JP3170718B2 - Screen for wet tube mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screen provided in a wet tube mill for producing a slurry and for separating coarse particles in solid particles, and more particularly to a screen for a wet tube mill capable of improving durability. .

[0002]

2. Description of the Related Art The structure of a screen provided at the outlet of a conventional wet tube mill is shown in FIGS. FIG.
As shown in FIG. 1, a cylindrical mill main body 1 includes an outlet pipe 4 concentrically fixed to the mill main body 1 and a trunnion bearing 3 that rotatably supports the outlet pipe 4. Further, on the open side of the outlet pipe 4, a screen 5 stretched in a basket-shaped frame formed by a cylindrical outer frame 12 and an end frame 15 is integrally and concentrically fixed to the mill body 1. I have. A slurry tank 8 is provided at a lower portion of the screen 5, and a coarse-grain tank 9 is provided adjacent to the slurry tank 8 at a lower portion of the end frame 15 on an open side opposite to the mill body 1. .

[0003] The solid particles placed in the mill body 1 are mixed with a liquid, and become a fluid slurry by the rotation of the mill body 1, and pass through a slit 2 provided between the mill body 1 and the outlet pipe 4. And overflows into the outlet pipe 4. The slit 2 has a weir action so that the ball in the mill body 1 does not spill outside, and the gap of the slit 2 is smaller than the diameter of the ball and only the slurry can pass.

The slurry in the outlet pipe 4 is discharged by a screw 14 provided on the inner wall of the pipe with the rotation of the mill body 1 downstream of the mill, that is, rightward in the drawing, and supplied to the screen 5. The screen 5 has an opening having a maximum particle size required for a slurry product, and the slurry that has passed through this opening falls into the slurry tank 8 as a product slurry. Particles larger than the openings stay along the inner surface of the screen 5, gradually fall outside the end frame 15 of the screen 5, and are collected in the coarse particle tank 9. In this way, the product slurry is separated from coarse particles that do not conform to the product specifications, and the coarse particles are circulated again into the mill.

An apparatus of this type is disclosed in Japanese Utility Model Laid-Open No. 1-847.
As described in Japanese Patent Publication No. 41, there is known a mill in which gas is supplied from one end of a mill and steam is discharged together with the gas from the other end.

[0006]

In the prior art having the above-described structure, the screen 5 has a single screen as shown in FIG. An aa line shown in FIG. 12 indicates a joining line when the screen 5 is rounded into a cylindrical shape. According to the above configuration, the coarse particles separated by the screen 5 are discharged to the coarse particle tank 9 by natural overflow. Therefore, if the coarse particles are not stored to some extent, they are not discharged. As a result, the coarse particles stay on the inner peripheral surface of the screen 5, so that the inner peripheral surface is rubbed with the coarse particles and worn. For example, when crushing coal and water slurries, the abrasion may cause the screen 5 to form holes in less than one month. In this case, when the worn screen 5 is replaced, even if the worn part is only a part, the whole must be replaced, and there is a problem that labor and cost increase.

In particular, when the mill is large, the cylindrical diameter of the screen 5 is 2 m or more, and the weight of the screen 5 is several tens of kilograms.
g. For this reason, it is difficult to carry by human power,
It was difficult to mount the screen, and the surface of the screen became uneven. Further, when the screen 5 is inspected or replaced, when a person steps on the screen 5, the screen 5 is dented, and there is a problem that uneven wear is promoted.

An object of the present invention is to provide a screen for a wet tube mill which can improve durability and facilitate replacement and maintenance.

[0009]

In order to achieve the above-mentioned object, the present invention provides a wet tube mill which pulverizes a solid and a liquid in a mixed state, and which is provided concentrically with an outlet pipe of the wet tube mill, and is rotated integrally with the mill. In a screen for a cylindrical wet tube mill provided with a screen for discharging a slurry,
Are divided into multiple parts along the axis of rotation of the wet tube mill.
Screens, these multiple screens
Are characterized by different wear resistance.
You. In addition, multiple screens can be
It is characterized by being formed of a kind, material or linear shape.

Further, the screen is formed of a plurality of screens divided in parallel in the circumferential sliced shape and the axial direction
It is, the plurality of screens, respectively manpower
It may be formed to have a transportable weight . This weight is 20k
It is preferable that the weight is equal to or less than g because it can be surely transferred manually.

Further, each divided screen is:
At least any two of a plain woven wire mesh, a punch plate, and a wedge wire may be combined.

Further, the screen may be formed of a plurality of layers having different openings.

[0013]

According to the above arrangement, the screen can be divided into blocks and divided into blocks in the longitudinal direction to form blocks. By changing the type of screen for each block, it is possible to change the thickness of the screen or use a screen having a different structure depending on the degree of wear. Therefore, by applying a screen having high wear resistance particularly to a portion where the wear is severe, it is possible to extend the period until the correction due to the wear as a whole.

[0014] In addition, since only a portion that is heavily worn can be replaced by blocking, it is economical and requires less time for replacement. In addition, by setting the weight of one block to a size that can be easily operated manually, replacement work is facilitated, and occurrence of deformation or the like due to poor workability during mounting can be prevented.

Further, by forming the screen into a plurality of layers and making the outer screen a thick wire diameter, the overall strength can be improved and deformation due to external force can be prevented.

[0016]

An embodiment of the present invention will be described with reference to the drawings.

1 to 5 show one embodiment of the present invention. In these figures, portions corresponding to those of the conventional example shown in FIG. 11 are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The overall configuration of the wet tube mill is the same as the conventional example shown in FIG. 11, and the feature of the present embodiment lies in the configuration of the screen 5.

As shown in FIG. 1, the screen 5 has a four-part ring shape. The screen 5 has six longitudinal portions 12a and a ring-shaped portion 12b as shown in FIGS.
And are stretched inside the outer frame 12 formed in an annular shape. The screen 5 is also divided into three in the circumferential direction, a total of 12 outer periphery of the split screen 5, as shown in FIG. 5, the ring-shaped portion 12 b and circumferentially 3 divided among pressing plate 11 And is fixed with screws 13.

FIG. 6 is an exploded view of the divided state of the screen 5. As shown in FIG. 6, in the longitudinal direction, a, b,
The ring is divided into four blocks C and D, and one ring is further divided into three blocks a, b and c. For example, when the screen in the area (a) is severely worn and needs to be replaced, the screw 13 is loosened on the inner holding plate 11 surrounding the screen, and the screen is replaced with a new one. By reducing the weight of the screen portion to a predetermined weight of 20 kg or less, preferably about 5 kg or less,
A human operator can easily carry the inside of the screen 5. Also, there is no need to disassemble the entire screen,
Easy replacement in a short time.

In the four-block screens (a), (b), (c) and (d), the amount of coarse particles separated from the slurry by the screen 5 increases toward the downstream side, and the amount of wear increases. For example, if it is assumed that the screen 5 is worn out at twice the wear rate of the block A in the case of the block A, the block 2 is す る と in comparison with the case A when the same screen is used.
Only the life of the battery will be lost. Therefore, different types of screens are used depending on the wear rate.

The types of the screen include a screen having a different wire diameter, a material having a different wear resistance,
Some have different screen structures. Examples of these screens are shown in FIGS. FIG. 7 shows a plain weave wire mesh, FIG. 8 shows a punch plate, and FIG. 9 shows a wedge wire screen. Among these types of screens, variations with different aperture ratios and plate thicknesses are made as appropriate, and selected in consideration of economy, life, and the like. As a result, it is possible to extend the life of the entire screen,
The number of screen replacements due to wear can be reduced, and the mill stop time can be reduced.

FIG. 10 shows another embodiment of the present invention. FIG.
At 0, a coarse reinforcing screen 6 is provided outside the screen 5 so as to be double, and the outer frame 12 and the inner pressing plate 11 sandwich the two screens. As a result, the screen 5 having a fine opening is in close contact with the reinforcing screen 6, so that the screen 5 can be prevented from being deformed even when an outward force is applied from the inside. As a result, occurrence of uneven wear due to deformation can be avoided, and the life of the entire screen is improved. In this embodiment, the structure is simple and the material cost and the processing cost can be reduced.

Here, a structural member other than the screen, such as a wire mesh, can be used for the reinforcing screen 6, and the reinforcing frame 6 is shaped so as to be inscribed in the outer frame 12 without having a structure sandwiched by the frame. 12 may be welded. However, in any case, it is important that the reinforcing screen 6 is brought into close contact with the inner screen 5, and the close contact makes it possible to prevent plastic deformation.

Also, the end frame 15 forming the frame at the most downstream portion of the screen 5 is formed to have a divergent tapered shape as shown in FIG. Can be easily discharged to the coarse-grain tank 9. As a result, abrasion of the screen 5 due to retained coarse particles can be minimized.

Further, the head of the screw 13 for fixing the inner holding plate 11 for fixing the screen 5 shown in FIG. 5 is retracted to the same or inside the inner surface of the inner holding plate 11 as a flathead screw or hexagonal / square hole bolt. Shape. This prevents the head of the screw 13 from being unnecessarily hit by the rough flow applied to the screen 5, and
Third, head wear can be avoided. At the same time, it is possible to prevent the coarse particles from being caught on the head of the screw 13 and unnecessarily staying on the screen 5 for a long time.

By appropriately combining the features of the above embodiments, the abrasion resistance of the screen 5 and the workability of replacement can be improved.

In each of the above embodiments, the case where the screen 5 is divided into four in the axial direction and three in the circumferential direction, that is, divided into twelve in total, has been described. The number of divisions is appropriately selected.

The aperture, material, and specifications of the screen 5 are not particularly limited. Even in the case of the inner and outer double screen structure, the exchange workability can be improved by the split and fixed structure. it can.

[0029]

According to the present invention, the cylindrical screen provided concentrically at the mill outlet end and rotating integrally is divided into a plurality of detachably detachable screens, so that the durability of the screen is improved and the replacement work is performed. As a result, the operability, reliability and economy of the wet tube mill can be improved.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing the overall configuration of a screen for a wet tube mill of the present invention.

FIG. 2 is a view taken along the line AA of FIG. 1;

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a perspective view showing a configuration of an outer frame of FIG. 1;

FIG. 5 is a partial perspective view showing a structure for fixing the screen of FIG. 1 to an outer frame.

FIG. 6 is a developed view of the screen of FIG. 1 cut in a longitudinal direction.

FIG. 7 is a plan view showing a configuration example of a screen.

FIG. 8 is a plan view showing a configuration example of a screen.

FIG. 9 is a plan view showing a configuration example of a screen.

FIG. 10 is a perspective view of a main part showing a configuration of another embodiment of the present invention.

FIG. 11 is a side sectional view showing an example of a conventional screen for a wet tube mill.

12 is a developed view of the screen of FIG. 11 cut in a longitudinal direction.

[Explanation of symbols]

 1 Mill body 4 Outlet pipe 5 Screen

Claims (6)

(57) [Claims] 1. A cylindrical wet tube provided concentrically with an outlet tube of a wet tube mill for crushing a solid and a liquid in a mixed state, and having a screen which rotates integrally with the wet tube mill and discharges a slurry. In a mill screen, the screen is a rotating shaft of the wet tube mill.
It is formed by a plurality of screens divided in the direction,
A screen for a wet tube mill , wherein the plurality of screens have different wear resistance . 2. The screen for a wet tube mill according to claim 1, wherein the plurality of screens are different in at least one of a material and a linear shape. 3. The screen according to claim 1, wherein the plurality of screens are a combination of at least two of a plain woven wire mesh, a punching plate, and a wedge wire.
Or the screen for a wet tube mill according to 2 . 4. The screen is formed by a plurality of screens divided in a circumferential ring shape and parallel to the axial direction.
It has been, screen the plurality of, respectively, manpower transport Allowed
The screen for a wet tube mill according to claim 1, wherein the screen has an effective weight . 5. The screen according to claim 4, wherein the weight is 20 kg or less. 6. The screen according to claim 1, wherein the plurality of screens are formed of a plurality of layers having different openings .
The screen for a wet tube mill according to any one of the preceding claims.