amount of ungranulated coal of 0.5 wn or less will be generated. Recovery with a screen becomes impossible, and as a result, the recovery rate of combustible components is drastically reduced.

However, on the other hand, since petroleum fuel oil, which is more expensive than coal, is used as a binder, if deashed coal is to be supplied as a low-cost fuel, it is necessary to suppress the amount of binder as much as possible. Therefore, in a conventional granulator,
The only way to improve the recovery rate of combustible component granules is to lengthen the residence time, which requires increasing the number of granulators installed or increasing the capacity, which naturally reduces the installation area of the equipment. There was a drawback that the amount increased significantly.

In addition, since a single stirrer is used to stir the inside of a large-capacity container,
The stirring efficiency was poor, and as a result, the amount of ungranulated coal increased, making it impossible to improve the recovery rate of combustible components, and there were also problems in that a large amount of power was required for stirring.

In order to prevent the formation of ungranulated coal, there is a proposal to install the granulated coal outlet of the granulator above the granulator main body, but there is a risk of clogging the granulator (as mentioned above). These shortcomings have yet to be resolved.

Therefore, the present invention was made to eliminate such conventional drawbacks, and is particularly suitable for producing granulated coal using a binder from coal/water slurry 1). The granulation operation is performed while rolling the coal evenly inside the device, making it possible to make the device dimensions extremely compact, and also significantly increasing the recovery rate of combustible components in the coal. It has the following features.

That is, in the granulator of the present invention, a pair of rotating shafts that rotate in opposite directions are provided in a cylindrical container having an oval cross section, stirring blades are attached alternately to the pair of rotating shafts, and stirring blades are attached alternately to the pair of rotating shafts. A pair of upper and lower chevron-shaped guides are provided in the intermediate portion of the rotary blade to sequentially transfer the material to be granulated from around one stirring blade to around the other rotary blade along the rotational periphery of the rotary blade. It is something.

The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a perspective view showing an outline of the present invention, FIG. 2 is a plan view, cross-sectional view 1, and FIG. 3 is an axial sectional view.

First, the granulator 1 of the present invention is composed of a cylindrical container 3 having an oval cross section 2, and a pair of rotating shafts 4 and 5 provided inside the container 3 and rotating in opposite directions. . The installation positions of the rotating shafts 4 and 5 can be arbitrarily selected within the cylindrical container 3, and the rotation shafts 4 and 5 are installed at the centers of the left and right semicircles of the oval cross section 2, respectively, so that the entire device This is preferable in terms of making the volume compact and eliminating pot space to improve stirring efficiency.

Further, the cylindrical container 3 can have any shape as long as its cross section is oval, and as shown in FIG.
A shape in which a rectangular part C is interposed between the diameter semicircular parts a and b is also acceptable. Alternatively, as shown in FIG. part d
It can also be shaped like a force (existence).

However, in Fig. 2 A, the left and right agitation processing capacities are equal, and as described later, if we take the example (7-point force that increases the granulation efficiency from coal/water slurry), Fig. 2 A is Second
Preferable I/A0 compared to Figure B Next, in the present invention,
Stirring blades are attached alternately to a pair of rotating shafts 4 and 5.
).

Here, "alternately" means that, as shown in FIG. 3, when the stirring blades 6 are first attached to the rotating shaft 4, the stirring blades are attached to the corresponding positions on the rotating shaft 5 on the opposite side. This means that no stirring blade is attached to the rotating shaft 4 at the position corresponding to the stirring blade 7 similarly attached to the rotating shaft 5. However, stirring blades 7 and 9 are attached to the rotating shaft 5, respectively.

Furthermore, in the present invention, the material to be granulated is transferred from around the stirring blade of one rotating shaft 4 to the middle part of the rotating shafts 4 and 5 of the other rotating shaft 5.
A chevron-shaped guide 11 for moving around the stirring blade of
, 13 , 19 and 12゜14,
. . . 20 are attached along the rotating periphery of each stirring blade in pairs, one above the other.

As is clear from FIGS. 3 and 4, the expression "in pairs above and below" means that the chevron-shaped guide 11 is first attached to the lower part of the stirring blade 6, and the same-shaped guide forms a pair therewith. 12 is attached to the upper part, and then for stirring R1, a guide 13 is attached to the lower part, and a guide 14 is attached to the top part in a pair. They are installed in pairs between the rotating shafts 4 and 5, one above the other.

As is clear from FIG. 3 and FIG.
B, 29, and side walls 30, 31 can be separated, which has the advantage that maintenance, stirring blade replacement, etc. can be easily carried out.

Next, the function of the granulator of the present invention will be explained based on FIGS. 1 and 3, taking as an example the granulation of coal/water slurry using a binder.

First, a coal/water slurry to which a binder has been added is supplied via the feed pipe 21 to the left granulation chamber 22 around the left rotating shaft 4 by a slurry pump (not shown). The supplied coal/water slurry is stirred by the stirring blades 6, and the coal particles are transferred while circulating along the inner wall of the left granulation chamber 22. Furthermore, the coal particles are passed through the stirring blades 6 along the guides 11 and 12 provided vertically in pairs in the parallel portion C (FIG. 2A) between the left granulation chamber 22 and the right granulation chamber 23.
While maintaining the velocity energy given by , it is sent to the right granulation chamber 23 and circulates around the inner wall of the right granulation chamber 23 . In the right granulation chamber 23, the mixture is stirred again by the stirring blade 1, and transfer energy is further applied.

Next, the coal particles orbiting around the stirring blade 7 are moved back to the left granulation chamber 22 along guides 13 and 14, which are similarly attached in pairs above and below in the parallel section C (FIG. 2A). to move to.

In the left granulation chamber 22, the stirring blades 8 and guides 15, 16 repeat the transfer of the coal particles to the right granulation chamber 23, and in the same manner, the stirring blades sequentially stir the coal particles, transfer energy is added, and so on. The coal particles are transferred between the left and right granulation chambers guided by the guide, and the granulation operation is carried out during this time.

The finally obtained granulated coal passes through a funnel 24 provided around the rotation shaft 5 at the rear end of the right rotation shaft 5, and is taken out from the discharge pipe 25.

FIG. 5 shows the material recovery rate ηm by the solid-liquid mixing device of the present invention.
(◎ mark) and the material recovery rate (◎ mark) when high speed rotation and residence time are significantly lengthened in a conventional granulator. As is clear from this figure, in the device of the present invention, 95
Considering that a material recovery rate of 4 or more is possible, and that most of what is discarded as waste liquid is non-flammable components,
The combustible component recovery rate in the apparatus of the present invention is even higher.

The horizontal axis in FIG. 5 is the transfer distance LR of coal particles calculated from the blade rotation speed N, blade diameter D, and residence time T.
According to the study results of the present inventors, under conditions where the amount of binder is constant, the material recovery rate is approximately proportional to LR.

Therefore, in the conventional granulator, the material recovery rate ηm is ηm=C-LR(N, D, T) (C is a constant).

On the other hand, in the present invention, the material recovery rate ηm is 4m =
C' ・LSI (N', (2D'+AW), T
), it is possible to achieve a high recovery rate. Note that tw represents the guide wall length.

As described above, according to the present invention, since a cylindrical container having an elliptical cross section is used, the material to be granulated is stirred and circulated along the inner wall of the container without receiving significant resistance.

Furthermore, in the present invention, two rotating shafts that rotate in opposite directions are provided, stirring blades are attached alternately to the rotating shafts, and a pair of upper and lower guides are installed along the rotational periphery of each stirring blade in the middle of the rotating shaft. , the coal/water slurry can be sequentially transferred between the left and right stirring blades along this guide. During this transition, the coal particles roll while maintaining the high-speed kinetic energy given to them by the stirring blades, and each time they are alternately stirred by the left and right stirring blades, the transferred energy is further increased. Therefore, efficient granulation can be achieved.

Furthermore, since the device of the present invention has a two-shaft structure with a pair of stirrers on the left and right sides, the stirring shaft can be shortened, and the volume of the device can be made significantly smaller compared to conventional granulators. Not only can this be done, but the residence time can be significantly shortened. Unlike conventional granulators, increasing the residence time may require an increase in the size of the equipment or increase the power consumption due to the high speed rotation of the agitator. do not have. Therefore, for coal types that are relatively easy to crush, a high recovery rate can be achieved with relatively low speed rotation, and the recovery rate will not decrease due to excessive crushing of coal particles, making it suitable for use. It is also possible to expand the range of coal types.

In addition, coarse powdered coal, which has increased in diameter faster than other particles, is always present on the vessel wall due to centrifugal force, so it is gradually
Since the migration to the rear discharge port side is more rapid than that of fine particles, it is possible to eliminate the problem of clogging in the granulator due to retention of coarse-grained granulated coal.

[Brief explanation of the drawing]

FIG. 1 is a perspective schematic view showing an embodiment of the present invention, FIG. 2 is a plan sectional view thereof, FIG. 3 is a sectional view in the direction of the rotation axis, and FIG. 4A is a direction of the rotation axis of the cylindrical container according to the present invention. Cross section, 4th
FIG. B is a sectional view of a cylindrical container in another embodiment in the direction of the rotation axis, and FIG. 5 is a diagram showing the relationship between the material recovery rate and transfer distance of the granulator of the present invention and the conventional granulator. 3... Cylindrical container, 4, 5... Rotating shaft, 6, 7.8,
9゜10... Stirring blade, 11, 12, 13.14...
・・・・・・・・・2o・・・Yamagata guide. Agent: Patent Attorney Makoto Ogawa − Patent Attorney: Ken Noguchi Patent Attorney: Kazuhiko Saishita

Claims (1)

[Claims] A pair of rotating shafts that rotate in opposite directions are provided in a cylindrical container having an elliptical cross section, and stirring blades are attached alternately to the pair of rotating shafts. A granulator characterized in that a pair of upper and lower chevron-shaped guides are provided to sequentially transfer the material to be granulated from around one stirring blade to around the other rotor blade along a rotating periphery.