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
  • F28F9/00—Casings; Header boxes; Auxiliary supports for elements; Auxiliary members within casings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F3/00—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems
  • F24F3/12—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling
  • F24F3/14—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification
  • F24F3/1411—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification by absorbing or adsorbing water, e.g. using an hygroscopic desiccant
  • F24F3/1423—Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems characterised by the treatment of the air otherwise than by heating and cooling by humidification; by dehumidification by absorbing or adsorbing water, e.g. using an hygroscopic desiccant with a moving bed of solid desiccants, e.g. a rotary wheel supporting solid desiccants
• • 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
• • 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
  • F28D19/041—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 with axial flow through the intermediate heat-transfer medium
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1004—Bearings or driving means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1008—Rotary wheel comprising a by-pass channel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1012—Details of the casing or cover
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1032—Desiccant wheel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/104—Heat exchanger wheel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1068—Rotary wheel comprising one rotor
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1084—Rotary wheel comprising two flow rotor segments
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F2203/00—Devices or apparatus used for air treatment
  • F24F2203/10—Rotary wheel
  • F24F2203/1096—Rotary wheel comprising sealing means

Definitions

• a rotatable heat exchanger A rotatable heat exchanger.
• the present invention relates to a rotatable heat exchanger of the kind set forth in the preamble of claim 1.
• Rotatable heat exchangers of this kind are used to recove heat, cold and/or moisture from a first gas flow and transfer the heat, cold and/or moisture recovered to a second gas flow.
• the first and second gas flows may be, for instance, ventilation air exiting and entering a building, or some other form of gas flows, such as process gas flows.
• the active part of the rotary heat exchanger, i.e. the rotor is provided with axially extending chan- nels permitting the through-passage of said gas flows.
• the rotor may have mutually different diameters, from about 500 mm to about 5000 mm or thereabove, in order to accommodate mutually different gas flows.
• the length of the rotor in its axial direction may be kept relatively short, normally about 200 mm, even when demands on effi ⁇ ciency are high.
• the rotor is embraced by a housing or rotor casing which has formed therein openings which are directed axially towards the gas flow channels in the rotor.
• a housing or rotor casing which has formed therein openings which are directed axially towards the gas flow channels in the rotor.
• prior art rotary heat exchangers have been provided with axially extending peripheral seals arranged on both sides of the rotor. This positioning of the peripheral seals enables the rotor to be removed laterally without needing to remove the peripheral seals, which saves time when carrying out maintenance work, e.g. cleansing the rotor gas-throughflow channels.
• Another method of preventing leakage is to use axially extending peripheral seals which are elastically biased into powerful abutment with the peripheral surface of the rotor.
• the powerful abutment pressure exerted by these seals engender high frictional resistance forces and increase the energy costs of running the heat ex ⁇ changer.
• Such highly pre-tensioned seals are subjected to a great deal of wear and the seals are there ⁇ fore quickly worn down, with subsequent leakage problems.
• Leakage may also occur as the result of rotor throw or of rotor distortion, since the rotor is often constructed from a comparatively soft material, such as thin aluminium plate.
• the size of these distortions or deformations is normally in the order of from about 1-3 mm.
• a heat exchanger which will be well sealed . around its periphery irrespective of any rotor tilting or rotor deformation that may occur.
• a further object is to provide a -rotary heat exchanger which is of simple Con ⁇ struction, low manufacturing costs, and which can be quickly and readily dismantled and reassembled for repair and maintenance purposes.
• Figure 1 is a perspective, exploded view of a prior art heat exchanger
• Figure 2 is a longitudinal sectional view of the heat exchanger shown in Figure 1, and illustrates leakage flow
• Figure 3 is a partly cut-away axial view of the heat exchanger shown in Figure 1, and illustrates leakage- flow;
• FIG. 4 is a perspective view of a heat exchanger con ⁇ structed in accordance with the present invention, and il ⁇ lustrates a rotor unit in a partially withdrawn position, the side plate or cover plate being omitted for the sake of clarity;
• Figure 5 is a longitudinal sectional view of the heat exchanger shown in Figure 4, and illustrates the construc ⁇ tional principle of the peripheral seals;
• Figure 6 illustrates part of a rotor fitted with a periph ⁇ eral ' seal
• Figures 7a-j illustrate examples of different variants of peripheral seals according to the invention.
• FIGS 1-3 illustrate an earlier known heat exchanger 10 housed in a casing 22 which incorporates openings 14 for accommodating first and second gas flow channels 16, 18. These gas flows may comprise, for instance, supply air an exhaust air flows in an air ventilation system.
• the chan nels are connected to the casing 12 in a standard manner, e.g. with the aid of the indicated connection flanges or pipe-stubs 20.
• a heat exchange rotor 22 Arranged within the casing is a heat exchange rotor 22 having a closed hub portion 24 sur ⁇ rounded externally by through ⁇ flow openings.
• the rotor shaft shown solely by the shaft centre axis 26, is jour- nailed or firmly attached to a frame structure 28.
• the frame structure 28 of the illustrated heat exchanger is known from Applicant's Swedish patent application SE-A- 8200696-6, and comprises two bars, strips or beams 30 which incorporate the rotor shaft journals or rotor at- tachment means and which are rigidly connected together by a cross-piece 32.
• the frame 28 can be inserted into or withdrawn from the casing 12 on rails 34, which are fitted to the . inside of the casing between the connection openings 14 of the two gas-flow channels.
• the rotor and frame pass through an opening 36 in one side wall of the casing which is covered by a side plate 38 or the like, which may be secured to the frame 28.
• a drive motor 40 e.g.
• a belt-drive motor which is connected to a junction box 44 by means of an electric cable 42.
• the channel orifices facing the rotor are sealed by means of axially extending peripheral seals 46 and by means of diametral seals 48 arranged on the rails 34 or on the bars or the like 30.
• a first gas flow passes through the channel 16 and delivers its heat to the rotor material.
• the rotor rotates across to the other channel 18, the rotor delivers the heat stored therein to the second gas flow. Since gaps 50 will appear, at least with time, between the rotor 22 and primarily the peripheral seals 46, as mentioned above, leakage gas flows 52 will pass on one side of the rotor through the space 54 surrounding the rotor in the casing interior. This leaking gas will pass the rotor and either return to the same channel from which it leaked (c.f. in particular Figure 2) or will enter the other gas-flow channel, as illustrated in Figure 3. Both of these occurrences have deleterious effects, as mentioned above.
• FIG 4 illustrates a construction according to the in- vention by means of which leakage at the peripheral seals is eliminated.
• This construction generally shown at 55, includes a transverse wall 56 provided with an opening 58 for accommodating the rotor 22 on a withdrawable frame 28, and a peripheral seal 60 arranged between the peripheral surface 62 of the rotor and the transverse wall 56.
• Exam- ples of different variants of the seal 60 are given below with reference to Figures 6 and 7.
• the transverse wall 56 abuts the floor 64 and the ceiling 66 of the casing 12 through the intermediary of guide and sealing rails 68.
• the trans ⁇ verse wall 56 has at least one angled flange web 70, 72 having at its free end an angularly curved stiffening flange 74.
• the outer and inner end edges of the transverse wall 56 are each provided with at least one flange web 70, 72 and a stiffening flange 74 for sealing abutment with the rear wall 76 of the casing 12 and with the inner surface of the side cover-plate 38.
• the rear.wall 76 and the side cover-plate 38 and/or said at least one flange may be covered with an appropriate material, such as rubber, preferably foamed rubber.
• the transverse wall 58 also carries a housing 78 for the rotor drive motor 44.
• the drive from the motor 44 to the rotor is effected over a drive belt 80 or some equivalent drive means, which connects with the peripheral surface 62 of the rotor.
• the housing 78 has a sealed lead-through (not visible) through which the cable 42 passes to the junction box 44.
• the side cover-plate 38 is securely fitted to the frame 28, in which case the incoming power supply cable to the drive motor is -drawn through the cover plate 38 and connected to an electric socket by means of a cable shoe or plug.
• two diametrical seals 48 are arranged on the longitudinal bars or beams 30 of the frame 28, at least on one side.
• the diametral seals 48 merge integrally with axially extending peripheral seals 82 which extend to the transverse wall 56.
• the peripheral seals 82 present openings for through-passage of the drive belt 80 on the drive-belt side of the transverse wall. This enables the drive belt and peripheral seal arrangement to be con ⁇ figured so as to obtain the minimum of gap, e.g. by driv ⁇ ing the motor with an inverted V-belt.
• the drive belt may be fitted in a groove in the drive rotor so as to lie flush with the peripheral rotor surface 62. It is possible to reduce the area of the leakage gap at the drive-belt through-pass to at most one or two square millimeters.
• these seals may be placed on the guide rails. In this case the peripheral seals 82 are preferably sunk to the plane of the frame 28.
• FIG. 5 is a cross-sectional view of a heat exchanger constructed in accordance with the invention.
• the heat exchanger casing of this embodiment has no internal space in which overflow can take place from one channel to the other.
• Any smal-l leakage flow 84 which might manifest at the peripheral seal 80 passes directly from the one channel side to the other.
• Even relatively pronounced tilting or deformation of the rotor 22 will only result in insignificant changes in radius at the seal, these changes lying within the normal elastic abutment resil ⁇ ience of the seal.
• the magnitude of this change in radiu can be calculated geometrically. When the rotor is tilte through the angle , the maximum change in radius result ⁇ ing therefrom will be (1-cos ⁇ )r.
• a corresponding maximu change at an axially directed peripheral seal is sin ⁇ r.
• Leakage as a result of irregularities in rotor attitude is also smaller in the radial direction of the rotor than in its axial direction. Due to the short length and larg diameter of the rotor, deformations will occur mu ⁇ h more readily in the axial direction than in the radial direc- tion.
• Figure 6 illustrates in detail the arrangement of a seal 60 between the transverse walls 56 and the peripheral sur face 62 of the rotor.
• the seal illustrated in Figure 6 corresponds to the variant shown in Figure 9a, and com ⁇ prises a brush seal 60a secured to the cross wall 56 with the aid of an attachment means 86.
• Figure 7 comprises a number of schematic, cross-sectional views of the transverse wall 56, its connecting part to the guide and sealing rail 68, and the peripheral seal against the peripheral surface 62 of the rotor 22.
• the variants illustrated in Figures 9a-9e have on one side a projecting flange 70 provided with a rearwardly curved stiffening flange 74.
• the variants il- lustrated in Figures 7f-7j correspond to the above, with the exception that these variants are also provided with a substantially L-shaped edge reinforcement 88 having a long connecting flange 90, a flange web 72 and a stiffening flange 74.
• the long connecting flange is secured to the transverse wall 56 in some suitable known manner, e.g.
• edge rein ⁇ forcement 88 and the guide and sealing rail 68 are ar ⁇ ranged so as to prevent leakage of gas from taking place.
• the use of an edge reinforcement 88 results in symmetric guidance of the transverse wall 56 in the guide and seal ⁇ ing rails 68.
• Figures 7a-e and 7f-j illustrate corresponding variants of peripheral seals on a transverse wall 56 without or with an edge reinforcement 88.
• the variants 9a and 9f include a peripheral 'seal 60 having a brush-type sealing element 60a and an attachment means 86.
• the variants il ⁇ lustrated in Figures 7b and 7g include a seal which has the form of an elastic lip, e.g. a rubber lip 60b, and which has an upwardly " folded side edge in abutment with the peripheral surface 62. This seal may exhibit a double fold, in which . case the free end is folded in respective directions.
• a seal 60b shall be directed in different directions in the two channels 16, 18.
• Figures 7c and 7h illustrate a felt seal or a multi ⁇ fold lip seal 60c having an attachment means 86.
• Figures 9d and 9i illustrate a radially extending labyrinth seal 60d, which also includes a part which is secured to the peripheral surface 62 of the rotor.
• Figures 7e and 7j illustrate a seal 60e provided with a brush-sealing element corresponding to the seal 60a in Figure 7a and 7f, but with a differently configured at ⁇ tachment element 86'.
• the attachment element 86' includes a flange or cuff 96 which projects axially outwards from the transverse wall 56 and which is preferably made of a resilient material, such as rubber.
• the flange 96 is attached to a holder part 98, which carries the actual seal. Sealing elements 60b, 60c and 60d may also be used.
• the seal 60e affords a given degree of elastic adjustment to wear in the flange or the cuff 96, and because it can be fitted aod dismantled readily in the axial, direction greatly facilitates maintenance.
• the heat exchanger frame 28 may have a configuration dif ⁇ ferent to that of the illustrated embodiment.
• the frame may also include braces which extend per ⁇ pendicularly to the bars or beams 30, which are connected to the transverse wall 56 and guided by the guide and sealing rail 68.
• the frame may comprise a casing or housing which totally embraces the rotor. This housing has a stationary transverse wall 56 fitted to the inside thereof and is displaceable into and out of the outer heat exchanger casing 12.
• the illustrated embodiment comprises a rotor which has a horizontal shaft and which can be displaced linearly in a horizontal direction. It will be understood, however, that the rotor may be provided with vertically extending gas channels and a vertical shaft and arranged for with- drawal and insertion in a horizontal direction. Although other orientations of the rotor shaft and the direction in which the rotor is withdrawn are also conceivable in principle, but result in practical problems and should therefore be avoided.
• junction box 44 may also accommodate other types of electrical components, such as a rotor speed control device, automatically acti- vated or externally activated emergency stop means or electric switches, and parts of different instruments for monitoring the function of the heat exchanger.
• a rotor speed control device such as a rotor speed control device, automatically acti- vated or externally activated emergency stop means or electric switches, and parts of different instruments for monitoring the function of the heat exchanger.
• Such electrical components are within themselves known to the art and the novelty represented by such components re ⁇ sides in the positioning of said components on a heat exchanger part which can be withdrawn from the heat ex ⁇ changer casing together with the rotor.
• the side cover-plate 38 is separate from the frame 28 and is fitted to the casing 12 on, e.g., hinges (not shown).
• the electric cable is not drawn through the cover_plate and may advantageously be connected-to an electric socket fitted to the inside of the casing, or alternatively connected to an electric socket on the rotor unit, preferably to the junction box.
• the junction box may, alternatively, be placed on a sta ⁇ tionary part of the casing 12, e.g. on an external surface thereof.
• the electric cable 42 is drawn through the cover plate 38 and connected to the junction box by means of a plug or cable shoe.
• Additional electric cables for powering e.g., measuring instruments and monitoring and operating devices, may be connected in a corresponding manner, with the aid of plugs or the like which enable the cables to be quickly dis ⁇ connected.
• the rotor may be driven, e.g., by a friction drive against the peripheral surface 62 of the rotor, in a known manner. This eliminates the necessity of the belt groove and therewith obviates subsequent leakage risks at the periph ⁇ eral seal 82.
• the rotor 22, the frame 28,- the transverse wall 56, the radially di ⁇ rected peripheral seal 60, the side cover-plate 38 (when fitted), the drive motor 40 and, when fitted, the junction box 44 together form a rotor unit 55 which can be with ⁇ drawn from and inserted into the heat exchanger casing 12 in the form of a single package.
• the rotor unit When inserted into the casing 12, the rotor unit is sealed against the casing walls in the flow direction and between the channels by means of the guide and sealing rails 68 and the diametral seals arranged in connection with the bars or beams 30 and/or corresponding guide rails 34.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Thermal Sciences (AREA)
• Physics & Mathematics (AREA)
• Combustion & Propulsion (AREA)
• Chemical & Material Sciences (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
• Separation By Low-Temperature Treatments (AREA)
• Air-Conditioning For Vehicles (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Sealing Devices (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

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ID=20368227

Family Applications (1)

Country Status (11)

Cited By (1)

Families Citing this family (14)

Family Cites Families (6)

• 1987
  • 1987-04-16 SE SE8701606A patent/SE456694B/sv not_active IP Right Cessation
• 1988
  • 1988-04-11 KR KR1019880701620A patent/KR930012242B1/ko not_active IP Right Cessation
  • 1988-04-11 EP EP88903452A patent/EP0355106B1/de not_active Expired - Lifetime
  • 1988-04-11 DE DE8888903452T patent/DE3865197D1/de not_active Expired - Lifetime
  • 1988-04-11 WO PCT/SE1988/000179 patent/WO1988008112A1/en active IP Right Grant
  • 1988-04-11 JP JP63503533A patent/JPH0635919B2/ja not_active Expired - Fee Related
  • 1988-04-11 AT AT88903452T patent/ATE67844T1/de not_active IP Right Cessation
  • 1988-04-11 AU AU16229/88A patent/AU1622988A/en not_active Abandoned
  • 1988-12-13 NO NO885517A patent/NO168914C/no not_active IP Right Cessation
• 1989
  • 1989-10-12 FI FI894829A patent/FI91674C/fi not_active IP Right Cessation
  • 1989-10-16 DK DK511289A patent/DK164305C/da not_active IP Right Cessation

Non-Patent Citations (1)

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