Patent Application
20080315047
This invention relates to support devices for supporting elongated members. In particular, the present invention relates to support devices for use in connection with tube bundles in heat exchangers and similar fluid-handling equipment to reduce vibration of the tubes within the tube bundle. The support devices in accordance with the present invention include at least one locking assembly to prevent unintentional removal of the support devices once installed in the tube bundle.
Shell and tube heat exchangers and similar items of fluid handling devices utilize tubes organized in bundles to conduct the fluids through the equipment. In such tube bundles, there is typically fluid flow both through the insides of the tubes and across the outsides of the tubes. The configuration of the tubes in the bundle is set by the tubesheets into which the tubes are set. One common configuration for the tubes is a square formation with the tubes set in aligned rows with tube lanes (the straight paths between the tubes) between each pair or rows, aligned orthogonally to one another. This configuration is illustrated in
Fluid flow patterns around the tubes as well as the changes in the temperature and density of the fluids which arise as a result of the heat exchange between the two fluids flowing in and around the tubes may give rise to flow-induced vibrations of an oscillatory nature in the tube bundle. If these vibrations reach certain critical amplitudes, damage to the bundle may result. Tube vibration problems may be exacerbated if heat exchange equipment is retubed with tubes of a different material to the original tubes, for example, if relatively stiff materials are replaced with lighter weight tubes. Flow-induced vibration may also occur when equipment is put to more severe operating demands, for example, when other existing equipment is upgraded and a previously satisfactory heat exchanger, under new conditions, becomes subject to flow-induced vibrations. Vibration may even be encountered under certain conditions when an exchanger is still in the flow stream but without heat transfer taking place.
Besides good equipment design, other measures may be taken to reduce tube vibration. U.S. Pat. No. 7,032,655 to Wanni et al., U.S. Pat. No. 7,117,935 to Wanni et al., and U.S. Pat. No. 7,128,130 to Wanni et al. disclose various tube support devices that effectively mitigate flow-induced vibration in tube bundles. These tube support devices utilize elongated members that are adapted to be received within tube lanes to engage adjacent tubes and effectively reduce vibration to improve operation.
Co-pending U.S. patent application Ser. No. 11/128,884 to Wanni et al., also discloses another tube support device, the disclosure of which is hereby incorporated in its entirety specifically by reference. This tube support device is also effective in mitigating vibration within the tube bundle to improve operation. With reference to
While the cables are effective in securing the support devices within the bundle, the use of such cables has potential drawbacks. There may be difficulties associated with installing the cable around the tube bundle. The cable may fret at the point where the cable passes through an associated aperture in the support device, which could lead to the potential failure of the cable. Additionally, the flow of fluid around the tubes of the tube bundle may cause the cable to rub on the outer surface of the outermost tubes in the tube bundle, which may cause wear.
There is a need for a locking assembly for securing a tube support device in a desired location within the tube bundle that does not cause wear to the locking assembly, the tube support device and/or the tube bundle.
It is an aspect of the present invention to provide a support device for a bundle of elongated members having locking assembly that maintains the support device in proper orientation within the bundle while preventing accidental removal of the support device.
In accordance with the principles of the present invention, a support device for a bundle of elongated members is provided. The bundle of elongated members includes a plurality of spaced rows of elongated members. The bundle may have a square tube pattern configuration, either 90 or 45 degree layout. The bundle of elongated members having an interior and an outer periphery. The support device includes an elongated support adapted to be located between adjacent spaced rows of elongated members. Each elongated support is preferably formed from a pair of metal strips that are selectively secured together. The elongated support having a first side and a second side. The first side being arranged to be positioned adjacent one row of the spaced rows of elongated members and the second side being arranged to be positioned adjacent another row of the spaced rows of elongated members. The elongated support having a plurality of support members spaced along the elongated support. Each support member has a first supporting assembly located on the first side for supporting one of the elongated members in the one row and a second supporting assembly located on the second side for supporting one of the elongated members in the other row. The plurality of support members are preferably spaced along substantially the entire length of the elongated support. The supporting assemblies engage the elongated members within the bundle to stabilize the elongated members and thus reduce vibration when fluids flow through and around the elongated members at higher velocities.
In order to maintain proper orientation of the support devices within the bundle of elongated members and prevent removal of the same, the support device further includes at least one locking assembly for locking the support device between the adjacent rows of elongated members. The locking assembly prevents inadvertent removal after the support device has been properly oriented within the bundle of elongated members. Each locking assembly is located between adjacent supporting assemblies. Each locking assembly is sized to contact adjacent elongated members in the same row of elongated members in the bundle, which prevents the displacement of the support device with respect to the bundle of elongated members. Preferably, the locking assembly having a thickness that is greater than the thickness of the supporting assemblies. Each locking assembly may extend from opposing sides of the elongated supports. It is also contemplated that the locking assembly may extend only from a single side of the elongated support such that the locking assembly contacts the adjacent elongated members on only one side of the support.
While it is contemplated that the supporting assemblies are spaced along substantially the entire length of the support device, the locking assemblies are intended to be located between supporting assemblies that are located near the outer periphery of the bundle. This arrangement of locking assemblies is sufficient to ensure that the support devices are properly maintained within the bundle of elongated members.
In accordance with an embodiment of the present invention, each locking assembly includes a locking block having a slot formed therein. The slot is sized to receive a portion of the elongated support therein. The locking block is preferably formed from metal. The locking block may be formed as a cast component or a strip of metal that is bent to form a generally U-shape. The locking block preferably contains rounded edge surfaces to prevent damage to the elongated members contacted the locking assembly.
The invention will now be described in connection with the following drawings in which like reference numerals designate like elements and wherein:
In order to mitigate vibration and improve performance, at least one support device 10 may be inserted in the lane between adjacent rows of elongated members 1, as shown for example in
When the support devices 10 are inserted into the bundle of elongated members, the raised support members 13, 14 have to be pushed past the elongated members until the support device 10 is in its proper place in the bundle, such that the elongated members 1 are accommodated in corresponding saddles 15 on the support members 13 and 14. Each support member has to be pushed through the gap or lane between each pair of opposed tubes until the support device is in place. Because the total depth of the support members is preferably slightly greater than the spacing between elongated members, the elongated members have to bend slightly to let the saddles pass, although this maintains the support in place when it is in its final position.
While the frictional engagement between the support devices 10 and the elongated members 1 will provide for retention of the support devices 10 in the bundle, the support devices 10 are preferably fixed into place using at least one locking assembly 20, shown in
As shown in
The generally U-shaped locking block 21 of the locking assembly 20 preferably has rounded edges 22, as shown in
The operation of the support device 10 in connection with the locking assembly 20 will now be described in greater detail. The locking assemblies 20 are located and secured to the support device 10 at select locations along the support device 10. The locking assemblies 20 are located adjacent or near one end of the strips 11 and 12. Preferably, the locking assemblies 20 are located adjacent or in the vicinity of one end of the strips 11 and 12, which are located near the outer periphery of the tube bundle, as shown in
When the support devices 10 are inserted into the bundle to reduce vibration, as described in co-pending U.S. patent application Ser. No. 11/128,884 to Wanni et al., the elongated members 1 contact the tube-receiving saddles 15 causing the elongated members 1 to flex as the saddles 15 pass the elongated members 1 until the device 10 is properly located within the bundle. When the tube support device 10 is properly positioned within the bundle, the tubes 1 rest in the tube-receiving saddles 15, as shown in
A variation of the locking assembly is illustrated in
It will be apparent to those skilled in the art that various modifications and/or variations may be made without departing from the scope of the present invention. It is contemplated that the present invention is not intended to be limited to the support device 10 described herein; rather, it is intended that the locking assembly 20 may be used with other suitable support devices, as disclosed for example in U.S. Pat. No. 7,032,655 to Wanni et al., U.S. Pat. No. 7,117,935 to Wanni et at., and U.S. Pat. No. 7,128,130 to Wanni et al., wherein the locking assemblies 20 may be positioned between adjacent sets of tube engaging zones. It is intended that the present invention covers the modifications and variations of the method herein, provided they come within the scope of the appended claims and their equivalents.
