US3533467A - Tubular heat exchange assembly - Google Patents

Tubular heat exchange assembly Download PDF

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Publication number
US3533467A
US3533467A US724497A US3533467DA US3533467A US 3533467 A US3533467 A US 3533467A US 724497 A US724497 A US 724497A US 3533467D A US3533467D A US 3533467DA US 3533467 A US3533467 A US 3533467A
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US
United States
Prior art keywords
tubes
duct
heat exchange
exchange assembly
cross
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US724497A
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English (en)
Inventor
Roman Rummel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Von Roll AG
Original Assignee
Von Roll AG
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Filing date
Publication date
Application filed by Von Roll AG filed Critical Von Roll AG
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Publication of US3533467A publication Critical patent/US3533467A/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/02—Tubular elements of cross-section which is non-circular
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00—Making other particular articles
    • B21D53/02—Making other particular articles heat exchangers or parts thereof, e.g. radiators, condensers fins, headers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B21/00—Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically
    • F22B21/34—Water-tube boilers of vertical or steeply-inclined type, i.e. the water-tube sets being arranged vertically or substantially vertically built-up from water tubes grouped in panel form surrounding the combustion chamber, i.e. radiation boilers
    • 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
    • F28D7/08—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 otherwise bent, e.g. in a serpentine or zig-zag
    • 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
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S165/00—Heat exchange
    • Y10S165/355—Heat exchange having separate flow passage for two distinct fluids
    • Y10S165/40—Shell enclosed conduit assembly
    • Y10S165/427—Manifold for tube-side fluid, i.e. parallel
    • Y10S165/436—Bent conduit assemblies
    • Y10S165/437—Coiled
    • Y10S165/438—Helical
    • 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
    • Y10T29/49373—Tube joint and tube plate structure

Definitions

  • a tubular heat exchange apparatus for use with two fluids comprising, within a gas-tight casing, a plurality of tubes and two headers, said tubes being connected with such headers
  • the tubes are arranged in one or more rows or ranges around a central duct of variable cross section.
  • the heat exchange apparatus is adapted to convey combustion gases from a furnace or the like.
  • the present invention relates to an improved tubular heat exchange assembly for use with two fluids, such as liquids, vapours and/or gases, and. is of the type comprising, within a gas-tight casing a plurality of tubes operably connected with two headers, one of the fluids flowing through the tubes and the other one outside and along them.
  • tubes of straight or curved shape are arranged so as to provide between them a central channel for the fluid flowing outside the tubes,
  • the present invention seeks to obviate these inconveniences.
  • the invention provides a heat exchange assembly,.morespecifically for heat transmission by radiation, comprising tubes with both ends connected to respective headers, said tubes surrounding and defining a central duct of variable cross: section for a heat transmitting fluid for instance.
  • a particular aspect of the invention is that in a heat exchange assembly as described above, and with tubes regularly arranged side-by-side, close fitting over their entire length, one of the tubes parameters, i.e. the direction of the axis or the shape of the cross section, is for all tubes and in any plane orthogonal to the ducts axis, a single and definite function of the size of the respective cross-sectional area of the duct.
  • a preferred embodiment of the heat exchange assembly according to the invention incorporates a vertical duct of variable cross section, delimitated or bounded by helicoidal tubes of variable inclination.
  • a further preferential embodiment of the heat exchange assembly according to the invention may incorporate at least two rows or ranges of tubes which are coaxially arranged.
  • Still another preferential embodiment of the heat exchange assembly teaches a vertical duct of variable but circular cross section throughout, with tubes of equal length and shape.
  • a still further preferential embodiment of the heat exchange assembly according to the invention embodies a vertical duct shaped as a hyperboloid of revolution, with straight tubes lying within the surface of said hyperboloid.
  • Another feature relates to an improved process for the fabrication of a heat exchange assembly with a centralduct of variable but circular cross section throughout, using tubes of equal length and shape, all tubes being connected in identical way and arrangement with the respective headers.
  • FIG. 1 is a longitudinal section of a heat exchange assembly with helicoidal tubes of variable inclination
  • FIG. 2 is a longitudinal sectional view of a heatexchange assembly as illustrated in FIG. 3, taken along the line ll-ll thereof, with tubes shaped in accordance with their respective distance from the ducts axis; v
  • FIG. 3 is a transverse sectional view of a heat exchange assembly of the type illustrated in FIG. 2, and taken along the line Ill-III thereof;
  • FIG. 4 is a transverse sectional view of a heat exchange assembly as illustrated in FIG. 2, taken along the line IV-IV thereof;
  • FIG. 5 is an enlarged transverse sectional view of a heat exchange assembly as illustrated in FIG. 2 taken along the line V-V thereof; 1
  • FIG. 6 is a longitudinal sectional view of a heat exchange assembly with two rows or ranges of tubes which are coaxially arranged;
  • FIG. 7 is a perspective representation of a hyperboloidshaped heat exchange assembly provided with straight tubes.
  • FIG. 1 the heat exchange assembly depicted, by way of example, incorporates two headers l and 2 and a plurality of tubes 3 having their upper and lower ends connected with these two annular headers l and 2.
  • the tubes 3 are located in close-fitting, side-by-side arrangement, to thus define a central duct 4 for one of the media involved in heat transmission, generally the heat transmitting medium.
  • the circular cross section of this duct 4 which for convenience has been designated by reference numeral q, is variable in size along the ducts axis A,.
  • the heat exchange assembly as illustrated in FIG. 1, which may be assumed to be mounted on' top of a high-temperature furnace operating with molten slag, and wherein the stream of hot combustion gases issues from said furnace with a pronounced twist or spin, will flow upwards through the duct 4 of the heat exchange assembly. Small particles entrained by the gas-stream, e.g. droplets of molten slag will be separated by increased centrifugal forces in the narrow part of the duct 4 and will flow back into the furnace along the smooth inner surface of the duct 4.
  • the tubes 3 are all of identical helicoidal shape, with the inclination angle a varying in dependence upon the size ofthe respective cross-sectional area 4: said variable angle of inclination being such that the tubes 3 are maintained in closefltting, side-by-side position over their whole length and that, at no place, will there occur any superposition of neighboring or contiguous tubes 3.
  • any plane E orthogonal to the ducts axis A the angle of inclination a of the axis A; of any tube 3 will depend solely upon the size of the respective cross-sectional area 4q, said angle of inclination a of the axis A; of any tube, thereby constituting a characteristic tube parameter;
  • the inclination angle a of the helicoidal tubes 3 will be determined both by the size of the respective cross-sectional area 4q and by the desired spacing between neighboring tubes.
  • the inclination angle a will be greatest in the plane E of the smallest cross section -4q. with tangent a 7 possibly being infinite, so that in that plane, the tubes 3 may be arranged with their axes parallel with the ducts axis A, This is visible in FIG.
  • Circular cross sections 4q are furthermore of advantage, since the thermal load is evenly distributed at all tubes, thereby avoiding thermal stresses within the heat exchange assembly.
  • the tubes 3 there is provided a gas-tight casing which is accommodated to the longitudinal profile or shape of the duct 4.
  • studs may be provided on these tubes 3 which then serve to retain or support a layer of refractory material in order to protect the tubes 3 against excessive thermal load in a manner well known in the art.
  • the two headers I and 2 are connected by means of a plurality of tubes 3 which serve to define a central duct 4', with circular cross sections 4q' of variable size along the ducts'axis A
  • the tubes 3' are curved in conformity with the longitudinal profile of the duct 4', with their axes (marked A lying in planes E, passing through the duct's axis A, (of. FIGS. 3 and 4').
  • the shape and size of its cross section 3q' varies in dependence upon the respective distance S between said tube 3' and'the ducts axis A, the relationship being such that in spite of the variation of the duct's cross-sectional area 4q' the tubes remain in closefitting, side-by-side position, i.e. without any free spacing or interval and that, furthermore, at no place of the duct 4', does there occur any superposition of contiguous or neighboring tubes 3'.
  • the shape of the cross sections 3q' of these tubes constitutes a characteristic tube parameter, being determined in any plane E (FIG. 2) orthogonal or perpendicular to the ducts axis A,, by the size of the cross-sectional area 4q of the duct in said plane E.
  • tubes 3' will have a circular cross section 3q', which will be gradually flattened the nearer the tubes come to lie to the ducts axis A, such being in direct dependence upon the size of the respective cross-sectional area 4q'.
  • FIG. 5 depicts in an enlarged scale the cross section 3q of such a flattened tube 3' as such occurs in the narrowest part of the duct 4, that is in the plane E with the smallest cross-sectional area 4q' (cf. section-lines IV-IV and V-V in FIG. 2).
  • the contour of the tubes cross section is angularly flattened towards'the duct's axis, as is visualized by the two tangential lines marked T.
  • the tubes 3' are surrounded by a gas-tight casing 5 which follows the longitudinal profile of the duct 4' and once again,
  • the tubes 3' may be provided on their inner face with studs or the like and a layer of refractory material for protection of such tubes against excessive thermal load.
  • any desired spacing between them may be adopted-.
  • any other cross-sectional shape may be adopted for the duct 4.'However, here again, ducts of circular cross section are preferable, since, not only are the tubes 3' of identical shape and length, but, besides, an even distribution of the thermal load is ensured.
  • the embodiment of the invention described above in conjunction with FIGS. 2 to 5 is particularly suited for lengthwise extending heat exchange assemblies.
  • the tubes 3 and 3 serve as boiler tubes with a high thermal load.
  • they are located in close-fitting side-by side arrangement, that is to say, without intervals or with small intervals or spacing of not more than a few millimeters.
  • the tubes may be spaced from each other, that is, arranged with greater spacing or intervals, thus embracing a greater periphery with the same number of tubes. In both embodiments, spaced arrangements may be adopted, with equal spacing over the entire length of the tubes or varying in width.
  • FIG. 6 represents a heat exchange assembly with two ranges or rows of tubes R, and R which are coaxially arranged in a duct 4" having the longitudinal axis A". These tubes R, and R, have their ends connected to two headers l and 2.
  • the external row or range R, of the tubes 3" defining the duct 4" proper is in principle shaped and arranged as in the embodiment according to FIGS. 2-5, with however, wider intervals between the tubes, said intervals being equal for all tubes 3".
  • the tubes 3: of the inner row or range R placed coaxially within the duct 4" and defining a second, inner duct 4i, are similarly shaped and arranged, with equal intervals of larger width, e.g. millimeters for all tubes 3i, to thereby allow outer range R, are still more closely arranged.
  • Both rows or ranges R, and R may have their tubes located in coinciding or displaced position with respect to each other.
  • the cross-sectional area 4q of the duct 4 is variable along the ducts axis A,", but of circular shape throughout and so is the cross-sectional area 4qi of the inner duct 4i" defined by the inner range or row of tubes R
  • the tubes 3" of the outer range R are all equal in length and shape and so are the tubes 3i of the inner range R
  • the gas-tight casing 5 fits or encloses the contour of the outer tube range or row R,.
  • FIG. 7 there is shown a further embodiment of the heat exchange assembly according to the present invention, with a duct marked 4 having the shape of an hyperboloid of revolution, incorporating straight tubes 3g lying within the hyperboloids surface, all tubes having the same shape and length.
  • the embodimcnt of the heat exchange assembly represented in H6. 7, is based.
  • the direction of the tubes axes constitutes a tubeparameter for all tubes 3g in any plane E orthogonal to the axis A of the hyperboloidal duct 4 said-tube parameter depending upon the size of the cross-sectional area 4.
  • the distance between the axes of two contiguous tubes 3g. is a minimum.
  • the distance between two contiguous tubes is increasing in a linear. i.e. continuous way, to reach a maximum at the upper and lower ends of the hyperboloid.
  • hyperboloids of slender profile i.e. with a less pronounced neck, as is the case in practice, the deviation in distance along the entire length of the duct 4 is very small, so that the tubes 3g may be considered as beingat equal distances.
  • the duct 4 is of circular cross section in any sectional plane E along its entire length. equal thermal load for all tubes 3g is ensured.
  • the tubes At high thermal loads, the tubes have to be arranged in close fit side-by-side, as already mentioned, in other words with no spacing or intervals or with very small intervals of a few. millimeters.
  • the embodiment with the hyperboloidshaped duct 4 fulfills this requirement, since in the neck of the duct, i.e. in the place of highest heat concentration, the distance between contiguous tubes is minimum.
  • the inclination of the straight tubes 3g may be chosen either to the left or to the right, i.e. corresponding or opposed to the spin of the gas-stream issuing from the furnace, thereby increasing or reducing the initial turbulence of the gas-stream, it is obvious that the embodiment with hyperboloid-shaped duct, is adaptable to requirements as may arise in practice.
  • the basic longitudinal profile of the duct 4 is predetermined by the hyperbola generating the hyperboloid in contrast to the embodiments according to FIG. 1, FIGS. 2 5 and FIG. 6. where any desired longitudinal profile is possible.
  • the hyperboloidal-shaped duct is not only easily adaptable to all thermal and aerodynamical requirement. but moreover, this embodiment is advantageous in that, for ducts'with variable cross section along their axes. straight tubes 3;; of equal length may be used and arranged in close-fitting position over their entire length. Thus. expensive labor for the curved shaping of the tubes may be spared.
  • two or more ranges can be arranged coaxially within the hyperboloid-shaped duct 41 in' the manner already described in connection with FIG. 6.
  • the position could be reversed by directing such fluid to flow through .the tubes proper. with the heat-absorbing fluid then flowing in this case through the duct.
  • a tubular heat exchange apparatus adapted to convey combustion gases from a furnace or the like, especially for heat transmission by radiation, comprising wall means defin ing a gas-tight casing, a plurality of tubes located within said gas-tight casing and in contiguous relation with said wall means, an inlet header and an outlet header at opposite ends of said casing, said plurality of tubes being operatively connected with said headers.
  • said tubes being arranged adjacent one another throughout their entire length and defining acentral duct of variable cross section, said tubes having their lengthwise axes curved in accordance with the longitudinal profile of said duct and disposed in axial planes of said duct, and the circumferential cross-sectional shape of said tubes, varying as a function of their distance from the longitudinal axis of said duct. substantially angularly flattened toward the ducts axis in that portion of said duct wherein said tubes are closest to said longitudinal axis, whereby with high gas velocities in chambers of intense radiation the free flow of the combustion gases is not hindered.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Geometry (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
US724497A 1967-05-05 1968-04-26 Tubular heat exchange assembly Expired - Lifetime US3533467A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CH643167A CH462214A (de) 1967-05-05 1967-05-05 Wärmeaustauschkörper und Verfahren zu seiner Herstellung

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US3533467A true US3533467A (en) 1970-10-13

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US724497A Expired - Lifetime US3533467A (en) 1967-05-05 1968-04-26 Tubular heat exchange assembly

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US (1) US3533467A (forum.php)
BE (1) BE714614A (forum.php)
CH (1) CH462214A (forum.php)
DE (1) DE1778362A1 (forum.php)
FR (1) FR1560998A (forum.php)
GB (1) GB1220867A (forum.php)
NL (1) NL6806350A (forum.php)
SE (1) SE341702B (forum.php)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4840678A (en) * 1984-03-26 1989-06-20 B. V. Gerbs. Ter Braak Pipe coil cooker
US5568781A (en) * 1995-02-17 1996-10-29 The United States Of America As Represented By The Secretary Of The Navy Induced flow undersea vehicle motor cooling jacket
WO1996039600A1 (en) * 1995-06-06 1996-12-12 Erickson Donald C Coiled tubular diabatic vapor-liquid contactor
US6467253B1 (en) * 1998-11-27 2002-10-22 Volvo Aero Corporation Nozzle structure for rocket nozzles having cooled nozzle wall
US6468153B2 (en) * 2000-12-21 2002-10-22 Deere & Company Air blast duct for cleaning axial separator

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2118708A (en) * 1982-04-22 1983-11-02 Powrmatic Ltd Heat exchanger for a gas fired heater
ATE28802T1 (de) * 1983-12-19 1987-08-15 Tuzelstec Kutato Es Fel Val Staubabscheider mit rekuperator, insbesondere zyklon.
GB2234809A (en) * 1989-08-03 1991-02-13 John Barrie Timmons Ventilation systems

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4840678A (en) * 1984-03-26 1989-06-20 B. V. Gerbs. Ter Braak Pipe coil cooker
US5568781A (en) * 1995-02-17 1996-10-29 The United States Of America As Represented By The Secretary Of The Navy Induced flow undersea vehicle motor cooling jacket
WO1996039600A1 (en) * 1995-06-06 1996-12-12 Erickson Donald C Coiled tubular diabatic vapor-liquid contactor
US5713216A (en) * 1995-06-06 1998-02-03 Erickson; Donald C. Coiled tubular diabatic vapor-liquid contactor
US6467253B1 (en) * 1998-11-27 2002-10-22 Volvo Aero Corporation Nozzle structure for rocket nozzles having cooled nozzle wall
US6468153B2 (en) * 2000-12-21 2002-10-22 Deere & Company Air blast duct for cleaning axial separator

Also Published As

Publication number Publication date
BE714614A (forum.php) 1968-09-30
NL6806350A (forum.php) 1968-11-06
CH462214A (de) 1968-09-15
FR1560998A (forum.php) 1969-03-21
GB1220867A (en) 1971-01-27
SE341702B (forum.php) 1972-01-10
DE1778362A1 (de) 1971-10-07

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