GB2478533A - Modular extraction tool for extracting a heat exchange bundle - Google Patents

Abstract

A modular extraction tool 1 for extracting a heat exchange bundle 21 from the shell 22 of a heat exchanger 19 comprises a brace frame 2 through which the heat exchanger bundle 21 is extracted. The brace frame 2 is formed from releasably connected brace members 3, allowing it to be easily constructed and dismantled. The extraction tool 1 may comprise a load distribution frame 8 attached to a proximal side of the brace frame 2, and one or more shell engagement frames 14 attached to a distal end of the brace frame 2. The load distribution frame 8 may comprise a flange plate 10 upon which a shackle 11 is mounted. A kit of parts for forming a modular extraction tool and a method of extraction of heat exchanger bundles using a modular extraction tool is also claimed.

Description

1 Modular Arxaratus for ExtractinQ a Heat ExchanQer Bundle 3 The present invention relates to the field of linear force application devices, i.e., devices to 4 apply a force to one linearly elongated object so as to move it with respect to another, while at the same time retaining the second linearly elongated object in a static position.

6 More specifically, the present invention relates to a heat exchanger bundle moving device 7 and in particular one designed to pull a heat exchanger bundle from a horizontally 8 elongated heat exchanger shell.

Heat exchangers are used in chemical processing plants, such as petroleum refineries and 11 distilling facilities for absorbing heat created by high temperature reactions. These heat 12 exchangers utilise long metal tubes arranged in a cylindrical bundle. The bundles are 13 generally heavy and vary in their diameter and length. For example, these bundles may be 14 thirty centimetres to two meters in diameter, three to sixteen meters long and may have a weight of two to forty tons.

17 An individual bundle is usually inserted into a horizontally disposed shell and coupled to an 18 inlet and an outlet in the heat exchanger system which typically comprises multiple 19 bundles. To facilitate heat exchange, fluid enters into a bundle from its inlet in the heat 1 exchanger thereby flowing through the individual tubes of the bundle and exits via the 2 outlet. Heat exchanger fluid flows through the shell, past the outside of the tubes before 3 being collected for reuse or recycling. In practice the tube and shell fluids may travel 4 through a series of horizontally stacked bundles before exiting the system. During use, the individual tubes of the bundle are subject to fouling and corrosion and also have a finite 6 operating lifetime. Thus, each bundle in the heat exchanger requires regular maintenance 7 of the individual tubes of the bundle and eventually replacement of the whole bundle is 8 required.

The physical size and weight of the bundles create significant obstacles for maintenance 11 and replacement. For maintenance, the bundle must be removed from its shell by a 12 bundle extractor. During this extraction process there is also a need to support and 13 balance the bundle as it is pulled from the shell. These problems are compounded by the 14 fact that the bundles vary in length and weight and that space is of a premium within chemical processing plant where they are deployed.

17 A heat exchanger bundle is typically removed from its shell by pulling on a bundle 18 connector of the extractor that is arranged to exert a pulling force on a tube plate which is 19 fixed to the ends of the tube bundle. Significant force is often required to break the bundle free from its shell due to normal product corrosion between the bundle and tube plate and 21 the shell. A pulling mechanism such as a winch, hydraulic jack, or screw drive and motors 22 are typically used with the bundle connector to break the bundle free. Once free, a crane 23 and hoisting sling mechanism, as described for example in US patent number 3,658,191, 24 may be employed to support the bundle as it is being extracted from the shell. However, the use of hoisting slings is known to be cumbersome and can be dangerous for the 26 personnel required to secure them in place.

28 Alternatively, once the bundle is free from the shell it is known to locate the bundle on a 29 sliding carriage mounted on a frame of the extractor such that the carriage can be moved along the frame as the bundle is pulled from the shell. Different types of equipment have 31 been used to support the carriage and frame of the extractors in their operative position for 32 pulling of heat exchanger tubes bundles. For example, US patent nos. 3,836,015 and 33 4,053,062 disclose an aerial supported carriage and frame that is required to be lifted into 34 position by a crane and which may be moved off site using the crane or a helicopter.

1 Another approach is to mount the frame on a telescoping column of a truck bed, as 2 disclosed in US patent numbers 4,575,305 and 5,403,145. Alternatively, US patent 3 numbers 5,562,400 and 6,685,423 discloses extractors that utilise wheels or tracks, 4 respectively, in conjunction with a drive means to provide a self-propelled bundle extractor.

6 Extractors which require the use of cranes to position the frame at the shell of the heat 7 exchanger bundle are not practical for use in areas with limited clearance between the 8 heat exchanger unit and other structures. Similarly, extractors mounted on truck beds 9 and, to a lesser extent, self-propelled bundle extractors also suffer from the same space concerns. In these limited clearance areas, there may not be adequate space to 11 manoeuvre or position a crane, truck or self-propelled bundle extractor between the 12 structures.

14 Over and above the above issues of space extractor systems described in the prior art require the employment of large motors to extract the bundle. Such motors are expensive 16 to run and so add to the overall running costs of the heat exchangers. Furthermore, these 17 extractor systems often require the use of two or more personnel which again adds to the 18 operating costs.

It is therefore an object of an aspect of the present invention to obviate or at least mitigate 21 the foregoing disadvantages of the extractor systems known in the art.

23 Summary of Invention

According to a first aspect of the present invention there is provided a modular extraction 26 tool for extracting a heat exchange bundle from the shell of a heat exchanger, the modular 27 extraction tool comprising a brace frame through which the heat exchange bundle is 28 extracted, wherein the brace frame is formed from a plurality of releasably connected 29 brace members.

31 Employing a modular extraction tool having a brace frame through which the heat 32 exchange bundle is extracted and formed from plurality of releasably connected brace 33 members allows the tool to be quickly and easily constructed and dismantled at locations 34 where space is of a premium. The formation of the releasably connected brace members 1 into the brace frame also provides the modular extraction tool with sufficient mechanical 2 strength so as to allow for the safe extraction of the heat exchange bundle.

4 The brace frame may further comprise two runners releasably attached to a side of the frame. In use the side to which the runners are attached defines the lower side of the 6 modular extraction tool.

8 Optionally the modular extraction tool comprises two or more brace frames. Employing 9 two or more brace frames allows for the length of the modular extraction tool to be varied so that it may be deployed to extract heat exchange bundles of varying lengths.

12 It is preferable for each of the plurality of brace members to have the same physical 13 dimensions. By employing brace members having the same physical dimensions the skill 14 required to construct the brace frame is reduced. In a similar manner the costs in producing the modular extraction tool are also reduced.

17 The brace frame may comprise ten brace members arranged so as to form an open sided 18 cube. In this arrangement the open side of the cube defines a distal side of the brace 19 frame while the side opposite to the distal side defines a proximal side.

21 The brace members preferably comprise a length of tubing having first shaped flanges 22 attached at opposite ends. The first shaped flanges may be rectangular flanges.

24 It is preferable for the brace members to further comprise two second shaped flanges attached to the length of tubing. The second shaped flanges may be L-shaped flanges 26 attached such that they cover sections of the same two sides of the length of tubing.

28 It is preferable for the modular extraction tool to further comprise a load distribution frame 29 releasably attached to a proximal side of the brace frame. The incorporation of a load distribution frame acts to transfer the loads experienced when extracting the heat 31 exchange bundle through the brace frame.

33 Preferably the load distribution frame comprises a flange plate upon which is mounted a 34 first shackle. The load distribution frame may further comprise one or more lengths of tube employed to releasably connect the flange plate to the brace frame.

2 It is preferable for the one or more lengths of tube to comprise a third flange that provides 3 a means of attaching the length of tube to the flange plate. The third flange may be 4 square shaped.

6 It is preferable for the one or more lengths of tube to comprise a fourth flange that provides 7 a means of attaching the length of tube to the brace frame. The fourth flange may have an 8 irregular pentagon shape.

The modular extraction tool may further comprise one or more shell engagement frames 11 releasably attached to a distal side of the brace frame. The incorporation of the one or 12 more shell engagement frames acts to transfer the loads experienced when extracting the 13 heat exchange bundle from the brace frame to the shell.

Preferably the one or more shell engagement frames comprise a brace member attached 16 to which are one or more reaction flanges.

18 The modular extraction tool may further comprise a tube plate engagement frame suitable 19 for attachment to a tube plate of the heat exchange bundle. Preferably the tube plate engagement frame comprises a second shackle that provides a means for attaching the 21 tube plate engagement frame to a winch.

23 According to a second aspect of the present invention there is provided a kit of parts that 24 can be assembled to form an extraction tool for extracting a heat exchange bundle from the shell of a heat exchanger, the kit of parts comprising plurality of brace members having 26 one or more releasable attachment means that enable the brace members to be 27 assembled into a brace frame through which the heat exchange bundle is extracted.

29 The kit of parts may further comprise two runners suitable for releasable attachment to a side of the brace frame.

32 Optionally the plurality of brace members enables the assembly of two or more brace 33 frames.

1 It is preferable for each of the plurality of brace members to have the same physical 2 dimensions.

4 The kit of parts may comprise ten brace members so as to enable the assembly of an open sided cube.

7 The one or more releasable attachment means preferably comprise first shaped flanges 8 attached at opposite ends of the brace member. The first shaped flanges may be 9 rectangular flanges.

11 It is preferable for the one or more releasable attachment means to further comprise two 12 second shaped flanges located along the length of the bracing member. The second 13 shaped flanges may be L-shaped flanges attached such that they cover sections of the 14 same two sides of the bracing member.

16 It is preferable for the kit of parts to further comprise one or more angled members having 17 one or more releasable attachment means and a flange plate, the one or more releasable 18 attachment means enabling the one or more angled members and the flange plate to be 19 assembled into a load distribution frame for releasable attachment to a proximal side of the brace frame.

22 Preferably the flange plate comprises a first shackle.

24 It is preferable for the one or more releasable attachment means to comprise a third flange that provides a means of attaching the angular member to the flange plate. The third 26 flange may be square shaped.

28 It is preferable for the one or more releasable attachment means to comprise a fourth 29 flange that provides a means of attaching the angular members to the proximal side of the brace frame. The fourth flange may have an irregular pentagon shape.

32 The kit of parts may further comprise one or more reaction flanges that enable the brace 33 members and the one or more reaction flanges to be assembled into one or more 34 releasable shell engagement frames.

1 The kit of parts may further comprise a tube plate engagement frame suitable for 2 attachment to a tube plate of the heat exchange bundle. Preferably the tube plate 3 engagement frame comprises a second shackle that provides a means for attaching the 4 tube plate engagement frame to a winch.

6 Embodiments of the second aspect of the invention may comprise features to implement 7 the preferred or optional features of the first aspect of the invention or vice versa.

9 According to a third aspect of the present invention there is provided a method for extracting a heat exchange bundle from the shell of a heat exchanger, the method 11 comprising the steps of 12 -constructing an extraction tool at the location of the heat exchanger; and 13 -employing the extraction tool to extract the heat exchange bundle.

Preferably the step of constructing an extraction tool comprises constructing a modular 16 extraction tool in accordance with the first aspect of the present invention.

18 Most preferably the step of constructing an extraction tool comprises constructing an 19 extraction tool from the kit of parts in accordance with the second aspect of the present invention.

22 Embodiments of the third aspect of the invention may comprise features of the first or 23 second aspects of the invention to implement preferred or optional additional method 24 steps.

26 Brief Descriition of DrawinQs 28 Aspects and advantages of the present invention will become apparent upon reading the 29 following detailed description and upon reference to the following drawings in which: 31 Figure 1 presents a schematic perspective view of a modular extraction tool in accordance 32 with an embodiment of the present invention; 34 Figure 2 presents a schematic perspective view of the modular extraction tool of Figure 1 deployed with a heat exchanger; 2 Figure 3 presents a schematic perspective view of a modular extraction tool in accordance 3 with an alternative embodiment of the present invention; and Figure 4 presents a schematic perspective view of a modular extraction tool in accordance 6 with a yet further alternative embodiment of the present invention deployed with a heat 7 exchanger.

9 Detailed Descriition 11 Figure 1 presents a schematic perspective view of a modular extraction tool 1 in 12 accordance with an embodiment of the present invention. The modular extraction tool 1 13 can be seen to comprise a brace frame 2, the brace frame 2 being constructed from ten 14 identical, releasably attached, brace members 3 arranged such that the brace frame 2 exhibits a substantially cube shape.

17 Each brace member 3 comprises a length of box tubing 4, having a substantially square 18 cross section, two rectangular flanges 5 located at either end of the box tubing 4 and two 19 L-shaped flanges 6 located towards opposite ends of the box tubing 4 and arranged to cover sections of the same two sides of the box tubing 4. It is the arrangement of the 21 rectangular flanges 5 and the L-shaped flanges 6 that allow the ten brace members 3 to be 22 releasably attached e.g. bolted together so as to form the brace frame 2. The L-shaped 23 flanges 6 also provide a means for releasably attaching two runners 7 along one side of 24 the brace frame 2. It should be appreciated that the side of the brace frame 2 which is incomplete defines its distal end while the side to which the runners 7 are attached defines 26 the lower side the brace frame 2 when the modular extraction tool 1 is in use, as described 27 in further detail below.

29 Located at the proximal end of the brace frame 2 is a releasably mounted load distribution frame 8. In the presently described embodiment the load distribution frame 8 comprises 31 four sections of angled box tubing 9 and a flange plate 10 attached to which is a first 32 shackle 11. Each of the sections of angled box tubing 9 comprise a square flange 12 at 33 one end and an irregular pentagon shaped flange 13 at the other. The square flanges 12 34 allow the sections of angled box tubing 9 to be releasably attached to the flange plate 10 such that the first shackle 11 is positioned towards the brace frame 2 when the irregular 1 pentagon shaped flanges 13 are releasably attached to the four rectangular flanges 5 that 2 project from the proximal end of the brace frame 2.

4 Located at the distal end of the brace frame 2 are two releasably attached shell engagement frames 14. Each shell engagement frame 14 can be seen to comprise a 6 brace member 3 attached to each end of which, via the rectangular flanges 5, are corner 7 brackets 15. Bolted to the L-shaped flanges 6 of the brace frame 2 are two reaction 8 flanges 16. The corner brackets 15 provide the means for releasably attaching the shell 9 engagement frame 14 to the rectangular flanges 5 such that the shell engagement frames 14 are located across the open edges of the distal end of the brace frame 2. In so doing 11 the reaction flanges 16 are orientated so as to face away from the brace frame 2.

13 The final component of the modular extraction tool 1 is a tube plate engagement frame 17.

14 The tube plate engagement frame 17 can be seen to comprise a tube plate connector 18 attached to which is a second shackle 11. When the tube plate connector 18 is deployed 16 with a tube plate of a bundle to be extracted from a shell the second shackle 11 is 17 orientated towards the brace frame 2.

19 The described brace frame 2 of the preferred embodiment comprises an open sided cube structure. It will be appreciated that alternative frame structures having a various shaped 21 cross sections (e.g. triangle, rectangular, pentagon, hexagon etc.) may alternatively be 22 employed. However all of these embodiments are less preferable since corresponding 23 changes would be required to be made to the flanges of the corresponding brace 24 members e.g. pivotally mounted and/or greater skill would be required by the operator for their construction.

27 In further alternative embodiments it will be appreciated by the skilled reader that the 28 number of shell engagement frames 14 may be varied and/or the number of reaction 29 flanges 16 mounted on the shall engagement frames 14 may also be varied. In a similar manner the number of the number of sections of angled box tubing 9 may also be varied 31 however this would reduce the effectiveness of the load transferred from the load 32 distribution frame 8 to the brace frame 2. Similarly the number of runners 7 incorporated 33 within the brace frame 2 may be more or less than two. The lengths of box tubing 4 and 34 angled box tubing 9 may also be replaced with corresponding solid components, although it is appreciated that this would act to increase the weight of these components.

2 Each of the component parts of the modular extraction tool 1 are designed such that they 3 weigh less than 25kg. This is important for health and safety reasons since 25kg is the 4 maximum permitted weight that a single operator is permitted to lift. Thus, by so limiting the weight of each of components of the modular extraction tool 1 the tool can be 6 constructed and dismantled by a single operator, as will now be described in further detail 7 with reference to Figure 2.

9 In the first instance, the brace frame 2 is constructed from its component parts, as described above, at the location of the heat exchanger 19 with which it is to be deployed.

11 The tube plate engagement frame 17 is then attached to the tube plate 20 of the heat 12 exchanger bundle 21 to be extracted. This is achieved via the tube plate connector 18.

13 With the brace frame 2 located in close proximity to the heat exchanger bundle 21 the two 14 shell engagement frames 14 are constructed and attached to the distal end of the brace frame 2 such the reaction flanges 16 abut the shell 22 of the heat exchanger 19. The load 16 distribution frame 8 is then constructed upon the proximal end of the brace frame 2.

17 Finally, a winch (not shown) is then connected to the second shackle lib with the winch 18 line initially been threaded through the first shackle 1 la.

It will be appreciated that the employment of different flange types e.g. the rectangular 21 flanges 5, the L-shaped flanges 6, the square flanges 12 and the irregular pentagon 22 shaped flanges 13, assists in the construction of the modular extraction tool 1 since it is 23 relatively simple for an operator to identify where each end of the various components 24 should be attached. This obviously reduces the risk of the modular extraction tool 1 being constructed incorrectly.

27 Operation of the winch acts to provide a substantially horizontal linear force to the bundle 28 21. The bundle 21 is therefore pulled from the shell and guided along the runners 7 29 located within the brace frame 2. The reaction forces created during this process are transmitted via the load distribution frame 8 through the brace frame 2 and onto the shell 31 engagement frames 14. Since the shell engagement frames 14 abut the shell 22 the 32 reaction forces are transferred to the shell 22 and not the bundle 21 being extracted thus 33 reducing the chance of the bundle 21 being damaged during the extraction process.

1 Given the variation on the outer diameter of the bundle 21, stabilising blocks (not shown) 2 may be located between the extracted bundle 21 and the runners 7 50 as to maintain the 3 bundle 21 in a substantially horizontal orientation and therefore further assist in reducing 4 the potential for damage to the bundle 21.

6 The winch mechanism may be a hand cable puller winch such that the construction, 7 operation and dismantling of the modulation extraction tool can be carried out by a single 8 operator without the need for a dedicated drive source. Alternatively an automated winch 9 mechanism could be employed.

11 Once the required work has been carried out on the bundle 21 and it has been housed 12 again with the shell 22 the modular extraction tool 1 can be simply dismantled and 13 efficiently stored away until it is required to be deployed again.

It will be readily apparent that the modular nature of the described tool allows for the length 16 of the modular extraction tool 1 to be varied. This is demonstrated with reference to 17 Figures 3 and 4 which present a schematic perspective view of a modular extraction tool 18 lb and lc comprising of two brace frames 2 and five brace frames 2, respectively. Each 19 additional brace frame 2 is simply incorporated by attaching its distal end to the proximal end of the previous brace frame 2. Once the required number of brace frames 2 are 21 present then the load distribution frame 8 is attached to the proximal end of the last brace 22 frame 2, as previously described. In this way, the modular extraction tool 1 may readily be 23 adapted for use with heat exchangers 19, and hence bundles 21, of a variety of lengths 24 and weight.

26 The described modular extracting tool offers a number of advantages over those described 27 in the prior art. In the first instance its modular nature allows the component parts to be 28 efficiently stored when the device is not in use. The modular nature also allows the tool to 29 be constructed in small inaccessible areas. These features are particularly advantageous in chemical processing plants where space is of a premium.

32 The modular nature of the apparatus also allows for construction, operation and 33 dismantling by a single operator. Each of the components are designed to weigh less than 34 25 kilograms therefore allowing Health & Safety requirements with respect to lifting of equipment to be met.

2 The incorporation of various flange designs also assists in simplifying the construction of 3 the tool and thus avoids mistakes being made by an operator during the construction 4 process.

6 Once used or if required to be deployed in an alternative location the modular nature 7 allows the extraction tool to be simply dismantled and stored away or quickly reassembled, 8 as appropriate.

A further advantage of the described apparatus is that by employing a hand operated 11 winch to manoeuvre the bundle the operating costs of the described apparatus is 12 significantly cheaper than those described in the prior art.

14 The foregoing description of the invention has been presented for purposes of illustration and description and is not intended to be exhaustive or to limit the invention to the precise 16 form disclosed. The described embodiments were chosen and described in order to best 17 explain the principles of the invention and its practical application to thereby enable others 18 skilled in the art to best utilise the invention in various embodiments and with various 19 modifications as are suited to the particular use contemplated. Therefore, further modifications or improvements may be incorporated without departing from the scope of 21 the invention as defined by the appended claims.