ELEMENT OF WEAR-RESISTANT ROLLING LINING OF A BALL DRUM MILL

Abstract

This utility model relates to linings for the cylindrical section of drum mills and can be used in the cement, chemical, and mineral processing industries. It aims to create a wear-resistant rolling lining with an extended service life, ensuring consistent grinding operation. This is achieved by constructing the wear-resistant rolling lining element of a ball drum mill as alternating prismatic rolling elements 1, 2, 3, and 4 of varying heights, interconnected by interlocking joints and configured to be bolted to the housing 6.In the proposed solution, the first rolling element 1 is made with a straight upper edge, and the subsequent rolling elements 2, 3 and 4 are made with inclined upper edges, forming a common surface inclined at an angle to the tangent to the circumference of the housing 6 of the mill drum, with the possibility of providing a coefficient of adhesion with the grinding bodies, allowing them to be raised to the height of separation.

Description

[0001] The utility model relates to linings of the cylindrical part of drum mills and can be used in the cement, chemical and mining industries.

[0002] An armor lining of the tubular part of a ball mill body is known [patent for invention RU No. 2729985C1 IPC B02C 17 / 22, published 08 / 13 / 2020, bulletin No. 23], made in the form of lining the inner surface with wear-resistant armor elements with a ball-lifting relief of the working surface, laid on a leveling cement layer, in which sections of rolled sections made of spring steel are used as armor elements, while the sections of rolled sections have holes for fastening bolts on a thickened middle strip, and the connection of the sections with ball-lifting ridges is carried out by clamping their soles with specially profiled edges of adjacent sections of armor profiles.

[0003] The disadvantage of this design is the complexity of installation, the presence of a large number of bolted connections, which reduces the strength of the mill body and the degradation of the cement grout used for a tighter fit of the rolled sections to the mill body, resulting in the risk of their premature failure from impact loads.

[0004] A stepped lining for a ball drum mill is known [patent for utility model RU No. 179532U1 IPC B02C 17 / 22, published 05 / 17 / 2018, bulletin No. 14], made in the form of alternating smooth plates and plates with protrusions, fixed to the body.

[0005] The disadvantage of this design is the high wear of the working surface and the inability to ensure a constant operating mode of the ball load.

[0006] The closest to the proposed technical solution, adopted as a prototype, is the armor lining of the inner surface of the drum mill housing [Author's Certificate for Invention SU No. 1200977 IPC B02C 17 / 22, published 30.12.85, Bulletin 48], including repeating sections of alternating rolled sections (elements) of prismatic shape of different heights, connected to each other by means of bolted connections and embedded parts, wherein the ratio of the minimum to the maximum height of the rolled section is proportional to tgβ / n, where β is the angle formed by the straight line connecting the profiles with the minimum and maximum heights and the tangent to the circumference of the housing, equal to 5-35°, and n is the number of elements located from the maximum to the minimum in the cross-section of the mill.

[0007] The disadvantage of this design is the high wear of the working surface, as a result of which the constant operating mode of the grinding media is not ensured, and thereby the service life is reduced, the complexity of installation due to the need to maintain the ratio of the minimum and maximum heights of the rolling profile and a large number of fasteners, low efficiency of the grinding process.

[0008] The following set of features of the prototype coincide with the essential features of the claimed utility model: alternating rolled elements of prismatic shape of different heights, connected to each other using locking joints and made with the possibility of bolted connection to the body.

[0009] The utility model is aimed at creating a wear-resistant rolling lining with an increased service life, ensuring a constant operating mode of the grinding load.

[0010] This is achieved by the fact that the wear-resistant rolling lining element of the ball drum mill is made in the form of alternating rolling elements of prismatic shape of different heights, connected to each other by means of locking joints and made with the possibility of bolted connection with the body, and the subsequent rolling elements are made with inclined upper edges, forming a common surface inclined at an angle to the tangent to the circumference of the mill drum body, with the possibility of providing a coefficient of adhesion with the grinding bodies, allowing them to be raised to the height of separation.

[0011] The essence of the utility model is explained by drawings, where Fig. 1 shows a cross-section of a ball drum mill with a wear-resistant rolling lining installed, Fig. 2 - the design of the wear-resistant rolling lining, Fig. 3 - the movement of grinding media in the cross-section of the mill drum, Fig. 4 - the same in the form of trajectories of movement of grinding media.

[0012] The wear-resistant rolling lining of a ball drum mill is formed in the form of repeating sections of alternating rolling elements 1, 2, 3, and 4 of varying heights. The first rolling element 1 is prismatic, rectangular in cross-section, and has a height H with a straight upper edge. The subsequent rolling elements 2, 3, and 4 are prismatic in shape, with an inclined upper edge such that their height decreases in the direction of rotation. The first rolling element 1 and one subsequent rolling element 3 are secured, for example, by a bolted connection 5 to the housing 6 of the mill drum. The first rolling element 1 and the subsequent rolling elements 2, 3, and 4 are connected to each other, for example, by a locking connection.In this case, the upper edges of the subsequent rolling elements 2, 3 and 4 form a common surface inclined at an angle δ to the tangent to the circumference of the housing 6 of the mill drum, with the possibility of providing a coefficient of adhesion with the grinding bodies, allowing them to be raised to the height of separation.

[0013] The repeating sections can be made with an optimal length l=2πRб / n, that is, with a step of α=360° / n, where Rб is the inner radius of the drum, n is the number of repeating sections, based on the placement of at least four grinding balls of maximum diameter d on the repeating sections.

[0014] The wear-resistant rolling lining of ball mill can be produced using multi-product hybrid production based on laser metal deposition additive technology.

[0015] The wear-resistant rolling lining of a ball drum mill operates as follows. The mill drum housing 6, which is secured with repeating sections of alternating rolling elements 1, 2, 3, and 4 of varying heights, is fed with grinding material, such as cement clinker, via a bolted connection 5.

[0016] During numerical simulation, it was determined that, during rotation of the mill drum housing 6, the first rolling element 1 and subsequent rolling elements 2, 3 and 4 facilitate the lifting of the grinding media to the breakaway height from the alternating rolling elements. They then break away and move under the action of inertial forces, transitioning to a free fall along a parabolic trajectory, which ensures the greatest intensity of grinding media movement. When the grinding media fall along a parabolic trajectory into the area of ​​the material being ground, the grinding media collide with the material particles, which leads to its grinding. Due to the common formed surface of the first rolling element 1 with a straight upper edge and subsequent rolling elements 2, 3 and 4 with an inclined upper edge inclined at an angle to the tangent to the circumference of the mill drum housing 6, a coefficient of adhesion with the grinding media is ensured, allowing them to be lifted to the breakaway height with uniform wear.This, in turn, ensures a constant operating mode of the grinding load, thereby increasing the service life of the lining.

[0017] Thus, the proposed wear-resistant rolling lining of the ball drum mill ensures a constant operating mode of the grinding charge, which increases its service life.

Claims

An element of the wear-resistant rolling lining of a ball drum mill, made in the form of alternating rolling elements of prismatic shape of different heights, connected to each other by means of locking joints and made with the possibility of bolted connection with the housing, characterized in that the first rolling element is made with a straight upper edge, and the subsequent rolling elements are made with inclined upper edges, forming a common surface inclined at an angle to the tangent to the circumference of the housing of the mill drum, with the possibility of providing a coefficient of adhesion with the grinding bodies, allowing them to be raised to the height of separation.

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