SU1281301A1 - Classifying lining of ball multiple-compartment mill - Google Patents

Abstract

The invention can be used for fine grinding of solid materials, including for grinding clinker in tube ball mills. The goal is to improve the classification efficiency of grinding bodies along the length of the mill chamber. The invention contains a classified lining consisting of paired reinforcement bars 1 and 2, which are joined together by the same end faces between themselves and fixed to the housing 3 of the mill. The mill chamber contains the charging part 4 and the zone of the inter-chamber partition 5, separated by an inclined ring 6 of smooth lining. The inclined ring of the smooth lining is limited by alternating face parts of the plates. Offset relative to each other of the adjacent plates 1/4 of the length of the plate provides in the radial plane the laying of armor plates with different heights of protrusions. 2 hp f-ly, 4 ill. (Ls

Description

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This invention relates to a technique for grinding comminuted materials and can be used in cement industry for grinding clinker in 5 pipe balls.

The aim of the invention is to increase the efficiency of the classification of cutting bodies along the length of the mill chamber.

FIG. 1 shows a drum mill, classifying lining, longitudinal section; FIG. 2 is a section A-A in FIG. 1, in FIG. 3 - section BB and FIG. 1, in FIG. 4 - lining section of the mill chamber, isometry.

The classifying lining contains paired armored plates 1 and 2, conjugated by the same end faces between themselves and fixed on the body 3 of the mill.

The mill contains the loading part 4 and the zone 5 of the inter-chamber partition, separated by an inclined ring 6 of the smooth lining 7. The inclined ring of the smooth lining is limited by alternating face parts of the plates. The pairs of mating slabs are shifted relative to the adjacent longitudinal row (along the drum-forming mill) by 1/4 of the slab length, which ensures in the radial plane (Fig. 2) the laying of armor plates 1 and 2 with different protrusion heights. In zone 6 of the inclined ring, the height of the projections of the armor plates is the same (FIG. 3).

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in the loading section 4 chambers of a mill - paired armored plates shifted

relative to the adjacent longitudinal row in the direction of movement of the material, and in zone 5 of the inter-chamber partition, they are displaced in the direction opposite to the movement of the material (Fig. 4). The displacement of the plates relative to each other by 1/4 of the length of the plate provides for obtaining deep trough-like channels of a given direction. The laying of armor plates in zone 5 ensures the formation of screw channels, the direction of which coincides with the direction of rotation of the mill body, and in zone 5 it is opposite to the rotation of the mill body. The screw channels in the central part of the mill chamber are in contact with the inclined rings 6 of smooth lining, limited

 alternating face pieces of plates.

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The length of the smooth lining ring does not exceed 0.15-0.25 of the length of the mill chamber, the height of the surfaces of the outer plates protruding into the ring zone is half the diameter of the bodies.

Lining works as follows.

When a mill with a classifying lining is operated, the mill body 3 rotates in the V direction, and the material moves inside its drum from left to right.

Before the start of the mill, the grinding bodies consisting of large and small balls are distributed evenly along the length of the chambers, the large ones - in the loading part 4, and the small ones - in the zone 5 of the inter-chamber partition. During the operation of the mill, the grinding bodies rise 20 under the action of centrifugal forces, as well as by means of projections of paired armor plates 2 and 1 to a certain height, from which they are dropped by parabolic trajectory to fly-lining. The presence of screw flute-shaped channels in the loading part 4 and zone 5 ensures the directional movement of the sorted grinding bodies.

In the loading part 4, the direction of the screw channels coincides with the direction of rotation of the mill, which ensures the movement of large balls to the loading opening of the mill (direction T, Fig. 4) and excludes their distribution along the entire length of the mill chamber. In zone 5, the direction of the screw channels is opposite to

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mills, dd the movement of small balls to the inter-chamber partition (direction K, Fig. 4), i.e. a process similar to that in boot part 4 is observed. but the direction of movement of the grinding bodies is the opposite.

Grinding bodies trapped in the zone

6, an inclined ring of a smooth lining, is subjected to intensive influence in mutually opposite axial directions N and S from the end surfaces of the armor plates bounding the inclined ring. In addition, the grinding bodies, under the influence of centrifugal forces arising in the rotating drum, rise to a certain height (lower than the loading part 4 and zone 5 due to the presence of a smooth lining) in the radial

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plane. The turbulent motion of grinding bodies that fall into the zone of an inclined ring ensures their effective separation. Large balls, in which the center of gravity is above the upper edges of the protruding surfaces of the armor plates, roll both from the end surfaces (direction N) and from the radially protruding parts of the plates into the screw front channels located in the loading part 4 and move on them in the direction of loading.

Small balls, in which the center of gravity is also located above the protruding surfaces of the armor plates, roll into the screw channels located in zone 5 and move along them to the inter-chamber partition in the direction S. Thus, the grinding bodies are classified according to the length of the mill chamber. The presence of an inclined smooth lining ring in the mill chamber not only facilitates the classification of grinding bodies, but also intensifies the grinding process (abrasive effect due to the lower angle of elevation of the grinding bodies by the smooth lining as compared to adjacent zones that have large adhesion ratios between protruding armor plates and grinding bodies At the boundaries of the inclined ring of the smooth lining with the loading part A and zone 5, shear deformations of the layers of the grinding bodies are observed (Fig. 2 and 3), which intensifies the In addition, the intensive movement of the grinding bodies in the axial directions N and S (Fig. 4) also contributes to the effectiveness of the grinding process. The displacement of the paired plates relative to each other along the generator of the mill housing 1/4 of the length of the plate ensures the formation of deep gutter channels: in boot

Part 4 — along the course of rotation of the bar — 50 along the length of the loading part 4 and of the side of the mill; in zone 5, against the x of rotation.

The displacement of the plates by a large amount does not allow to obtain pronounced gutter-shaped channels of a given direction: at a displacement of 1/2

 the length of the plate channels are split into two, with a displacement of 3/4 the length of the plate changes the direction of the channels (screw).

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The length of the smooth lining ring should not exceed 0.15-0.25 of the length of the mill chamber. These limitations are due to the following considerations. For the most common cement mills with dimensions of 2.6–13 m, 3.2–15 m, 4–13.5 m, the length of the first chamber is 7.4 m, 7.5 m and 6.7 m, i.e. the minimum length of the smooth lining ring is 1, 11, 1, 12 and 1.0 m. With smaller values of the ring length, effective movement of the grinding bodies in axial directions is not achieved.

5 N and S, a narrow layer of grinding bodies arranged on a smooth lining, is entrained by adjacent layers of balls located in the loading part 4 and zone 5 and moves as a monolithic layer without relative sliding against each other. In addition, the small length of the smooth lining ring (less than 1 m) does not provide an effective classification of grinding bodies in the loading part 4 and zone 5 due to the limited mobility of the balls in the axial directions.

With maximum ring lengths (Ch., 25), its value for the specified mill sizes is 1.85 m, 1.88 m and 1.08 m, respectively. However, to teach that the smooth lining ring is tilted due to displacement of the armor plates relative to each other (Fig. 1), its zone of action is limited by the projections of its extreme points P and M horizontal, i.e. R main .-- /. Maximum numerical values

0 p (at the angle of inclination of the ring L 60) are for mills: 2.6-13 m - Рр 3.35 m, 3.2-15 m Р 3.73 m, 413.5 М-- Рр 3.99 . When the values of the length of the smooth lining 1 hlf.

5 more than 0.25 mill chamber length, the area of the inclined ring of the smooth lining exceeds 4 m, which reduces the effect of the waterfall mode of grinding bodies in limited

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The height of the surfaces of the extreme plates protruding into the zone of an inclined ring should not exceed half the diameter of 55 large balls, and the height of the oppositely located plates should be half the diameter of small balls.

In case of violation of this condition (at the location of the center of the tin

balls below the protruding surfaces of armor plates) the classification of grinding bodies is difficult.

Claims (3)

Invention Formula A lining of a multi-chamber ball mill, containing a set of trapezoidal plates with longitudinal grooves and displaced rows, characterized in that, in order to improve the classification of grinding bodies along the length of the mill chamber, the lining is formed by paired plates that are in contact with the same name of the grinding chamber mill, that are facing the same length of the mill chamber, contiguous with the same length of the mill chamber, the lining is formed by paired plates that are in contact with the same name of the mill chamber, the same lining is formed by paired plates that are in contact with the same name of the mill chamber, the same lining is formed by paired plates that are in contact with the same name of the mill chamber, the same lining is formed by paired plates that are in contact with the same name of the grinding chamber, and the same lining is formed by paired plates that are in contact with similarly sized grinding chambers along the length of the mill chamber. due to their displacement along the mill casing, screw gutter-shaped channels, with an inclined ring mounted in the central part of the mill chamber fl-a / Editor A.Vorovich / / 7 Fig4 Compiled by V.Sevost new Tehred M. Hodankch Proofreader M. Demchik smooth lining, limited to the torus surfaces of the plates. 2. The lining according to claim 1, that is, that the paired plates are displaced relative to each other by 1/4 of the plate length, and the direction of the screw channels formed in the loading part of the mill coincides with the direction of rotation of the mill body, and in the zone of the intercameral partition - the opposite. 3. Lining of pop. 1, which differs from the fact that the length of the inclined ring of the smooth lining does not exceed 0.15-0.25 of the ring length of the smooth chamber of the mill, and the height of the surfaces of the extreme plates protruding into the area of the ring half the diameter of .r grinding bodies. / /