Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
  • F28D7/16—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation
  • F28D7/1607—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation with particular pattern of flow of the heat exchange media, e.g. change of flow direction
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
  • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
  • F28D7/16—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged in parallel spaced relation
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
  • F28F9/22—Arrangements for directing heat-exchange media into successive compartments, e.g. arrangements of guide plates
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
  • F28F9/26—Arrangements for connecting different sections of heat-exchange elements, e.g. of radiators
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
  • F28F9/22—Arrangements for directing heat-exchange media into successive compartments, e.g. arrangements of guide plates
  • F28F2009/222—Particular guide plates, baffles or deflectors, e.g. having particular orientation relative to an elongated casing or conduit
  • F28F2009/224—Longitudinal partitions
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F2230/00—Sealing means
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/4935—Heat exchanger or boiler making
  • Y10T29/49361—Tube inside tube

Definitions

• the present invention relates to a heat exchanger shell assembly and a method of assembling a heat exchanger shell structure.
• a shell-and-tube heat exchanger is an indirect heat exchanger. Heat is transferred between a fluid passing through the tubes of a tube bundle (the tube side) extending in a heat exchanger shell, and a fluid passing through the space outside the tubes (the shell side) .
• shell-and-tube heat exchangers can for example be found in Perry's Chemical Engineers' Handbook, 7 ⁇ h edition, 1997, McGraw-Hill Inc., page 11-33 to 11-46.
• Shell-and-tube heat exchangers can be distinguished according to the number of passes for fluid in the shell side and in the tube side. In each pass, the respective fluid flows substantially along the entire length of the heat exchanger, which is typically horizontally elongated. In multiple shell passes, the fluid flow meanders a plurality of times back and forth the length of the shell.
• the heat exchanger shell has inlet and outlet nozzles for the shell-side fluid.
• an inlet nozzle is typically arranged at one end of the shell, in particular on top of the shell, and an outlet nozzle is arranged at the opposite end, in particular at the bottom.
• the inlet and outlet nozzles are suitably arranged at the same end.
• Expanded metal is produced from sheet metal that is slit and expanded. Expanded-metal baffles are for example known from International patent applications with publication Nos. WO 2003/067170, WO2005/015107 and WO2005/061982, incorporated herein by reference, and turn out to have significant advantages in practice, such as less fouling tendency, lower pressure drop, and improved heat transfer due to turbulence created in the shell fluid.
• the flow of shell fluid is longitudinal.
• a problem is encountered when the number of shell- side passes is to change between even and uneven, since then one of the nozzles is unsuitably located.
• it can be envisaged to arrange an internal flow path for shell-side fluid from one end of the shell to the other. It is an object of the invention to provide a heat exchanger shell arrangement that allows to modify the number of shell-side passes.
• the present invention provides a heat exchanger shell arrangement comprising an outer shell having a nozzle at its lower side; an inner shell member within the outer shell and forming an intermediate space with the outer shell, the inner shell member having an opening at its lower side; wherein the arrangement further comprises a seal member arranged to fit in the intermediate space, the seal member providing a sealed passageway for fluid between the opening and the nozzle.
• an inner shell member By arranging an inner shell member, it is possible to direct shell side fluid from one shell end to the other, using the intermediate space.
• the inner shell space in which the actual heat exchange with a tube bundle is to take place, needs to be sealed against the intermediate space, otherwise shell side fluid could flow along a shortcut route, lowering heat transfer efficiency.
• a seal member between inner shell member and outer shell is provided for this purpose.
• the seal member is a gravity seal member, wherein sealing force is provided by the gravity force exerted on the seal member by the inner shell member.
• the seal member is not connected to at least one of the outer shell and the inner shell member, preferably it is not connected to both the outer shell and the inner shell member.
• the seal member is a plate having upper and lower surfaces that are arranged to conform to the outer shell and inner shell member surrounding the nozzle and the opening, preferably comprising a gasket at the upper and/or lower surface.
• the nozzle forms a first nozzle of the outer shell and the opening forms a first opening of the inner shell member
• the outer shell further comprises a second nozzle and the inner shell member comprises a second opening
• the second nozzle and the second opening are arranged to be fluid communication via the intermediate space.
• the invention further provides a method of assembling a heat exchanger, comprising providing an outer shell having a nozzle at its lower side and an inner shell member having an opening; sliding the inner shell member into the outer shell to form an intermediate space with the outer shell and to reach a position in which the opening is above the nozzle ; arranging the inner shell member in a lifted position in the outer shell; sliding a seal member into the intermediate space, the seal member providing a passageway for fluid between the opening and the nozzle; and lowering the inner shell member so that the gravity force exerted on the seal member acts as sealing force.
• the method is particularly useful for revamping a heat exchanger, wherein the outer shell is maintained and a new tube bundle is arranged within an inner shell member .
• Figure 1 shows schematically heat exchanger with a heat exchanger shell assembly according to the invention
• Figure 2 shows the heat exchanger of Figure 1 is cross-section along line II-II;
• Figure 3 shows schematically a top view of the seal member 25 in Figures 1 and 2. Where the same reference numerals are used in different Figures, they refer to the same or similar objects .
• the heat exchanger shell assembly 2 comprises an outer shell 4 and an inner shell member 5.
• the outer shell 4 has an inlet nozzle 8 (second nozzle) at its upper side and an outlet nozzle 9 (first nozzle) at its lower side.
• the inner shell member 5 extends cylindrically between a tube sheet 12 and floating head 14, thereby forming an intermediate space 16 with the outer shell.
• the inner shell member has an inlet opening (second opening) 21 in the form of a plurality of holes around its upper side near the end opposite to the inlet nozzle 8, and an outlet opening 23 (first opening) at its lower side at the same end.
• the inner shell member 5 is preferably provided with longitudinal sliding bars 24 on which the inner shell member can be slid into the outer shell 4.
• a seal member 25 is placed in the intermediate space 16, the seal member providing a sealed passageway 26 for fluid between the outlet opening 23 and the outlet nozzle 9.
• the seal member 25 is only very schematically shown in Figure 1, and is best seen in Figures 2 and 3. Its basic structure is formed of an arcuated plate 28 conforming to the outer shell and inner shell member. A handle 31 serves for handling the seal member during installation.
• the inner shell member is provided with a plate 30 that is welded around the outlet 23, to form a contact surface for the seal member.
• the seal member is provided with top and bottom gasket rings 32,33, suitably arranged in a circular groove seating machined into plate 28 of the seal member.
• a suitable gasket material is polytetrafluoroethylene (PTFE) for temperature resistance up to 250 degree C. Good results have been obtained with 100% expanded PTFE (e-PTFE), multidirectional orientated fibre structure, type Gore-Tex Series 300. The temperature range of this material is between -240 0 C and +250 0 C, with allowable peak temperatures up to 315 0 C.
• PTFE tape of 3 mm thickness was used. For the sealing of the floating head and baffle sealing tape with a thickness 2 mm was used. Before placement of the gasket rings, the seating was cleaned with alcohol and the gasket was glued into the seating.
• the seal member 25 is arranged to seal by gravity. It can be introduced loosely into the intermediate space 16 while the inner shell is lifted. Sealing force is provided by the gravity force exerted on the seal member by the inner shell member, and sealing is achieved without the seal member being fastened to either one of the shells 4,5. After installation of the seal member, the inner shell member does not rest on the sliding strips 24 in the vicinity of the outlet opening 23.
• the inner shell member houses the tubes 35,36 extending from the tube sheet 12 to floating head 16, and the tubes contribute to the weight pressing on the seal member.
• the weight can for example be more than 1000 kg such as 5000 kg.
• a longitudinal baffle 38 with an opening 39 serves to provide a two-pass configuration of the shell side.
• the inner shell member can be constructed of upper and lower half shells, between which the longitudinal baffle is clamped.
• the tube side of the heat exchanger 31 is indicated with dots.
• the tube side has a two-tube- pass arrangement.
• the tube side has an inlet 41 to a tube inlet header 43.
• the tube inlet header is in fluid communication with the lower part of the tube bundle, tubes 36 which extend to the tube end sheet 44 connected to the floating head 14 which in turn is in fluid communication with the upper part of the tube bundle, tubes 35 extending into the tube outlet header 47 where the outlet 49 from the tube side is arranged.
• the inlet and outlet tube heads 43,47 are separated by a horizontal plate 51 extending horizontally along in the centre of the outer shell 4 from the shell end to the tube sheet 12 in which the tubes are fixed.
• the tube sheet is secured to the shell by flanges (not shown), through which the inlet end of the shell can be opened for inserting or removing the internals. Flanges through which the end part of the shell can be removed are also arranged at the rear end near floating head 14.
• the tube end sheet 44 at the opposite end also fixes the tubes, but unlike the tube sheet 12, the tube end sheet 44 and the floating head 14 to which it is connected, are not connected to the shell 34, i.e. the end header is floating. This allows thermal expansion of the tubes within the shell. Instead of an end header, which receives and distributes all tube fluid, also separate U-tubes could be applied.
• the tubes are supported by a plurality of transverse baffles 65. They can in particular be expanded metal baffles, but rod baffles or other baffles can also be applied.
• an expanded metal grid 66 is illustrated supporting the tubes 35 in the upper half. Only few tubes are shown extending and supported by through the windows of the expanded metal structure . Suitably the tubes 36 in the lower half are supported in the same way.
• tube- side fluid can be (cold) crude oil and shell-side fluid can be (hot) long residue from the crude distillation unit.
• expanded metal baffles in the shell side are advantageous because they suppress fouling.
• Tube-side fluid is passed via inlet 41 and tube inlet header 43 along the tubes 36, and further via the floating head 14 to along the upper part of the tube bundle to outlet header 47 and outlet 49. During that passage, it is heated by exchanging heat with the shell side fluid.
• Hot shell-side fluid is introduced via inlet nozzle 8 into the outer shell, where it flows along the intermediate space towards the inlet 21 of the inner shell member.
• This inlet is formed of a plurality of holes spread around the upper part of the inner shell member. In this way an optimum distribution of shell fluid around the tubes 35 is achieved.
• the shell-side fluid flows towards the tube sheet 12, turns via the opening 39 and continues towards the outlet 23. From outlet 23 it passes through the passageway 26 formed by the seal member to the outlet nozzle 9, with a lower temperature than at the inlet nozzle 8.
• the lower half of the intermediate space (annulus) between outer shell 4 and inner shell member 5 is filled with non- or slow flowing shell fluid.
• This fluid will adopt a temperature somewhere near the tube side inlet temperature. Since the seal member does not interconnect outer shell 4 and inner shell member 5, they can thermally expand differently in response to different temperatures they will have in the course of operation.
• a method of assembling the heat exchanger shell structure 2 of Figure 1 will be discussed. First the outer shell is provided, not including the end portions of the tube inlet/outlet header and the floating head, so that suitably both longitudinal ends are open. In the case of a revamp, the outer shell of the original heat exchanger is maintained, and new internals, typically tube bundle and internal shell, are provided.
• the tube sheets, inlet/outlet headers, floating head may need to be modified or replaced.
• the inner shell member 5, suitably including the tube bundle, is slid on the sliding bars 24 into the outer shell until the opening 23 is directly above the outlet nozzle 9. Then the inner shell member is lifted sufficiently so that the seal member can be passed into the intermediate space between the outlet opening 23 and the outlet nozzle 3. The inner shell member is lowered, so that the gravity force exerted on the seal member acts as sealing force. Then the heat exchanger can be completed by attaching the end parts with flanges. If cleaning of the heat exchanger is required, it can be disassembled in reverse order, cleaned, and assembled again .

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)

Priority Applications (2)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

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• 2008
  • 2008-05-27 ES ES08760085T patent/ES2381609T3/es active Active
  • 2008-05-27 EA EA200901643A patent/EA016175B1/ru not_active IP Right Cessation
  • 2008-05-27 KR KR1020097026601A patent/KR20100029215A/ko not_active Application Discontinuation
  • 2008-05-27 WO PCT/EP2008/056487 patent/WO2008145652A2/en active Application Filing
  • 2008-05-27 MX MX2009012833A patent/MX2009012833A/es unknown
  • 2008-05-27 EP EP08760085A patent/EP2156128B1/de not_active Not-in-force
  • 2008-05-27 AU AU2008257595A patent/AU2008257595B2/en not_active Ceased
  • 2008-05-27 PT PT08760085T patent/PT2156128E/pt unknown
  • 2008-05-27 DK DK08760085.4T patent/DK2156128T3/da active
  • 2008-05-27 US US12/601,325 patent/US20100282450A1/en not_active Abandoned
  • 2008-05-27 JP JP2010509805A patent/JP2010528253A/ja active Pending
  • 2008-05-27 PL PL08760085T patent/PL2156128T3/pl unknown
  • 2008-05-27 BR BRPI0812266-0A2A patent/BRPI0812266A2/pt not_active IP Right Cessation
  • 2008-05-27 NZ NZ582155A patent/NZ582155A/en not_active IP Right Cessation
  • 2008-05-27 MY MYPI20095007 patent/MY151638A/en unknown
  • 2008-05-27 CN CN2008800178401A patent/CN101680720B/zh not_active Expired - Fee Related
  • 2008-05-27 CA CA002688713A patent/CA2688713A1/en not_active Abandoned
  • 2008-05-27 AT AT08760085T patent/ATE552470T1/de active
• 2009
  • 2009-11-17 ZA ZA200908090A patent/ZA200908090B/xx unknown

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