| JPS57136092 | REGENERATIVE HEAT EXCHANGER |
| JP6180407 | The wavelike pattern of a heating element |
| JPH03168543 | HEAT EXCHANGE UNIT FOR AIR CONDITIONING SYSTEM |
BARNETT NATHAN (US)
| WO2007137406A1 | 2007-12-06 |
| US6155339A | 2000-12-05 | |||
| EP2798301A2 | 2014-11-05 |
| CLAIMS We claim: 1 . A tube insert system for a heat exchanger, said system comprising: a tube insert having two axially opposing terminating surfaces; a header plug having a head and a body, wherein a diameter of a cross section of said head is greater than a diameter of a cross section of said body; and a connector for attaching a terminating surface of said tube insert to said body of said header plug, wherein said header plug is configured to fit into an external surface of a header of a heat exchanger, thereby creating a fluidic seal. 2. The tube insert system of claim 1 , wherein said connector allows for independent axial rotation of said header plug and said tube insert. 3. The tube insert system of claim 2, wherein said connector is a ball joint. 4. The tube insert system of claim 1 , wherein said connector fixes axial rotation so that said header plug and said tube insert axially rotate concurrently. 5. The tube insert system of claim 4, wherein said connector is a rod and said rod is attached to said body of said header plug. 6. The tube insert system of claim 4, wherein said connector is a first tab with at least one hole and a second tab with at least one insert. 7. The tube insert system of claim 1 , wherein said tube insert is statically positioned inside a tube of said heat exchanger. 8. The tube insert system of claim 1 , wherein said tube insert is dynamically positioned inside a tube of said heat exchanger. 9. The tube insert system of claim 1 , wherein said connector allows for rotation of said tube insert inside of said heat exchanger. 10. The tube insert system of claim 1 , wherein said body of said header plug is threaded. 1 1 . The tube insert system of claim 1 , wherein said diameter of said cross section of said body is greater than a diameter of a cross section of said tube insert. 12. A heat exchanger comprising: a header box having a plurality of plug holes; a plurality of conduits, fluidically connecting said plurality of header boxes; wherein each of said conduits is axially aligned with a center of at least one of said plurality of plug holes; a tube insert having two axial ends, configured to fit within said conduit while allowing a fluid to pass through said conduit; and a header plug configured to seal one of said plurality of plug holes in said headers, wherein said header plug is connected to an axial end of said tube insert by a connector. 13. The heat exchanger of claim 12, wherein said connector allows for independent axial rotation of said header plug and said tube insert. 14. The heat exchanger of claim 12, wherein said connector is a ball joint. 15. The heat exchanger of claim 12, wherein said connector fixes axial rotation so that said header plug and said tube insert axially rotate concurrently. 16. The heat exchanger of claim 12, wherein said connector is a rod and said rod is welded to said header plug. 17. The heat exchanger of claim 12, wherein said connector is a first tab with at least one hole and a second tab with at least one insert. 18. A method for securing a tube insert within a tube of a heat exchanger, said method comprising: providing a heat exchanger comprising: a header box having a plurality of plug holes; a plurality of conduits, fluidically connecting said plurality of header boxes; wherein each of said conduits is axially aligned with a center of at least one of said plurality of plug holes; providing a header plug, having a head and a body, configured to fit into one of said plurality of plug holes, wherein a diameter of a cross section of said head is greater than a diameter of a cross section of said body; affixing a tube insert to said body of said header plug by a connector; positioning said tube insert into said tube by introducing said insert through one of said plurality of plug holes; and sealing said plug hole with said header plug, thereby securing said tube insert in said tube. 19. The method of claim 18, wherein said heat exchanger is an air cooled heat exchanger. 20. The method of claim 18, wherein said heat exchanger is a liquid cooled heat exchanger. 21 . The method of claim 18, wherein said diameter of said cross section of said body is greater than a diameter of a cross section of said tube insert. 22. The heat exchanger of claim 12 comprising a plurality of header boxes. The method of claim 18 comprising a plurality of header boxes. |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001 ] This present application claims priority to U.S. Provisional Patent Application No. 62/331 ,261 filed May 3, 2016 the disclosures of which are incorporated by reference herein.
BACKGROUND
[0002] Heat exchangers are used in a wide range of industrial applications, including distillation towers, separators, and reactors. Additionally, heat exchangers handle a variety of fluid types (both air and liquid), including corrosive and high viscosity fluids. In most applications, one fluid is passed through internal tubes of the exchanger, while a second fluid is passed on the outside of the tubes. Heat transfer occurs between the fluids across the tube wall. In order to increase the heat transfer efficiency between the fluids, outside tube geometries are varied (e.g. obround, finned). Also, tube inserts can be used to impart turbulent flow to the inside fluid, which further increases heat transfer. However, there are several drawbacks with internal tube inserts, including corrosion and cleaning problems.
SUMMARY OF THE INVENTION
[0003] Internal tube inserts are usually fixed in place during assembly with an external tube sheet. Removing them for replacement (e.g. corroded inserts, different heat transfer fluids) or cleaning of the internal tubes, requires removal of the tube sheet and disassembly of the heat exchanger. This is a time consuming and costly process. Therefore, there is a need for heat transfer tube inserts that are easily installed and removed in a finished heat exchanger assembly, as well as being reliable. [0004] The systems and methods provided herein relate generally to the installation and removal of tube inserts in heat exchangers. The provided systems and methods simplify installation of tube inserts and allow fast and efficient installation, removal or replacement of a wide variety of tube inserts. In embodiments, the systems utilize a header plug attached to a tube insert. The tube insert is installed through a plug hole in the header box of a heat exchanger aligned with a tube so that the insert can be placed within the tube through the plug hole. The tube insert can then be positioned within the tube while the header plug seals the plug hole of the header box. The plug remains attached (directly or indirectly) to the tube insert, allowing the plug to be removed in order to pull out and remove the tube insert through the same plug hole through which it was installed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 provides a schematic of a header plug affixed to a tube insert.
[0006] FIG. 2 provides an external view of a header plug and tube insert partially inserted into a heat exchanger.
[0007] FIG. 3 provides an internal view of aspects of FIG. 2, with dashed lines representing internal features.
[0008] FIG. 4 provides an interval view of aspects of a header plug and tube insert installed, with the header plug creating a seal in a plug hole of the header box.
[0009] FIGS. 5A-5D show example embodiments of connectors between the tube insert and the header plug. FIG. 5A provides a ball joint connector. FIG. 5B provides a rod welded onto the body of the header plug. FIG. 5C provides a tab and insert connector. FIG. 5D provides a threaded connector in which the tube insert has a threaded male connection and the header plug has an interior female connection.
[0010] FIG. 6 provides an exterior view of an embodiment of a heat exchanger, with dashed arrows indicating direction of fluid flow. DETAILED DESCRIPTION OF THE INVENTION
[0011 ] In general the terms and phrases used herein have their art-recognized meaning, which can be found by reference to standard texts, journal references and contexts known to those skilled in the art.
[0012] FIG. 1 illustrates a header plug 100 attached to a tube insert 108 by a connector 106. The head 102 of the header plug 100 has a larger cross sectional diameter than the body 104, and the head 102 is positioned opposite the connector 106 and the tube insert 108, so that it forms a seal when placed in a heat exchanger. The cross sectional diameter of the body 104 of the header plug 100 is larger than the cross sectional diameter of the tube insert 108, so that the tube insert may be installed through the plug hole of the header box with the head 102 of the header plug 100 sealing the plug hole. The connector 106 can be any type of connector, either fixing the axial rotation of the header plug 100 and the tube insert 108 so that they rotate together, or allowing independent rotation of each.
[0013] FIG. 2 shows a header plug 100 and tube insert 108 attached by a connector 106 partially inserted into a heat exchanger. The tube insert 108 is inserted through the header box 200 and into a heat exchanger tube 206 through a plug hole 202 in the header box 200 aligned with the heat exchanger tube 206. FIG. 3 provides an internal component view of FIG. 2 with dashed lines representing internal components. FIG. 3 illustrates the interior volume 300 of the header box 200, and shows the tube insert 108 passing through the interior volume 300 of the header box 200 and the heat exchanger tube 206.
[0014] FIG. 4 illustrates an installed header plug 100 creating a seal in the plug hole 202 in the header box 200. The header plug 100 remains attached to the tube insert 108 by the connector 106 so that the header plug 100 may be removed in order to remove the tube insert 108 from the heat exchanger tube 206. In some embodiments, the connector 106 may be longer so that the end of the tube insert 108 is even with the entrance of the heat exchanger tube 206, reducing the amount of volume occupied by the header plug/tube insert in the interior volume 300 of the header box 200.
[0015] FIGS. 5A-5D show example embodiments of connectors between the tube insert and the header plug. FIG. 5A provides a ball joint connector 500, which allows independent rotation of the plug 100 and the tube insert 108. FIG. 5B provides a rod 502 welded onto the body of the header plug. The welding points 504 are on the body of the header plug 100, and, in some embodiments, on the tube connector 108. In some embodiments, the rod is a portion of the tube insert 108, itself. FIG. 5C provides a tab and insert connector, with a tab with insert 508 being positioned so that the insert passes through a tab with a hole 506. FIG. 5D provides a threaded connector in which the tube insert has a threaded male connection 510 and the header plug has a threaded female connection in the interior of the bottom, with the opening axially opposed to the head. In some embodiments, the connector has a rotation locking device which allows for independent rotation of the plug with respect to the tube insert while the device is disengaged and prevents independent rotation between the plug and tube insert when the device is engaged.
[0016] FIG. 6 shows an external view of an embodiment of a heat exchanger and indicates the direction of internal fluid flow with dashed arrows. The heat exchanger has two header boxes 200 and 602, the former having an inlet 600 and the latter having an outlet 601 . Fluid enters the header box 200 via the inlet 600 and flows through the tubes 206, which are exposed to an external counter-flowing fluid with a different temperature, as indicated by solid arrows. The internal fluid flows out of the tubes 206 into the header box 600 where it combines and exits the heat exchanger via the outlet 601. The header plugs 100 provide a seal to keep the internal fluid from escaping the header boxes 200 and 602 and, as indicated previously, may be attached to a tube insert running through the internal volume of the tubes 206. [0017] One of ordinary skill in the art will appreciate that the terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention that in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is
recognized that various modifications are possible within the scope of the invention. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of the present invention.