EP2985087B1

EP2985087B1 - Treatment of curved surfaces

Info

Publication number: EP2985087B1
Application number: EP15180493.7A
Authority: EP
Inventors: Janne Karjalahti
Original assignee: Pb Tank Service Oy
Current assignee: Elffi Oy
Priority date: 2014-08-12
Filing date: 2015-08-11
Publication date: 2017-11-29
Anticipated expiration: 2035-08-11
Also published as: FI20145712A; ES2661264T8; ES2661264T3; FI126028B; NO2985087T3; DK2985087T3; EP2985087A1

Description

FIELD OF THE INVENTION

The invention relates generally to treatment of curved surfaces. More particularly, the invention relates to treatment of curved interior surfaces of large containers.

BACKGROUND

Typically high interior walls are cleaned by first building multi-layer structures against the wall for people to climb up the structure and wash the walls with a pressure washer, for example. However, this type of cleaning, or other type of treatment, is not efficient. Therefore, more reliable, secure and time- and cost-efficient solution is needed.
Some known arrangements are disclosed in documents US4417542 , which discloses an arrangement for treatment of horizontally curved interior walls of a container in accordance with the preamble of claim 1 and a corresponding method, and WO2010/140952 .

BRIEF DESCRIPTION OF THE INVENTION

The invention is defined by the independent claims.
Some embodiments of the invention are defined in the dependent claims.

LIST OF THE DRAWINGS

In the following, the invention will be described in greater detail with reference to the embodiments and the accompanying drawings, in which

Figure 1 presents an arrangement inside a container, according to an embodiment;
Figure 2 shows supports of a circular horizontal frame, according to some embodiments;
Figure 3 shows lifting a vertical frame to upright position, according to the invention;
Figures 4A, 4B, and 4C illustrate examples of attachment units, according to some embodiments;
Figure 5 depicts an example mounting unit, according to an embodiment;
Figures 6A, 6B, and 6C depict some features of a coupling unit, according to some embodiments; and
Figure 7 illustrates a method, according to an embodiment;
Figures 8A and 8B show treatment of curved outer surfaces, according to some embodiments.

DESCRIPTION OF EMBODIMENTS

The following embodiments are exemplary. Although the specification may refer to "an", "one", or "some" embodiment(s) in several locations of the text, this does not necessarily mean that each reference is made to the same embodiment(s), or that a particular feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.
Although the surfaces to be treated may of any kind and belong to any structure, let us consider in the following a scenario where interior walls of a large cylindrical container with a radius of e.g. 20 meters and a height of e.g. 25 meters needs to be cleaned. The container may be also called a tank, a silo or a reservoir, for example. In practise the volumes of the containers may vary from several hundred cubic meters to thousands cubic meters, and the height may vary from several meters to tens of meters. The material that may have been stored in the container may vary. The stored material may be oil, tar, tall oil, gasoline, to mention only a few non-limiting examples.
Even after being emptied, some stored material may have stuck on the walls of the tank and these walls may need to be cleaned or otherwise treated before the condition of the surfaces of the tank may be examined or before new material may be brought in. Such treatment of the surface may include cleaning (such as water pressure washing), blasting (such as sand blasting, abrasive blasting, pressurized cold air blasting), painting, coating, marking, etc. However, treating such high walls in the prior art means is dangerous, cumbersome and needs improvement.
Therefore, there is proposed an arrangement, as shown in Figure 1, for treatment of horizontally curved interior walls 102 of a container 100. The container 100 may have an annular shape or an elliptic shape. Basically any shape which comprises curved walls 102 in horizontal plane is feasible. The container 100 may be a cylindrical container or a conical container, for example. As said, the container 100 is large, typically at least ten meters in perimeter and in height.
The arrangement may comprise a circular horizontal frame 110 which follows the perimeter of the container walls 102 horizontally and is supported by at least a fixed surface. The circular horizontal frame 110 may also be called a track as it may form a closed track along which a vertical frame 112 travels inside the container 100, as will be described. As shown, in an embodiment, the circular horizontal frame 110 has a smaller perimeter than the perimeter of the container wall 102. The circular horizontal frame 110 is open or closed, that is, the track 110 need not be a complete circle but it may be open. It may be enough, depending on the shape of the perimeter of the container walls 102, that the track 110 is curved. That is, it need not necessarily be a circle, but an ellipse form may be sufficient as well. However, in an embodiment, the track 110 forms a closed circular rim.
In an embodiment, the fixed surface is ground. However, in one embodiment, the fixed surface is the floor 104 of the container 100.
In an embodiment, the track 110 is mounted directly on the floor 104 of the container 100. However, in another embodiment, as shown in Figure 2 which depicts a bottom corner 101 of the container 100, the track 110 is supported by a plurality of length-wise adjustable floor supports 200 adapted to support the circular horizontal frame 110 against the bottom surface, such as the floor 104. Thus, the track 110 is raised above the bottom surface. This may be beneficial as many containers may comprise additional structures close to the bottom surface, such as heating pipes 108 of Figure 2. Gravity forces the track 110 towards the bottom surface. The length of the floor supports 200 may be adjusted by applying a screw-bolt structure, for example, as shown in Figure 2 with reference numeral 200'. Any other types of adjustment means known to a skilled person are similarly feasible. An example height of the track 110 is between 90 and 120 centimetres.
As a further support, the arrangement may comprise a plurality of length-wise adjustable wall supports 202 adapted to support the circular horizontal frame 110 against the interior walls 102 of the container 100. It may be noted that as the track 110 makes a circle, the opposite sides of the perimeter of the track 110 push each wall support 202 towards the container interior wall 102. Thus, these wall supports further steadily fix the position of the track 110 inside the container 100.
These wall supports 202 may similarly be length-wise adjustable via the adjustment means 202' of Figure 2, such as a screw-bolt structure. It may be important to adjust the lengths of the wall supports 202 in order to steadily fix the track 110 against the walls 102 throughout the perimeter of the container walls 102. Moreover, the perimeter of the interior walls 102 may have small irregularities, for example. By adjusting the length, these irregularities may be compensated for.
In an embodiment, there may be diagonal support 204 connecting the supports 200 and 20. The diagonal support 204 may further hold the supports and stabilize and fix the position of the track 110 inside the container 100.
The supports 200, 202, and 204 may be of aluminium, steel, wood, or plastic, for example. The density of the supports along the track 110 may vary. Such supports 200, 202, 204 may be according to an interval of about one meter, for example. The material of the track 110 may similarly be aluminium, steel, wood, or plastic, for example. The track 110 may comprise several parts forming the complete track 110. The parts may be of couple of meters in length. Cross-sectional shape of the track 110 may rectangular or round, for example.
In this manner, the circular track 110 is provided inside the container 100 to follow the perimeter of the interior walls 102. Let us then look further at Figure 1. The arrangement may further comprise the vertical frame 112 following the container wall 102 vertically and configured to be movably coupled at its lower part to the circular horizontal frame 110. The vertical frame 112 may be of any length. An example length varies from a few meters to tens of meters. The material of the vertical frame 112 may similarly be aluminium, steel, wood, or plastic, for example, or any other sufficiently robust and steady material. The vertical frame 112 may comprise several modules/parts forming the complete vertical frame 112.
The arrangement further comprises a mounting unit 114 movably attached to the vertical frame 112. The mounting unit 114 may be for mounting at least one machine tool for treating the interior wall 102 of the container 100. The machine tool may be a tool designed for cleaning (such as water pressure washing), blasting (such as sand blasting, abrasive blasting, pressurized cold air blasting), painting, coating, marking, etc. The machine tool may be mounted to the mounting unit 114 with screws or with any other type of attachment, such as quick clamps. Both, the circular horizontal frame 110 and the vertical frame 112, may be spaced apart from the container walls 102 so as to make room for the mounting unit 114.
In this manner the arrangement shown in Figure 1 is obtained. The arrangement may then enable treatment of substantially the entire of the curved walls 102 of the container 100 with the same setting of the arrangement. This is because the mounting unit 114 is controllably moved vertically along the vertical frame 112, as shown in Figure 1 with vertical dotted arrows. Moreover, the vertical frame 112 may be controllably moved horizontally along the circular horizontal frame 110, as shown in Figure 1 with curved dotted arrows. By moving the vertical frame 112 horizontally along the track 110 and by moving the mounting unit 114 vertically along the vertical frame 112, practically each location of the walls 102 may be treated, as shown with dotted replicas of the vertical frame in different position of the track 110.
The movement along the track 110 and the movement along the vertical frame 112 may be accomplished by use of manpower or by a use of hydraulic or electric step motors controllably running the movement processes, for example. The moving elements (e.g. the mounting unit 114 and the vertical frame 112) may be equipped with wheels or slides, for example, for allowing easy movement.
In accordance with the invention, with reference to Figure 3, the vertical frame 112 comprises a hinge 300 at the lower part for pivoting the vertical frame around a horizontal axis. As shown, such hinge may be beneficial when lifting the vertical frame 114 to a correct upright position to follow the contours of the vertical wall 102. Rotation about the hinge 300 does not take as much effort as lifting a complete vertical stand 112 on the track 110. In this manner, the vertical frame 112 may be compiled on the ground level horizontally, and then rotated about the hinge 300 to the correct position. The height of the vertical frame 112 may be adapted according to the height of the interior space of the container 100 so that, when lifted to the upright position, the vertical frame 112 reaches almost to the ceiling 106 of the container 100. A typical height may run from a few meters to tens of meters.
Figure 3 further shows at least one attachment unit 302 for movably attaching the vertical frame 112 to the container wall 102. That is, when lifted to the upright position, the attachment unit 302 becomes attached to the wall 102. It may be noted than once the machine tool, such as pressure water injection is executed, the vertical frame 112 may start tilting away from the wall 102 about the hinge 300 if there was no attachment unit 300 holding the frame 112 within a pre-set distance from the wall 102. The distance may be set with an arm 303 of the attachment unit 302.
In an embodiment, the attachment unit 300 may be for supporting the upper part of the vertical frame 112 against the wall 102. In an embodiment, the lower part of the vertical frame 112 is kept within the pre-set distance from the wall via the track 110 and the wall supports 202 of the track 110, because the vertical frame 112 is coupled at its lower part to the track 110. However, in an embodiment, the wall supports 202 are not necessarily needed for this purpose. In such case, there may be another attachment unit 304 (similar as the attachment unit 302, for example) for holding the lower part of the vertical frame 112 in the pre-set distance from the wall 102.
The attachment 302/304 is shown with more details throughout Figures 4A-4C. Figure 4A shows an embodiment of the attachment unit 302 comprising at least one magnet 400. The magnet may be a permanent magnet or electronically controllable magnet. The magnet 400 may exert magnetic forces to attach to the wall 102, which is typically of steel or other material to which magnets may be attracted to. For moving the vertical frame 112 horizontally along the wall 102, the magnetic forces may be released (in case of electrically controllable magnet). Then, once the new position is reached, the magnet may be activated and the treatment process of the wall 102 continued.
However, in one embodiment, the movability of the attachment unit 302/304 along the wall 102 is accomplished as shown in Figure 4B. That is, the attachment unit 302/304 may comprise a plurality of magnetic elements 402A, ..., 402N (e.g. each similar than the magnet 400) surrounding at least one rotating wheel 404A, 404B. Such structure may enable the vertical frame 112 to move horizontally along the container wall 102 by the rotation of the magnets 402A, ..., 402N around the at least one roll 404A, 404B. In an embodiment, the magnets 402A, ...402N may be glued or otherwise attached to a belt which is disposed to rotate around a closed loop formed by the at least two wheels 404A, 404B. In another embodiment, there is only one wheel 404A which has magnets 402A, ..., 402N on its outer surface. The magnetics may grip tightly against the wall 102, but still detach relatively easily when the rotating wheel 404A,404B rotates and pulls the magnets 402A, ... 402N off the wall 102 one-by-one. Simultaneously, the rotating wheel/ roll 404A, 404B brings a new magnet, one-by-one, against the wall 102.
In one embodiment, the at least one wheel 404A, 404B is inclined with respect the horizontal line 406 so as to force the at least one wheel 404A, 404B to move slightly upwards from the horizontal line 406. This is shown in Figure 4C where the magnets 402A, ..., 402C travel on the wall 102 slightly upwards but still substantially horizontally. As said, this slight upwards movement may be accomplished by inclining the wheels 404A, 404B by an angle 408 with respect the horizontal line 406. The angle 408 may be e.g. 0.5 degrees, 1 degree, 1.5 degrees, or 2 degrees, to mention only a few non-limiting examples. This may be beneficial because then the movement of the attachment unit 302/304 lifts the vertical frame 112 periodically upwards and thus easies the weight of the vertical frame 112 on the track 110 on which the lower part of the vertical frame 112 is mounted on. It may be noted thought that the slight upward movement of the attachment unit 302/304 does not lift the vertical frame 112 off the track 110. After each slight periodical upward movement, the attachment unit 302/304 drops back to the original height.
However in another embodiment, the wheels 404A, 404B are directed along the horizontal line 406 to allow steady movement of the vertical frame 112 along the track 110.
Other types of attachment units 302/304 are possible as well instead or in addition to the magnetic type of attachment units. These other types may comprise electronically controllable suction pads, for example.
In an embodiment, the mounting unit 114 is attached on one side of the vertical frame 112. However, in another embodiment, the mounting unit 114 surrounds the vertical frame 112. This is shown in Figure 5 in which the mounting unit 114 is disposed around the vertical frame 112. The mounting unit 114 surrounding the vertical frame 112 may be beneficial to ensure that the mounting unit 114 is firmly and a steadily connected to the vertical frame 112.
In an embodiment, the mounting unit 114 may comprise at least one wheel 502 for enabling the vertical movement of the mounting unit 114 along the vertical frame 112. The wheels 502 may be driven by a step engine, for example. In another embodiment, the mounting unit 114 may be slid along the vertical frame 112. Thus, wheels 502 are not necessary.
In an embodiment, the mounting unit 114 may comprise a carrying element 504 for attaching the mounting unit 114 to a rope, strap or a belt. The rope/belt may be used to raise or lower the mounting unit 114 with human effort or with a step engine coupled to the rope/belt.
In an embodiment, the vertical frame 112 is hollow. The hollow interior of the vertical frame 112 may be used to transport and protect cables, water hoses or any other equipment needed by the machine tool 506.
In one embodiment, as shown in Figures 6A-6C, the vertical frame 112 further comprises a coupling unit 600 for coupling the lower part of the vertical frame 112 to the circular horizontal frame 110. The coupling unit 600 may be such that it positions the vertical frame 112 closer to the wall 102 of the container 100 than the circular horizontal frame 110. As shown in Figure 6A, the distance between the wall 102 and the vertical frame 112 is smaller than the distance between the track 110 and the wall 102. This may be beneficial as then the vertical frame 112 naturally tends to tilt/fall towards the wall 102, and not towards the middle part of the container 100. This balances the vertical frame 112 for the treatment of the wall 102.
In an embodiment, the coupling unit 600 is coupled to the circular horizontal frame 110 in at least three coupling locations 610A, 610B, 610C, as shown in Figure 6B, thereby forming at least a triangular support for the vertical frame 112 on the track 110. Triangular support may be strong support and balances the weight optimally on the coupling unit 600.
In an embodiment, the coupling unit 600 comprises an L-element 601 attached at one of its ends to the lower end of the vertical frame 112. The other end of the L-element may be attached to one arm of a T-element 602. The T-element 602 may be the one that is then movably coupled to the circular horizontal frame 110 by the at least three coupling points 610A-610C. These coupling points 610A-610C may located at each arm of the T-element 602, for example. By having an L-element (or similar structure, such as a standing right-angled triangle) and the T-element (or other element having multiple arms, such as an X-element), two different triangular supports are generated, as shown in Figures 6A and 6B. One triangular support is generated in the horizontal plane and one in the vertical plane. These provide for a strong and steady support of the vertical frame 112 on the track 110.
As said, the T-element may be replaced with another element with multiple arms, wherein at least one of the arms is connected to the lower part of the vertical frame 112, and at least three of the arms are movably coupled to the track 110. The connection centre of the multi-arm element may extend to inside the perimeter of the track 110. That is, the connection centre of the multi-arm element may be further from the wall 102 than the track 110. This may ensure good weight balance for the vertical frame 112 on the track 110 because the vertical frame 112 itself is on one side of the track 110 whereas part of the coupling unit 600 is on the other side of the track 110. Further, by having several coupling locations 610A-610C, the weight is evenly distributed to many locations on the track 110.
It may be further noted that, in an embodiment, one coupling point 610B is the point closest to the track 110 from the lower end of the vertical frame 112. This also contributes to weight balance of the vertical frame 112 on the track 110.
In one embodiment, the vertical frame 112 is coupled to the track 110 in only one point to provide simplicity of the coupling.
In an embodiment, the circular horizontal frame 110 is a rectangular pipe along which the coupling unit travels. In an embodiment, as shown in Figure 6C, the coupling unit 600 further comprises moving units 604 via which the coupling unit 600 is coupled to the track 110 in the at least three coupling points 610A-610C. These moving units 604 may each comprise wheels 606 for enabling the horizontal movement of the coupling unit 600 along the circular horizontal frame 110. In an embodiment, there are wheels 606 on both sides of the track 110, as shown in Figure 6C. In an embodiment, there is one wheel on the inner side surface of the track 110 and two wheels on the outer side surface of the track 110. There may further be wheels on the top surface of the track 110, although not shown in Figure 6C. The wheels 606 may be adapted to be pushed against the track's 110 side surfaces and in that way hold the moving unit 604 firmly on the track 110. Such pushing force may be provided with springs, for example.
The movement of the coupling unit 600 on the track 110 may require human effort (manual pushing/pulling along the track 110) or the coupling unit 600 may be moved controllably along the track110 with a step motor, for example. The step motor may e.g. push/pull the coupling unit 600 on the track 110 or control the rotation of at least one of the wheels 604, for example.
Figure 7 shows a method of compiling an arrangement for treating curved interior walls 102 of the container 100. The method may be performed inside the container 100. The needed material may be brought in through the entry/exit door of the container 100, which typically is rather small, such as a hole having a diameter of less than a meter.
The method comprises, in step 700, building, inside the container 100, the circular horizontal frame 110 following the perimeter of the container interior walls 102 horizontally. The circular frame 110 may have a diameter of many meters. In one embodiment, a plurality of direct pipes (i.e. parts) is used for building the track 110. The direct pipes may be one-by-one attached together and forced to the required curved shape to eventually form the circular, or other substantially circular, shape. The bending of the direct pipes may take place, e.g., by attaching one end of the pipe to the already-built part of the track 110 (or to at least one floor/wall support 200, 202) and forcing the pipe to the required curved shape. The forcing may be accomplished by inserting a strap inside the hollow direct pipe and pulling the strap to reshape (i.e. bend) the pipe. For example in this manner the track 110 may be built inside a container of any diameter.
There may be floor supports 200 between the bottom surface and the track 110 to lift the track 110 from the bottom surface. This may ensure that the circular horizontal frame 110 is supported by at least the bottom surface, such as the floor 104.
In one embodiment, the method comprises providing wall supports 202 to the circular horizontal frame 110 so as to support the circular horizontal frame 110 against the walls 102 of the container 100, as shown in Figure 2. The wall supports 202 on opposite sides of the perimeter of the circular horizontal frame 110 push each wall support 202 towards the container interior walls 102.
In step 702, the vertical frame 112 is built, wherein the vertical frame 112 comprises the hinge 300 at its lower part. The building may take place on the floor level, e.g. substantially horizontally inside the container 100. Compiling on the floor level may be easier than compiling in the vertical position. The required height of the vertical frame 112 may be first measured. The vertical frame 112 may comprise a plurality of modules attached to each other to increase the height of the vertical frame 112 until the desired height.
Then, in step 704, the movable mounting unit 114 may be attached to the vertical frame 114. Similarly, any required one or more machine tools may be attached to the mounting unit 114, as well as any needed cables, hoses, etc.
In step 706, the lower part of the vertical frame 112 may be movably coupled to the circular horizontal frame 110. The coupling may take place even before the step 702 by coupling the lowest module of the vertical frame 112 to the track 110. The lowest module may comprise the hinge 300 so that all the other modules may be connected to together on the floor level.
The coupling may take place via the coupling unit 600 to ensure that the vertical frame 112 is closer to the wall 102 of the container 100 than the circular horizontal frame 110 in order to ensure correct weight balance of the vertical frame 112 with respect to the track 110 once rotated to the upright position.
Finally, in step 708, the vertical frame 112 may be rotated, about the hinge 300, to the upright position, so as to follow the container interior walls 102 vertically. The rotation may be performed with a motor or via manpower. This setting of the arrangement may be used to treat the entire surface of the interior walls 102 of the container 100 because the vertical frame 112 may enable vertical movement of the mounting unit 114 along the vertical frame 112, and the circular horizontal frame 110 enables horizontal movement of the vertical frame 112 along the circular horizontal frame 110, as explained above.
The method may further comprise attaching at least one attachment unit 302/304 to the vertical frame 112 so that the attachment unit 302/304 becomes attached to the container interior wall 102 once the vertical frame 112 is rotated to the upright position. This may ensure that the vertical frame 112 stays in the upright position during the wall treatment.
As described above, the arrangement may be used for treatment of horizontally curved interior walls 102 of a container, such as a cylindrical container. However, in another embodiment, the arrangement may be used for the treatment of any walls, including outdoor walls having horizontally curved shape, such as the outer surface of the container 100. For this, as shown in Figure 8A, the track 110 may be built on the outer surface of the container's ceiling 106. Typically the ceiling 106 may comprise a safety roof rail which may be used for this purpose. The safety roof rail may be supported by the roof serving as the fixed surface. The coupling element 600 may be turned upside down and the vertical frame 112 may hang from the coupling unit 600 downwards. In a similar fashion, the track 110 may be built the ground 800 (as the fixed surface), as shown in Figure 8B. In this case, the track 110 follows the outer perimeter of the container walls and the vertical frame 112 moves along the track 110 horizontally to work on the outer surface of the container walls.
It should be noted that the container 100 need not be equipped with any permanent elements for the setting of the arrangement. Instead all the elements needed for the setting of the arrangement and for the wall treatment process are brought in when the arrangement is to be built and are taken out of the container 100 after the treatment process is completed.
It should be noted that the container 100 is otherwise closed but typically has the entry/exit door and possible a few relatively small check holes. The entry/exit door may be for bringing the required elements in and out of the container 100. The required electric cables, water hoses, or any other equipment needed by the working of the machine tool may pass through the entry/exit door and/or through the check holes.
In an embodiment, there may be an apparatus comprising a control circuitry (CTRL), such as at least one processor, and at least one memory including a computer program code (PROG), wherein the at least one memory and the computer program code (PROG), are configured, with the at least one processor, to cause the machine tool to be moved as required by the user and to execute the machine tool as required. The apparatus may thus be used to control the movements of the mounting unit 114 along the vertical frame 112 and the movements of the vertical frame 112 along the track 110. The apparatus may be part of the arrangement.
The apparatus may also comprise a user interface comprising, for example, at least one keypad, a microphone, a touch display, a display, a speaker, etc. The user interface may be used to control the machine tool by the user.
The apparatus may further comprise communication interface (TRX) comprising hardware and/or software for realizing communication connectivity according to one or more communication protocols. The TRX may provide the apparatus with communication capabilities to access the radio access network, for example.
In an embodiment, at least one camera, such as a normal camera, infrared camera, an X-ray camera, and/or a video camera, is mounted on the mounting unit 114 for capturing images or recording video of the walls 102 of the container 100. This image/video footage may be transmitted to an external entity for remote checking of the container 100 or for remote control of the machine tool. As one example, in case the remote controller detects damage on the wall 102, the remote controller, or the automatics of the machine tool, may spray a mark on the wall 102, so that the repair worker finds the spot easily. The spray machine may be one of the machine tools mounted to the mounting unit 114, in addition to the camera. In one embodiment, there is a welding machine as one machine tool on the mounting unit 114 and the damage may be readily repaired by welding the damaged part via remote instructions. The word "remote" may denote a control from the ground level, control from the outside the container, or control from a distant location. Control commands
(e.g. for executing the machine tool 506, for moving the mounting unit 114, for moving the vertical frame 112) may be transmitted from the control apparatus to the arrangement via wired interface or wirelessly.
Even though the invention has been described above with reference to an example according to the accompanying drawings, it is clear that the invention is not restricted thereto but can be modified in several ways within the scope of the appended claims. Therefore, all words and expressions should be interpreted broadly and they are intended to illustrate, not to restrict, the embodiment. It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. Further, it is clear to a person skilled in the art that the described embodiments may, but are not required to, be combined with other embodiments in various ways.

Claims

An arrangement for treatment of horizontally curved interior walls (102) of a container (100), comprising:
a circular horizontal frame (110) configured for following the perimeter of the walls (102) of the container (100) horizontally and configured to be supported by at least a fixed surface;

a vertical frame (112) configured for following the wall (102) of the container (100) vertically and configured to be movably coupled at its lower part to the circular horizontal frame (110); and

a mounting unit (114) configured to be movably attached to the vertical frame (112) and to mount at least one machine tool for treating the wall (102) of the container (100),

wherein the mounting unit (114) is configured to move vertically along the vertical frame (112), and the vertical frame (112) is configured to move horizontally along the circular horizontal frame (110), characterised in that the vertical frame (112) comprises a hinge (300) at the lower part for pivoting the vertical frame (112) around a horizontal axis.
The arrangement of claim 1, further comprising:
a plurality of length-wise adjustable wall supports (200) adapted to support the circular horizontal frame (110) further against the walls (102) of the container (100).
The arrangement of any of claims 1 to 2, wherein the vertical frame (112) further comprises at least one attachment unit (302, 304) for movably attaching the vertical frame (112) to the wall (102) of the container (100).
The arrangement of claim 3, wherein the attachment unit (302, 304) comprises a plurality of magnetic elements surrounding at least one rotating wheel (404A, 404B) for allowing the vertical frame (112) to move horizontally along the walls (102) of the container (100).
The arrangement of claim 4, wherein the at least one wheel (404A, 404B) is inclined with respect the horizontal line (406) so as to force the at least one wheel (404A, 404B) to move slightly upwards from the horizontal line (406).
The arrangement of any of claims 1 to 5, wherein the vertical frame (112) further comprises a coupling unit (600) for coupling the lower part of the vertical frame (112) to the circular horizontal frame (110), wherein the coupling unit (600) is configured to position the vertical frame (112) closer to the wall (102) of the container (100) than the circular horizontal frame (110).
The arrangement of claim 6, wherein the coupling unit (600) is coupled to the circular horizontal frame (110) in at least three points, thereby forming at least a triangular support for the vertical frame (112) on the circular horizontal frame (110).
A method of compiling of an arrangement for treating horizontally curved interior walls (102) of a container (100), the method comprising:
building, inside the container (100), a circular horizontal frame (110) following the perimeter of the interior walls (102) of the container (100) horizontally, wherein the circular horizontal frame (110) is supported by at least a bottom surface;

building a vertical frame (112) comprising a hinge (300) at its lower part for pivoting the vertical frame (112) about a horizontal axis;

attaching a movable mounting unit (114) to the vertical frame (112) for mounting at least one machine tool;

movably coupling a lower part of the vertical frame (112) to the circular horizontal frame (110); and

rotating, about the hinge (300), the vertical frame (112) to an upright position so as to follow the interior wall (102) of the container (100) vertically, wherein the mounting unit (114) is configured to move vertically along the vertical frame (112), and the vertical frame (112) is configured to move horizontally along the circular horizontal frame (110).