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
  • F28F19/00—Preventing the formation of deposits or corrosion, e.g. by using filters or scrapers
  • F28F19/01—Preventing the formation of deposits or corrosion, e.g. by using filters or scrapers by using means for separating solid materials from heat-exchange fluids, e.g. filters

Definitions

• the present invention relates to improvements made to the tubes of heat exchangers, in order to avoid clogging of the inlets of these tubes by materials in suspension in the fluid intended to circulate in the tubes.
• This invention is concerned with this problem and it aims to equip the inlet of the heat exchanger tubes with a simple and inexpensive means, capable not only of retaining the detritus entrained by the fluid entering these tubes and to prevent them from being applied against the entry of these tubes by sealing them, but also to cause upstream of this entry of the tubes sufficient turbulence to avoid clogging of the entry of the tube, while ensuring homogenization of the fluid temperature.
• the subject of the invention is a heat exchanger tube with a generally circular section, at the entrance of which a rigid helical element is maintained, this tube being characterized in that the rigid helical element protrudes from the outside the tube, at the entry thereof, in order to keep away from this entry the materials likely to block the entry of the tube, conveyed by the fluid intended to circulate in this tube.
• This rigid helical element has the effect of not only opposing the entry into the tube of various suspended materials entrained by the fluid, but also of causing a significant turbulence of this fluid at the entrance of the tube, thus avoiding that the materials conveyed can completely seal the inlet of the tube.
• the rigid helical element projects upstream from the inlet of the tube over a distance of between approximately 1 and 10 times the external diameter of the associated tube and, preferably, between 2 and 8 times this diameter.
• the rigid helical element can be held in position at the inlet of the tube by any attachment means known in the art, capable of holding it inside or outside the tube according to the exchanger technology.
• such a hooking means can be constituted, for example, in a manner known per se, by a rigid fixing member with U-shaped profile, said "pin" in the technique, which is arranged outside the tube, with the ends of the branches of the U elastically close to one another and engaged in the inlet of the tube, while the helically wound wire is attached to the base of the U.
• the helically wound wire may have turns of diameter smaller than the internal diameter of the tube, but its turns may also bear against the internal wall of the tube.
• any other means of attachment can also be used, for example a system for attaching the rigid helical element to lugs of the tube, inside or outside of it, or even a joining by welding d 'a part of the helical element on the tube.
• the rigid helical element is made integral with the end of the tube at the entrance of which it projects outwards without the aid of any auxiliary fixing member, firmly supported by its turns elastically deformed, against the internal face of the tube, as described in FR-A-2 611 879 in another application, or against the external face of this tube.
• FR-A-2 611 879 relates, in fact, to heat exchanger tubes, in which are placed in a fixed position obstacles intended to cause turbulence in the fluid which circulates therein, with a view to improving the heat exchanges between this fluid and the wall of the tube and reduce the risk of solid waste deposits on the internal surface of this wall.
• a simple way of making such obstacles consists in placing tubes of circular cross section inside, in a fixed position at contact of their internal wall, a wire, for example metallic, wound helically.
• a particularly simple means consists in using a wire of helical profile which is elastically deformable, the diameter of the turns of which is normally greater than the internal diameter of the tube, in stretching this wire longitudinally to reduce the diameter of its turns, in order to be able to introduce it into the tube, and, after having thus introduced it, to release it so that its turns tend to resume their initial diameter inside the tube, by coming to be applied firmly against the inner wall thereof, without the risk of the wire being displaced by the fluid caused to circulate in the tube.
• the invention therefore proposes to adapt this known technique, with a view to obtaining a different result, by similarly arranging a wire wound helically inside the exchanger tube. thermal, in the vicinity of the entry of this tube, but with a projecting part " outside the tube, in order to oppose the passage of the materials conveyed in the fluid.
• the rigid helical element can, when the shape of the tube plate of the heat exchanger, or any other similar device, makes it possible to have tubes of which an outer part of their upstream end can be used, elastically enclosing this end of the tube along part of its length and protruding upstream from the inlet of the tube.
• the rigid helical element advantageously has turns of diameter normally smaller than the external diameter of the tube and it is elastically deformed so as to increase the diameter of certain turns, in order to be able to engage the end of the next tube therein. part of its length, before releasing these turns so that they enclose the tube.
• the rigid helical element can, in all these embodiments, be constituted by a simple rigid wire wound in a helix.
• the ratio of the pitch of the propeller to the diameter of the turns is between 0.1 and 5.0 and, preferably, between 0.5 and 3.0.
• the rigid helical element may possibly extend along the entire length of the tube.
• the diameter of the last turn of the rigid helical element, located outside the tube is less than the diameter of the other turns of this element.
• the invention makes it possible to very effectively prevent the blocking of the entries of the exchanger tubes by suspended materials likely to be pressed against these entries, and the invention therefore also relates to heat exchangers, in particular water coolers and condensers, comprising at least one tube of the type defined above.
• heat exchangers in particular water coolers and condensers, comprising at least one tube of the type defined above.
• Figure 1 is a schematic section of a water supply box, loaded with suspended materials, tubes constituting a heat exchanger, equipped with a wire wound in a helix, which is engaged in the tube and protrudes towards the outside at the entrance to it;
• Figure 2 is a view of a wire wound in a helix and attached to a pin consisting of a metal wire bent in a U and engaged in a heat exchanger tube, outside of which the wire projects;
• FIG. 3 is a schematic view illustrating another embodiment of the invention, in which a helically wound wire, which surrounds the external upstream end part of a tube, projects outside of it .
• FIG. 1 represents a box 1 for supplying water to tubes 2 of circular cross section of a heat exchanger, this box itself being supplied with water by a conduit 3.
• the helical turn formed by the wire 5 preferably has a diameter at greater rest the inside diameter of the associated tube and is elastically deformable.
• the helically wound wire 5 which projects outside the tube 2, may occupy only a short length thereof, near its entry, or extend inside this tube along a major part its length, if it serves at the same time to promote turbulence.
• a wire 6 wound in a helix which is housed at the inlet of a tube 7 of heat exchanger and protrudes outside thereof.
• This wire is not necessarily pressed against the internal wall of the tube, but is held in position in the latter by a pin formed by a metal wire bent in the shape of a U, the two branches of which can be brought together elastically. on the other to be engaged in the tube 7, while the base of the U, to which is simply hooked one end of the wire 6 wound in a helix, projects outside the tube.
• FIG. 3 illustrates another embodiment of the invention, in which the helically wound wire 10 surrounds the upstream end of the heat exchanger tube 11 and projects in " 10a. Beyond the entry of this tube.
• the helical turns normally have a diameter smaller than the external diameter of the tube, as seen by part 10a. protruding, and some of them have been elastically deformed to increase their diameter, so as to be able to engage the end of the tube, to then be released, in order to grip the tube.

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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)

Applications Claiming Priority (3)

Publications (3)

Family

ID=9534310

Family Applications (1)

Country Status (7)

Family Cites Families (11)

• 1998
  • 1998-12-22 FR FR9816222A patent/FR2787564B1/fr not_active Expired - Fee Related
• 1999
  • 1999-12-21 WO PCT/FR1999/003226 patent/WO2000037874A1/fr not_active Ceased
  • 1999-12-21 DE DE69927053T patent/DE69927053T2/de not_active Expired - Fee Related
  • 1999-12-21 ES ES99961127T patent/ES2249051T3/es not_active Expired - Lifetime
  • 1999-12-21 AT AT99961127T patent/ATE303574T1/de not_active IP Right Cessation
  • 1999-12-21 EP EP99961127A patent/EP1144934B9/de not_active Expired - Lifetime
  • 1999-12-21 AU AU17846/00A patent/AU1784600A/en not_active Abandoned

Non-Patent Citations (1)

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