Classifications

• • 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
  • F28D19/00—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium
  • F28D19/04—Regenerative heat-exchange apparatus in which the intermediate heat-transfer medium or body is moved successively into contact with each heat-exchange medium using rigid bodies, e.g. mounted on a movable carrier
  • F28D19/047—Sealing means

Definitions

• the present invention in a first aspect relates to a regenerative heat exchanger of the kind specified in the preamble of claim 1 and in a second aspect to a method for operating a regenerative heat exchanger as specified in the preamble of claim 8.
• Such a heat exchanger is known e.g. through SE 176375, disclosing a support in the form of rolling bodies, mounted in the outer ends of sector-shaped plates closed to both ends of the rotating part and rolling on a flange along the periphery at the top and bottom end of the rotor.
• graphite has excellent lubrication properties and like carbon has an ability to maintain the flanges of the rotating body clean when adhering a lubricating layer o carbon or graphite on the flanges.
• the abrasion of the sliding shoe also secures a correct contact with parallel contact surfaces so that the contact takes place on the complete sliding shoe surface.
• Carbon and graphite also have a good acceptance of the high temperature and the acid environment that are present. By the abrasion of the sliding shoes they will gradually be consumed and have to be replaced. The degree of abrasion, however, will vary widely, so that one or more sliding shoes might be worn down so much that the clearance reaches zero, whereas other sliding shoes will be almost unaffected.
• Each sliding shoe therefore is adjustable in a direction perpendicular to the contact surface.
• a similar solution is disclosed in WO95/00809, in which there is provided a measuring rod adjacent to the sliding shoe, which measuring rod is directed parallel to the adjustment direction. The measuring rod from a resting position can be momentary brought in contact with the related flange and indicates when the size of the clearance requires advancement of the sliding shoe a distance so that the initial clearance is restored.
• the object of the present invention is to attain a regenerative heat exchanger of the kind in question having contact-free support means without the drawbacks entailing earlier known constructions.
• the invention is particularly but not exclusively suitable for such heat exchangers where the plates are sector shaped plates located closed to the end surfaces of the rotor so that the support means are axially directed.
• fig. 1 is a partial axial section through a first preferred embodiment of a heat exchanger accord ⁇ ing to the invention
• fig. 2 is an axial section through the support means along line II-II of fig. 1
• fig. 3 is a section corresponding to that of fig. 1 but illustrating a second embodiment of the invention
• fig. 4 is a partial axial section through the support means according to a third embodiment of the invention
• fig. 5 is a section corresponding to that of fig. 4 but illustrating a fourth embodiment of the invention.
• the heat exchanger illustrated in fig. 1 is of conventional type having a stationary casing 1 an a cylindrical rotor 2 containing the regenerative mass 3.
• the rotor has a hub 4 and an upper fixed sector shaped centre plate 5 with a movable sector plate 6 pivotally connected thereto and corresponding lower fixed centre plate 7 and movable sector plate 8.
• the two sets of plates 5, 6 and 7, 8 have the function to seal against the upper and lower ends of the rotor 2 a tight as possible and thereby separate the heat exchanging media flowing to and from the roto through axial openings connected to media ducts (not shown).
• Fig. 2 illustrates a part of the casing and the upper edge flange 12 of the rotor and the upper movable sector plate 6.
• one of the devices 10 is fixed by screws.
• the device includes an outer sleeve 15 with a mounting flange 16, which with an intermediate sealing ring 17 is attached to the sector plate 6 by means of screws 18.
• the outer sleeve 15 has an internal thread 19 and within the outer sleeve 15 there is an inner sleeve 20 having an upper part with an external thread, partly screwed into th thread 19.
• the inner sleeve is provided with a packing 22, which sealingly contacts the inside of the outer sleeve 15.
• the upper end of the inner sleeve 20 is provided with a nut 23 welded thereto and its lower end is provided with a bottom plate 24 welded thereto.
• a circular sliding shoe 25 of graphite or carbon is exchangeable attached by means of a recessed screw 26 screwed into the bottom plate 24.
• the sliding shoe 25 has a front surface 62 facing and being parallel to the circumferentially continuous guiding surface 61 of the flange 12.
• the upper end of the outer sleeve 15 is provided with an external annular flange 27 to which the upper end of a sealing bellow 28 of metal is screwed by means of a mounting ring 29, an annular packing 30 and screws 31.
• the lower end of the bellow 28 is provided with a mounting ring 32, which by means of screws 33 and an intermediate packing 34 is attached in a circular hole in the casing 1 so that a pre ⁇ determined axial force will be applied downwards on the plate 6 due to the spring effect of the bellow 28.
• a measuring device 13 is provided for measuring the clearance between the plate 6 and the flange 12. It includes a tube 40, attached with its lower end in a hole 41 in the sector plate 6 and with its upper end in a hole 42 in the flange 27, and thus extends within the bellow 28. Inside the tube there is a measuring rod 43, the upper end of which is fixed in the shown position to a sleeve 44 by means of a not shown spring and an external flange on the rod, which sleeve 44 is screwed on to the tube 40. In that position a scaled part 45 of the upper end of the rod 43 projects out through the sleeve 44, and the bottom end of the rod 43 is aligned with the underside of the sector plate 6.
• Water thereby is supplied from the water source 64 to the guiding surface 61 of the flange 12.
• the temperature of the flange is about 350° C, which will result in complete or partial vaporization of the water that comes into contact therewith.
• the pressure of the water is sufficient to force the water to continuously flow from the channels 66 and escape between the guided surface 62 and the guiding surface 61, which thereby are pressed away from each other In that way a cushion of the vaporized water is formed between these surfaces 61, 62, having an axial thickness of a fraction of a mm. Since there will be no contact between the surfaces 61, 62 no wear of the sliding shoe will occur. Sufficient water pressure in some applications will be attained by the ordinary line pressure, but in other applications a pump for raising the pressure might be necessary.
• Figs. 4 and 5 illustrate two preferred alternatives in which these channel 66 are arranged to promote the creation of the steam cushion.
• the channels 66 at the bottom side ends in a cavity 67 facing the guiding surface 61 of the flange 12, and the walls 68 of the cavity 68 are preferably tapered.
• the channels 66 are inclined relative to the axial direction and meet centrally at the guided surface 62 of the sliding shoe 25.

Landscapes

• 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 (2)

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• 1995
  • 1995-02-10 SE SE9500476A patent/SE503962C2/sv not_active IP Right Cessation
• 1996
  • 1996-02-09 DK DK96903291T patent/DK0807237T3/da active
  • 1996-02-09 EP EP96903291A patent/EP0807237B1/de not_active Expired - Lifetime
  • 1996-02-09 PL PL96321712A patent/PL321712A1/xx unknown
  • 1996-02-09 WO PCT/SE1996/000156 patent/WO1996024812A1/en active IP Right Grant
  • 1996-02-09 DE DE69611519T patent/DE69611519T2/de not_active Expired - Fee Related

Non-Patent Citations (1)

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