SU1759463A1 - Pulverizer - Google Patents

Abstract

Use: fine grinding materials. SUMMARY OF THE INVENTION: The chopper comprises a rotating table 2 with plates 1 on a grinding track, above which are cylindrical rolls 3 with horizontal axes of rotation. Plates 1 have an outer horizontal portion a and an inner sloping portion c. At the interface of these sites, transverse depressions (in the circumferential direction) are filled. 1 hp f-ly, 2 ill. (L S C o l o S O

Description

This invention relates to a technique for fine grinding materials and can be used in the building materials industry, in the chemical, energy, and processing industries.

A distinctive feature of such roller mills is the presence of grinding rolls, which rotate freely on the axis, and equipped with pressure devices, a table lined with plates and rotating from the drive, loading and unloading devices.

Roller mills with working surfaces of the grinding rolls and working surfaces of the plates of a rotating table, having smooth asymmetrically arranged curvilinear sections 1,2, as well as roller mills with working surfaces of the grinding rolls having annular grooves and ledges combined with working surfaces of the plates are known. rotating table, having curvilinear without ledges and ledges of section 3.

Also known is a roll mill with tapered rollers and flat, stepped plates with successively decreasing ring portions 4.5 from the outer to inner edge.

The combination of the above-mentioned working surfaces of the grinding rolls and plates of the rotating table improves the conditions for gripping the material being crushed, and the presence of parallel zones or zones narrowing at a small angle at the exit site contributes to an increase in the degree of grinding materials.

The closest in technical terms is a chopper with cylindrical rollers having free rotation around horizontal axes and a horizontal rotary table from the drive 6.

A significant disadvantage of the known device is the weak grip (in the axial direction of the rolls) of the pieces of the material to be ground, which reduces the efficiency of grinding. In addition, the working surfaces of the rolls and plates in the known device due to the greater difference in relative speeds on the grinding surface have increased wear.

The aim of the invention is to increase the grinding efficiency.

The goal is achieved by the fact that, in a known grinder, containing cylindrical rolls with horizontal axes, a table with plates on it is rotatably rotary from a drive around a vertical axis.

annular grinding track, loading and unloading device, each plate is made with two concentric sections: the outer horizontal and

internal inclined from the last downward at an angle of 3-6 °, and the ratio of the width of the horizontal section to the inclined is 0.5-1.

Each plate at the junction of the horizontal

and the sloping sections are made with recesses.

Figure 1 shows a roll mill; figure 2 - schematic arrangement of the grinding roller and the table.

A roll mill includes a device for grinding bodies consisting of plates 1 of table 2, cylindrical grinding rolls 3. Plates 1 have horizontal peripherals

sections a and inclined sections c (angle of inclination n 3–6 °) with a ratio

Ј - -1 - 1 n

s-2. 1-0The justification of the angle of inclination of the plate. Diameter of chopping is accepted

roll 1000 mm. Moreover, its width ,, 4x1000 400 mm.

about

With a ratio of 0.5; -1.0.

For the lowest value and

a b and c | b mm

at h d.

Capture of a piece (for mm) (5–15–30 mm, the size of which is established by the practice of grinding materials in roller mills of a disc-roller type (with fine grinding) d 0.03, then (,, 03x1000 30 mm.

Practically 6-15-30 mm.

In this case, the angle of the armor

45/1 arctg | arctg -3 °

15 270

D, arcidio arcs1d «6 °

30,270

50

Consequently, to grip a piece of material with rollers (in the radial direction

roll) at –0.03 is sufficient, depending on the size of the initial feed, to have a plate inclination angle.

and - the length of the horizontal section;

c is the length of the inclined section (in the projection);

b is the total length of the plate;

d - the size of a piece of the crushed material;

h - the height of the ledge of the inclined part of the plate;

/ is the angle of inclination of the slab.

The rationale for the relationship between the horizontal and inclined portions of the working surface of the shredder plate in the claims.

The figure below shows the relationship between the horizontal and inclined sections of the plate, as well as between the peripheral speeds at the extreme and middle points of the sections of the plate and the rolls, where

a is the value of the horizontal unit;

c - value (.accn site of the plate;

The center of the bend of the horizontal-facing section of the plate to the inclined section (corresponds to the radius Ro of the circumference around the vertical axis of rotation of the plate);

RI and R2 are the radii of the inner and outer edges of the plate, respectively;

(DC is the angular velocity of rotation of the table relative to the vertical axis 0-0

gv is the radius of the cylindrical roll;

 - the angle of rotation of the table;

 and A V2 - times, osgi between the circumferential speeds of the foot and roll roll, respectively, at the extreme edges of the plate, defined respectively by the radii of the circles RI and R2.

The relationship between the horizontal section a and the inclined section c (as, 5: 1.0) adopted in accordance with the claims is based on the following.

EFFECT: higher efficiency of material pre-grinding in zone c and fine grinding of material in zone a.

ABOUT

This ratio establishes the most favorable condition under which, as a combination in two zones of the plate, there are sufficiently good effects from

grinding by crushing and abrasion by reducing the slab wear from abrasion in both zones. Since the greatest wear from abrasion takes place on the horizontal

5 section of the plate (in the parallel zone of the working bodies the layer of fine material is crushed, which most strongly influences the wear rate, and the least wear from abrasion occurs in the capture zone of the relatively large pieces of the plate and particles of the material (the smaller area of contact of pieces of material with sloping part of the slab). Therefore, it is advisable to reduce the size

15 horizontal plate section

Increasing the size of the inclined CRSTY helps to increase the aching ability of the pieces of material zpa between the slab to the roll. With relatively small

20 angles of inclination of the slope of p -ites () as the length of the inclined section increases with pits, the size of the gap d between the plate and the roller w, increases. (tg D At / 3 const; d k- s, where / 5 const,

25 t.e. increasing with increases the gripping ability of the plate and the grip.

When increasing the slope of the plate with, respectively, if a + c const,

30, the size of the horizontal section of the plate a decreases and, consequently, the wear of the plate decreases, apparently from the features of the device of this shredder and the ratios of the relative peripheral velocities of the plates below, which are located on a table rotating around the vertical axis 0-0.

Accordingly, at the initial, transition (point OC) and the final plate sections on

40 table with the corresponding radii of circles RI, RO and R2 (Ri R0-c;) the circumferential speeds of the plate sections will be V2 iOc Gfc (Ro + a) V0 + (Vc a-Vc + AV2. Here D. / 2-V0 a is an increment (increased) relative speed of the plates of the table, since o) with R 2

Therefore, the smaller the size of the horizontal section of the plate a, the smaller the difference in the peripheral speed of the plate

50 r 2 - ftfo in (with theorist and

ft o const and respectively 7 r const).

CD

In order to ensure a sufficient crushing effect by rubbing 55 particles of material on the horizontal section of the plate a and reducing the plate wear, it is necessary for experimentally different optimal sizes of a: to be different for the size, size, and erasivity of the materials to be ground.

When grinding using plate-roller mills (roller mills of medium-speed) materials of average hardness usually take the value of the ratio ™ f lR T Г ° -3- ОКОДЭ

ZHO and the size of the crushed pieces of 0.5 -O.

Assuming that the size of pieces that penetrate under the roll along its axis should be two to three times smaller than the size of pieces of comminuted material that fall under the roll by rolling a roll, i.e. average d 0,3 d, then we get

3xO ,, 015xD.

For the average diameter of the rolls of the plate-roller mill mm, we get

,, 3x1500 450 mm.

five

From the figure it is clear that C

at, tg / 0.05-0.1,

, 015x0 0,015x1500 22.5 mm.

c -t§75 ii-450MH: C2 W ff 225MM

The value is not acceptable, because there is no horizontal plate section.

Average is accepted.

g - C1 + C2 450 4- 225 007 gdd1 C y oJ7 mm.

C 337 From here tg 4c; about 075 is assumed

as the maximum value.

In order to preserve the fine grinding effect, g

, 7 or about 5: 1.0, i.e. at ts

 mm will be mm and mm, which corresponds to the claims.

Slabs in the transition zone of the inclined section with in the horizontal section and have a transverse recess 4.

The device works as follows.

The source material moving to the periphery on the rotating table is captured in the area of the wedge-shaped gap formed by the inclined section from the plate.

1, and the cylindrical roller 3 is subjected to grinding by the rollers and continues to move to the periphery of the table 2. In the parallel zone in the area a of the plate 1, intensive fine grinding of the material continues, mainly the attrition resulting from the increasing velocity difference as the material moves to the periphery of the table 2.

If necessary, fine grinding of the material, in which the thickness of the crushed material layer is significantly reduced, the device of plate 1 with a transverse groove 4 is applied. Due to the filling of this groove

the crushed material forms an elastic buffer, which softens the possible impacts of the grinding rolls on the plates and contributes to the stabilization of the grinding process (the constant layer

material on site a plate).

The proposed mill has the following advantages over the prototype: the design of the plate and the grinding roll is simplified; the term increases

Claims (2)

1. Grinder containing cylindrical rolls with horizontal axes, A table with plates on its annular grinding path, mounted below them for rotation from a drive around a vertical axis, is a loading and unloading device, characterized in that that, in order to increase the grinding efficiency, each plate is made with two concentric sections: an external horizontal and an internal inclined from the last downwards at an angle of 3-6 °, and the ratio of the width of the horizontal section to the slope is 0.5-1. 2. The shredder of claim 1 is distinguished by the fact that each plate at the junction of the horizontal and inclined sections is made with a recess. 1