GB2461538A

GB2461538A - Adjustable lifting frame

Info

Publication number: GB2461538A
Application number: GB0812072A
Authority: GB
Inventors: Stefan Roman
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-07-02
Filing date: 2008-07-02
Publication date: 2010-01-06
Anticipated expiration: 2028-07-02
Also published as: GB0812072D0; GB2461538B

Abstract

A lifting frame comprises load attachment means 13, 14, 15 such that each load lifting point 16, 17, 18 can be independently adjusted, and the vertical axis passing through the centre of the frame's apex can be displaced relative to the centre of gravity of the load, figure 2. Each load attachment means 13, 14, 15 are connected to each other and a top-lifting eyelet 4 by a series of struts 8, 9, 10 and diagonal ties 1, 2, 3, and comprise a lifting plate 13, 14, 15 and shackle pin block 16, 17, 18 that can be manually adjusted to minimise tilt during lifting an unbalanced load. The shackle pin block may be displaced horizontally within the lifting plate and its position controlled by steel restraining packs or shims (5, figure 3).

Description

A Lifting Frame

I. Description

The invention relates to a bespoke modular Lifting Frame and its method of operation. The frame is able to lift and lower vertically positioned loads such as cylindrical vessels. In particular, the frame may be used for lifting and lowering redundant cut sections of boilers in a decommissioning Power Plant, where access is restricted or there is a danger of collision with adjacent plant. This invention has specifically established the design parameters and the optimal kinematics arrangement for the lifting frame, to overcome the irregularity of applied loads and the eccentricity of the Centre of Gravity relative to a vertical axis of symmetry, in order to minimise the load's horizontal tilt.

The example was based on a boiler vessel that would be required to be cut horizontally in several cylindrical sections, each weighting up to one hundred and twenty tonnes, before being removed for disposal.

Statement of Invention

To compensate for the eccentricity of a vertical axis passing through the Centre of Gravity (COG) of a cylindrical vessel, relative to a vertical axis passing through the centre of the frame's apex, and to minimise tilt, the present invention proposes a three lifting points Lifting Frame that is manually adjustable at each Lifting Plate. In particular, the frame may lift cylindrical vessels, such as boiler cut-sections, in a perfectly horizontal plane, or with no more than fifty millimetres vertical tilt, to include the frame's displacement under load. The design was based on an eccentricity of COG ranging from zero to two hundred and fifty millimetres.

The frame configuration already provides in its design for an initial COG eccentricity of fifty millimetres. This means that the frame would now be required to be adjusted only for the remaining fifty to two hundred and fifty millimetres eccentricity. The initial fifty millimetres COG offset, built into design, caused an asymmetrical arrangement for the Shaped Lugs at the apex and, consequently, dictated slightly different dimensions for the rest of the components.

Advantages 1. The load is lifted in a horizontal plane or with no more than fifty millimetres tilt.

2. The design minimises the risk of unbalanced loads, thus minimises the consequent risk of load collision with adjacent plant during the load lifting, lowering or traversing operations.

3. The frame was designed for fatigue and buckling type of failures.

4. The frame's operation can be used in conjunction with existing or customized computer software, in order to determine the vessel's mass, Centre of Gravity offset, drilling locations for shackle pins, amount of tilt, and to find out the manual adjustments required at each Lifting Plate.

5. The frame is of modular build, allowing for manual piecemeal erection or for hoisting into position fully assembled. Conversely, the frame can be easily dismantled, to allow for lifting or lowering through the limited inter-space areas and to allow its compact storage.

6. The assembly and dismantling operations can be done with relative ease, with no special tools, by no more than three operators, working for no more than three hours.

7. The frame has hard wearing major components, built to last a minimum of 5 years before requiring replacement. Design life 10 years, with minimum maintenance required.

8. The frame can be used in various environmental conditions: temperature range of minus 150 C to plus 40° C, humidity up to 90%. Frame has no adverse effect from dirt and dust.

9. Design prevents frame from overturning.

ExampLe

A non-limiting example of the present invention will now be described by way of example and with reference to the accompanying drawings in which aLl dimensions are in millimetres and in which Figure 1 -illustrates an Isometric view of the Lifting Frame, where the components have been numbered as follows: 1 Diagonal Ties 1 (Dl) 2 Diagonal Ties 2 (D2) 3 Diagonal Ties 3 (D3) 4 Top Lifting Eyelet Connecting Plate 6 Shaped Lugs 7 Solid Rod 8 Horizontal Strut I (HI) 9 Horizontal Strut 2 (H2) Horizontal Strut 3 (H3) 11 Lower Triangular Bracings 12 Pin with Nut 13 Lifting Plate 1 (LP1) 14 Lifting Plate 2 (LP2) Lifting Plate 3 (LP3) 16 Shackle Pin Block at LP1 17 Shackle Pin Block at LP2 18 Shackle Pin Block at LP3 Figure 2 -illustrates a Side view of the Lifting Frame lifting the tilted vessel (boiler cut-section).

The COG is shown as being offset from the vertical axis of symmetry.

Figure 3 -shows a 2D view of the rectangular Shackle Block, positioned within the Lifting Plate's cut-slot, where the components have been numbered as follows: 1 Lifting Plate 2 Diagonal Tie joining the Lifting Plate 3 Cut-slot 4 Shackle Pin Hole Steel Packs (shims) of various widths 6 Hole for the Securing Bolt securing the Steel Packs 7 Shackle Block Figure 4 -illustrates an Isometric view of the assembled Lifting Frame Figure 5 -illustrates a 3D exploded view of the Shackle Pin Block assembly, where the components have been numbered as follows: I Lifting Plate 2 Cut sections of Diagonal Ties joining the Lifting Plate 3 Shackle Block adjustable within the cut-slot 4 Steel Packs (shims) Retaining Plate for the Steel Packs 6 Shackle Pin 7 Shackle Nut 8 Securing Bolt securing the Steel Packs 9 Securing Bolts for the Retaining Plate Figure 6 -illustrates the Top, Front, Isometric and Right views of the apex assembly, where the components have been numbered as follows: 1 Top Lifting Eyelet 2 Connecting Plate 3 Shaped Lugs Figure 7 -illustrates the Top and Isometric views of the Lifting Plate I and the half-cut sections of the Horizontal Struts Figure 8 -illustrates a Top view of the assembled frame, where LP1 Lifting Plate 1 LP2 Lifting Plate 2 LP3 Lifting Plate 3 Figure 9 -illustrates a Side view of the assembled frame, where LP1 Lifting Plate 1 LP2 Lifting Plate 2 Figure 10 -illustrates the InputlOutput worksheet Figure 11 -illustrates an example of the Lifting Plates 1, 2 and 3 adjustments. In particular, it shows the position within the cut slot where the shims should be inserted and the gap, in millimetres, they must fill up, at each individual Lifting Plate.

With reference to Figure 1, the Lifting Frame comprises of four main assemblies: 1. the apex assembly comprising of components 4, 5 and 6 2. the double Diagonal Ties 1, 2 and 3 connected to the Shaped Lugs and the Lifting Plates by Pins and Nuts.

3. the Horizontal Struts 8, 9 and 10 4. the equidistant and individually adjustable Lifting Plates 13, 14 and 15.

Each Lifting Plate allows incremental movements of the Shackle Pin Block, within the Lifting Plate cut slot, by means of inserting steel restraining packs (shims).

The operation of the Lifting Frame shall now be briefly described, with reference to drawings in Figures 1 to 11.

The inputloutput key parameters are validated with the aid of specially written software, i.e. Microsoft Excel (Figure 10). Flat Load Cells (flat jacks) would be inserted into three predetermined cut slots positioned around the bottom rim of the vessel. The loads are measured independently by each Load Cell. Circumferential distances are measured between each adjacent Load Cells to ascertain whether the cylindrical vessel is not deformed in a horizontal plane. The height of the vessel also has to be measured on-site. All on-site measurements will be input into the programme.

The programme calculates the offset position of the COG in a horizontal plane perpendicular to the vessel's central vertical axis, i.e. the Offset in the X direction' and the Offset in the Y direction'.

The programme outputs the adjustments to be made at all Lifting Plates. Lifting Plates 2 and 3 will always be adjusted by the same amount.

With reference to Figure 10 and Figure 11, the input/output data for the software is as follows Input Data: * Circumferential Distances between each adjacent Load Cell * Loads at each Load Cell Output Data: * COG Offset in the X direction * COG Offset in the Y direction * Adjustment to be made to Lift Plate 1 * Adjustment to be made to Lift Plate 2 and 3 * Tilt Figure 11 shows the location, within the cut slot, where the shims should be inserted and the gap they must fill, for each individual Lifting Plate.

By utilising the data obtained by the on-site measurements in conjunction with customised computer software, the operator may detennine: 1. the total accurate weight of the vessel 2. the COG offset in the X and Y directions 3. the drilling locations, on the circumference of the vessel, for the three Shackle Pins holes, positioned around the top rim of the vessel 4. the desired location of the Shackle Pin Block within each cut slots 5. the gap to be filled up by the shims and their individual thickness 6. the amount of vessel tilt

Claims

II. Claims 1. A Lifting Frame comprising load attachment means such that each load lifting point can be independently and manually adjusted and the vertical axis passing through the centre of the frame's apex can be displaced relative to the vertical axis passing through the load's Centre of Gravity.
2. A Lifting Frame according to claim 1, in which the load attachment means is adjustable so that the amount of tilt of the load can be varied.
3. A Lifting Frame according to any of the preceding claims, in which the attachment means for attaching the frame to a load is provided by three Lifting Plates, preferable of a rectangular shape, each Lifting Plate including a slot to allow linear displacement, in a horizontal plane, of a Shackle Pin Block.
4. A Lifting Frame according to any of the preceding claims, in which the displacement of Shackle Pin Blocks is controlled by shims.
5. A Lifting Frame according to any of the preceding claims, in which two out of three Lifting Plates are designed identically and four out of six Diagonal Ties are designed identically.
6. A Lifting Frame according to any of the preceding claims, wherein the frame is built to compensate for an initial offset of the vertical axis passing through the centre of the frame's apex relative to the vertical axis passing through the load's Centre of Gravity.Amendment to the claims have been filed as follows Claims I. A Lifting Frame independently and manually adjusted at each lifting point, in which the means for attaching the frame to a load is provided by three Lifting Plates, preferable of a rectangular shape, each with a slot to allow linear horizontal displacement of a Shackle Pin Block to allow the vertical axis, passing through the centre of the Frame's apex, to be displaced relative to the vertical axis passing through the load's Centre of Gravity.2. A Lifting Frame according to claim 1, in which the displacement of Shackle Pin Blocks is controlled by shims.3. A Lifting Frame according to any of the preceding claims, in which two out of three Lifting Plates are designed identically and four out of six Diagonal Ties are designed identically. I... * * . *. * * * **** S. * * S * * IS S.. * S S... a *..pS * .**SS( * a S