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
  • F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
  • F28F21/08—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal
  • F28F21/081—Heat exchange elements made from metals or metal alloys
  • F28F21/084—Heat exchange elements made from metals or metal alloys from aluminium or aluminium alloys
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
  • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
  • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
  • F25J3/04406—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system
  • F25J3/04412—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system in a classical double column flowsheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J5/00—Arrangements of cold exchangers or cold accumulators in separation or liquefaction plants
  • F25J5/002—Arrangements of cold exchangers or cold accumulators in separation or liquefaction plants for continuously recuperating cold, i.e. in a so-called recuperative heat exchanger
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J5/00—Arrangements of cold exchangers or cold accumulators in separation or liquefaction plants
  • F25J5/002—Arrangements of cold exchangers or cold accumulators in separation or liquefaction plants for continuously recuperating cold, i.e. in a so-called recuperative heat exchanger
  • F25J5/005—Arrangements of cold exchangers or cold accumulators in separation or liquefaction plants for continuously recuperating cold, i.e. in a so-called recuperative heat exchanger in a reboiler-condenser, e.g. within a column
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F13/00—Arrangements for modifying heat-transfer, e.g. increasing, decreasing
  • F28F13/003—Arrangements for modifying heat-transfer, e.g. increasing, decreasing by using permeable mass, perforated or porous materials
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F3/00—Plate-like or laminated elements; Assemblies of plate-like or laminated elements
  • F28F3/02—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations
  • F28F3/025—Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations the means being corrugated, plate-like elements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2250/00—Details related to the use of reboiler-condensers
  • F25J2250/02—Bath type boiler-condenser using thermo-siphon effect, e.g. with natural or forced circulation or pool boiling, i.e. core-in-kettle heat exchanger
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2250/00—Details related to the use of reboiler-condensers
  • F25J2250/04—Down-flowing type boiler-condenser, i.e. with evaporation of a falling liquid film
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
  • F25J2290/32—Details on header or distribution passages of heat exchangers, e.g. of reboiler-condenser or plate heat exchangers
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
  • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
  • F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
  • F25J2290/44—Particular materials used, e.g. copper, steel or alloys thereof or surface treatments used, e.g. enhanced surface
• • 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
  • F28D21/00—Heat-exchange apparatus not covered by any of the groups F28D1/00 - F28D20/00
  • F28D2021/0019—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for
  • F28D2021/0033—Other heat exchangers for particular applications; Heat exchange systems not otherwise provided for for cryogenic applications
• • 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
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/12—All metal or with adjacent metals
  • Y10T428/12014—All metal or with adjacent metals having metal particles

Definitions

• the present invention relates to a corrugated fin for plate and fin heat exchanger and to a vaporizer-condenser comprising fins.
• plate and fin heat exchangers there are different types of plate and fin heat exchangers, each adapted to a field of use.
• the invention advantageously applies to a vaporizer-condenser of an air separation unit or of mixtures containing mainly hydrogen and carbon monoxide by cryogenic distillation.
• the invention applies in particular to the main evaporator-condensers of air distillation apparatus. These vaporizers-condensers vaporize the liquid oxygen under low pressure (typically slightly higher than atmospheric pressure) collected at the bottom of a column, by condensation of medium pressure nitrogen (typically from 5 to 6 bars absolute) circulating in neighboring passages.
• low pressure typically slightly higher than atmospheric pressure
• medium pressure nitrogen typically from 5 to 6 bars absolute
• Double column type cryogenic air separation systems include an air compressor whose energy consumption is conditioned in particular by the temperature difference between the oxygen vaporized in the low pressure column and the nitrogen present in condensed form in the medium pressure column. This temperature difference is itself linked to the pressure difference between the two columns. A reduction in this temperature difference makes it possible to considerably improve the energy consumption of the air compressor, the latter then having to supply air under a lower pressure than in the case where the temperature difference is higher.
• phase change exchangers consist of plates between which waves or fins are inserted, thus forming a stack of vaporization "passages” and condensation "passages".
• waves such as straight waves (Figure 1), herringbone (“herringbo ⁇ e”, Figure 2) perforated or partially offset ( Figure 3).
• the vaporization side of a bath “vaporizer-condenser” has two distinct exchange zones: o A convective exchange zone in the lower part of the vaporizer. The waves are in contact with a liquid phase and heat it up to its saturation temperature.
• the waves are in contact with a two-phase mixture (Liquid / gas).
• the vapor bubbles appear on the wall as soon as the local overheating reaches a certain value called ⁇ T " 0 nset boiung" (the local overheating being the temperature difference ⁇ T sat between the wall temperature T p and the saturation temperature of the fluid T sat ). This value varies depending on the fluid as well as the structure and nature of the material used.
• EP-A-0 303 493 projection of a mixture of metal and plastic particles on a conductive surface. After vaporization at 500/600 ° C of the plastic particles, the surface has a porous layer.
• - US-A- 4 371 034 configuration of plate vaporizer and using porous surfaces on the vaporization side. The porous layer is formed by high speed bombardment of molten particles on the flat surface or by bonding of particles on the wall.
• - FR-A-2 443 515 manufacture of a porous copper surface. The method consists in coating a tube or a plate with a crosslinked organic foam and depositing inside this foam, an electrolytic coating of copper. The foam is then pyrolyzed.
• - US-A-4,064,914 manufacture of a porous copper or steel layer on a copper or copper alloy base.
• This porous layer consists of metallic powder assembled by bonding and then brazed.
• - US-A-3 384 154 use of a porous layer for boiling a liquid.
• This porous layer must be bonded to a conductive metal wall and made up of conductive particles linked together and forming interconnected cavities. The manufacturing procedures are preferably sintering, welding, brazing and other processes.
• the thickness of the porous layer must be greater than the diameter of the particles and preferably less than three times the diameter of the particles.
• the problem is to obtain an exchange surface which responds to both: o the fact of having an overall geometry of wave or fin type which can be brazed in an exchanger, in particular a vaporizer-condenser, o the having a structure intensifying the boiling and whose characteristics are a high density of cavities, a size and a shape of cavities adapted to the fluid and cavities connected together.
• Manufacturing methods by mechanical treatment require a certain thickness of the conductive surface. These mechanical treatments are difficult to apply to the waves used in a vaporizer-condenser since the sheet thicknesses vary from 0.2 to 0.5 mm.
• the methods of chemical or laser attacks generate a limited surface state since these present cavities at only one level of the surface and not interconnected.
• Sintered materials in wave form which make it possible to obtain a wave or fin type exchange surface and which has a porous layer formed by a plurality of diameters of interconnected cavities:
• Sintered materials (“sintered porous structure”) are commonly used in industry for the filtration of gases and liquids. Standard products are in stainless steel and bronze. However, manufacturing from highly conductive materials (such as copper or aluminum) is technically possible. These porous materials can be made from metal particles or metallic fibers or even metallic fabrics.
• these porous structures made of highly conductive materials are used for a heat transfer application and more precisely for nucleated boiling of a liquid.
• One of the parameters which varies the porosity of a frit is the size of the metal particles used. Indeed, the diameters of the cavities created after sintering is directly related to the size of the metal particles used. It is possible to select a size of metal particles to be used in order to obtain cavities of desired average diameter. These are (mostly) aluminum particles with sizes between 45 and 200 ⁇ m (3%> 200 ⁇ m and 15% ⁇ 45 ⁇ m).
• the porosity (after sintering) is 20%. It is also possible to use several sizes of metal particles in order to obtain a range of cavity diameters. Because the plurality of cavity diameters promotes boiling. The distribution of cavity diameters (particle size) is heterogeneous (random) if the metal particles are mixed together beforehand. Waveforming can be done either directly during sintering using waveform molds, or by machining (EDM) grooves after sintering a thick porous plate.
• EDM machining
• a typical heat exchanger consists of a stack of all identical rectangular rectangular plates, which define between them a plurality of passages for fluids to be brought into indirect heat exchange relationship. These passages are successively and cyclically passages for a first fluid, for a second fluid and for a third fluid.
• Each passage is bordered by closing bars which delimit it, leaving free entry / exit windows for the corresponding fluid.
• wave-spacers or corrugated fins serving both as thermal fins, as spacers between the plates, especially during brazing and to avoid any deformation of the plates when using fluids under pressure, and for guiding the flow of fluids.
• the stack of plates, closing bars and spacer waves is generally made of aluminum or aluminum alloy and is assembled in a single operation by brazing in the oven.
• Fluid inlet / outlet boxes generally semi-cylindrical in shape, are then welded to the exchanger body thus produced so as to cover the rows of corresponding inlet / outlet windows, and they are connected to pipes. supply and evacuation of fluids.
• the object of the invention is therefore to propose a fin which overcomes the disadvantages of the prior art, and which can be used in industrial exchangers, in particular plate and fin heat exchangers of a separation unit of air or H 2 / CO mixtures by cryogenic distillation, and in particular in a vaporizer / condenser.
• the subject of the invention is a corrugated fin for a plate and fin heat exchanger, of the type having a main general direction of undulation, and comprising a set of wave legs connected alternately by a wave vertex. and by a wave base, characterized in that the wave legs, the vertices and the wave bases are formed from a strip of sintered metal particles.
• the wave legs, the vertices and the wave bases form, in cross section relative to the main direction of undulation, rectilinear segments, the vertices and the bases being parallel to each other; -
• the particles are made of aluminum, an aluminum alloy containing at least 90% mol.
• a vaporizer-condenser of the type comprising a stack of parallel plates, closing bars and possibly spacer waves, which define a first series of passages for a fluid to be vaporized supplied at source, and a second series of passages contiguous to the first for at least one fluid for heating said fluid to be vaporized, said passages of the first series are divided into three successive zones, from the bottom to the top of the vaporizer-condenser: - a first zone configured to favor heat exchange by convection; - a second zone configured so as to favor the nucleated boiling phenomenon; - a third zone configured so as to favor the phenomenon of convective boiling; characterized in that at least the second zone and possibly the third zone contains fins according to any
• this vaporizer is of the bath vaporizer type.
• a vaporizer-condenser of the film vaporizer type containing fins according to any one of claims 1 to 5.
• an apparatus for separating air by cryogenic distillation comprising at least one vaporizer-condenser according to one of claims 6 to 8.
• the apparatus may comprise at least two columns thermally connected together by means of a vaporizer according to one of claims 6 to 8.
• These fins can be of the partial offset type, straight or perforated straight.
• the invention further relates to a heat exchanger equipped with at least one fin as described above.
• a fin according to the invention has wave vertices 121, defined by the vertices of the slots, flat and horizontal. It has wave bases 122, defined by the bases of the slots, also flat and horizontal. The vertices and the bases alternately connect plane and vertical wave legs 123, the mean plane of which extends perpendicular to the direction D1.
• the fins of Figures 1 to 3 have a thickness t between 0.25 and 0.6 mm and the pores (not shown) formed in the fin have a diameter ranging from 10 to 100 ⁇ m.
• the vaporizer-condenser of Figure 4 is almost completely submerged in the liquid oxygen collected in the tank of the low pressure column of an air distillation apparatus. A passage is therefore supplied "in source” with liquid oxygen. This liquid oxygen first enters a first zone of passage 2 to be heated there by the nitrogen circulating in the contiguous passages of the vaporizer-condenser.
• this first zone preference is given to heat exchange by convection and the materials which constitute it are given a configuration which maximizes this type of exchange.
• this first zone is filled by heat exchange waves having a large exchange surface without however providing too high pressure losses, such as waves with partial offset (called “serrated waves” Figure 3), or straight waves perforated or not (Figure 1), or herringbone type waves (Figure 2) "herringbone” defining numerous and narrow corridors for the passage of liquid oxygen.
• a density of at least 10 fpi (10 waves per inch in width, ie 3.9 waves per cm) is recommended, preferably from 14 to 30 fpi (5.5 to 11, 8 waves cm).
• this first zone can extend over approximately 1/3 of the total height of the vaporizer-condenser, for example over a height of 40 cm for a vaporizer-condenser 1, 20 m high, dimension which is classic for air separation devices.
• the heat exchange waves could be replaced by a padding of metal foam or a material such as aluminum.
• the oxygen rising in the passage then enters a second zone 3 where it is sought to promote a phenomenon of boiling nucleated by the formation of bubbles of gaseous oxygen on the walls of the waves located in the passage.
• waves of sintered aluminum particles are used so that the porosities of the wave multiply the possible initiation sites for the formation of bubbles.
• Porosities or micro-reliefs can also be provided both on the walls of the plates of the exchanger delimiting the passage. Indeed, even more than in the first zone, it is important to limit the pressure losses of the fluid so as not to hinder the ascent of the liquid oxygen-gaseous oxygen mixture present.
• the oxygen in liquid and gaseous form rising in the passage finally enters a third zone 4 where it is again sought to promote heat exchanges with the fluid passing through the contiguous passages. It aims to be in a convective boiling regime. Waves of sintered aluminum particles can also be installed there in order to favor the increase of the bubbles of gaseous oxygen present.
• the walls of the waves and the plates are covered with a layer of liquid oxygen through which heat exchange takes place. Its thickness depends above all on the flow conditions of the liquid oxygen-gaseous oxygen mixture.
• the heat exchanges are all the more favored as the speed of the fluid is high. It is therefore important to limit as much as possible the pressure drop of the oxygen during its ascent in this third zone.
• this third zone can represent approximately half of the total height of the passage, or 60 cm for a vaporizer-condenser of 1.20 m high.
• each of the zones described above can be divided into several sub-zones having exchange surfaces configured in different ways, provided that in each of these sub-zones, the phenomenon to which the corresponding zone is dedicated is effectively privileged: convective exchange for the first zone, nucleated boiling for the second zone, convective boiling for the third zone.
• the invention can also be applied in vaporizers-condensers treating gases other than oxygen if the advantages which it presents can be exploited.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• General Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Dispersion Chemistry (AREA)
• Separation By Low-Temperature Treatments (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)

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• 2004
  • 2004-01-12 FR FR0450068A patent/FR2865027B1/fr not_active Expired - Fee Related
  • 2004-12-17 JP JP2006548332A patent/JP2007520682A/ja active Pending
  • 2004-12-17 CN CNB2004800403153A patent/CN100478639C/zh not_active Expired - Fee Related
  • 2004-12-17 EP EP04816575A patent/EP1730461A2/de not_active Withdrawn
  • 2004-12-17 WO PCT/FR2004/050722 patent/WO2005075920A2/fr active Application Filing
  • 2004-12-17 US US10/585,843 patent/US20080230212A1/en not_active Abandoned
• 2010
  • 2010-08-19 US US12/859,344 patent/US20100313599A1/en not_active Abandoned

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