Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K15/00—Electron-beam welding or cutting
  • B23K15/0046—Welding
  • B23K15/0053—Seam welding
  • B23K15/006—Seam welding of rectilinear seams
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/0053—Details of the reactor
  • B01J19/0073—Sealings
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J6/00—Heat treatments such as Calcining; Fusing ; Pyrolysis
  • B01J6/008—Pyrolysis reactions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
  • B23K26/20—Bonding
  • B23K26/21—Bonding by welding
  • B23K26/24—Seam welding
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
  • C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
  • C10G9/18—Apparatus
  • C10G9/20—Tube furnaces
  • C10G9/203—Tube furnaces chemical composition of the tubes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
  • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
  • B23K2101/00—Articles made by soldering, welding or cutting
  • B23K2101/04—Tubular or hollow articles

Definitions

• the invention also relates to a method of manufacturing such a tube.
• furnaces comprise a convection portion for preheating the products to be treated and a radiation portion in which the reforming or cracking reaction takes place.
• the radiation of these furnaces consists of tubes of great length at the entrance of which is injected the product to be treated previously preheated in the convection, namely methane for reforming, and ethane, propane, butane, naphtha and heavier hydrocarbons for cracking.
• the tubes must therefore withstand creep, that is to say mechanical deformations at high temperature, it being understood that the pressure in the reforming furnaces can reach 30 bar, but they must also withstand the oxidation in the atmosphere ovens.
• Nickel stabilizes the austenitic structure. Nickel and chromium contribute to the reduction of corrosion (carburization, oxidation, etc.).
• These alloys also contain carbon. Carbon forms carbides that oppose the deformation of the metal at high temperature and thus increases the creep resistance.
• Silicon is also used to help increase corrosion resistance.
• the tubes used in the furnaces have a length of the order of several meters, generally from 3 to 6 meters. Their internal diameter is 35 to 200 millimeters.
• the tubes used in petrochemical furnaces can sometimes be made by forging.
• International patent application WO 03/011507 also discloses a mechanical method by broaching which makes it possible to make depressions and bumps on the internal face of the tubes of petrochemical furnaces.
• This method consists in scratching the material inside the tube by means of a pin inserted into this tube.
• the spindle has cutting tools whose shape corresponds to the hollow shape and bumps that it is desired to obtain on the inner face of the tube. This process requires several passes of the spindle in the tube, the change of cutting tools between each pass and the recovery of the chips generated by a passage of the spindle in the tube.
• the tube of the invention comprises six attached radial strips which are regularly distributed circumferentially on the inner face of the wall of the tube and which extend over the entire length of the tube whose internal diameter is between 50 and 60 millimeters, and each bar has in section a height of between 8 and 15 millimeters and a width of between 3 and 5 millimeters.
• each bar is secured to the inner face of the wall of the tube by a continuous weld line.
• the invention also relates to a method of manufacturing the previously described tube, which method comprises at least one step of electron beam welding from outside the tube of at least one radial strip attached to the inner face of the wall of the tube.
• this method comprises at least the following steps: insertion into the tube of a bar-holder comprising at least one receiving housing of a bar to be welded, positioning of the bars to be welded on the front bar-holder; after the insertion of the bar-holder into the tube, the positioning of the bars to be welded in the tube at a distance close to the internal face of the wall of the tube, or by the insertion of the bar-holder previously provided with the bars, either by insertion of the bars on the bar-holder previously introduced into the tube, - electron beam welding from outside the tube of the bars on the inner face of the wall of the tube, and removal of the bar-holder.
• a height h of a bar of 12 millimeters is provided for a width 1 of 4 millimeters.
• the bars 4a, 4b, 4c, 4d, 4e, 4f are rectangular section.
• Each housing Ha, Hb, Hc, Hd, He, Hf is such that each bar 4a, 4b, 4c, 4d, 4e, 4f can be held in place in its respective housing.
• Each bar 4a, 4b, 4c, 4d, 4e, 4f is introduced into its respective housing Ha, Hb, Hc, Hd, He, Hf on the bar carrier 10.
• each housing 11a, 11b lie, Hd, Ile, Hf on the door bars
• the electron beam 14 penetrates into the thickness of the wall 2 of the tube 1 by generating enough heat to cause the melting of the wall 2 of the tube 1 at this point on the one hand, and the melting of the end of the tube the bar 4a close to the inner face 3 of the wall 2 of the tube on the other hand, which causes the welding of the bar 4a to the wall 2 of the tube 1 and the joining of each bar 4a, 4b, 4c, 4d, 4th, 4f to the inner face 3 of the wall 2 of the tube 1.
• the bars 4a, 4b, 4c, 4d, 4e, 4f are welded one by one all along the tube 1. To do this, the electron beam 14 is applied to the tube 1 in the direction of a bar 4a since the tube inlet 8
• this electron beam 14 undergoes a linear stroke over the entire length of the tube 1 and up to the end of the tube 1 not shown in the figures.
• the tube 1 it is possible to provide for the tube 1 to translate beneath the electron beam.
• a registration of the position of the bars 4a, 4b, 4c, 4d, 4e, 4f at the inlet of the tube 1 is provided.
• the fixing of a bar 4a on the inner face 3 of the tube 1 may be carried out either by a continuous weld line 15a over the entire length of the tube (FIGS. 10 and 11), or by a discontinuous weld line along the length of the tube 1 (FIGS. 12 and 13).
• a continuous weld the outer face 16 of the tube 1 will have a rib 15a extending along the tube 1 and indicating the presence a bar 4a secured to the inner face 2 of the wall 2 of the tube 1 under this blister 15a.
• Creep tests through the welding bead were performed. These tests demonstrate that the properties of the tube have not been altered.
• the tests consist in evaluating the rupture time in hours under stress of 17 MPa at a temperature of 1100 ° C.
• the break time is greater than or equal to 100 hours.
• the break time is 114 hours.
• the weld bead therefore has satisfactory properties to withstand the stresses imposed in petrochemical ovens.
• the tube of the invention 1 is that of FIGS. 1 and 2, and the tube of the invention 2 is that of FIGS. 3 and 4.
• dT is the difference between the temperature of the gas at the outlet of the tube in question and the temperature of the gas at the outlet of the front tube 1.
• dP is the pressure drop of the gas between the inlet and the outlet of the tube in question. It is found that the heat transfer gain is greater for the tubes of the invention than for a tube having depressions and bumps on its inner surface.
• the pressure drop for the tube of the invention 1 is greater but remains acceptable and the pressure drop in the tube of the invention 2 is quite satisfactory.
• Fixing the strips on the inner face of a tube by welding from the outside of the tube has many advantages.
• the welding bead which provides the connection between the bars and the tube is able to withstand the thermal and mechanical stresses of operation of the high temperature tube.
• the extra weight provided by the bars is significantly lower than that provided by the bumps and troughs of the tubes described in patent applications EP 980729 and WO 03,011507 since there is a reduction of excess weight of about half on the tube of the invention. This allows the tube of the invention to be more easily installed in suspension in the furnaces.
• this cord provides a thermal bridge between the tube and the bar.
• this process applies to any type of metal tubes that are forged or cast centrifuged.
• an electron beam weld it will be possible to use laser welding.
• the radial bars are in the form of segments regularly distributed over the length of the tube.
• the welding process for manufacturing leaves a great freedom of choice both in terms of the materials to be used and the configuration of the bars to be adopted and this, for an efficiency at least equal to that of the tubes with increased internal surface known.

Landscapes

• Chemical & Material Sciences (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Mechanical Engineering (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Thermal Sciences (AREA)
• Optics & Photonics (AREA)
• General Chemical & Material Sciences (AREA)
• Plasma & Fusion (AREA)
• Heat Treatment Of Articles (AREA)
• Welding Or Cutting Using Electron Beams (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Arc Welding In General (AREA)
• Rigid Pipes And Flexible Pipes (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (10)

Families Citing this family (6)

Family Cites Families (9)

• 2007
  • 2007-10-19 FR FR0758445A patent/FR2922636B1/fr not_active Expired - Fee Related
• 2008
  • 2008-02-01 US US12/738,673 patent/US20100230083A1/en not_active Abandoned
  • 2008-02-01 CN CN2008801204140A patent/CN101896789A/zh active Pending
  • 2008-02-01 EP EP08762030A patent/EP2201317A1/de not_active Withdrawn
  • 2008-02-01 BR BRPI0816593-9A2A patent/BRPI0816593A2/pt not_active IP Right Cessation
  • 2008-02-01 CA CA2702863A patent/CA2702863A1/fr not_active Abandoned
  • 2008-02-01 WO PCT/FR2008/050170 patent/WO2009050356A1/fr not_active Ceased
  • 2008-02-01 JP JP2010529430A patent/JP2011500910A/ja active Pending
  • 2008-02-01 MX MX2010004267A patent/MX2010004267A/es not_active Application Discontinuation
  • 2008-02-01 KR KR1020107010852A patent/KR20100101564A/ko not_active Withdrawn

Non-Patent Citations (1)

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