US3734140A - Cross-rifled vapor generating tube - Google Patents

Cross-rifled vapor generating tube Download PDF

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Publication number
US3734140A
US3734140A US00051434A US3734140DA US3734140A US 3734140 A US3734140 A US 3734140A US 00051434 A US00051434 A US 00051434A US 3734140D A US3734140D A US 3734140DA US 3734140 A US3734140 A US 3734140A
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United States
Prior art keywords
tube
cross
rifled
range
vapor generating
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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
US00051434A
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English (en)
Inventor
H Nakamura
M Tanaka
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.)
Nippon Steel Corp
Original Assignee
Sumitomo Metal Industries Ltd
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Filing date
Publication date
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C37/00—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
    • B21C37/06—Manufacture of metal sheets, rods, wire, tubes, profiles or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
    • B21C37/15—Making tubes of special shape; Making tube fittings
    • B21C37/20—Making helical or similar guides in or on tubes without removing material, e.g. by drawing same over mandrels, by pushing same through dies ; Making tubes with angled walls, ribbed tubes or tubes with decorated walls
    • B21C37/207—Making helical or similar guides in or on tubes without removing material, e.g. by drawing same over mandrels, by pushing same through dies ; Making tubes with angled walls, ribbed tubes or tubes with decorated walls with helical guides
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L9/00—Rigid pipes
    • F16L9/02—Rigid pipes of metal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/10—Water tubes; Accessories therefor
    • F22B37/101—Tubes having fins or ribs
    • F22B37/103—Internally ribbed tubes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B37/00—Component parts or details of steam boilers
    • F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
    • F22B37/10—Water tubes; Accessories therefor
    • F22B37/12—Forms of water tubes, e.g. of varying cross-section
    • 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
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element

Definitions

  • ABSTRACT A vapor generating tube of the two-phase type which is operated at a pressure between sub-critical and critical pressure of the vapor has a tube-like body through which fluid is passed.
  • the inner wall surface of the tube is crossed-rifled to provide a plurality of quadrilaterally shaped projections uniform and regularly spaced along the cross-rifled axes.
  • the minor inside diameter (1, the projection height h of each projection, the projection pitch P, projection width b, and spiral lead angle a and B have the following relationships: P/h is from 5 to 4 h/d is from 0.005 to 0.08, b/P is in the range of 0.2 to 0.8, and the spiral lead angles a+B are from 20 to 80 4 Claims, 4 Drawing Figures TEMPERATURE PATENTED 3,784,140
  • This invention relates to improvements in vapor generating tubes to be operated mostly under a pressure below the critical pressure and to be subjected to high heat flux, and more particularly to a cross-rifled vapor generating tube provided uniformly with many projections of a rhombic or parallelogramic shape made on the inside wall surface by cross-rifling the inside surface.
  • the above mentioned uniform projections are regularly set by cross-rifling the inside surface of a tube to be used mostly as a wall tube for a high temperature-high pressure boiler using a fossil fuel (such as coal, heavy oil or natural gas), so that there is produced a remarkable improvement in the critical heat flux so as to be higher than in a smooth tube by promoting the maintenance of nucleate boiling of the fluid passing through the tube.
  • a fossil fuel such as coal, heavy oil or natural gas
  • the safety of the operation of vapor generating tubes of a boiler depends on the wall temperature of the tube. That is to say, it is related so closely with the coefficient of heat transfer on the inside surface of the tube, the temperature of the operating liquid (such as the mixture of steam and water) and the heat flux that it is necessary to always pay careful attention to the wall surface exposed to strong flame radiation during its operation.
  • the operating liquid such as the mixture of steam and water
  • the heat flux that it is necessary to always pay careful attention to the wall surface exposed to strong flame radiation during its operation.
  • Today due to the increase of the adoption of an oil burning system and the general use of a oncethrough boiler, there has increased the possibility of the local presence of a condition exceeding in some cases the critical heat flux causing physical burn-out (breakdown) of the vapor generating tube.
  • a tube called a ribbed tube made by forming spiral lands on the inside surface of a vapor generating tube is suggested, for example, in U.S. Pat. No. 3,088,494 (or Canadian Pat. No. 684,836).
  • An object of the present invention is to provide a cross-rifled vapor generating tube having the effect of remarkably improving the critical heat flux to be higher than in a smooth tube by promoting the maintenance of nucleate boiling of the fluid passing through the tube.
  • FIG. 1 is a sectional view of an embodiment of a cross-rifled vapor generating tube according to the present invention
  • FIG. 2 is a sectional view showing another embodiment of the tube shown in FIG. 1;
  • FIG. 3 is a graph showing a comparison of inside sur face temperatures of a smooth tube and a cross-rifled tube of the present invention in the case of a pressure of 210 atmo (Kg/cm and a mass velocity of 700 to 710 l(g./m see;
  • FIG. 4 is a graph showing a comparison of the maximum values of the inside surface temperatures to the heat fluxes of a smooth tube and a cross-rifled tube of the present invention in the case of a pressure of 210 atmo (Kg/cm);
  • the cross-rifled tube according to the present invention has many projections such as 18 or 20 formed on the inside surface of a tube as shown in the embodiment in either FIGS. 1 or 2.
  • Test tubes A-l A2 B-l 8-2 Outside diameter D, (in mm) 20.27 20.16 20.09 20.06 Minor inside diameter d, (in mm) 9.66 9.54 13.27 13.18 Height h (in mm) of e projection 0.55 0.64 0.47 0.52 Number of spiral 12 12 12 12 (number per cross-section) Width 11 (in mm) of the projection 3.16 3.16 3.75 3.75 Lead angle 0: 2220 2220 2148 2148 Lead angle [3 1845 1845 1837 1837 Lead angle a 5 4105 4105 4025 4025 littlll p (in llllll.)[ l(:t(l (in lltight 7.32 7.32 11.
  • the inside surface temperatures of the smooth tube and the cross-rifled tube of the present invention in the case of a pressure of 210 atmo (Kg/cm) and a mass velocity of 700 to 710 kg/m sec. are shown for bulk average specific enthalpy with the heat flux as a parameter in FIG. 3.
  • the heat flux q is taken in the range of X 10' to 50 X 10 kcal/m hr.
  • the test data of the inside surface of the smooth tube are shown with solid lines and those of the cross-rifled tube according to the present invention are shown with dotted lines to compare the relative effects and a quality scale is also given on the abscissa for reference.
  • the maximum value (Tw max.) of the wall temperature vs. the heat flux at that time as shown with the mass velocity as a parameter is as in FIG. 4.
  • the smooth tube and the cross-rifled tube of the present invention are compared with each other for the three conditions of mass velocities of 900, 700 and 400 kg/m sec.
  • the above mentioned maximum value (Tw max.) of the wall temperature is much lower than in the case of the smooth tube and, in this respect, too, the effect of the cross-rifled tube is shown to be remarkable.
  • the cross-rifled tube the present invention can well endure physical burn-out at a heat flux of 60 X 10 kcallm hr. even under such severe condition as of a mass velocity of 400 kg/m. sec.
  • the maximum local heat flux of an oil burning oiler is 50 to 60 X 10 kcal/m. hr., if such cross-rifled tube is used in high heat flux parts of an ordinary boiler using a fossil fuel, there is no danger of a physical burn-out and it contributes much to the design of a subcritical pressure boiler.
  • the superiority of this cross-rifled tube can be proved even from the results of the two-phase airwater flow test at normal temperature and pressure. That is to say, according to the flow test, in the crossrifled tube, in the case of bubble flow, bubbles are more likely to concentrate in the center part of the tube than in the smooth tube and the ribbed tube of the prior art and, in the case of annular flow, the water film thickness becomes larger. Therefore, it is thought that the cross-rifled tube of this invention is superior to tubes of any other type and shape in both fast burn-out and slow burn-out and enables an increase in the critical heat flux. Further, what is to be specifically noted is that the pressure drop in the cross-rifled tube in a single-phase flow and two-phase flow is small. This a remarkable superiority to the ribbed tube having a large lead angle.
  • the cross-rifled tube of the present invention is made by using a cold-drawing process with a die and plug.
  • a plug on which a plurality of spiral grooves are made in advance is inserted into a tube and a plurality of spiral lands are formed on the inside surface of a smooth tube which is a mother tube by the free rotation of this plug and then as a second step working, another plug on which a plurality of spiral grooves with the lead angle reversed are made or on which straight grooves are made is inserted into the above mentioned tube in which the spiral lands are made and a part of the spiral lands made in said tube is plastically pressed down by the free rotation or straight drawing of this plug so that many projections of a rhombic or any shape may be uniformly and discontinuously made on the inside surface of the tube.
  • projections are set on the inside surface of the tube.
  • the shape of the projection is different depending on the shape of the plug to be used or the combination of such dimensional data as the percentage of the area reduction.
  • a vapor generating tube as in claim 1 wherein said tube-like body has a minor inside diameter d and each of said projections have a projection height h, a projection pitch P, and a projection width b, wherein P/h is in the range of 5 to 40, h/d, is in the range of 0.005 to 0.08, and b/P is in the range of 0.2 to 0.8, the spiral lead angles of the cross-riflings are a and B and a B is in the range of 20 to 80.
  • a vapor generating tube as in claim 2 wherein P/h is in the range of 8 to 25, h/d is in the range of 0.01 to 0.07, b/P is in the range of 0.3 to 0.6 and a B is in the range of 30 to 4.
  • a vapor generating tube as in claim 2 wherein 20 a 43 and B 0.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Geometry (AREA)
  • Rigid Pipes And Flexible Pipes (AREA)
  • Metal Extraction Processes (AREA)
US00051434A 1969-07-02 1970-07-01 Cross-rifled vapor generating tube Expired - Lifetime US3734140A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP44052752A JPS4931863B1 (enrdf_load_stackoverflow) 1969-07-02 1969-07-02

Publications (1)

Publication Number Publication Date
US3734140A true US3734140A (en) 1973-05-22

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Family Applications (1)

Application Number Title Priority Date Filing Date
US00051434A Expired - Lifetime US3734140A (en) 1969-07-02 1970-07-01 Cross-rifled vapor generating tube

Country Status (7)

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US (1) US3734140A (enrdf_load_stackoverflow)
JP (1) JPS4931863B1 (enrdf_load_stackoverflow)
CH (1) CH510847A (enrdf_load_stackoverflow)
FR (1) FR2050447B1 (enrdf_load_stackoverflow)
GB (1) GB1290588A (enrdf_load_stackoverflow)
SE (1) SE358720B (enrdf_load_stackoverflow)
ZA (1) ZA704552B (enrdf_load_stackoverflow)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2552679A1 (de) * 1974-11-25 1976-06-16 Hitachi Ltd Waermeuebertragungsrohr
EP0025975A3 (en) * 1979-09-21 1981-12-30 Combustion Engineering, Inc. Once through sliding pressure steam generator
US4690211A (en) * 1984-06-20 1987-09-01 Hitachi, Ltd. Heat transfer tube for single phase flow
US4715436A (en) * 1984-10-05 1987-12-29 Hitachi, Ltd. Construction of a heat transfer wall of a heat transfer pipe
EP1137905A4 (en) * 1998-11-02 2002-08-21 Outokumpu Copper Franklin Inc POLYEDRICAL NETWORK HEAT TRANSFER TUBE
US20040079428A1 (en) * 2000-12-14 2004-04-29 Houston Graeme J. Fluid flow in tubing
US20150231946A1 (en) * 2014-02-14 2015-08-20 Unique Fabricating, Inc. Noise attenuated air duct
US10344580B2 (en) * 2017-05-03 2019-07-09 Ge Oil & Gas Esp, Inc. Passive multiphase flow separator
US11324370B2 (en) * 2018-03-22 2022-05-10 Hilti Aktiengesellschaft Vacuum cleaner hose

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE363164B (enrdf_load_stackoverflow) * 1972-05-23 1974-01-07 Ctc Ab
JPS5623603A (en) * 1979-08-01 1981-03-06 Mitsubishi Heavy Ind Ltd Forced flowinggthrough boiler
DE3048959C2 (de) * 1980-12-24 1985-08-29 Wieland-Werke Ag, 7900 Ulm Verfahren und Vorrichtung zur Herstellung eines Rippenrohres für Wärmeübertrager o.dgl.
GB2278912B (en) * 1991-02-21 1995-09-06 American Standard Inc Internally enhanced heat transfer tube
US5070937A (en) * 1991-02-21 1991-12-10 American Standard Inc. Internally enhanced heat transfer tube
FR2708492B1 (fr) * 1993-08-05 1995-10-20 Balon Roger Leopold Procédé et installation pour la fabrication de tubes d'échangeur de chaleur et tubes obtenus.

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2552679A1 (de) * 1974-11-25 1976-06-16 Hitachi Ltd Waermeuebertragungsrohr
EP0025975A3 (en) * 1979-09-21 1981-12-30 Combustion Engineering, Inc. Once through sliding pressure steam generator
US4690211A (en) * 1984-06-20 1987-09-01 Hitachi, Ltd. Heat transfer tube for single phase flow
US4715436A (en) * 1984-10-05 1987-12-29 Hitachi, Ltd. Construction of a heat transfer wall of a heat transfer pipe
EP1137905A4 (en) * 1998-11-02 2002-08-21 Outokumpu Copper Franklin Inc POLYEDRICAL NETWORK HEAT TRANSFER TUBE
US20040079428A1 (en) * 2000-12-14 2004-04-29 Houston Graeme J. Fluid flow in tubing
US7114524B2 (en) * 2000-12-14 2006-10-03 Tayside Flow Technologies Limited Fluid flow in tubing
US20150231946A1 (en) * 2014-02-14 2015-08-20 Unique Fabricating, Inc. Noise attenuated air duct
US10344580B2 (en) * 2017-05-03 2019-07-09 Ge Oil & Gas Esp, Inc. Passive multiphase flow separator
US11324370B2 (en) * 2018-03-22 2022-05-10 Hilti Aktiengesellschaft Vacuum cleaner hose

Also Published As

Publication number Publication date
DE2032891A1 (de) 1971-02-04
GB1290588A (enrdf_load_stackoverflow) 1972-09-27
JPS4931863B1 (enrdf_load_stackoverflow) 1974-08-26
SE358720B (enrdf_load_stackoverflow) 1973-08-06
DE2032891B2 (de) 1972-11-09
CH510847A (de) 1971-07-31
FR2050447B1 (enrdf_load_stackoverflow) 1973-10-19
FR2050447A1 (enrdf_load_stackoverflow) 1971-04-02
ZA704552B (en) 1971-03-31

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