Support for a heat exchanger tube bundle

There is provided a support for supporting a bundle of exchanger tubes that has plurality of tubes and support plates that engage and support the plurality of tubes. The support has a cradle with a plurality of support surfaces spaced along the length of the cradle to support the bundle of exchanger tubes, a carriage that is movably mounted to a track extending along the length of the cradle such that the carriage traverses at least a portion of the cradle as it moves along the track. The carriage has a receiver portion that moves along the cradle above the support surface and is sized to receive a support plate of the bundle of exchanger tubes, and one or more lifts positioned along the cradle length, the lifts moving vertically between an extended position above the carriage relative to the cradle and a refracted position below the support surfaces.

TECHNICAL FIELD

This relates to a support for supporting a bundle of tubes, such as a bundle that may be found in a heat exchanger.

BACKGROUND

Many industrial operations require the use of heat exchangers. Some types of heat exchangers have a housing with a bundle of exchanger tubes within the housing. When it becomes necessary to service the heat exchanger, which may include repairs and cleaning, the bundle of tubes must often be withdrawn from the housing. As heat exchangers can be large and heavy, specialized equipment is required in order to remove and reposition the bundle of tubes outside the housing. This often involves the use of a crane or a bundle extractor such as an aerial tube bundle extractor available from Peinemann Equipment B.V. located in Hoogvliet, The Netherlands. This allows bundles to be extracted from the exchanger housing without the need for a crane.

SUMMARY

According to an aspect, there is provided a support for supporting a bundle of exchanger tubes, the bundle of exchanger tubes comprising a plurality of tubes and support plates that engage and support the plurality of tubes, the support plates being perpendicular to the tubes, the support comprising, a cradle having a length, a plurality of support surfaces spaced along the length of the cradle to support the bundle of exchanger tubes on the cradle, a carriage that is movably mounted to a track of the cradle, the track extending along the length of the cradle such that the carriage traverses at least a portion of the cradle as it moves along the track, the carriage having a receiver portion that moves along the cradle above the support surface and that is sized to receive a support plate of the bundle of exchanger tubes, and one or more lifts positioned along the length of the cradle, the lifts moving vertically between an extended position above the carriage relative to the cradle and a refracted position below the plurality of support surfaces.

According to another aspect, the cradle may further comprise ground engaging wheels that support the cradle above a ground surface.

According to another aspect, the plurality of support surfaces may comprise a plurality of rollers, the rollers rolling in a direction perpendicular to the length of the cradle.

According to another aspect, the plurality of rollers may be spaced along the length of the cradle to engage a plurality of the support plates of the bundle of exchanger tubes.

According to another aspect, the plurality of rollers may comprise a plurality of sets of rollers, each set of rollers may comprise two or more rollers, each roller in each set of rollers may be disposed along a curve that approximates a curvature of the exchange tubes.

According to another aspect, the plurality of rollers may comprise at least one driven roller that applies a rotary force to the bundle of exchanger tubes to roll the exchanger tubes along an axis parallel to the length of the cradle.

According to another aspect, the lifts may comprise a curved engagement surface that approximates the curvature of the bundle of exchanger tubes.

According to another aspect, the cradle may further comprise a collection tray for collecting wash fluid and contaminants falling from the bundle of exchanger tubes during cleaning, the collection tray having a drain.

According to an aspect, there is provided a method of servicing a bundle of exchanger tubes, the bundle of exchanger tubes comprising a plurality of tubes, and support plates that engage and support the plurality of tubes, the support plates being perpendicular to the tubes, the method comprising the steps of providing an exchanger tube support comprising a cradle having a length, a plurality of support surfaces spaced along the length of the cradle, a carriage that is movably mounted to a track of the cradle, and one or more lifts positioned along the length of the cradle, withdrawing a portion of the bundle of exchanger tubes from an exchanger housing, causing a receiver portion of the carriage to engage a support plate of the portion withdrawn from the exchanger housing, continuing to withdraw the bundle of exchanger tubes from the exchanger housing while moving the carriage along the cradle, the receiver portion moving above the support surfaces and supporting the exchanger tube portion, once the bundle of exchanger tubes is positioned above the cradle, causing the lifts to extend vertically upward to engage and lift the exchanger tubes above the support surfaces and above the carriage, removing the carriage from below the bundle of exchanger tubes, and lowering the lifts until at least some of the plates of the bundle of exchanger tubes support the bundle of exchanger tubes on the support surfaces.

According to another aspect, the cradle may further comprise ground engaging wheels that support the cradle above a ground surface.

According to another aspect, the plurality of support surfaces may comprise a plurality of rollers, the rollers rolling in a direction perpendicular to the length of the cradle.

According to another aspect, the plurality of rollers may be spaced along the length of the cradle to engage a plurality of the support plates of the bundle of exchanger tubes.

According to another aspect, the plurality of rollers may comprise a plurality of sets of rollers, each set of rollers may comprise two or more rollers, each roller in each set of rollers may be disposed along a curve that approximates a curvature of the exchange tubes.

According to another aspect, the plurality of rollers may comprise at least one driven roller and may further comprise the step of applying a rotary force to roll the bundle of exchanger tubes along an axis parallel to the length of the cradle.

According to another aspect, the lifts may comprise a curved engagement surface that approximates the curvature of the bundle of exchanger tubes.

According to another aspect, the cradle may further comprise a collection tray, and the method may further comprise the step of washing the bundle of exchanger tubes and collecting wash fluid and contaminants that fall from the bundle of exchanger tubes during cleaning.

DETAILED DESCRIPTION

A support for supporting a bundle of exchanger tubes, generally identified by reference numeral10, will now be described with reference toFIGS. 1-9.

Referring toFIG. 3, there is shown a bundle of exchanger tubes12that has a plurality of tubes14and support plates16that engage and support the plurality of tubes14. Support plates16are transverse to tubes14. Generally, support plates16will be perpendicular, but some bundles may have a helical design, such that they may not be perpendicular. When in use, bundle12is contained within a heat exchanger housing, and must be withdrawn from the housing in order to be services, such as to repair or clean exchanger tubes14. It will be understood that bundle10may take various forms and may be various sizes. In a preferred embodiment, support plates16have a round circumference, and are positioned periodically along tubes14in order to maintain their separation and their overall shape and relative position.

Referring toFIGS. 1 and 2, support10has a cradle20. Preferably, support10is mobile and has a set of ground engaging wheels22and a fifth wheel attachment24. This allows support10to move bundle12to another service location, such as a cleaning bay or repair shop. It will be understood that support10may be made mobile in various ways and that the depicted embodiment is merely one example. For example, cradle20may be self-powered. In the depicted embodiment, wheels22are mounted to an axle frame26, which is built sufficiently strong to bear the weight of cradle20and a bundle of exchanger tubes12when loaded. Given that the size of bundles12may vary, it may be desirable to have the ability to move the relative position of ground engaging wheels22with respect to cradle20in order to equalize the load on cradle20. This is done by providing actuators (not shown) that are able to shift axle frame26relative to cradle20in order to properly position the center of gravity. Preferably, this is done by calculating the size and weight of exchanger bundle12before it is loaded on cradle20. Cradle20also preferably has outriggers21to stabilize cradle20when loading and unloading bundle12, and a control box23for housing electrical or hydraulic controls, equipment, etc.

Referring toFIG. 1, cradle20also has support surfaces28that extend along the length of cradle20. Support surfaces28support bundle of exchanger tubes12on cradle20, as shown inFIG. 4. Rollers28that are spaced along the length of cradle20are preferred as these permit bundle12to be rotated when mounted on cradle20. In order to facilitate this, there may be one or more driven roller. This may vary, but preferably rollers28that are closest to the control box23will be driven for simplicity. There may be many driven rollers that are linked together such as by a chain and sprocket design to the rollers that are driven directly. Other non-driven rollers are idlers that support and permit the rotation of bundle12. If rotation is not required, it may be possible to merely provide support surfaces28as a stationary, single surface, or segmented surface that supports bundle12.

As shown inFIG. 8, rollers28are preferably provided in a group of rollers28that are positioned along an arc that approximates the curvature of bundle12. Preferably, rollers28engage support plates16, such that it is the curvature of support plates16that should be matched. In some embodiments, the position of rollers28along the curvature may be adjusted in order to adjust to different sizes of bundles of exchanger tubes12. Rollers28are also positioned along the length of cradle10in order to engage multiple plates16at the same time. As will be understood, it is preferred to support bundles12by plates16in order to reduce deformation and for ease of handling.

In order to help position bundle12above cradle20, a carriage32is provided. As shown inFIGS. 3 and 4, carriage32is mounted on a track35that extends along the length of cradle20and has rollers37that permit carriage32to move along track35. Using track35, carriage32is able to traverse at least a portion of cradle20. As shown inFIG. 9, carriage32has a receiver portion34that moves along cradle20above rollers28. Receiver portion34is shown to have a slot36that receives a support plate16of bundle12that is being serviced. It will be understood that other designs of carriage32are possible beyond what is depicted. For example, carriage32may have two receiver portions in order to simultaneously support two support plates16. Carriage32may move along track35using a different design. Rather than a slot36, receiver portion34may take other forms, such as a clamp. As shown, slot36is adjustable using bolts38that allow the size of slot36to be adjusted to match bundle12being serviced. Receiver portion34receives an end of bundle12as it is withdrawn from an exchanger housing (not shown) or as it is received from bundle extraction equipment (not shown). As bundle12is moved over cradle20, carriage32preferably engages one of the support plates16at a first end of bundle12and acts as a support to bundle12at that locations as bundle12is moved across and positioned above cradle20. Once positioned above cradle20in the desired position, lifts38are used to lift bundle12above and out of engagement with carriage32. This allows carriage32to be removed, either by sliding carriage32further along cradle20, or by removing it from cradle20altogether. Preferably, carriage32is left on cradle20is space permits due to its weight. When dealing with heavy weights, it is preferred to use two points of contact, and two lifts38are shown. If the length of bundle12is such that carriage32will be over one of the lifts, it may be necessary to use the bundle extraction equipment to support one end. As can be seen, the rear end of cradle is lower, which provides room for the equipment if necessary. In addition, rollers30are designed to be removed to provide additional space in order to properly support bundle12during lifting or lowering operations.

Referring toFIGS. 5 and 6, lifts38are in the form of actuators that move between an extended position in which the support surface40of lifts38extend above rollers28and carriage32and a refracted position below rollers28, or at least the portion of rollers28that engage bundle12. Lifts38allow bundle12to be lifted and allow carriage32to be removed, such that bundle12can then be lowered onto rollers28and cradle20as shown inFIG. 7. As shown, lifts have a support surface40that is preferably curved in order to match the curvature of bundle12, and in particular, the curvature of plates16. Preferably, lifts38are long enough to engage multiple support plates16to spread the load along bundle12to reduce the risk of damage.

In some embodiments, it may be desirable to use support10to not only support bundle12, but also to provide a surface to service and clean bundle12and to move bundle12to different locations. For this purpose, support10is preferably mobile, and support surface28is preferably rollers to allow bundle12to be repositioned. Other features may also be provided. For example, cradle20may include clamps that can be used to support a skirt (not shown) that contains any spray or debris to cradle20. In addition, cradle20is provided with a collection tray42below rollers28. Collection tray42is useful in collecting wash fluid and contaminants that falling from bundle12during cleaning or servicing. Collection tray42preferably has a drain (not shown) to drain the liquids and contaminants. When cleaning, it may be desirable to erect a curtain or other barrier (not shown) around bundle12once it is mounted on the top of cradle20. This can be done by mounting supports directly to the sides of cradle20, or by mounting the supports on the ground if necessary. As shown inFIG. 8, collection tray42slopes toward the sides to collect fluid and debris. By adjusting the outriggers, the slope of collection tray42can be adjusted toward drains at one end or the other. As shown inFIG. 1, tray42also has an extension opposite the end with hitch24. This allows fluid and debris to be collected from a lancing operation, where high pressure nozzles are inserted into tubes to clean the inside of each tube.

The scope of the following claims should not be limited by the preferred embodiments set forth in the examples above and in the drawings, but should be given the broadest interpretation consistent with the description as a whole.