EP3840890A1 - Vertical ball mill, stator segment for a vertical ball mill and method for maintaining a vertical ball mill - Google Patents

Abstract

The invention relates to a vertical ball mill (100), in particular for the pre-grinding of minerals, comprising: a rotor (204), which is axially and radially supported at an upper end and hangs downward; a stator (102), which radially extends around the rotor (204), is not loaded by the weight of the rotor (204), stands in a self-supporting manner and has a lateral surface that is oriented tangentially to the rotor (204) and that is approximately cylindrical within a shape tolerance; and a base plate (200), which supports the weight of the stator (102), wherein: the stator (102) is composed of at least two stator segments (112), which can be separated from one another, stand unsupported in the separated state and can be moved relative to one another; each of the stator segments (112) has, on at least one side edge of a wall (116) which forms the lateral surface (104), which side edge runs from a top edge of the wall (116) to a bottom edge of the wall (116), a sealing surface for sealing to the other stator segment (112), and has, on the bottom edge, a standing surface (122) dimensioned appropriately for the load, for sealing to the base plate (200); the stator segment (112) rests standing orthogonally on a load-bearing surface (201) of the base plate (200) within an angular tolerance, with the standing surface (122) on the base plate (200).

Description

 Vertical ball mill, stator segment for a vertical ball mill and method for maintaining a vertical ball mill

Field of the Invention

The invention relates to a vertical ball mill, in particular for pre-grinding ground material such as minerals, a stator segment for a vertical ball mill and a method for maintaining a vertical ball mill.

Technological background

In a ball mill, grinding media are used to crush the ground material. The regrind is taken up in a suspension, which is also known as slurry or slurry, and moved in the mill. The grinding media are generally spherical and are also referred to as grinding balls or grinding beads. The ground material is to be understood in particular as minerals and mineral aggregates, such as metallic ores, but also substances of similar hardness, such as coal ores, recycling materials, etc. The following description describes the mincing of minerals as an example.

In conventional mills, the minerals are mixed with the grinding balls to crush the minerals. Some of the grinding balls and minerals are raised by a design-determined distance and fall from this height back into a bed of the rest of the grinding balls and minerals. The meet

falling grinding balls on lying grinding balls. Minerals in between are shattered.

A conventional ball mill can, for example, have a horizontal drum, ie a drum rotating about a horizontal axis, in which minerals are crushed with the aid of grinding balls. In an agitator mill, gravity is also used as an essential element for generating crushing forces (so-called "gravity induced mills"). In a mill that mainly uses gravity, a hydrostatic pressure builds up, which supports the grinding. This design means that the grinding media are raised again and again. This requires lifting work, which is carried out, for example, by a rotating screw. The grinding takes place in

Ball bed. The main stress is caused by gravity and a smaller proportion by centrifugal forces. The proportion of grinding forces that can be attributed to gravity cannot be influenced. The regrind is also lifted by the screw and recirculates downwards at the periphery. The grinding material is primarily transported by the screw, a certain proportion by flow forces in the slurry. Such a grinding or transport mechanism can also cause the discharge of coarse goods. This usually requires the use of an external visual circuit.

Minerals crushers are widely used

Embodiments built and can be simply referred to as horizontal and vertical mills. DE 1 901 593 (Al) describes a vertically arranged agitator mill with auxiliary grinding bodies for homogenizing, dispersing and

Crushing solids in liquids is known. Vertical mills have also proven their worth in the raw materials industry (mines, etc.) (see, inter alia, WO 2007/019602 A2).

Alternatively, there are mills in which the crushing forces are predominantly generated in a fluidized grinding bed and can be generated and changed by the speed of a rotor (so-called "fluidized mills"). A vertically aligned one

Mineral mill for fine grinding was presented on the occasion of IMCET 2013 ("23rd International Mining Congress and Exhibition of Turkey", Kemer / Antalya / Turkey, April 16-19, 2013, in particular session 1: "Stirred Milling Technology - A new concept in fine grinding ", By I. Roitto et al." Outotec HIG-mills: a fine grinding technology "). The mineral mill presented here for the fine grinding of pre-ground minerals consists of a vertically aligned stator assembled from two half-shells with fixed ring-shaped grinding disks, which is suspended from a solid platform and a rotor mounted on one side on its shaft

Grinding disks are arranged. In addition to the central rotor, which is driven by geared motors mounted on the platform with an output of up to 5000 kW, the stator also hangs on this platform. Between the rotating grinding disks and stationary grinding disks attached to the housing, the heterogeneous mixture is included Water and crushed with grinding media until the ground material reaches the desired grain size and grain distribution. This is done with a net volume

(Filling volume) of maximum 30m ³ . The grinding process used (which is sometimes referred to as HIG process; ultra fine grinding technology) requires pretreated, multi-stage minerals in order for the grinding process to take place at all.

Disclosure of the Invention and Some Embodiments

Against this background, the approach presented here becomes a vertical ball mill, in particular for roughly pre-grinding minerals, a stator segment for a vertical ball mill and a method for maintaining a vertical one

Ball mill presented according to the independent claims. Beneficial

Further developments and improvements of the approach presented here result from the description and are described in the dependent claims.

Embodiments of the present invention can advantageously make it possible to reduce the use of energy for the pre-grinding of minerals and thus to achieve an increase in efficiency and to modify a structural design of a mill which can be used for the pre-grinding in such a way that it is easily assembled, disassembled and can be serviced. In particular, the approach presented here creates a robust construction which can be constructed less material-intensive and considerably lighter than previous concepts. The construction can be relatively easily dismantled and brought close to the mineral extraction sites or to a place of use. Due to the approach presented here, required regular

Maintenance work can be significantly shortened and simplified. By the

The machine concept can reduce the risk of an accident. A revision of the mill presented can be relatively easy to carry out, so that no specially trained specialist personnel may be required. The approach presented here can also enable improved process control and easier adaptation to the material quality present in the mining process. The shredded material can be processed or refined and / or directly

downstream process. In the case of overhauls and repairs, no additional lifting gear is usually required for disassembly and assembly.

Spare parts can be at the same level as the main ones to be replaced Components such as a mill shaft with grinding disks or individual grinding cylinders can be stored on site to save space. A horizontal movement and positioning of the spare parts can be carried out safely by a few people, for example using rails and rollers. This also includes safe and quick emptying of the grinding cylinder without extensive material loss.

According to a first aspect of the invention, a vertical ball mill, in particular for the pre-grinding of regrind such as minerals, is proposed. The vertical ball mill has (i) an axially and radially supported, downwardly hanging rotor at an upper end, (ii) a radially surrounding self-supporting stator with a rotor tangential to the rotor, which is not loaded by the weight of the rotor

aligned, approximately cylindrical within a shape tolerance

Lateral surface, and (iii) a base plate supporting a weight of the stator. In this case, the stator is composed of at least two stator segments that can be separated from one another, are self-supporting in the separated state and can be displaced relative to one another

composed. Each of the stator segments has on at least one side edge of a wall a sealing surface for sealing on the other stator segment, and on a lower edge a load-bearing surface for sealing on the base plate. The said side edge of the wall extends from an upper edge of the wall forming the lateral surface to a lower edge of the wall. The stator segment is standing with the footprint on the base plate orthogonally within an angular tolerance on a load-bearing surface of the base plate.

Furthermore, according to a second aspect of the invention, a self-supporting stator segment for a vertical ball mill is presented according to the approach presented here. This has (i) a wall which is approximately in the form of a cylindrical segment within a shape tolerance, (ii) at least one sealing surface arranged on a side edge of the wall running from an upper edge of the wall to a lower edge of the wall for sealing on another stator segment, and (iii) one on the Bottom edge arranged load-bearing area, with which the stator segment can be set up orthogonally within an angular tolerance on a load-bearing surface of a base plate of the ball mill. From several stator segments, a self-supporting stator can be assembled with a wall-shaped, within a shape tolerance circular cylindrical outer surface, which can support standing in an assembled state on the base plate from supporting a weight of the stator. Furthermore, according to a third aspect of the invention, a method for maintaining a vertical ball mill, in particular for pre-grinding ground material such as minerals, is presented. The vertical ball mill can correspond to the aforementioned ball mill according to an embodiment of the first aspect of the invention and in turn has a rotor which is axially and radially supported at a top and which hangs downwards, and a self-supporting standing rotor which surrounds the rotor radially and is not loaded by a weight of the rotor Stator with a tangent to the rotor

aligned, approximately cylindrical within a shape tolerance

Shell surface, and a base plate supporting a weight of the stator. The stator is composed of at least two stator segments that can be separated from one another, are self-supporting in the separated state, and can be displaced relative to one another. Each of the stator segments has on at least one sealing surface for sealing on the respective other stator segment on at least one side edge of the wall running from an upper edge of a wall forming the outer surface to a lower edge of the wall, and on the lower edge has a load-bearing area for sealing on the base plate. The stator segment stands upright with the footprint on the

Base plate orthogonal to a load bearing within an angular tolerance

Surface of the base plate. The method has at least the following

Process steps, preferably in the order given, on:

separating the stator into the stator segments, the stator being separated at the sealing surfaces,

arranging auxiliary devices under at least one of the stator segments, and laterally displacing the stator segment and the auxiliary devices using a displacement device.

Before the auxiliary devices are arranged, the stator segment can be lifted off the base plate using lifting devices and placed on the auxiliary devices using the lifting devices.

Ideas for embodiments of the present invention, among others, but without limiting the invention, can be considered based on the thoughts and knowledge described below.

A vertical ball mill can be understood to mean a device for comminuting a ground material using grinding bodies. The regrind can be, for example, pre-broken rock or minerals from a mine. The rock or the minerals can, for example, in a crusher, a Gutbwalzmühle, an oxy-fuel or semi-autogenous mill are crushed and screened before they are fed to the vertical ball mill.

The vertical ball mill described herein can be used as a grinding stage

Raw material extraction can be used. The regrind is fed to the ball mill in lumps or as a suspension in a liquid carrier medium or transport medium. The carrier medium can be water, for example. The regrind can have a proportion of a desired raw material. For example, the regrind can have an ore fraction. A major part of the regrind can be deaf, i.e. not have the desired raw material. The crushing creates small particles that can be processed in subsequent process steps. The proportion of particles with the desired raw material can, for example, in a subsequent one

Concentration step can be increased. For example, a difference in density between particles from the deaf material and particles with the desired raw material can be used in the concentration step.

The vertical ball mill described herein can have a large filling volume of more than 20 m ³ . In praxi mills with a net volume (filling volume) of 20 m ³ to 150 m ^{3 are} required for the economical pre-grinding of minerals. To the

The vertical ball mill is dimensioned accordingly to enable the high filling volume and is therefore large and heavy. The speed of rotation of the grinding disks can be up to 15 m / s. The power of the drive motors can be up to about 12500 kW.

The grinding media can be spherical, for example. The grinding media can be made of a low-wear material. In particular, the grinding media can have a greater hardness than the grinding stock. The grinding media can consist, for example, of a metal material, in particular steel, or ceramic material.

The grinding media, the grinding stock and the carrier medium are enclosed in a fluid-tight container. The container is immovably connected to a surface during operation. The container can thus be called a stator. The grinding media are driven to move in the container by a driving element of the ball mill. The driving element can be referred to as a rotor. The grinding media can be moved in the stator without any appreciable upward movement and / or downward movement on an approximate circular path. The circular path can be within an angular tolerance perpendicular to a vertical main axis of the ball mill run. The angular tolerance can be referred to as the position tolerance. The

Angular tolerance can be, for example, 10 ° or less, preferably 5 ° or less, particularly preferably 2 ° or less.

The regrind is ground or crushed between the grinding media when grinding media of different speeds collide and / or roll against each other. A speed difference between the grinding media is achieved by moving the grinding media in close proximity to the rotor approximately at a speed of movement of a surface of the rotor. In contrast, grinding media in the immediate vicinity of the stator do not move approximately. A speed profile of the grinding media expands between the rotor and the stator. The faster grinding media, which are arranged closer to the rotor, collide or rub with the slower grinding media, which are arranged closer to the stator.

The rotor can be aligned on the main axis within the angular tolerance. The rotor can be rotatable about the main axis. The rotor can be mounted on the fly. The rotor can then be unsupported at a lower end. Additional storage at the lower end does not have to be excluded. Due to its own weight, the rotor can be in a hanging orientation, i.e. essentially perpendicular to a surface.

The stator can be open at the top. The rotor can dip essentially vertically from above into the carrier medium with the regrind and the grinding media. The rotor can be mounted independently of the stator. The stator can be spatially, statically and / or mechanically separated from the rotor or a rotor bearing of the rotor.

The stator has an approximately cylindrical outer surface within a shape tolerance. In other words, the stator can enclose a cylindrical, in particular circular cylindrical volume. For this purpose, the stator can preferably have an approximately circular cross-sectional area within the shape tolerance and thus be rotationally symmetrical. The stator may also have an oval, triangular, octagonal, n-square or generally polygonal cross-sectional area. The cross-sectional area can remain the same from a lower edge of the stator to an upper edge of the stator within a shape tolerance. The shape tolerance describes a permissible deviation from a cylindrical shape. The shape tolerance can be, for example, 10% or less, preferably 5% or less, particularly preferably 2% or less based on the overall dimensions of the stator. In other words, the stator can be out of round within the shape tolerance.

An outer surface describes an interface for the grinding media, the carrier medium and the regrind. The outer surface can be represented by an inner surface of the stator. The lateral surface can be vertical or perpendicular within the angular tolerance.

A base plate introduces a weight of the stator, the grinding media, the carrier medium and the grinding material completely or at least to a large extent into the foundation and is designed to be load-bearing. The base plate can be firmly connected to the foundation. The base plate can have a load-bearing surface as an interface to the stator. The load-bearing surface can be one of the

Cross-sectional area of the stator have a shape corresponding to the shape tolerance. The base plate can be flat on one surface or on two opposite surfaces. The base plate can have an insert for reinforcement in the area of the load-bearing surface. The base plate can be made of a metal material. The base plate can for example be a separate component and on the

Lay the foundation. The base plate can also stand on support feet and be spaced from the foundation. The base plate can alternatively be designed as a specially shaped area of the foundation.

A stator segment can have an essentially arcuate basic shape. A wall of the stator segment forms a partial area of the lateral surface. The wall can represent an angular area of the lateral surface. If the stator has two stator segments, both walls can each represent an angular range of 180 °. With three stator segments, each wall can cover an angular range of 120 °. With n> 3 stator segments, each wall can represent an angular range of (360 / n) °. The stator segments can be divided differently in the circumferential direction.

The wall has a wall thickness designed for the load. In particular, the wall of the stator segment can be designed structurally, that is to say in particular on account of its wall thickness and / or on the basis of reinforcement measures, to be able to withstand the forces and loads which arise in the mill described, in particular where the stator segments stand at the bottom. The inside of the wall can be equipped with a protective layer to prevent direct contact between the grinding media and the wall. The wall can have stiffening ribs on the outside.

Side edges of the wall can run perpendicular to the upper edge and / or lower edge within the angular tolerance. A sealing surface can be aligned transversely to a pulling direction of connecting elements for connecting the stator segments. With a tangential pulling direction, the sealing surface can be aligned radially. With a radial pulling direction, the sealing surface can be oriented tangentially. The footprint can be oriented transversely to an expected load direction. The footprint can be aligned horizontally within the angular tolerance. The sealing surface and / or the standing surface can be formed by stiffening ribs arranged on the edges of the wall.

The stator segments are mobile or can be lifted off the base plate. A mechanical connection to the base plate can be released beforehand. The vertical ball mill can be easily opened due to the mobility of the stator segments. The rotor is easily accessible on the open ball mill and maintenance work can be carried out easily on the inside of the stator segments.

A plurality of vertically spaced, horizontal, ring segment-shaped ribs can be arranged on an inner side of the walls of the stator segments. The ribs can form inwardly projecting annular surfaces on the assembled stator, which are referred to herein as braking surfaces. The rotor can have a plurality of horizontally spaced horizontal disks, each with an external one

annular surface, which is referred to herein as a drag surface. The ribs and the disks can be arranged alternately in the vertical direction.

An inner diameter of the braking surfaces can be smaller than an outer diameter of the towing surfaces. The braking surfaces and the towing surfaces can thus at least partially overlap in the horizontal direction. A meandering labyrinth can be formed between the ribs and disks. The labyrinth increases a flow resistance for the turbidity through the ball mill. The ribs can therefore also be viewed as deflection surfaces. The ribs can be inside the

Angular tolerance to be aligned perpendicular to the wall. The disks can be aligned perpendicular to the rotor shaft within the angular tolerance. The disks can approximate a circular shape within the shape tolerance. The slices can also be polygonal. Like the walls, the ribs or the braking surfaces can have a protective layer in order, for example, to make direct contact with the grinding balls prevent. The panes can also have a protective layer. The

Protective layer can be interchangeable. The ribs, which form a common braking surface on the assembled stator, can be at the same height on the

Stator segments can be arranged and have the same width or height. The ribs and disks can be arranged at regular intervals. The disks can be between the drag surfaces and the rotor shaft

Have breakthroughs. The drag surfaces on the rotor generally increase a contact surface of the carrier medium, the millbase and the grinding media with the rotor. The carrier medium, the regrind and the grinding media can be better driven by the drag surfaces. A speed of movement of a point on the disks increases in proportion to a distance of the point from the axis of rotation of the rotor. The drag surfaces with the highest are on the outside diameter of the rotor

Movement speed moves. The braking surfaces on the stator enlarge a contact surface of the carrier medium, the material to be ground and the grinding media to the stator. The braking medium or drag surfaces can be used to brake or drive the carrier medium, the regrind and the grinding media in an improved manner. During operation, there is a high speed difference between the towing surfaces and the braking surfaces. This creates a large speed gradient in the carrier medium, regrind and the grinding media, which is too high

 Differences in speed between the individual grinding media leads. The high speed differences result in high impact or frictional forces and the regrind is crushed efficiently. A main grinding area of the vertical ball mill can be arranged between the drag surfaces and the braking surfaces.

The stator segments can each have stop elements on an outer side for lifting and moving the respective stator segment. Stop elements can be fixed points specially designed for attaching hoists. The

Stop elements can be dimensioned according to the load. The stop elements can be connected to the wall and / or the reinforcing ribs via a reinforcing structure. For example, the stop elements can be connected via additional ribs. The stop elements can be oversized for safety. Stop elements can be designed specifically for a type of hoist.

For example, stop pins can be used for belts, ropes and chains and plates. Lifting eyes can be provided for hooks. Stop surfaces can be used to apply compressive forces from lifting devices. The stator segments can each be in the area of the lower edge of the wall

Have stop elements which are configured in particular for attaching hydraulic jacks. For this purpose, the stop elements can have, for example, essentially horizontally oriented stop surfaces. The stop elements can also have a special interface geometry. For example, spherical or spherical cap-shaped surfaces on the stop element or lifting device with balls or spherical caps on the lifting device or stop element

Work together to achieve an angle-insensitive support.

The stop elements can define corner points of a virtual horizontal polygon, in particular a triangle, the geometric center of which lies on a vertical axis through a center of gravity of the standing stator segment. In the case of a triangle, the geometric center lies at an intersection of bisectors of the triangle. In the case of a quadrilateral, the geometric center lies on an intersection of the diagonals of the quadrilateral. A weight distribution between the stop elements can be predetermined by a position of the stop elements. By matching the axis through the center of gravity and the center of the polygon, tilt stability when lifting a stator segment can be maximized.

The ball mill can have a displacement device for laterally displacing the stator segments which are separated from one another, the displacement device having mobile auxiliary devices which are designed to be in the raised position

Stator segment between the stop elements and arranged on the floor, parallel rails and to be moved with the stator segment placed on the stator segment along the rails. The rails can be firmly connected to the foundation. The auxiliary devices can have slide bearings or rolling elements to reduce friction when moving. Rolling elements can, for example, be rotatably mounted rollers. The rollers can themselves be roller or slide bearings. In the case of a plain bearing, the weight of the stator segment is distributed over a large area, as a result of which a low surface pressure can be achieved. The plain bearing can be lubricated using a lubrication system. As an alternative or in addition, a pair of materials between the slide bearing and the rail can have a low coefficient of friction. For example, the sliding bearing can have a sliding surface made of PTFE, POM or a similar material. The stator segment can be moved with the auxiliary devices using a moving device. The movement device can be arranged between the stator segment and a fixed point and tensile forces and / or compressive forces in one through the rails exercise defined direction of movement. The movement device can, for example, have at least one cable hoist, chain hoist or hydraulic cylinder.

The displacement device can have at least one tilt support for supporting a stop element that is spaced vertically from the standing surface on at least one of the rails, in order to prevent the stator segment from tilting during lifting and displacement. A tilt support can support the stator segment at a relevant distance from the floor. For this purpose, the tilt support can connect the rail with the higher-lying stop element at an oblique angle. The tilt support can be mobile, that is to say it can be moved independently of the stator segment and can only be attached to the stator segment when the stator segment is to be moved.

Alternatively, the tilt support can be firmly connected to the stator segment and remain in place during operation. The tilt support can be connected to a lower stop element via a lower connection. The lower connection can prevent the anti-tipper from moving sideways. The tilt support can also be used to align the vertical flanges. One of the stop elements for lifting the stator segment can be arranged on the tilt support. Then two more of the stop elements for lifting can be arranged on the lower edge of the wall, which are arranged essentially on a connecting line through the center of gravity of the standing stator segment.

The stator segment can have at least one working platform. The

Working platform can be aligned horizontally on the standing stator segment within a position tolerance. The work platform can run along an outer contour of the stator segment. The lowest working platform can be arranged at head height on the stator segment. Between vertical work platforms, at least standing height can be maintained as a vertical distance. A ladder can be arranged on the tilt support, via which the work platform is accessible. The work platform and the ladder can have railings and / or fall protection devices. The stator segment can be easily accessible for maintenance work via the work platform. Thanks to the work platform, there is no need for a mobile scaffold for maintenance work.

The rails can be embedded in the foundation of the ball mill and, optionally, can be covered by covering devices when not in use. The rails can for example be concreted. The rails can be arranged in depressions in the foundation. The cover devices protect the rails from dirt and damage. In particular, a surface of the rails can be so

Damages are protected. An upward-facing surface of the rails or a covering device covering this rail can be flush with a surface of the foundation. The covering devices can be passable. An environment of the vertical ball mill is kept accessible.

The ball mill can have an emptying device for emptying the ball mill. Since the grinding media remain in the ball mill during operation, the grinding media can be drained through the emptying device with residues of the carrier medium and the grinding media before the stator is opened. The

Emptying device can for example be designed as a flap or slide in the wall of a stator segment.

The emptying device can have a sloping floor within the load-bearing surface of the base plate. One of the stator segments can be in the area of a

Low point of the sloping floor have an emptying opening of the emptying device. Due to a sloping bottom, the grinding media can

Drain the gravity-driven drain from the side. The sloping floor has a slope from a lowest point to a highest point. The slope can be, for example, within an angle tolerance between 1 ° and 5 °, preferably between 2 ° and 3 °, particularly preferably 2.5 °. The sloping floor can be designed as an inclined plane. The sloping floor can also be designed as a spatially shaped surface aligned with the low point. The drain opening provides a through opening through the wall. The drain opening can be designed as a pipe connection. The pipe connection can be standardized, for example. The pipe connection can, for example, be DN 150. The drain opening can have a suitable fitting, such as a slide, a flap, a tap or a valve.

One of the stator segments can have at least one flushing opening of the emptying device in the region of a high point of the sloping floor. Through the

Flushing opening, a flushing fluid, in particular a flushing liquid, can be conducted into the interior of the stator in order to flush it out. The flushing opening can be designed as a pipe connection. The rinsing opening can be made standardized, for example. The flushing opening can be designed with a size of DN 100, for example. The Flushing opening can have a suitable fitting, such as a slide, a flap, a tap or a valve. The flushing opening can be the emptying opening

be arranged opposite one another. The ball mill can be emptied by flushing. For example, liquid can be introduced through the flushing opening, which generates a flushing flow via the inclined bottom.

The ball mill can have a frame separate from the stator. Supports of the frame can be supported on the foundation of the ball mill, spaced laterally from the stator. At least one cross member of the frame can connect the supports above the stator. A bearing device of the rotor can on the

Cross member to be supported. In other words, a frame can be provided for the ball mill, which frame is designed to be load-bearing separately from the stator and not on the stator, the bearing and

Drive arrangement is held and supported so that these components do not rest on the stator. The frame can, for example, be composed of steel girders, in particular screwed together. The frame can be designed as a portal, under which the stator is arranged. Due to the frame, the stator can be disassembled without having to change the rotor. The stator segments can, for example

Maintenance measures are moved to the side of the rotor.

The ball mill can have a disengaging device for laterally disengaging the rotor that can be uncoupled from an overhead clutch. The release device can have at least one rail and a coupling device. The coupling device can be designed to be connected to the rotor in the area of the coupling, to be lowered onto the rail with the rotor and to be moved along the rail with the rotor. A disengaging device can close the rotor

Move the servicer into an accessible position while the drive remains in place. The rotor can be separated from the drive on the coupling. The coupling can be screwed together with several screws, for example. A stop element can be coupled to the clutch in order to lift the disengaged rotor with a crane. The coupling device can have a geometry adapted to a contour of the rotor in the area of the coupling. The coupling device can enclose the rotor shaft. The coupling device can have stop elements for attaching lifting gear. In particular, the stop elements can be designed for attaching hydraulic jacks. The rail can also have stop elements for attaching the hydraulic jacks. The release device can in particular have two rails which are arranged on both sides of the rotor shaft. The frame can have a maintenance cabin in the area of the coupling of the rotor. The coupling can be accessible from the maintenance cabin. The maintenance cabin can be used for the protected storage of tools. The

Maintenance cabin can protect the coupling from environmental influences.

It is pointed out that some of the possible features and advantages of the invention are described herein with reference to different embodiments of the ball mill, the stator segment or the method for maintaining the ball mill. A person skilled in the art recognizes that the features of the ball mill, the stator segment and the method can be combined, transmitted, adapted and / or exchanged in a suitable manner in order to arrive at further embodiments of the invention.

Brief description of the drawings

Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings, wherein neither the drawings nor the

Description to be interpreted as limiting the invention.

Fig. 1 shows a spatial representation of a vertical ball mill according to an embodiment;

2 shows a spatial representation of an opened vertical ball mill according to an embodiment;

3 shows a spatial representation of a stator segment of a vertical ball mill according to an exemplary embodiment;

Fig. 4 shows a sectional view through a vertical ball mill according to an embodiment;

5 shows a sectional illustration through a vertical ball mill according to an exemplary embodiment;

6 shows a flow diagram of a method for maintaining a vertical

Ball mill according to an embodiment; 7 shows a spatial representation of a closed vertical ball mill according to an exemplary embodiment;

8 shows a spatial representation of an opened vertical ball mill according to an exemplary embodiment;

9 shows a spatial representation of a stator segment of a vertical ball mill according to an exemplary embodiment;

10 shows a spatial representation of a work platform of a vertical one

Ball mill according to an embodiment;

11 shows a spatial representation of a displacement device of a vertical ball mill according to an exemplary embodiment;

12 shows a detailed illustration of a standing flange of a vertical ball mill according to an exemplary embodiment; and

13 shows a detailed illustration of a sealing flange of a vertical ball mill according to an exemplary embodiment.

The figures are only schematic and are not to scale. In the figures, the same reference symbols denote the same or equivalent features.

Embodiments of the invention

1 shows a spatial representation of a vertical ball mill 100 according to an exemplary embodiment. In the ball mill 100 is very large with a filling volume of over 12 m ³ to about 150 m ³ and in a continuous grinding process a suspension of coarsely broken ground material in a liquid carrier medium can be moved by moving grinding media with an average initial size by a factor of 10 to 100 be reduced to an average target grain size. The grinding media can in particular be metallic and / or ceramic balls with a diameter that is approximately 2 to 50 times larger than the initial size. The

The initial size can be up to 15 millimeters here. The grinding media can be between 5 millimeters and 50 millimeters in size. The ball mill 100 can thus be used as a crushing stage in a multi-stage disintegration process, for example in the extraction of raw materials. There, the regrind can contain desired minerals and deaf rock to be separated.

The ball mill 100 has a hanging rotor for moving the grinding media.

A free-standing stator 102 encloses as a container for the suspension and the

Grinding body a working space of the ball mill 100 and the rotor radially. On

Working space inside the stator 102 of the ball mill 100 shown here is between 12 cubic meters and 150 cubic meters. The working area is mostly filled with a grinding media bed made up of many grinding media. The suspension with the coarsely broken ground material is continuously introduced into the bed of the grinding media in a lower area of the working area at a flow rate between 50 cubic meters per hour and 5000 cubic meters per hour. The ground material is crushed as it flows through the grinding media bed. In an upper area of the working space, the suspension with the ground material flows out of the

Grinding media bed and is discharged from the work area while the grinding media remain in the work area.

A shear flow is formed between the stator 102 and the rotor during the grinding process with the rotor rotating, since a rotor boundary layer of the suspension surrounding the rotor with the grinding media contained therein is separated from the rotor in

Essentially entrained at an angular velocity of the rotor and a stator boundary layer of the suspension with the grinding media contained therein is kept essentially stationary on the stator 102. A speed curve of the shear flow forms between the rotor boundary layer and the stator boundary layer, since the closer the rotor is, the faster the suspension and the grinding media are moved. Due to the speed curve, there are massive collisions between fast and slow grinding media, in which the material in between is crushed. The ground material is crushed by an upward flow of the resulting from the flow of the suspension through the bed of grinding media

Carrier medium washed up in the work area.

The stator 102 has an outer surface 104 which is substantially cylindrical in shape and, in the illustration shown in the figure, hides the rotor. The rotor is mounted axially and radially above the stator 102 at an upper end and hangs into the working space. A bearing and drive device 106 of the rotor is supported directly on a foundation 110 of the ball mill 100 via a free-standing frame 108. The bearing and drive device 106 here has four electric motors 107 with a total output between 0.8 megawatts and 12.5 megawatts, which drive the rotor via a common gear. It is also possible to use fewer or fewer electric motors. There is no load-bearing contact between the frame 108 and the stator 102. A drive torque of the bearing and

Drive device 106 is derived via the frame 108 into the foundation 110. The stator 102 is self-supporting on a base plate of the ball mill 100. The base plate supports a weight of the stator 102, a counter-torque of the drive torque and a weight of the grinding media, the minerals and the carrier medium on the foundation 110. The base plate is covered by the stator 102 in FIG. 1.

The stator 102 can be divided in particular for maintenance purposes. Here the stator 102 is composed of two essentially identical stator segments 112. The stator 102 can also be composed of more than two stator segments 112. The stator segments 112 are connected to one another via sealing flanges 114. The

Sealing flanges 114 run from an upper edge of the stator 102 to a lower edge of the stator along side edges of a wall 116 of the stator segments 112

Connecting the stator segments 112, the sealing flanges 114 can be screwed together, for example. The screws can be loosened again to separate the stator segments 112. The adjacent stator segments 112 can alternatively also be mechanically detachably connected to one another in another way. The

Sealing flanges 114 form sealing surfaces 118 for fluid-tight sealing of the work space. Additional seals can be arranged between sealing surfaces 118. The sealing surfaces 118 or seals prevent leakage of the suspension at the separation points of the stator 102. Sealing flanges 114 can also be used

Leakage channels should be provided. Leakage channels can possibly escape

Derive the carrier medium in a targeted manner into a collection system. The wall 116 of a

Stator segment 112 forms a segment of the lateral surface 104 of the stator 102 that approximates a cylindrical segment shape and is stiffened on the outside by a plurality of tangentially oriented stiffening ribs 117. In addition, the wall 116 is reinforced on the outside by a few reinforcing ribs 119 running in the axial direction. The sealing flanges 114 essentially correspond to axial stiffening ribs 119 running along the side edges. The stiffening ribs 117, 119 stiffen the stator 112, inter alia, against a hydrostatic pressure caused by the

Carrier medium.

The stator segments 112 each have a circumferential standing flange 120 on the lower edge. The stand flange 120 is essentially one along the bottom edge of FIG Walls 116 tangent rib. About the stand flanges 120

Stator segments 112 connected to the base plate, in particular in such a way that forces due to a weight of the stator segments 112 and possibly due to a weight of the grinding media and the grinding stock can be dissipated into the base plate. For example, the standing flanges 120 can be screwed to the base plate. The standing flanges 120 form a standing area 122 of the stator 102 which is dimensioned for the load. The entire weight of the stator 102 is supported on the base plate via the base 122. The standing surface 122 is also a sealing surface 118 and seals on the base plate. A seal can also be arranged between the base 122 and the base plate. Leakage channels can also be formed between the base 122 and the base plate.

To get to the rotor, the work area can be emptied, i.e. Grist and grinding media are removed. Then the stator segments 112 can be moved laterally. Before moving, a mechanical connection of the stator segments 112 to one another and the stator segments 112 to the base plate is released. The stator segments 112 can then be raised individually by means of a lifting device in order to be laterally moved freely from the base plate. Hydraulic jacks, for example, can be used as the lifting device. Each stator segment 112 has a plurality of stop elements 124 for lifting. The stop elements 124 are arranged in the region of the lower edge of the wall 116. The stop elements 124 are designed here as brackets projecting beyond the standing surface 122 and have downward-facing stop surfaces.

In one embodiment, the ball mill 100 has a displacement device 126. The displacement device 126 has three sliding paths 128 for each stator segment 112, via which the stator segment 112 can be moved laterally guided away from the other stator segment 112. The sliding paths 128 are predefined here by rails 130 anchored in the foundation 110. The rails 130 and the foundation 110 are designed to safely carry the weight of a stator segment 112. To move, the raised stator segment 112 is lowered onto auxiliary devices using the lifting device. The aid facilities are between the

Stop elements 124 and the rails 130 are arranged and support the weight of the stator segment 112 lowered thereon via the rails 130. Through the

Auxiliary devices maintain a distance between the base 122 and the base plate even in the lowered state. The stator segment 112 is moved along the sliding path 128 with the auxiliary devices. In one exemplary embodiment, the auxiliary devices are designed as sliding shoes which slide on a surface of the rails 130 by means of a sliding coating and an optional lubricant. Train systems and / or push systems can be used to move the stator segment 112 along the rails 130.

In an alternative exemplary embodiment, for moving the stator segment 112, heavy-duty rollers are arranged between the stop elements 124 and the foundation 110 dimensioned for the load, by means of which the weight of the stator segment 112 is supported directly on the foundation 110. The stator segment 112 can be moved freely on the heavy duty rollers.

In one exemplary embodiment, at least one tilt support 132 is arranged on at least one of the stator segments 112. The tilt support 132 can be fixedly attached to the stator segment 112 or, alternatively, can be provided on the stator segment before being moved

Stop elements 124 of the stator segments 112 are attached. The tilt support 132 can be supported on the foundation 110 by a heavy-duty roller. Alternatively, the tilt support 132 can be part of the displacement device 126. Then the tilt support 132 is coupled to one of the rails 130 by means of a further auxiliary device 134. The further auxiliary device 134 can be designed as a sliding shoe. The further auxiliary device 134 can be secured against being lifted off the rail 130. For this purpose, the auxiliary device 134 can at least partially encompass the rail 130. The auxiliary device 134 can thus introduce compressive forces and tensile forces into the rail 130. In addition, the tilt support 132 is adjustable in length in order to be able to compensate for the stroke or one when the stator segment 112 is raised and lowered

Correct angular position of the stator segment 112 relative to the other stator segment 112.

In the illustrated embodiment, the rails 130 are arranged in recesses of the foundation 110. Thus, the rails 130 can be covered during the operation of the ball mill 100, whereby they are better protected against damage and contamination than if they were exposed.

2 shows a spatial representation of an opened vertical ball mill 100 according to an exemplary embodiment. The ball mill 100 corresponds to

Essentially the ball mill in FIG. 1. In contrast to the illustration in FIG. 1, the stator segments 112 have been separated from one another here. The stator segments 112 were raised on the stop elements 124 and thereby lifted off the base plate 200. Are between the stop elements 124 and the rails 130

Auxiliary devices 134 have been arranged on which the stator segments 112 have been placed. As a result, the standing surfaces 122 are spaced apart from a load-bearing surface 201 of the base plate 200. Using a pulling device 202, the stator segments 112 on the auxiliary devices 134 have been displaced laterally away from the base plate 200 along the sliding path 128 defined by the rails 130, in order to carry out maintenance work or maintenance work to be able to perform on the rotor 204 and / or an inner side 206 of the stator 102. In the example shown, the stator segments 112 have been moved in opposite directions.

On the inner sides 206 of the walls 116, the stator segments 112 can have a plurality of vertically spaced, horizontal, ring segment-shaped ribs 208. The ribs 208 of both stator segments 112 can be arranged identically. Flat sides of each rib 208 function as an annular one when the vertical ball mill 100 is operating

Brake surfaces 210 for the suspension. The ribs 208 also act as deflection surfaces in the direction of the rotor 204 for the suspension flowing through the ball mill 100 from the bottom. The ribs 208 are evenly spaced. The ribs 208 on the inside 206 can, but need not necessarily, have a greater height and / or greater vertical distances from one another than the tangential ones

Stiffening ribs 117 on the outside. An execution of the

Mill cylinders possible without internal ribs.

The rotor 204 is separated from the drive and bearing device 106 and shown laterally disengaged. The rotor 204 has a plurality of disks 212 which are arranged on a rotor shaft 205 and are spaced apart vertically from one another and oriented transversely to the rotor shaft 205. On its flat sides, each disk 212 has two annular drag surfaces 214 for driving the suspension. The disks 212 have openings 213 toward the rotor shaft 205. Through the openings 213 spokes 215 are formed between the drag surfaces 214 and the rotor shaft 205.

When the ball mill 100 is ready for operation, the ribs 208 and the disks 212 can be spaced apart from one another and alternately one above the other in the work space, the braking surfaces 210 and the drag surfaces 214 being able to overlap at least partially in the horizontal direction. Due to the overlapping of the ribs 208 and the disks 212, a labyrinth is formed between the stator 102 and the rotor 204 in the ready-to-operate state, which forms a flow path of the suspension extended by the ball mill 100. An embodiment without the inner ribs 208 is also feasible. At an upper end, the rotor 204 has a clutch 216, via which the rotor 204 can be detachably coupled to the bearing and drive device 106.

The frame 108 has a disengaging device 218 for disengaging the rotor 204. The disengaging device 218 has two rails 130, which are connected to the frame 108 and protrude laterally via cross members of the frame 108, and a coupling device 220. The rails 130 are arranged on opposite sides of the rotor shaft 205.

To disengage, the coupling device 220 is connected in the area of the clutch 216 to the rotor 204 coupled to the bearing and drive device 106. The coupling device 220 is essentially U-shaped and is pushed from the side onto the rotor shaft 205. An open end of the coupling device 220 is then closed by a latch 222. The clutch 216 has a larger diameter than the rotor shaft 205. The coupling device 220 is raised until it rests on the clutch 216 and the bearing and drive device 106 is relieved by a weight of the rotor 204 being intercepted by the coupling device 220. The clutch 116 is then released from the bearing and drive device 106. The coupling device 220 with the released rotor 204 is then lowered until it rests on the rails 130. The rotor 204 together with the coupling device 220 is then moved along the rails 130 until the coupling 216 next to the

Cross member is arranged and is accessible from above. The coupling 216 can then be lifted out of the coupling device 220 by means of an adapter with a crane. The coupling device 220 can have a sliding coating, for example.

Details of the exemplary embodiment, as shown in FIGS. 1 and 2, are explained in more detail below and with a partially modified choice of words.

Figures 1 and 2 show a ball mill 100 in which a storage and

Drive device 106 serving mill drive from motor (s) 107 and transmission together with a mill shaft serving as rotor shaft 205 is arranged on the top of the vertical mill on a platform or a mill frame, which serve as frame 108. The mill shaft carries grinding disks 212 and, together with these, can be referred to as rotor 204. The platform at the top of the mill only carries the weight of the rotor, motor and gear, which means that relatively small forces act. The Forces are particularly small compared to the acting forces when the entire mill is suspended at the top.

A grinding cylinder of the ball mill 100 acting as a stator 102 with a

Wear protection lining and stationary disks in the form of ribs 208 are structurally not connected to the mill drive. The grinding cylinder can be divided into two grinding cylinder halves with stationary discs. A seal on

The vertical flange and the radial flange are made with a hollow seal. A weight of the grinding cylinder, the stationary disks, the grinding media and the suspension of regrind and carrier medium, which is referred to here as slurry, is carried by the anchoring on the ground and discharged into the foundation. The grinding cylinder construction is stable enough to absorb the forces. The base plate 200 is anchored in the concrete on the floor to absorb and dissipate the grinding cylinder forces. An optional wear plate protects the base plate 200 and is only held by its own weight or can also be mechanically attached and can be easily removed. A slurry inlet is located sideways at the bottom and a slurry outlet is located sideways at the top.

During operation of the ball mill 100, the interior of the grinding cylinder or the milling cylinder is filled with grinding beads (not shown) up to 80% of the grinding cylinder height. In the spaces between the grinding beads and above the bed of grinding beads there is cloudy. Here, the ball mill 100 is emptied through openings in the mill floor.

The vertical ball mill 100 presented here can be used in particular for a

Primary grinding, that is, for a coarse grinding. Grist with a maximum grain size Fl 00 of 10 mm to 15 mm or with an F80 of 250 microns to 5 mm is finely ground to a fineness of P80 of 100 pm.

A variant of the ball mill 100 can be used for comminution in the fine range. Grinding to a fineness of product with a P80 of 40 to 300 pm is referred to here as the fine range. In the fine range, the feed fineness is preferably in the range of less than 500 pm.

In the vertical ball mill 100 presented here, the grinding media remain in the

Positioned essentially in the vertical direction. It essentially won't

Elevated work applied. The grinding takes place in the areas between the Rotor disks 212 and the housing disks formed by the ribs 208. The grinding chamber, and thus the stress on the material to be ground with the grinding media, is very well defined. This increases the grinding efficiency. The ones required for grinding

Grinding forces are essentially generated by centrifugal forces. Gravity causes an increasing contact force or pressure between the grinding elements from top to bottom and a hydrostatic pressure in the stator 102 increasing from top to bottom. The grinding forces can be influenced by the speed and the mass of the

Grinding media can be influenced and changed. The grinding material is transported in the vertical ball mill 100 by the drag forces in the slurry which is generated by the feed pump. The dwell time and thus the energy input can be influenced by an adjustable delivery rate of the feed pump. Finished goods are transported through the openings in the rotor and removed from the mill in the overflow. A separate external visual cycle is generally not necessary. However, such can be provided if necessary.

The fine material from the vertical ball mill 100 presented here reaches a narrow one which is advantageous for the subsequent treatment stage (flotation, leaching)

Grain size distribution (KGV). This corresponds to a steep course of a fineness curve shown in the RRRS diagram. A narrow grain size distribution is achieved by minimizing overgrinding. For this purpose, the already finished product is removed from the grinding process as quickly as possible with the approach presented here. The better this works, the steeper the P / E ratio. The grinding chamber of the vertical ball mill 100 is therefore designed in such a way that these requirements are met. This is essentially achieved through openings in the form of the openings 213 in the rotor disks 212. A pump conveys the slurry from bottom to top, passes through the openings and the grinding chamber and takes the fine parts of the ground material with it. The speed is determined by the

Flow rate of the pump determined. The delivery rate is set so that the product ground to the desired product fineness is removed and coarser material remains in the grinding chamber of the mill. The ground material, which has already reached the required fineness, is removed from the grinding chamber as quickly as possible. This avoids over-grinding.

Before maintenance work on the ball mill 100 can begin, the

Milling cylinder interior emptied. The grinding beads and the slurry are discharged through openings and pipes in the mill floor and by opening the corresponding valves. Due to its own weight, the grinding beads and the slurry leave the grinding chamber through the bottom openings. The emptying amount can be achieved through the valves regulated and supported by a rotation of the rotor. Pipelines lead the grinding beads and the slurry to a suitable conveyor system, which is attached below the mill floor. The conveyor system can be, for example, a conveyor belt, a screw conveyor, a pump or a bucket elevator. The list is not exhaustive.

The conveyor system transports the grinding beads and the sludge to the side of the ball mill 100 to a sufficient height so that they can be filled into a container or truck. This process continues until the ball mill 100 is completely emptied.

To open the stator 102 by moving one of the stator segments 112 in the form of the first grinding cylinder half, the slide rails 130 are covered and cleaned. In particular, a slide rail surface is cleaned. Then assembly supports or tilt supports 132 are mounted on both mill cylinder halves and pipe flange screw connections of the slurry feed and the slurry outlet pipe are loosened. Then the vertical and radial flange screw connections are loosened and three hydraulic cylinders are inserted per half of the grinding cylinder. Using the three hydraulic cylinders, a grinding cylinder half is raised by approx. 25 mm and three Teflon sliding blocks are attached to the grinding cylinder half and another sliding block to the assembly support. The grinding cylinder half is lowered with the three hydraulic cylinders until the Teflon sliding shoes stand on the sliding rails. Then the pull and push cylinders on both sides are connected to the provided lugs of the grinding cylinder or the sliding shoes. The mounting bracket is with your

Extend the hydraulic cylinder until the grinding cylinder half begins to rise. With the two pull and push cylinders, the grinding cylinder half is pulled to the intended maintenance position.

To dismantle the mill shaft, a shaft assembly carriage or shaft assembly carriage is moved to the installed shaft as a disengaging device 218. The shaft assembly slide is lifted upwards by approximately 25mm with four hydraulic cylinders and the shaft clamp is closed and clamped around the shaft. Then the coupling screws are loosened. The

The shaft assembly slide is lowered together with the clamped and uncoupled shaft by means of four hydraulic cylinders until the shaft assembly slide touches the slideway. With at least one hydraulic travel cylinder, the shaft assembly slide with the shaft is in a lateral position or one Lifting position at which the shaft can be lifted with the overhead crane, shifted. There a shaft holding device or an eyelet is installed on the shaft coupling. Now the shaft on the hook of the hall crane can be lifted away. The shaft can be stored in a hanging fixture or placed on a special maintenance trailer.

3 shows a spatial representation of a stator segment 112 of a vertical ball mill according to an exemplary embodiment. The stator segment 112 essentially corresponds to one of the stator segments 112 in FIGS. 1 and 2. In contrast to the illustration in FIGS. 1 and 2, the stator in the exemplary embodiment shown is composed of three stator segments 112. The wall 116 forms an arc of 120 °. The sealing flange 114 and the sealing surface 118 as well as the standing flange 120 and the standing surface 122 are provided with through-bores 121 so that they each have a correspondingly designed counterpart, that is to say a different sealing surface of another stator segment 112 or the load-bearing surface of the

Screw the base plate. The stator segment 112 shown here has a weight of approximately 30 tons. On the inside 116, nine rib segments are arranged at regular intervals one above the other.

The stop elements 124 designed as brackets project radially beyond the standing surface 122 and are connected to the wall 116 via two axially oriented stiffening ribs. Two of the stop elements 124 are arranged in the region of the lower corners of the wall 116.

4 shows a sectional view through a vertical ball mill 100 according to an exemplary embodiment. The ball mill 100 corresponds essentially to the ball mill shown in FIGS. 1 and 2. The ball mill 100 has one

Emptying device 400 for emptying the work space. The base plate 200 of the ball mill 100 has a sloping floor 402 as part of the emptying device 400. For the inclined floor 402, a surface enclosed by the load-bearing surface 201 supporting the weight of the stator segments 112 is over the surface

Surface 201 raised and obliquely aligned at an angle of approximately 2.5 ° to 30 ° with respect to the horizontal.

One of the stator segments 112 has an emptying opening 404 in the region of a low point of the inclined floor 402, that is to say where a surface of the inclined floor 402 is closest to the load-bearing surface 201. The drain port 404 is here designed as a radially aligned pipe connection flange. Is in operation

Drain opening 404 closed by a suitable fitting. The valve is opened to empty it. Here, in addition to the ball mill 100, the foundation 110 has a pit 406 in the area in front of the emptying opening 404, in which can be placed transport containers for emptying the working space in order to remove the grinding media. Through the emptying opening 404, the grinding media with adhering residues of the suspension can be gravity-driven into the transport containers arranged in the pit 406. During emptying, the rotor 204 can be driven in order to eject grinding media deposited on the disks 212 to the outside.

In one exemplary embodiment, the other stator segment 112 has at least one rinsing opening 408 in the region of a high point of the sloping floor 402, that is to say where the surface of the sloping floor 402 protrudes the most over the load-bearing surface 201. The rinsing opening 408 is also here as a radially oriented one

Pipe connection flange executed. The flush opening 408 is arranged diametrically opposite the drain opening. Through the rinsing opening 408, the emptying of the working space can be directed towards the emptying opening 404

Fluid flow are supported. The flush opening 408 is also closed during operation by a suitable fitting.

In addition to the upper radial and axial mounting in the bearing and drive device 106, the rotor 204 can also be mounted in the base plate 200 via a radial floating bearing. For this purpose, the rotor shaft has a bearing journal at the lower end, which is mounted in the floating bearing. Changes in length of the rotor 204 can by

Movements of the floating bearing can be compensated for on the journal.

5 shows a sectional illustration through a vertical ball mill 100 according to an exemplary embodiment. The ball mill 100 essentially corresponds to the ball mill in FIG. 4. In contrast, the base plate 200 at least partially covers the pit 406 here. The base plate 200 here has the at least one emptying opening 404. When the valve is opened, the contents of the work area flow through the

Drain opening 404.

In one exemplary embodiment, the base plate 200 has a plurality of emptying openings 404. The emptying openings 404 are distributed over the base plate 200 arranged. The plurality of emptying openings 404 together have an enlarged total cross-sectional area, as a result of which emptying takes place quickly.

In one exemplary embodiment, a transport system 500 for conveying the contents of the working space out of the pit 406 is arranged in the pit 406. For example, the conveyor system 500 can be designed as a conveyor belt or screw conveyor. The

Transport system 500 has a delivery height which is sufficient to transport the contents into transport containers which are parked at ground level. But also the

Transport container can be arranged under the mill, so that no conveyor is required.

6 shows a flowchart of a method 600 for maintaining a vertical ball mill according to an exemplary embodiment. Using the method 600, a ball mill, which is designed in particular for pre-grinding minerals, can be serviced. The method 600 has a step 602 of the

Separating, a step 606 of arranging and a step 610 of publishing.

The vertical ball mill has a downward-hanging rotor which is axially and radially supported at an upper end. Furthermore, the vertical ball mill has a self-supporting standing stator which radially surrounds the rotor and is not loaded by a weight of the rotor. The rotor has a lateral surface which is oriented tangentially to the rotor and, within a shape tolerance, approximates a cylindrical shape. Furthermore, the vertical ball mill has a base plate that supports a weight of the stator. The stator is composed of at least two stator segments that can be separated from one another, are self-supporting in the separated state, and can be displaced relative to one another. Each of the stator segments has at least one of one

Upper edge of a wall forming the lateral surface to a lower edge of the wall running side edge of the wall has a sealing surface for sealing on the other stator segment. Furthermore, each of the stator segments on the lower edge has a load-bearing surface dimensioned for sealing on the base plate. The stator segment rests orthogonally with the base within an angular tolerance on a load-bearing surface of the base plate.

In step 602 of the separation, the stator is separated into the stator segments, the stator being separated at the sealing surfaces. Mechanical connections between adjacent stator segments can be released for this. In step 606 of arranging, auxiliary devices are arranged under the stator segment. The auxiliary devices can be positioned and configured in such a way that the entire stator segment can be loaded on the auxiliary devices and moved with them.

In step 610 of the publishing house, the stator segment and the auxiliary devices are laterally moved using a moving device. At least one of the stator segments is shifted essentially horizontally, while the weight of the auxiliary devices preferably continues to rest on the foundation of the ball mill.

The ball mill with the stator opened in the manner described can then be easily maintained. In particular, the work area is easily accessible so that it can be cleaned and / or wearing parts can be replaced.

In one embodiment, method 600 includes a step 604 of raising and a step 608 of settling. In step 604 of lifting, at least one of the stator segments is raised using lifting devices, the stator segment being lifted off the base plate. Lifting the stator segment by a few millimeters or a few centimeters can be sufficient. The lifting can take place in particular with the aid of hydraulic lifting devices, which

Support the stop elements on the respective stator segment from below. In step 608 of setting down, the stator segment is set down on the auxiliary devices.

The standing on the base plate and thus indirectly on the foundation of the stator of the ball mill described herein thus enables the stator to be opened in a simple manner and preferably also by less trained personnel and / or in adverse conditions in order to then wait for the ball mill to be able to. Due to the configuration described above, maintenance can be carried out in a shorter period of time. Since the mill will then return to the

Productivity can be used, productivity is increased.

7 shows a spatial representation of a closed vertical ball mill 100 according to an exemplary embodiment. The ball mill 100 corresponds to

Essentially, the ball mill in FIG. 1. In addition, the ball mill 100 on the frame 108 and on the stator 102 has working platforms 700 on several levels one above the other. The work platforms 700 are secured all round by railings. The Stator segments 112 and frame 108 have work platforms 700 on two floors. The frame 108 also has work platforms 700 in two floors above. The ball mill 100 thus extends over four floors.

The work platforms 700 of a stator segment 112 are connected to one another via a conductor 702. The ladder 702 is attached to the tilt support 132 permanently installed here. The conductor 702 has a back protection cage. The tilt support 132 is on both work platforms 700 or with a support structure of the

Working platforms 700 connected and is aligned substantially parallel to the longitudinal axis of the stator 102. The tilt support 132 is spaced apart from the stator segment 112 by the work platforms 132. Due to the permanently installed tilt support 132, the stator 102 has only two stop elements 124 in the area of the sealing flanges 114. The third stop element 124 is at the lower end of the

Tilt support 132 arranged. The sealing flanges 114 are easily accessible for maintenance work over their full length via the work platforms 700 of the stator 102.

The work platforms 700 on the frame 108 are accessible via a stair tower 704. The stair tower is arranged next to the frame 108. On the third floor, the frame 108 has a maintenance cabin 706, from which protected access to the coupling between the bearing and drive device 106 and the rotor and the disengaging device is possible. The maintenance cabin 706 is encircling from

Work platforms 700 surrounded. The work platform 700 on the fourth floor is essentially arranged on a roof surface of the maintenance cabin 706 and extends around the storage and drive device 106

Drive device 106 here has a single electric motor 107.

The frame 108 is designed as a truss structure. The frame 108 on the side of the stair tower 704 is designed as a spatial framework and has six stands in two parallel rows. On the lower two floors of frame 108, work platforms 700 are arranged on the beams of the truss connecting the stands. The working platforms 700 of the stator are also accessible from the working platforms 700 of the frame 108 when the ball mill 100 is closed. On the side opposite the stair tower 704, the frame 108 is designed as a flat framework with three columns in a row.

8 shows a spatial representation of an opened vertical ball mill 100 according to an exemplary embodiment. The ball mill 100 corresponds to Essentially the ball mill in Fig. 7. The rotor is not shown here for reasons of clarity. Here the stator segments 112 are separated from one another and shown laterally displaced. In contrast to the representations in FIGS. 1 to 6, the base plate 200 is raised above a surrounding floor surface. The inclined floor 402 is designed as an inclined end face of a cylinder stump protruding beyond the load-bearing surface 201, and thus projects into the interior of the stator 102 when the ball mill 100 is closed.

The auxiliary devices 134 each have a frame 800, all three

Connects stop elements 124 of a stator segment 112 and fixes their relative positions. On the frame 800, the auxiliary devices 134 can simply be lifted, for example with the overhead crane, and moved to a storage location. After the stator segments 112 have been separated, the stator segments 112 are on the

Stop elements 124 have been raised to release them from the base plate 200. The auxiliary devices 134 with their frame 800 are between the

Stop elements 124 and the displacement device 126 have been arranged. The stator segments 112 have then been lowered onto the auxiliary devices 134. The auxiliary devices 134 have their own drive 802. Using the drive 802, the auxiliary devices 134 with the stator segments 112 mounted thereon have been moved laterally into the maintenance positions along the displacement device 126.

9 shows a spatial representation of a stator segment 112 of a vertical ball mill according to an exemplary embodiment. The stator segment 112 essentially corresponds to one of the stator segments in FIGS. 7 and 8. In contrast to the stator segments in FIGS. 1 to 5, the stator segment 112 has

Only one stiffening rib 117 on the outside. The stiffening rib 117 is arranged in a lower region of the lateral surface 104 above the axial stiffening ribs 119 of the stop elements 124.

The work platforms 700 are designed to run all around the lateral surface 104. On an inner side, that is to say on a side facing the lateral surface 104, the work platforms 700 have a semicircular arc-shaped cutout for the stator segment 112. The work platforms 700 are angular on an outside, that is to say on a side facing away from the lateral surface 104. The work platforms 700 have the railing and a coaming rim 900 along all outer edges. The coaming rim 900 stands up over a bottom surface of the work platforms 700 and prevents objects from falling.

The work platforms 700 have a cutout in the area of the sealing flange 114. The sealing flange 114 is therefore not interrupted by the work platforms 700. In the area of the cutout, the work platforms 700 are on one side of the

Stator segment 112 over a level of the sealing surface 118 or over the sealing flange 114. As a result, the sealing flange 114 is accessible from both sides and the stator segment 112 can be connected to the other stator segment (not shown here) in an ergonomic working position.

The ladder 702 is arranged on one side of the tilt support 132 and has a step through the back protection cage at the level of the two work platforms 700. The railing is interrupted in the area of the entrances.

10 shows a spatial representation of a work platform 700 of a vertical ball mill according to an exemplary embodiment. The work platform 700 corresponds essentially to one of the work platforms in FIG. 7. The work platform 700 is rectangular. The work platform 700 has two outer sides like that

Working platforms in FIG. 9 have a coaming rim 900 projecting over the floor surface and a railing. The working platform 700 has a supporting structure below the floor area. In particular, the bottom surface is stiffened by ribs. The ribs have mounting holes on two inner sides of the work platform 700 for fastening the work platform 700 to the ball mill.

At the four corners, the work platform 700 has a lifting bracket 1000 sunk into the bottom surface. Using the lifting lugs 1000, the work platform 700 can be easily and quickly assembled and disassembled with the indoor crane.

11 shows a spatial representation of a displacement device 126 of a vertical ball mill 100 according to an exemplary embodiment. The

Displacement device 126 essentially corresponds to that

8. The displacement device in FIG. 8. The displacement device 126 is placed on the rails 130. The auxiliary devices 134 are arranged between the stop elements 124 and the rails 130. The frame 800 is essentially V-shaped and connects the auxiliary devices 134 arranged on the stop elements 124 together. The two auxiliary devices 134 arranged on the stator segment 112 each have an electrical drive 802.

12 shows a detailed illustration of a standing flange 120 of a vertical ball mill 100 according to an exemplary embodiment. The standing flange 120 lies on the base plate 200. The base plate 200 corresponds to the illustration in FIG. 8. The standing flange 120 and the load-bearing surface 201 have grooves 1200 arranged in a uniform grid. The grooves 1200 in the load-bearing surface 201 are designed as T-grooves in order to receive T-groove screws (not shown here) for screwing the stator 102 to the base plate 200. In the released state, the T-slot screws can be removed laterally from the T-slots and the grooves 1200 of the stand flange 120 and thus do not represent an obstacle to the lateral displacement of the stator segments 112.

13 shows a detailed illustration of a sealing flange 114 of a vertical ball mill 100 according to an exemplary embodiment. The ball mill 100 is closed here. The sealing flanges 114 of the interconnected stator segments 112 are pressed against one another here by pivotable clamps 1300. The clamps 1300 have an essentially U-shaped base body 1302 and encompass both sealing flanges 114 from the outside. Hinges 1304, on which the clamps 1300 are pivoted horizontally, are arranged on the outside on one of the stator segments 112. The base bodies 1302 each have at least one threaded bore 1306 in which a screw spindle 1308 is rotatably mounted for pressing the sealing flanges 114 together.

In one embodiment, the sealing flanges 114 are pivotable

Jaws 1310 connected together. The jaws 1310 are pivotally mounted on the hinges 1304 horizontally. The jaws 1310 have a sloping vertical slot 1312. The slot 1312 is wider at its wider end than the two sealing flanges 114 together. At the narrower end, the slot 1312 is narrower than the sealing flanges 114. The sealing flanges 114 are inserted into the slot 1312 when the clamping jaws 1310 are pivoted. If the side surfaces of the slot 1312 abut the sealing flanges 114, the clamping jaws 1310 can be wedged onto the sealing flanges 114, for example by hammer blows. To release a jaw 1310, for example, a wedge between the

Clamping jaws 1310 and the outer surface 104 are driven in order to press the clamping jaws 1310 off the sealing flanges 114. In conclusion, it should be pointed out that terms such as "showing", "comprehensive", etc. do not exclude other elements or steps, and terms such as "one" or "on" do not exclude a large number. Reference signs in the claims are not as

View restriction.

Reference symbol list:

100 ball mill

 102 stator

 104 lateral surface

 106 Bearing and drive device

107 electric motors

 108 frame

 110 foundation

 112 stator segment

 114 sealing flange

 116 wall

 117 tangential stiffening ribs

118 sealing surface

 119 axial V ribs

120 stand flange

 121 through holes

122 footprint

 124 stop element

 126 relocation facility

128 sliding path

 130 rail

 132 tilt support

 134 auxiliary device

200 base plate

 201 load-bearing surface

202 pulling device

 204 rotor

 205 rotor shaft

 206 inside

 208 rib

 210 braking surface

 212 disc

 213 breakthroughs

 214 trailing area

215 spokes 216 clutch

 218 release device

 220 coupling device

 222 bars

400 emptying device

 402 sloping floor

 404 emptying opening

 406 pit

 408 flush opening

500 transport system

600 methods of maintaining a vertical ball mill

602 separation step

 604 step of lifting

 606 step of arranging

 608 step of weaning

 610 Step of Publishing

700 work platform

 702 leaders

 704 stair tower

 706 maintenance cabin

800 frames

 802 drive

900 coaming

1000 lifting tab

1200 groove

1300 ferrule

 1302 basic body

1304 hinge 1306 threaded hole 1308 screw spindle

1310 jaws 1312 slot

Claims

Expectations

 1. Vertical ball mill (100), in particular for pre-grinding ground material such as minerals, comprising:

 a rotor (204) which is axially and radially supported and hangs downwards at an upper end,

 a self-supporting standing stator (102) which radially surrounds the rotor (204) and is not loaded by a weight of the rotor (204) and which has a tangent to the rotor

(204) aligned, within a shape tolerance approximately

 cylindrical outer surface (104), and

 a base plate (200) supporting a weight of the stator (102),

 wherein the stator (102) consists of at least two separable, in separate

State of self-supporting, stator segments that can be displaced relative to each other

(112) is composed,

 wherein each of the stator segments (112) has at least one sealing surface (118) for sealing against the other on at least one side edge of the wall (116) running from an upper edge of a wall (116) forming the lateral surface (104) to a lower edge of the wall (116) Stator segment (112), and on the lower edge has a load-bearing surface (122) dimensioned for the purpose of sealing on the base plate (200),

 wherein the stator segment (112) with the base (122) on the base plate (200) orthogonally rests within an angular tolerance on a load-bearing surface (201) of the base plate (200).

2. ball mill (100) according to claim 1,

 in which on an inner side (206) of the walls (116) a plurality of vertically spaced, horizontal, ring segment-shaped ribs (208) are arranged, which form inwardly projecting annular braking surfaces (210) on the assembled stator, and

 in which the rotor (204) has a plurality of vertically spaced, horizontal disks (212), each with an outer annular drag surface (214),

wherein the ribs (208) and the discs (212) are arranged alternately in the vertical direction and the braking surfaces (210) and the drag surfaces (214) overlap at least partially in the horizontal direction.

3. ball mill (100) according to any one of the preceding claims,

 in which the stator segments (112) each have stop elements (124) on an outer side for lifting and moving the respective stator segment (112).

4. ball mill (100) according to claim 3,

 in which the stator segments (112) each have stop elements (124) in the region of the lower edge of the wall (116), which are configured in particular for attaching hydraulic jacks.

5. ball mill according to one of claims 3 to 4,

 in which the stop elements (124) define corner points of a virtual horizontal polygon, in particular a triangle, the geometric center of which lies on a vertical axis through a center of gravity of the standing stator segment (112).

6. ball mill (100) according to any one of claims 3 to 5,

 with a displacement device (126) for laterally displacing the stator segments (112) which are separated from one another,

 The displacement device (126) has mobile auxiliary devices (134) which are designed to be arranged when the stator segment (112) is raised between the stop elements (124) and parallel rails (130) arranged on the floor and when the stator segment (112) 112) with the stator segment (112) to be moved along the rails (130).

7. ball mill (100) according to claim 6,

 wherein the displacement device (126) has at least one tilt support (132) for supporting a stop element (124) vertically spaced from the standing surface (122) on at least one of the rails (130) in order to tilt the stator segment (112) during lifting and displacement ) to prevent.

8. Ball mill (100) according to one of claims 6 to 7, in which the rails (130) are embedded in a foundation (110) of the ball mill (100) and, optionally, can be covered by covering devices when not in use.

9. ball mill (100) according to any one of the preceding claims, with a

Emptying device (400) for emptying the ball mill (100).

10. Ball mill (100) according to claim 9, wherein the emptying device (400) within the load-bearing surface (201) of the base plate (200)

 Inclined bottom (402), one of the stator segments (112) in the region of a low point of the inclined bottom (402) having an emptying opening (404)

 Has emptying device (400).

11. Ball mill (100) according to claim 10, wherein one of the stator segments (112) in the region of a high point of the sloping floor (402) has a flushing opening (408) of the emptying device (400).

12. ball mill (100) according to any one of the preceding claims,

 with a frame (108) separate from the stator (102),

 supports of the frame (108) laterally spaced apart from the stator (102) are supported on a foundation (110) of the ball mill (100) and at least one

 Cross member of the frame (108) connects the supports above the stator (102) to one another, a bearing and drive device (106) of the rotor (204) being supported on the cross member.

13. ball mill (100) according to any one of the preceding claims,

 with a disengaging device (218) for laterally disengaging the rotor (204) that can be decoupled from an overhead clutch (216)

 wherein the disengaging device (218) has at least one rail (130) and a coupling device (220), the coupling device (220) being designed to be connected to the rotor (204) in the region of the coupling (216), to the rotor (204) to be lowered onto the rail (130) and to be moved with the rotor (204) along the rail (130).

14. Ball mill (100) according to claim 12 and 13, wherein the frame (108) in the region of the coupling (216) has a maintenance cabin (706).

15. Self-supporting stator segment (112) for a vertical ball mill (100) according to one of claims 1 to 14, comprising:

 a wall (116) in the form of a cylindrical segment within a shape tolerance,

at least one sealing surface arranged on a side edge of the wall (116) running from an upper edge of the wall (116) to a lower edge of the wall (116) (118) for sealing on another stator segment (112), and

 a load-bearing surface (122) which is arranged on the lower edge and can be set up orthogonally within an angular tolerance on a load-bearing surface (201) of a base plate (200) of the ball mill (100),

 wherein a self-supporting stator (102) can be assembled from a plurality of stator segments (112) with a lateral surface (104) formed by the walls (116) and approximately cylindrical within a shape tolerance, which in an assembled state on the base plate (200) for supporting one Weight of the stator (102) can stand upright.

16. Method (600) for maintaining a vertical ball mill (100), in particular for pre-grinding ground material such as minerals,

 wherein the vertical ball mill (100) has a rotor (204) which is axially and radially supported and hangs downwards at an upper end, and a self-supporting standing stator (102) which radially surrounds the rotor (204) and is not loaded by a weight of the rotor (204) with a tangential to the rotor (204) aligned, within a shape tolerance approximately cylindrical surface (104), and a base plate (200) supporting a weight of the stator (102), the stator (102) consisting of at least two separable, in separate State of self-supporting, stator segments (112) which can be displaced relative to one another,

 wherein each of the stator segments (112) has a sealing surface (118) on at least one side edge of the wall (116) extending from an upper edge of a wall (116) forming the lateral surface (104) to a lower edge of the wall (116)

 Sealing on the other stator segment (112), and on the lower edge a load-bearing area (122) that is dimensioned for the load

 Has base plate (200),

 wherein the stator segment (112) rests orthogonally with the base (122) on the base plate (200) within an angular tolerance on a load-bearing surface (201) of the base plate (200),

 the method (600) comprising:

 separating (602) the stator (102) into the stator segments (112), the stator (102) being separated at the sealing surfaces (118),

arranging (606) auxiliary devices (134) under at least one of the stator segments (112), and lateral displacement (610) of the stator segment (112) and the auxiliary devices (134) using a displacement device (126).

17. The method (600) according to claim 16, wherein the stator segment (112) under

 Use of lifting devices is lifted off the base plate (200) and placed on the auxiliary devices (134) using the lifting devices.