CZ2003398A3 - Lining for grinding mills and method for installing thereof - Google Patents

Abstract

The present invention describes a lining for grinding mills, consisting of a plurality of lining modules and lifters fixed in a removable way to the mill drum by appropriate fixing means. <IMAGE>

Description

The present invention relates to a wear-resistant modular lining of mills and a method for its assembly and installation.

BACKGROUND OF THE INVENTION

The prior art ceramic linings of mills consist of ceramic liner plates which are directly applied to the inner surface of the mill grinding chamber, referred to herein as the drum, to protect the drum wall from wear due to grinding and to extend the mill life and prevent contamination of the milled material .

These linings further include longitudinally extending rods, also referred to as jacks, which improve grinding within the mill and are apparently also subject to wear or damage.

Once worn or damaged, ceramic cladding boards and / or jacks must be removed and replaced with new lining.

At present, the replacement of ceramic linings is a very costly and time-consuming operation in which it is necessary to stop the mill production for several days. In fact, the mill must be completely emptied, the old lining must be completely removed using pneumatic hammers and the inner surface of the mill must be cleaned by nozzles before the new lining is placed.

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There is therefore a clear need to provide a ceramic lining for a mill that is easier to repair or replace in the event of damage or wear.

SUMMARY OF THE INVENTION

The present invention provides a mill lining comprising a plurality of modules consisting of a metal holder to which ceramic cladding plates are fixed, which modules are held adhered to said inner surface of the grinding drum by means of jacks attached to the drum by suitable fastening means.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a cross-section of a grinding drum with lining modules and jacks;

Giant. 2 shows a plan view of the inner surface of a grinding drum in a special embodiment of the invention (see below);

Fig. 3 shows in detail a cross-section of the cladding module;

Giant. 4 shows a special embodiment of fastening of cladding boards to a metal holder;

Fig. 5 shows in detail the engagement between the jack and the modules when mounted inside the grinding drum; and

Giant. 6 shows a special embodiment of means for attaching jacks.

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DETAILED DESCRIPTION OF THE INVENTION

The present invention makes it possible to overcome the above-mentioned problems by means of an easily replaceable ceramic lining, the ceramic lining consisting of modules as mentioned above.

The ceramic lining of the invention overcomes the disadvantages of the prior art ceramic lining of mills by providing an efficient ceramic lining of mills that can be easily replaced, wholly or partially, if necessary.

In addition, the present invention also defines a ceramic lining module as described above and a method of replacing a ceramic lining of a mill with minimal time loss.

According to the invention, the module 10 consists of a metal holder 11 and ceramic cladding boards 13 which are applied to and completely cover one surface of the metal holder 11 leaving two lateral free edges 14 (see FIG. 3).

The metal holder 11 is usually a metal plate, preferably shaped to mate with the inner surface of the grinding drum 12.

The jacks 15 consist of rods of ceramic, rubber, resin or other suitable material capable of fitting well into the space formed by the free edges 14 of two adjacent modules, and protrude above the facing panels of said adjacent modules. The jacks 15 are provided with suitable fasteners to be fastened to the grinding drum in an easily dismountable manner. Due to their mutual arrangement, the attachment of the jack to the grinding drum automatically means that the module will also be held fixed to the inner surface of the grinding drum.

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According to an embodiment of the present invention, the jack may advantageously be oriented on the inner surface of the grinding drum so as to form a suitable angle with the axis of the drum, i.e. form a spiral portion (see Fig. 2). When using the above embodiment, the jacks, in addition to improving grinding as mentioned above, also sort the grinding elements possibly used for grinding (such as balls used in a ball mill) by distributing them along the longitudinal axis of the drum according to their dimensions and weight . Giant. 2 also shows an opening 29 allowing access to the grinding drum for necessary repairs.

In a preferred embodiment of the invention, the cladding boards 13 are attached to the metal holder 11 by means of a film (adhesive film). Alternatively, the inner surface of the metal holder 11 is formed with protruding T-shaped projections 16 to which the cladding panels 13 can be anchored by appropriately shaped cavities 17, which can also, if preferred, be filled with adhesive (see Fig. 4).

The described embodiment makes it possible, when one or more facing panels are to be replaced, to replace the facing panels without having to remove the entire lining from the grinding drum. In fact, it will be sufficient to remove the jacks corresponding to the modules containing the damaged cladding boards and these modules can then be easily removed and replaced.

The jack fastening means according to a special embodiment of the present invention consist of a generally U-shaped metal structure 18 (see Fig. 6). This U-shaped structure 18 is formed with the first part.

19, which can hold the jack rod, and with the second portion 20, which can be attached to the grinding drum.

In a preferred embodiment of the invention said first part 19 of the U-shaped structure consists of a metal convex section in which the ceramic body of the jack rod can be locked, optionally with the aid of a suitable adhesive and / or resin.

In this embodiment, the anchorage between said ceramic body and the metal structure of the jack is preferably provided by side cavities 21 formed in the ceramic body in which the wall of the first part 19 can be accommodated and optionally filled with a suitable adhesive and / or resin. Advantageously, by suitable shaping (e.g., rounding) of the cavities 21, dangerous acute angles and corresponding high local stresses in the ceramic body of the jack are avoided.

In another preferred embodiment, said second portion 20 of the metal structure of the jack comprises a U-shaped metal section secured to the outer surface of the first portion 19 on the sides 22 and forming a free gap 23 with the bottom of the first portion 19.

Within this gap 23, screw heads 24 may be positioned extending through a corresponding guide 25 formed in the lower surface of the second portion 20 and then through the space left between the two metal holders of the two adjacent modules and through the other holes 26 formed in the grinding drum 12. The jack is finally fixed to the drum by nuts 27. In addition, the bottom of the first part 19 is welded to the bottom of the second part 20 at points 28.

In the method of the present invention, the first jack 15 is secured to the grinding drum 12 and then the first longitudinal row of modules 10 are stored, all along the length of the jack, so that its lateral free edge 14 is positioned between the inner surface of the drum. a lower surface of the metal structure 18 of the jack.

Then it is sufficient to tighten the jack fastening screws 24 by means of suitable nuts 27 operated on the outside of the grinding drum.

The same operations are repeated until the entire inner surface of the drum is covered with modules.

Preferably, the jack and the facing panel ₁₀ positioned along the free edge 14, each shaped so as to allow easy positioning of the jack by sliding in a channel formed by the free edge of the 14th

Represented by:

PATENTOVÉ

Claims (16)

Claims Milling lining, characterized in that a plurality of lining modules (4) and jacks (6) are mounted, detachably to the grinding drum, by suitable fastening means. Milling lining according to claim 1, characterized in that the modules (10) consist of a metal holder (11) to which the ceramic facing plates (13) are fixed such that they cover ₁₀ one surface of the metal holder (11) and leave two side free edges (14), wherein the jacks (15) are rods of ceramic, rubber, resin or other suitable material formed with suitable fastening means. Milling lining according to claim 2, characterized in that the metal support (11) is a metal plate and the ceramic cladding plates (13) are fixed thereto by means of an adhesive film. Milling lining according to claim 3, characterized in that the metal holder (11) is formed with a protruding T-shaped projection (16) for anchoring the cladding boards (13) by means of correspondingly shaped cavities (17), optionally filled with adhesive. Milling lining according to claim 2, characterized in that the fastening means of the jacks (15) are of metal construction 25 (18) formed with a first portion (19) for holding the jack rod and a second portion (20) for attachment to the grinding drum (12). Milling lining according to claim 5, characterized in that the first part (19) consists of a metal convex section, 0 · 0 0 • 0 ···· which may be blocked by the ceramic body of the jack rod, possibly using a suitable adhesive and / or resin. Mill lining according to claim 6, characterized in that the ceramic body of the jack comprises a lateral rounded cavity (21) for accommodating the wall of the first part (19), the cavity (21) optionally being filled with a suitable adhesive and / or resin. Milling lining according to claim 5, characterized in that the second part (20) consists of a U-shaped metal section fixed to the outer surface of the first part (19) on the sides (22) and forming with the bottom of the first part (19) a free space (23). Milling lining according to claim 8, characterized in that in the gap (23) there are screw heads (24) passing through the corresponding guide (25) present in the lower surface of the second part (20) and then through the space left between the two metal holders of two adjacent modules and finally through another opening (26) formed in the grinding drum (12). Mill lining according to claims 1 to 9, characterized in that the jack is oriented on the inner surface of the grinding drum so as to form a suitable angle with the drum axis, i.e. it forms a spiral part. Milling lining according to claims 1 to 10, characterized in that the mill is a ball mill. A method for installing a mill liner as defined in claim 1, characterized in that a first jack (15) is attached to the grinding drum (12) and subsequently the first longitudinal row of modules (10) is stored, all along the jack length, such that a side free edge (14) is located between the inner surface of the drum and the lower surface of the metal structure (18) of the jack, after which they are tightened by means of suitable nuts (26) actuated on the outside of the grinding drum, said operations being repeated until the entire inner surface of the drum is covered with modules. Milling lining lining module, characterized in that it consists of a metal holder (11) to which the ceramic facing plates (13) are fixed such that they cover one surface of the metal holder (11) and leave two side free edges (14) . Mills for jackets, characterized in that they consist of rods of ceramic, rubber, resin or other suitable material formed with suitable fastening means. Jacks according to claim 14, characterized in that they comprise fastening means as defined in claims 5 to 9. A mill formed with a lining as defined in claims 1 to 10. Represented by: