ES2591207T3 - Access system for cantilever or convex curvature walls - Google Patents

Abstract

Access system for cantilever or convex curvature walls, especially of tower-shaped buildings, such as cooling towers with - an upper carriage (18) that can be placed scrollable on the upper edge of the wall ( K), - a work platform (11) suspended from the upper carriages (18) by means of displacement or guide cables (12, 13), - a drive assigned to the displacement cables (12) to move the platform of work (11) vertically through the displacement cables (12) and - a boom (19) with two fixed arms (21) that are fixed on the work platform (11) distanced from each other and so that they rotate around of a common axis, fixing the arms (21) by means of support cables (25) in the upper carriage (18) and being able to rotate the assigned drive systems (24) through the support cables (25) with respect to the platform working (11), characterized by the arms they support the ballast weights (20), because the ballast weights (20) are fixed on the arms (21) in a longitudinally movable way, because actuation elements are provided to move the ballast weights (20) to along the arms (21) and why the support cables (25) are fixed on the ballast weights (20).

Description

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

DESCRIPTION

Access system for cantilever or convex curvature walls

The present invention relates to an access system for cantilever walls or convex curvature, especially of tower-shaped buildings such as cooling towers with

- an upper carriage that can be placed scrollable on the upper edge of the wall,

- a work platform suspended from the upper carriages by means of travel or crane cables,

- a drive assigned to the travel cables to move the work platform vertically through the travel cables and

- a boom with two fixed arms that are fixed on the work platform distanced from each other and so that they rotate around a common axis, which respectively support a ballast weight, fixing the arms by means of support cables in the upper carriage and being able to rot rotate the assigned drive systems through the support cables with respect to the work platform. The invention also relates to a pen for an access system of this type.

Different models of the access systems described above are known which are used in practice, for example, for the performance of repair and sanitation work in cooling towers of power plants and, especially, in fossil energy plants. These cooling towers are needed in eclectic plants to cool the generated water vapor and bring it back to the cooling circuit. In fossil power plants, cooling towers also serve (to serve) to expel previously purified smoke gases, that is, desulfurized and denitrified, into the environment. The outside concrete part of the cooling tower has to absorb these aggressive media without being damaged. Due to the constant request for smoke gases and / or water vapor, the exterior of concrete is exposed to some wear, so maintenance and coating work is necessary.

To perform these maintenance and repair work on the surfaces of the interior and exterior walls, generic access systems are used. These generally consist of one or several exterior and interior access systems. The two access systems have an upper carriage that rests on the upper edge of the cooling tower and travels along the edge. In the upper cars, a working platform is suspended by means of several travel and safety cables through which the vertical position can also be adjusted with the help of the corresponding drives. Means are also provided for pressing the work platform against the respective wall of the building, this being the aspect in which the exterior and interior access systems are fundamentally differentiated.

When it comes, for example, to work on the convex curvature wall of a cooling tower, the work platform of the interior access system is secured with tension cables in a lower carriage that travels along rails on the ground of the cooling tower.

The work platform of the external access system is grafted at a defined distance from the wall of the cooling tower. Specifically, the work platform rests on the wall through rolling elements in the form of rolling wheels. In order to guarantee the necessary tightening pressure, especially in the case of cantilever walls or convex curvature, a boom is placed on the work platform that protrudes from the work platform in the direction away from the wall and in the area of its free end it presents ballast weights. Generally the pen has two arms fixed respectively by one of its extreme areas on both sides of the work platform, from which they protrude in parallel, joining the free ends of the two arms between them by means of a basic support creating a pen U-shaped. The free end of the boom joins through two support cables, fixed in the area of the free ends of the arms, to the upper carriage. In addition, lathes are provided to shorten the length of the support cables and turn the boom upwards or, conversely, to increase the length of the traction cables and lower the arm. In the horizontal position of the boom the greatest pressures of pressure are exerted on the work platform. When the work platform rises, however, the horizontal forces exerted by the support cables on the upper carriage in case of horizontal orientation of the arm are excessively large. The same can be said of the forces acting on the support cables.

For this reason the boom is turned down extending the support cables through the winches when the work platform is near the upper edge of the wall. However, this descent can also cause problems, given that in the case of a boom turned too down, statically unfavorable situations can occur that result in the work platform separating too much from the wall of the cooling tower or tipping over.

Also considered negative is the fact that the winches, through which the support cables are fixed at the free ends of the boom, are not easily accessible for maintenance work.

From US-2,881,029 A another access system is known. This comprises a work platform in the form of a seat on which the boom arms are mounted. The arm has a ballast weights at its end.

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

This weight can be transferred. For this purpose the arm is made as a telescopic arm whose elements can be inserted or removed. This document also reveals all the features of the preamble of claims 1 and 9.

Therefore, the present invention poses the task of designing an access system as well as a pen for an access system of the type initially described, so that at least the risk of statically unfavorable geometries of the cables is reduced and, by consequently, a overturn of the work platform.

In an access system of the type initially described, this task is solved by guiding the movement of the ballast weights of the arms in the longitudinal direction and along the arms, providing drive elements to move the ballast weights along the arms. and fixing the support cables in the ballast weights. The pen according to the invention is characterized in that the ballast weights are held mobile in the arms in the longitudinal direction of the same, because actuation elements are provided to move the ballast weights along the arms and by that in the ballast weights fasteners are provided for mounting support cables.

Therefore, the invention is based on the consideration of arranging the ballast weights in a movable way in the arms, so that it is possible to change its position and, thus, the point of application of forces of the support cables acting on Ballast weights. For example, if the arm is lowered sharply, ballast weights can approach the work platform along the arm. Thus the angle between the support cable and the vertical cable is reduced, thereby reducing the horizontal forces that are introduced into the upper carriage. At the same time, the torque introduced through the ballast weight and the rotating arm on the work platform is reduced, since the ballast weights have a smaller distance from the work platform. As a consequence, statically unfavorable situations and the overturning of the work platform can be safely avoided.

According to a variant embodiment of the invention, it is anticipated that ballast weights can be displaced or shifted together. Thus it is achieved that the ballast weights are located respectively at the same distance from the work platform and that the forces applied to the support cables and, therefore, to the upper carriage as well as to the work platform, are uniform. However, when other loads occur, for example due to wind, it is also possible that the ballast weights move independently of each other to compensate for the external loads.

The drive elements for ballast weights can be configured, for example, in the form of toothed belt drives and conveniently controlled from the work platform.

As is known, the arms can also be joined by their free ends away from the work platform to form a fundamentally U-shaped pen that has great stability.

According to a preferred embodiment variant of the invention, it is provided that the ballast weights are held respectively in a frame that surrounds the corresponding arm or that forms this frame and that the frame can move in the arm in its longitudinal direction. With the formation of the frame a very compact and robust set is created. It is also possible to support the frame from all sides on the arm. In particular, the frame can be guided respectively by opposite sides on the arm, so that the cranes only have to absorb the pressure forces. This creates the possibility of supporting the frame easily and through rollers in the arm. This allows to reduce to the minimum in guiding work and avoid a blockage in the area of the cranes.

According to another variant embodiment of the invention, it is envisaged that in the ballast weights a drive device, especially in the form of a friction pulley lathe, is arranged respectively, and that the support cables are fixed through the devices of drive on the arms and actuate to rotate the arms. The drive devices for the support cables are provided, in a known manner, directly on the arm. Since they are positioned in the ballast weight and move along with it, it is possible to bring them closer to the platform for maintenance purposes, so that maintenance work can be carried out from the work platform.

Finally, it can be conveniently provided that the arms can rotate with respect to the platform by at least 120 °, especially at least 140 ° and preferably at least 160 °. This configuration offers the possibility of rotating the arms between an upper turning position and a lower turning position in which they practically adopt a vertical position, however separating slightly inclined from the wall to be treated.

In relation to other advantageous embodiments of the invention, the subclaims are indicated as well as the following description of an embodiment example and with reference to the attached drawing. In the drawing you see in the

Figure 1 a schematic representation of a cooling tower with an interior access system and an exterior access system according to the present invention;

Figure 1a the bottom end part of the interior access system of Figure 1;

Figure 2 the upper car of the interior access system with the work platform of Figure 1 in an enlarged representation;

Figure 3 a section of Figure 1a in an enlarged representation;

5

10

fifteen

twenty

25

30

35

40

Four. Five

fifty

55

Figure 4 the external access system according to the present invention of Figure 1 in an enlarged representation;

Figure 5 a cross-sectional view of an arm of the external access system with a frame movably guided thereon;

Figure 6 in a schematic representation of the operation of the external access system according to the invention;

Figures 7 to 9 different operating positions of the external access system according to the present invention and

Figure 10 in a schematic representation of an external access system in an unstable state.

A cooling tower K with an interior access system 2 and an external access system 3 according to the present invention is schematically represented in Figure 1. The interior access system 2 comprises an upper carriage 4 movably attached to the upper edge, that is, in the crown of the cooling tower K. The upper carriage 4 specifically has a basic support 5 extending from the face exterior of the cooling tower K towards the inner face and which rests on the upper face of the cooling tower through several sets of rolling rollers 6, moving along it. From the basic support 5, a support 7 goes downwards in which several sets of crane rollers 8 are held, which are supported horizontally on the lateral surfaces of an FK crane channel provided on the upper face of the cooling tower.

In the final area of the basic support 5 protruding from the edge of the cooling tower K outwards, a weight 9 is set that serves as a counterweight to the components suspended inside the upper carriage 4 of the interior access system 2. By the inner end of the basic support 4 a support construction 10 is provided that projects downwards in which a work platform 11 is suspended through travel and safety cables 12, 13, through which a vertical position of the work platform 11 by means of a cable winch not shown in the drawing.

The work platform 11 is supported by several rolling rollers 14 on the inner wall of the cooling tower K. On the other hand, the work platform 11 is secured by means of a tensioning cable 15 to the lower carriage 16 which is moves along the floor of the cooling tower K along rails 17.

The external access system 3 has an upper carriage 18 configured in the same way as the upper carriage 4 of the internal access system. The only difference is that the work platform 11 is fixed at the end protruding from the edge of the cooling tower K out of the basic support 5, whereby the counterweight 9 is suspended by the opposite inner end of the basic support 5 .

Also in this case the work platform 11 is suspended by means of displacement cables and wire 12, 13 in the upper carriage 18 and travels through a drive not shown in detail by means of these cables 12, 13 in the direction vertical. On the work platform 11, rolling rollers 14 are provided through which the work platform 11 is supported on the outer wall of convex curvature of the cooling tower K. The rolling rollers 14 are configured to allow a displacement in both vertical and horizontal directions. For this, the rolling rollers 14 can be configured as rotating. Alternatively, it is possible to provide two sets of rolling rollers 14 assigned to the direction of vertical movement or to the direction of horizontal movement, the non-active roller assembly 14 being able to be separated respectively.

On the work platform 11 a boom 19 is fixed with the possibility of turning in a vertical plane that protrudes from the work platform 11 in the direction that moves away from the cooling tower K and that holds ballast weights 20. The boom 19 it has two arms 21 respectively rotatably fixed at its free end on the two sides of the work platform 11, projecting parallel therefrom and joining the free ends of the two arms 24 between them by means of a basic support not shown in the drawing to form a U-shaped pen 19. In the embodiment variant shown, the two arms 21 rotate together with the work platform 11 in a mere 180 °, so that in the upper and lower end positions they respectively adopt almost the vertical position in which they can be easily removed from the wall to be treated.

In accordance with the invention the ballast weights 20 can be moved in the direction of the double arrow A of Figure 4 along the arms 21. For this purpose the ballast weights 20 are respectively held in a frame 22 surrounding the respective arm 21, as can be seen perfectly in figure 5, and which is supported and grooved thereon in a movable way. The frame 22 has, like the arm 21, a rectangular cross-section and is supported on each of the four outer sides of the arms 21 by means of grinding rollers 23. Thus the grinding rollers 23 only have to absorb pressure forces. Drives are also provided by means of which the frames 22 move.

Each frame 22 also has a cable winch 24 on its upper face, also a friction pulley winch, through which a support cable 25 connected by its free end to the upper carriage 18 can be wound or unwound, in order to rotate the boom 19 relative to the work platform 11 in a vertical plane.

During normal operation, the boom 19 is positioned more or less in a horizontal position and the frames 22 move with the ballast weights 20 to the end of the arms 21, so that through the ballast weights 20 they are applied pressure forces on work platform 11 (see figures 6 and 9). However, when the work platform 11 is lifted, as also shown in Figure 6, the forces

horizontal, which in case of horizontal orientation of the boom 19 are transmitted by the support cables 25 to the upper carriage 18, are too large. For this reason the boom 19 is turned down when the work platform 11 is near the upper edge of the cooling tower K, for which the support cables 25 are extended through the cable winches 24. However , this descent can also cause problems, given that in the case of a boom 19 turned too downward, statically unfavorable situations can occur that result in the work platform 11 being too far apart from the wall of the cooling tower or overturning , as indicated in figure 10. For this reason the ballast weights 20 approach in the position turned downwards, through the frames 22, to the work platform 11. A comparison between figures 7 and 8 shows thus reducing the angle a between the support cable 25 and the vertical one, whereby the horizontal forces acting on the upper carriage 18 are reduced. The distance between the point of attack of the weights is also reduced. of ballast 20 in the arms 21 and the work platform with the consequence that the turning torque acting on the work platform 14 decreases, this absorbing the turning torque as it separates from the cooling tower K.

fifteen

Claims (14)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 1. Access system for cantilevered or convex curvature walls, especially of tower-shaped buildings, such as cooling towers with - an upper carriage (18) that can be placed scrollable on the upper edge of the wall (K), - a work platform (11) suspended from the upper carriages (18) by means of displacement or GMA cables (12, 13), - a drive assigned to the travel cables (12) to move the work platform (11) vertically through the travel cables (12) and - a boom (19) with two fixed arms (21) that are fixed on the work platform (11) spaced apart from each other and so that they rotate around a common axis, fixing the arms (21) by means of support cables (25 ) in the upper carriage (18) and being able to rotate the drive systems (24) assigned through the support cables (25) with respect to the work platform (11), characterized in that the arms support the ballast weights ( 20), because the ballast weights (20) are fixed on the arms (21) in a movable direction in the longitudinal direction, because drive elements are provided to move the ballast weights (20) along the arms ( 21) and why the support cables (25) are fixed on the ballast weights (20). 2. Access system according to claim 1, characterized in that the ballast weights (20) move or can be moved together. 3. Access system according to claim 1 or 2, characterized in that the drive elements for the ballast weights (20) are configured in the form of toothed belt drives. 4. Access system according to any of the preceding claims, characterized in that the actuating elements for ballast weights (20) can be controlled from the work platform (11). 5. Access system according to any of the preceding claims, characterized in that the two arms (21) are joined together by their free end areas away from the work platform (11). 6. Access system according to any of the preceding claims, characterized in that the two arms (21) are arranged parallel. 7. Access system according to any of the preceding claims, characterized in that the ballast weights (20) are respectively fixed on a frame (22) that surrounds the corresponding arm (21) or is formed, the frame (22) being able to move in the arm (21) in its longitudinal direction. 8. Access system according to any of the preceding claims, characterized in that in the ballast weights (20) a drive device (24), especially in the form of a friction pulley lathe, is provided respectively, and in that the cables of support (25) are fixed on the arms (21) through the drive devices (24) and actuated to rotate the arms (21). 9. Pen for tightening a work platform suspended against a wall, especially against a cantilever or convex curvature wall, for an access system according to any of the preceding claims, with two arms (21) that are arranged spaced apart between sf and rotatably around a common axis in a work platform (11), characterized in that the arms have ballast weights (20) that are mobilely grooved in the arms (21) in their longitudinal direction, because they are prevented drive elements to move the ballast weights along the arms (21) and why in the ballast weights (20) fixing elements (24) are provided for the placement of the support cables (25). 10. Pen according to claim 9, characterized in that the two arms (21) are joined together by their free ends away from the fixing elements. 11. Pen according to claim 9 6 10, characterized in that the two arms (21) are arranged parallel. 12. Pen according to one of claims 9 to 11, characterized in that the ballast weights (20) are respectively fixed on a frame (22) that surrounds the corresponding arm (21) or is formed, the frame (22) being able to move in the arm (21) in its longitudinal direction. 13. Pen according to one of claims 9 to 12, characterized in that in the ballast weights (20) a drive device (24), especially in the form of a friction pulley lathe, is provided, being able to fix and operate the cables of support (25) in the arms (21) through the drive devices (24). 14. Pen according to any of the preceding claims, characterized in that the arms (21) can be rotated with respect to the work platform (11) by at least 120 °, especially at least 140 ° and preferably at least 160 °.