Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B02—CRUSHING, PULVERISING, OR DISINTEGRATING; PREPARATORY TREATMENT OF GRAIN FOR MILLING
  • B02C—CRUSHING, PULVERISING, OR DISINTEGRATING IN GENERAL; MILLING GRAIN
  • B02C17/00—Disintegrating by tumbling mills, i.e. mills having a container charged with the material to be disintegrated with or without special disintegrating members such as pebbles or balls
  • B02C17/18—Details
  • B02C17/22—Lining for containers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
  • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
  • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
  • B66F9/00—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes
  • B66F9/06—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks
  • B66F9/061—Devices for lifting or lowering bulky or heavy goods for loading or unloading purposes movable, with their loads, on wheels or the like, e.g. fork-lift trucks characterised by having a lifting jib

Definitions

• Grinding mills are used, for example, for splitting stone material and mineral sub- stances from larger material blocks to pieces of a smaller size.
• Mining industry is a typical example of an industrial sector carrying out the grinding of stone material.
• a grinding mill can be cylindrical, i.e. drum-like, the axle of which is normally horizontal, and in current applications, the drum diameter can typically be approximately 1 m ... 15m.
• Stone material is fed to the forward end of the grinding mill through a feed hopper. After this the stone blocks hit each other and the walls of the drum as the drum rotates, which causes the stone material to reduce to a smaller size.
• the grinding speed depends on the hardness of the material to be grounded, the rotation speed of the mill and the possible additive, which can be liquid added to the mill. Grinding can also be intensified by adding metal balls into the mill.
• grate plates At the discharge end of the output side of the ground stone material there are so-called grate plates, which can be provided with openings of a desired size so that stone pieces bigger than the opening cannot leave the drum.
• the particular end structure of the drum can then be constructed to operate with the same principle than a mechanical filter, and the structure can be used for selecting the maxi- mum size of the output material, i.e. the maximum diameter of the stone material to be of a desired type.
• the inner surface of the drum-type mill is exposed to hard mechanical stress and wear due to the hardness of the stone material and rotational movement of the material.
• the inner surface of the drum is coated with lining elements, hoists and shell plates, the material of which is steel or rubber, or a steel and rubber compound of a desired type.
• the hoists are attached to the drum circumference with bolts and the shell plates attach between the hoists.
• the mass of one hoist or shell plate element can be from a few tens of kilograms to as much as a couple of tons, so special devices and support structures have to be used in their detachment, installation and fastening. Because these lining elements wear out as the mill is in use, it must be possible to replace them with new ones.
• the replacement work of lining elements typically requires a separate service break, because the mill has to be stopped for the duration of service.
• the most critical work in the service break of mines generally entails the replacement of the grinding mill lin- ings. For cost reasons, it is desired to keep the length of the service break as short as possible; each service work hour may cause a loss of even tens of thousands of euros, calculated on the basis of interrupted production. Because of this there is a distinct need to produce an efficient method and apparatus for replacing the lining elements of mills.
• Publication AU 2004201 105 discloses a treatment apparatus for inner lining elements of a drum-type grinding mill, which comprises a horizontal support structure or platform, to which there is installed a conveyor belt or transporter, with which lining elements can be transported in and out of the mill.
• the transporter can also be a simple carriage-like structure placed on wheels. Close to the one end of the transporter there is located a crane, with which an individual part can be lowered and lifted in place from the transporter to the inner wall of the mill.
• the crane can include a boom structure, which is rotatable in relation to the support structure.
• the boom can be telescopic and hydraulically controlled.
• the apparatus may further contain a second crane, which is located at the opposite end of the transporter. The task of the second crane is to lift the lining elements from the transporter outside the mill and, respectively, new parts from outside the mill to the transporter.
• the second crane is otherwise similar to the first crane.
• Patent specification US 3,802, 150 describes a device for the treatment of inner surface elements of a mill, in which a "track" or slots are placed into the mill, onto which a carriage can be placed to travel.
• the track travels on the boom, which is supported from its ends.
• a treatment arm is installed to the carriage, with which the removal and installation of the lining plates of the upper half of the mill can be conducted by means of a catch tool at the end of the arm.
• the mill is then rotated half a cycle after this, it is possible to remove the lining elements of the second half of the mill and install new ones in the same way as above.
• Transporting the lining elements in and transferring them out through the opening at the end of the mill has been carried out by a conveyor-type transporter, which is partly pushed in at the second end edge of the mill.
• FIG. 1 a and 1 b A typical state-of-the-art release and installation method of elements has been based on the use of a fixed boom-type abutment. This situation is illustrated in Figures 1 a and 1 b.
• the mill 10 Upon the beginning of a service break, the mill 10 has been run as empty as possible, and a boom 1 1 is brought in through the opening at the input end of the mill, which is attached from its opposite end to the wall of the output end of the mill with a suitable fastening 12. From its input end the boom 1 1 can be supported directly to the ground using a vertical boom 13.
• a hoist 14 is placed in the boom 1 1 , with which a lining element 15 can be lifted into the air or lowered to the ground at a desired place or to the bottom of the mill 10 by using, for example, a cable wire, chain or some other respective means as the fastening element, which bears an element weighing several hundreds of kilograms.
• the hoist 14 is movable in the longitudinal direction of the mill so that the lifted lining element 15 can be transferred out from the mill 10, and respectively a new element 15 can then be moved into the mill 10.
• FIG. 1 b there is again illustrated a cross-sectional view seen from the end of the mill.
• the boom 1 1 and the hoist 14 attached to it are visible slightly above the midpoint of the mill.
• a lining element 15 is suspended at the end of the cable wire. It is characteristic for the shown state-of-the-art solution that only one lining element 15 at a time can be moved in the method according to the principle in question. This restricts very strongly the speed of the service work.
• An additional drawback is that with this installation arrangement it is only possible to treat one installation place at a time directly on the bottom of the mill. The method requires that the mill be rotated slightly between element installations, because the hoist can only be moved in the longitudinal direction of the mill.
• the time required for the replacement work of the grinding mill linings is approximately 120h using the boom solution of this known technology. Taking the boom solution into use takes about 8 hours and the removal of the boom from the mill about 6 hours. Thus the downtime becomes relatively long.
• the present invention discloses an apparatus for replacing the lining elements of the inner surface of a grinding mill, in which the apparatus comprises a first transporter arrangement for delivering the lining elements from the outside of the grinding mill into the grinding mill and vice versa, the transporter arrangement compris- ing at least one first hoist.
• the apparatus is characterized in that it further com- prises a carriage, which is movable inside the grinding mill by manual movement and which is possible to place below the first hoist, at least one installation arrangement, which comprises at least one second hoist so that a lining element on top of or on the carriage can be taken to be processed by the said hoist; in addi- tion, the operation of the first transporter arrangement in the apparatus has been arranged to be separate and independent in relation to the operation of the installation arrangement.
• the first transporter arrangement has been arranged to place or drop a new lining element to or on the car- riage.
• At least one electric winch has been attached to the first transporter arrangement, the fastening wire of the winch being connectable to an old lining element.
• At least one installation ar- rangement has been placed on wheels and it is movable on the bottom surface of the mill in its longitudinal direction.
• the apparatus comprises at least one additional carriage inside the mill, which works parallel with the carriage as the transporter of lining elements on top of the inner surface of the mill.
• the same inventive idea of the present invention includes the respective method for replacing the inner surface of the lining elements of the grinding mill. In the method the lining element is first detached from the inner surface of the mill.
• the lining element is pulled under the first transporter arrangement inside the mill by using an electric winch;
• the new lining element is moved on the carriage in the horizontal direction close to the installation place of the lining element; and - the new lining element is attached to the second hoist of the installation arrangement for delivering the lining element to the desired installation place beneath the installation arrangement.
• the installation arrangement is lifted into the air from the bottom surface of the mill, when all new lining elements of the section below the installation arrangement have been installed in place;
• a second lifting beam and at least one carriage are installed in place to the mill;
• a first hoist is used in the mill close to the first transporter arrangement as a lifting element for lifting the new lin- ing elements to their installation place.
• Figure 1 a illustrates a fixed boom solution used in the known technology in the replacement of the inner lining elements of the grinding mill
• Figure 1 b illustrates the situation of Figure 1 a as a cross-sectional view seen from the end of the mill
• Figure 2a illustrates an example of an apparatus of the invention in the dismantling work of inner lining elements used in the mill
• Figure 2b illustrates the dismantling situation of Figure 2a as a cross-sectional view seen from the end of the mill
• Figure 3a illustrates an example of an apparatus of the invention in the installation work of new inner lining elements of the mill
• Figure 3b illustrates the situation according to Figure 3a of the installation of elements and the apparatus as a cross-sectional view seen from the end of the mill
• Figure 3c illustrates another type of structure for the second lifting beam, which can be used in installation work inside the mill. Detailed description of the invention
• the present invention presents, for example, a new type of a method for replacing the inner lining elements of a grinding mill used in the grinding of ore and an apparatus applicable to be used in the said method.
• the transport of elements between the interior and exterior of the mill is an independent process of its own in relation to the detachment and installation work conducted inside the mill. This makes the replacement of elements to new ones considerably faster and shortens the length of the needed service break.
• an appropriate time has to be chosen for the service break of the mill.
• a time period when the interruption in the operation of the mill causes as little harm and costs as possible.
• the service downtime can be chosen, for example, to a period when the requirements for the production of ore are at their smallest.
• the dismantling method of elements of the invention is described first, and in this connection reference is made to Figure 2a.
• the mill 20 is depicted from the side so that the output end for the stone substance material of the mill is on the left. At the right edge there is the dismantling end, i.e. the output end for the ground mate- rial, but the structural details of this have not been illustrated more closely in the Figure.
• the feed hopper of the input end is removed and a lifting beam 21 is installed in place manually from outside of the mill or by using a forklift or some other similar auxiliary instrument in accordance with the Figure so that its one end extends somewhat inside the mill 20.
• the lifting beam 21 can be installed to the ground on support beams 22, and the material and thickness of the support beams are chosen so that a structure bearing the carrying and moving of elements weigh- ing hundreds of kilograms is achieved.
• a hoist 23 with a transfer car is attached to the lifting beam 21 , which can be installed on a rail (not shown) travelling in the lower edge of the lifting beam or a profile beam can be used as lifting beam, to the lower edge of which the transfer car can be installed.
• the hoist 23 gets its driving force from a motor, and the hoist includes a cable wire, chain or some other re- spective suspension element, to which the lining element 24 can be attached.
• the lifting beam there are more than one parallel hoists 23 in use.
• One option is to use two parallel hoists 23, which make the transfer of the lifting elements even faster than before.
• At least one electric winch 25 is additionally attached to the lifting beam structure, which acts as a separate actuator and tools in relation to the hoist 23.
• the power source for the electric winch 25 is a motor, and power is transmitted by a winch wire, which in this example has been installed above the lifting beam 21 , travelling through two guide rollers 26.
• the one end of the winch wire is guided to the interior of the mill, and in the example in the Figure it has been led as far as the second end of the mill.
• At the end of the wire there may still be a separate hook or catch structure 25k so that the end of the wire can be properly attached to the lining element. In this case the wire element naturally has to have a loop or a similar ele- ment, to which the hook can be fastened.
• the dismantling of the elements is carried out in the following manner.
• the worn lining elements 24 are detached from the inner wall of the mill using a desired state-of-the-art method.
• a support structure of a desired type can be used in the work, and any lifting device and tools can be used in the detachment of the element itself from the mill wall.
• the final result is a used lining element detached from the wall, which can be lowered to the bottom of the mill in the horizontal place, in which was attached.
• Figure 2b shows the same mill as in Figure 2a seen from the direction of the right- hand end side.
• the old element which is about to be de- tached, has first been bolted fast to the place 24'.
• the element When the element is disconnected from the mill wall, it can be moved to the place 24", in which it can be at- tached to the hook 25k of the electric winch wire. Another option is to attach the wire of the electric winch already at the place 24'; this arrangement is depicted by the winch wire shown with broken lines.
• the used lining element attached to the winch wire of the electric winch 25 is pulled by the electric winch from right to left in view of Figure 2a under the right end of the lifting beam 21 .
• the pulling force of the electric winch 25 achieves the moving of the element from the position 24' or 24" to the position 24"'.
• an actuator i.e. hoist 23 separate in relation to the winch can be taken into use.
• the element 24 is attached to the hoist, which then lifts the used element at least from the plane of the output hatch slightly upwards so that the element can be transferred through the opening in the horizontal direction. After this the hoist moves the element 24 in the horizontal direction on a rail, and the element 24 can be lowered to the place 24a on the planar surface 27 after the horizontal movement.
• the electric winch 25 can already begin to pull the next element 24 under the lifting beam 21 at the same time as the previous element 24 is still being lifted and moved out from the mill 20 with the hoist 23.
• new lining elements 24u for the mill are delivered to the proximity of the end side of the mill 20 to the planar surface 27, one or several at a time.
• a second lifting beam 31 is installed inside the mill 20.
• the said lifting beam 31 is shown in cross-sectional view, seen from the end of the mill in Figure 3b.
• the second lifting beam 31 can be assembled with bolt couplings, and the duration of this installation in a mill embodiment is only approximately 15 minutes.
• the carriage 30 transport- ing the lining elements.
• the carriage is a simple planar surface travelling on wheels or in slots, with or without edges, and bearing the weight of an individual lining element.
• the carriage 30 can be freely moved or pulled on the inner surface in the lower part of the mill.
• a new lining element 24u is transferred from the planar surface 27 to the hoist 23 on the lifting beam 21 , and the lining element 24u is lifted at least to the extent that, when moved in the lateral direction, the element fits in through the inlet of the grinding mill 20.
• the hoist 23 and element 24u have been moved to the proximity of the right end of the lifting beam 21 by means of a motor and on a rail, i.e.
• the element 24u is lowered down, and in this embodiment it is made onto the carriage 30.
• the hoist 23 is free to fetch the next new lining element from the planar surface 27, and separately from this process, the carriage 30 is movable on the inner bottom of the mill.
• the new element 24u can be transferred on the carriage 30 to the proximity of its horizontal installation place on the inner bottom surface of the mill (place marked on the right-hand side of the carriage in Figure 3a).
• Figure 3b illus- trates the cross-section of the mill seen from the end of the mill 20, the second lifting beam 31 and one or several hoists 23 attached to it being located in the middle.
• the second lifting beam has the support structures in accordance with the figure, and the entity is placed on tires or wheels 33.
• the second hoist 32 can take the new lining element 24u to be handled by it, and at the same time the carriage 30 becomes free to fetch a new element from the side of the mill's left edge referring to the situation in Figure 3a.
• the second lifting beam and the second hoist in Figure 3b form a structure travelling on wheels. Because of this the carriage can be moved to the desired installa- tion place of the element in the direction of the longitudinal axis of the mill, and after the place has been chosen, the wheels of the hoist structure 31 , 32 can be locked in place. In one place of the hoist structure the hoist 32 is able to handle an area of several meters wide on the bottom of the mill, i.e. it is possible to install all elements of the area beneath the lifting structure in place one or several elements at a time.
• the other areas of the mill circumference can be made to be handled beneath the hoist structure so that the hoist structure is first lifted slightly upwards from the bottom of the mill, for example, by the lifting handles or openings in the lifting beam, and after this the grinding mill can be rotated slightly so that the places bare of the elements can be moved under the hoist structure. After this the hoist structure can be lowered back to the bottom of the mill, and the installation work of the lining elements can start.
• the carriage can move as desired as the transporter and fetcher of the elements, and on the other hand, the transporter ar- rangement at the inlet of the mill can simultaneously work with its own process.
• the carriage 30 can be movable on wheels or it can be made to travel, for example, on double groove or rails temporarily installed onto the bottom of the mill's interior.
• the carriage itself can be, for example, a simple planar surface on two axles, wheels being attached to the axle ends.
• the carriage can be provided with low edge plates to prevent the element from falling.
• the planar surface of the carriage and the wheels and their fastening points have to bear a load of several hundreds of kilos, and when needed, of over a ton, provided that plates this big have to be moved.
• the lining element 24, 24u is typically in shape of a rectangular prism, and possibly slightly rounded at its edges.
• the lining elements are bolted through the mill wall with heavy bolts, and attached in this way to the surface of the inner circumference of the mill before the mill has initially been started.
• the used and worn lining elements can be detached from the interior of the mill, they have to be detached from the inner surface of the mill with some kind of a tool.
• a suitable tool such as a nut runner or some other tool can be used for this purpose depending on the manner, what kind of bolting has been chosen for the fastening.
• the hoist 23 is used for possibly lowering and installing a new element in place at the end of the mill's inlet end, other elements can simultaneously be transported and installed on the area of the rest of the mill's bottom surface by using the carriage 30 and the second hoist 32.
• the previously described electric winch 25 can be used in the installation work of new lining elements 24u taking place in the proximity of the inlet of the grinding mill.
• the guide rollers for the electric winch wire can be installed to the lifting beam so that at the place of the lifting beam end the electric winch 25 can be used as an extra hoist and lowering part of the elements. This is useful in the installation of lining elements in the proximity of the mill's input end (inlet end).
• the apparatus of the invention may also include separate guide rollers 26 to be fastened to the inner surface of the grinding mill, around which the wire of the electric winch 25 can be arranged to travel.
• Separate guide rollers can be attached, for example, to the cylindrical wall section or dismantling end of the grinding mill, as has been shown with broken lines in Figure 3a.
• the pulling wire extending through the guide roller attached to the dismantling end can be used for transferring lining elements 24u to be removed from and installed in the dismantling end.
• a third installation beam can be used in addition to the second lifting beam used for the installation (according to Figure 3b, parts 31 and 32); the third beam can be similar to that in Figure 3b or it can be of a structurally different type, which can be placed, for example, slightly to the side of the centre line of the mill, seen from the cross- section of the mill.
• Such an alternative lifting beam structure is illustrated next in Figure 3c.
• Figure 3c illustrates a second option for the structure of the second lifting beam 31 .
• This structure is, unlike the symmetrical structure of Figure 3b, unsymmetrical and it can thus be placed farther to the side from the centre line of the mill, when the situation is being examined from the end of the mill.
• the lifting beam 31 is provided with four support arms, the two shorter ones of which are placed close to the left edge of the lifting beam, and the two longer ones are again placed to support the right edge of the lifting beam.
• Tires or wheels 33 are placed at the junction of the support arms. The right tire will be located close to the centre line of the mill.
• the lifting beam extends only a little to the right side of this line so that the mass centre of the lifting beam remains on the left side of the centre line and thus the structure stays stable.
• a second hoist 32 is movable in the lifting beam, to which a new lining element 24u to be installed can further be attached.
• the lifting beam structure according to Figure 3c makes possible the installation of elements on a wider area at one time, because the element can be lowered considerably more to the side seen from the centre line of the mill. In this way the lifting beam needs to be lifted and the mill to be rotated more infrequently for completing the installation of elements of the entire mill.
• the lifting beam structure of the type in Figure 3c allows a bigger stone load 50 inside the grinding mill.
• the installation work using the lifting beam in question occurs in the more vertical section of the mill wall with the consequence that the new element to be installed falls better into contact with the previously installed element below, due to gravity. This way the lifting beam structure of Figure 3c makes the installation easier.
• any transporter can be more generally used, onto or on which the transportable lining element can be placed.
• the element can thus be suspended, for example, on a hook onto such a structure, which is on wheels or tires, or which is otherwise easily movable in the horizontal direction.
• a general advantage of the present invention is a considerably faster process in the replacement of lining elements.
• the length of the required service break is shortened considerably in relation to the state of the art.
• the work time saved in the installation of the lifting beam 21 is as much as approximately 7 hours.
• the dismantling work is fast, because there are two different lifting devices in use at the same time.
• the installation work there are two hoists in use, and further a carriage, which also makes the installation work considerably faster. If several carriages 30 are used in parallel, the moving of elements becomes even faster.
• the second lifting beam 31 and hoist 32 of the installation unit make possible the installation to the entire area below the beam at one time, and because of this the mill need not be rotated so often during the installation.
• the removal of both lifting beams is done considerably faster than in the state of the art; the saved work time in a mill example is approximately 5 hours.

Landscapes

• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Structural Engineering (AREA)
• Food Science & Technology (AREA)
• Civil Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Mechanical Engineering (AREA)
• Crushing And Grinding (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=54288582

Family Applications (1)

Country Status (3)

Cited By (3)

Citations (5)

• 2014
  • 2014-08-29 FI FI20145750A patent/FI126135B/fi active IP Right Grant
• 2015
  • 2015-08-26 FI FIU20154154U patent/FI11002U1/fi active IP Right Grant
  • 2015-08-28 SE SE1750266A patent/SE541844C2/en unknown
  • 2015-08-28 WO PCT/FI2015/050555 patent/WO2016030579A1/en active Application Filing

Patent Citations (5)

Also Published As

Similar Documents

Legal Events