JPS6136462B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a wet pulverizer.

There have been various types of wet pulverizers, and among them, the media agitation type pulverizer shown in FIGS. 1 and 2 is widely used because of its high pulverization efficiency.

The medium agitation type crusher 1 shown in FIG. 1 has a rotating body 5 fitted in a tank 2 with a certain gap 3 and attached to a hollow rotating shaft 4. The hollow rotating shaft rotates at high speed. A slurry made by continuously mixing water and particles of the material to be crushed at a constant ratio and balls as a crushing medium are put into the tank 2 through the lower end opening 4a, and the blades on the lower surface of the rotary cylinder 5 rotate at high speed. The slurry and balls are sent into the gap 3 by the pump action of 5a,
Here, the particles of the material to be crushed are finely pulverized by agitation by a rotary cylinder 5 rotating at high speed, while raising the gap 3 as shown by the arrow, and discharging it to the outside of the tank 2 from the discharge port 6 on the outer periphery of the upper end.
The discharged slurry and balls are sent to a sieve 8 through a discharge pipe 7, where the slurry and balls are separated.The slurry is sent to a slurry tank 9 through the discharge pipe 7 and stored therein, and the balls are sent to a ball washing tank 11 by a feeder 10. The washed balls are passed through a transport pipe 12 and passed through a sieve 1.
3, where the water is drained and only the balls are fed into the hollow rotating shaft 4 again by the feeder 10'. At this point, a new raw material, slurry, is also introduced.

The medium agitation type crusher 15 shown in FIG. 2 has an agitator 20 concentrically arranged in a tank 17 with a cooling jacket 16 provided on the outer circumferential surface and the bottom surface, and an agitator 20 having multiple stages of arms 19 orthogonally arranged on a rotating shaft 18. A required amount of slurry, which is a mixture of water and particles of the material to be crushed at a certain ratio, and balls as a grinding medium are put into the tank 17, and the agitator 20 is rotated for a required time to mix the slurry and balls. The particles of the material to be crushed are finely pulverized by stirring, and the drain valve 21 provided at the bottom of the tank
is opened, the circulation pump 23 provided in the middle of the circulation piping 22 is driven, the slurry is circulated through the circulation piping 22 and put into the tank 17, and the process of pulverizing the particles of the material to be crushed in the slurry is repeated. . During this wet pulverization of particles of the material to be pulverized, the balls, which are the pulverizing media, move in the direction of the arrow in the tank 17, but the ball surface B is at a much lower position than the slurry surface S due to natural sedimentation. The product slurry obtained by the agitator 20 rotating for a required time to wet-pulverize the particles to be crushed is transferred to the circulation pump 23 of the circulation piping 22.
The downstream valve 24 is opened to discharge the balls, and the balls in the tank 17 are discharged by tilting the tank 17 by 90 degrees.

By the way, each of the above-mentioned media stirring type crushers 1 and 15
In both cases, the slurry is stirred using balls as the grinding medium, so the inner surfaces of the tanks 2 and 17 are significantly worn and damaged, and the balls, which are the grinding medium, are also damaged.
As a result, impurities such as ball fragments and particles due to wear and tear of the tanks 2 and 17 are mixed into the product slurry, resulting in a decrease in the quality of the product slurry.

Further, in the media agitation type crusher 1 shown in Fig. 1, the balls as the grinding medium are circulated outside the tank 2, and in the medium agitation type crusher 15 shown in Fig. 2, circulation circuits are provided to circulate the slurry outside the tank. Not only do the costs for the associated equipment and operating costs become enormous, but also a great deal of labor and time is spent on maintenance, inspection, maintenance, etc.

Furthermore, in the media agitation type crushers 1 and 15 shown in Figs. 1 and 2, circulation passages for the slurry and balls are not clearly secured in the tanks 2 and 17, so the progress of grinding is limited to the inside of the tanks. Differences occur depending on the part. As a result, the particles in the product slurry are dispersed, and the particle size range of the particles is widened. In addition, when the medium agitation type crushers 1 and 15 are operated for a long time, the temperature of the circulating slurry increases and the water evaporates, so the slurry concentration gradually increases and the viscosity increases, causing mechanical troubles and reducing the slurry. This will impede circulation, cause motor overload, and also make it impossible to crush mildly hot materials.

The present invention was made to solve this problem, and it is possible to narrow the particle size range of the particles in the product slurry by circulating the slurry in the tank without the need for grinding media such as balls, and to eliminate impurities. It is possible to obtain a good quality product slurry without any contamination.
Furthermore, it is an object of the present invention to provide a wet-type pulverizer which prevents the temperature of the circulating slurry from rising even when operated for a long time.

An embodiment of the wet-type pulverizer according to the present invention will be described below with reference to FIGS. 3 to 5.
The fixed tank is supported on the lower half of the tank, and the inner peripheral surface of its lower half is provided with a large number of convex parts 27 along the generatrix line to form an uneven surface, and a discharge port 28 is provided in the tangential direction of the lower end. A valve 29 is provided. A cooling jacket 30 is provided on the outer peripheral surface of the lower half of this fixed tank 25, and a cooling water inlet 31 is provided at the lower end of the jacket 30.
A cooling water outlet 32 is provided at the upper end. 33
is a rotating tank fitted in the lower half of the fixed tank 25 with a certain gap 34, and the rotating tank 33 is fitted with the bearing 3.
5 and 36, and is rotatably supported on the pedestal 26 by the upper end of a vertical rotating shaft 37 that passes through the bottom plate of the fixed tank 25. The outer circumferential surface of the rotary tank 33 is provided with a large number of convex portions 38 along the generatrix line to form an uneven surface, and the inner circumferential surface 39 is formed in a conical shape and the circumferential wall is hollow. Also, this rotating tank 3
A plurality of openings 40, four in this example, are provided at equal angular intervals on the outer periphery of the lower end of the rotary tank 33, and an impeller 41 that performs a pumping action by high-speed rotation of the rotating tank 33 is provided inside the openings 40. A plurality of stirring blades 43, four in this example, are provided on the lower surface of the bottom plate 42 of the rotating tank 33. 44 is the fixed tank 25
In this upper space 44, a plurality of guides 45, in this example two arcuate guides 45 having a cross-section of ``shaped'', point from the upper inner circumferential surface of the fixed tank 25 toward the center of the rotating tank 33. A water collection pipe 46 is supported and communicated with the tips of both guides 45, and is vertically disposed at the center of the upper part of the rotating tank 33.
Reference numeral 47 denotes an upper lid casing provided at the upper end of the fixed tank 25, with an input port 48 facing the water collection pipe 46 in the center.
is provided. Reference numeral 49 denotes a cooling coil arranged in the rotary tank 33 and having an inner diameter larger than that of the water collecting pipe 46. The lower end of the cooling coil is bent vertically, passes through the upper lid casing 47, and is further bent horizontally to collect the cooling water. The upper end thereof is similarly bent vertically, passes through the upper lid casing 47, and is further bent horizontally to form a cooling water outlet 51. Piping (not shown) is connected to the cooling water inlet 50 and the cooling water outlet 51. 52 is a pulley fixed to the lower end of the vertical rotating shaft 37, and 53 is a drive belt, which is stretched around the pulley 52 and a pulley (not shown) on the rotating shaft of the electric motor.

Next, the operation of the wet pulverizer of the present invention constructed as described above will be explained. The valve 29 at the tip of the discharge port 28 provided at the lower end of the fixed tank 25 is closed, and the slurry, which is a mixture of water and pulverized particles at a certain ratio, is fed from the input port 48 through the water collection pipe 46 from the upper end of the rotating tank 33. After feeding to a position slightly above, an electric motor (not shown) is driven and the drive belt 53 rotates the rotating tank 33 at high speed.
The slurry inside is formed into a conical inner peripheral surface 3 by centrifugal action.
The impeller 41 descends in a downward swirling flow along the arrow 9 and performs a pumping action from the opening 40 at the lower end.
It enters the annular gap 34 between the rotating tank 33 and the stationary tank 25. The slurry that has entered this gap 34 becomes an upward swirling flow due to the rotational force of the rotating tank 33 that is rotating at high speed, and the particles of the material to be crushed in the slurry are given velocity energy and are transferred to the inner peripheral surface of the fixed tank 25. It collides with the uneven surface of the rotary tank 33 and is crushed.
The particles are subjected to a grinding action between the convex portion 38 on the outer circumferential surface of the fixing tank 25 and the convex portion 27 on the inner circumferential surface of the fixed tank 25, and are further pulverized into fine particles and transported upward. When the slurry comes out of the annular gap 34 and reaches the upper space 44 of the fixed tank 25, it is collected by the guide 45, guided to the center of the rotating tank 33, and converged in the water collecting tank 46, which is placed at the upper part of the rotating tank 33. Enter intensively. From now on, rotating tank 33
The circulation of → opening 40 → annular gap 34 → upper space 44 → rotary tank 33 is repeated for a certain period of time, and each time the particles of the material to be crushed in the slurry pass through the crushing zone of the annular gap 34, they are crushed to a predetermined level. particle size.

In the circulation of this slurry, since the rotating tank 33 has a cooling coil 49 at its center, the water collection pipe 4
When the slurry entering the rotary tank 33 from the rotary tank 6 is directed outward by centrifugal action, it comes into contact with the cooling coil 49, so that efficient cooling is performed.
5 has a cooling jacket 30 on the outer circumferential surface of the lower half thereof, and the slurry passing through the annular gap 34 in an upward swirling flow is sufficiently cooled. Therefore, the temperature of the circulating slurry does not rise even after long-term operation.
Since the water does not evaporate, the slurry concentration remains constant.

As described above, the slurry is repeatedly circulated for a certain period of time so that the particles in the slurry have a predetermined particle size.The product slurry is stored in a slurry tank through a transport pipe (not shown) by opening the valve of the discharge port 28.

During the circulation of the slurry, the particles to be crushed that settle to the bottom of the fixed tank 25 are stirred by the stirring blades 43 that rotate at high speed and are integral with the rotating tank 33, and are rotated outward along the bottom surface of the dish-shaped tank. while entering the annular gap 34 and being subjected to a crushing action.

Note that the cooling coils 49 in the rotating tank 33 may be doubled or tripled to further improve the cooling effect due to the passing contact of the slurry.

As described above, in the wet type pulverizer of the present invention, slurry containing water and particles to be pulverized at a certain ratio is passed through a rotating tank with a conical inner peripheral surface → an opening at the lower end of the rotating tank → an inner peripheral surface of the lower half of the fixed tank. The particles of the material to be crushed in the slurry are circulated repeatedly for a certain period of time in the order of the annular gap between the uneven surface and the uneven surface of the outer peripheral surface of the rotating tank → the upper space of the fixed tank → the rotating tank, and the particles of the material to be crushed in the slurry are transferred to the grinding zone of the annular gap. Since the powder can be ground to a predetermined particle size each time it passes through, there is no need for grinding media such as balls as in conventional wet pulverizers. In addition, since grinding media such as balls are not required, the inner surface of the fixed tank and the inner and outer surfaces of the rotating tank will not be damaged by wear, and impurities such as particles due to wear and tear of the fixed tank and rotating tank will not be present in the product slurry. Since there is no contamination, it is possible to prevent the quality of the product slurry from deteriorating. Furthermore, all particles of the product to be crushed in the slurry that is circulated and crushed pass through the crushing zone of the annular gap the same number of times, so there are no particles in the product slurry, and the particles have a sharp particle size distribution with a narrow particle width. A product slurry containing particles of a predetermined size can be obtained. In addition, the wet type pulverizer of the present invention can easily adjust the particle size of particles in the product slurry to a predetermined particle size by adjusting the operating time, the rotation speed of the rotary tank, etc. Furthermore, since the wet-type pulverizer of the present invention is of a type that uses all the space inside the machine to form a self-circulating path for the slurry, a circulation circuit is provided outside the machine like a conventional media agitation type pulverizer. There is no need to do so, and the costs of associated equipment and operating costs are eliminated, and maintenance, inspection, maintenance, etc., can be done only with this machine, making it extremely simple and saving a lot of labor and time. In addition, the wet type pulverizer of the present invention has a cooling coil concentrically within the rotating tank and a cooling jet on the outer circumferential surface of the fixed tank, so that the overall heat transfer coefficient of the circulating slurry is high as described above, and the slurry is efficiently milled. cooled down. Therefore, even if the system is operated for a long time, the temperature of the circulating slurry does not rise, the water does not evaporate, and the concentration of the slurry remains constant, so there is no mechanical trouble and there is no problem with the circulation of the slurry. , it is possible to crush mildly heat-sensitive materials without causing motor overload. Moreover, since it can be operated for a long time, it has many excellent effects such as being able to ultrafinely pulverize particles in the slurry.

[Brief explanation of the drawing]

1 and 2 are schematic sectional views showing a conventional medium stirring type pulverizer, respectively, FIG. 3 is a longitudinal sectional view showing an embodiment of the wet pulverizer of the present invention, and FIG.
Figure 5 is a cross-sectional view taken along line A--A in the figure, and Figure 5 is B- in Figure 3.
It is a sectional view taken along the line B. 25... Rotating tank, 27... Convex part, 28... Discharge port, 3
0... Cooling jacket, 33... Rotating tank, 34... Gap, 37... Vertical rotating shaft, 38... Convex part, 39... Inner peripheral surface, 40... Opening, 41... Impeller, 43... Stirring blade, 45... Guide, 46... Water collection pipe, 47... Upper lid casing, 48... Inlet, 49... Cooling coil.

Claims (1)

[Claims] 1. A fixed tank having a number of convex portions along the generatrix line in the lower half of the inner peripheral surface and having a discharge port in the tangential direction of the lower end;
A cooling jacket is provided on the lower half of the outer peripheral surface of the fixed tank, and a cooling jacket is supported on the upper end of the vertical rotating shaft and fitted with a certain gap in the lower half of the fixed tank, and a generating line is attached to the outer peripheral surface of the fixed tank. The inner circumferential surface was formed into a conical shape with a large number of convex portions along the side, and openings were provided at equal angular intervals at the lower end, an impeller was provided inside the openings, and stirring blades were provided on the bottom surface of the bottom plate. a rotating tank; a plurality of arcuate guides each having a cross section extending from the inner peripheral surface of the upper part of the fixed tank toward the center of the rotating tank;
a water collection pipe that is supported and communicated with the tip of each guide and arranged vertically at the center of the upper part of the rotating tank; an upper lid casing that is provided at the upper end of the fixed tank and has an input port that faces the upper end of the water collection pipe at the center; A wet-type pulverizer comprising a cooling coil arranged concentrically within the rotating tank and having an inner diameter larger than the water collection pipe.