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
  • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
  • F28D7/02—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being helically coiled
  • F28D7/022—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being helically coiled the conduits of two or more media in heat-exchange relationship being helically coiled, the coils having a cylindrical configuration

Definitions

• the invention relates to a heat exchanger' with two helical passages formed by two helical surfaces arranged between a core and a cylindrical casing, and both having substantially the same angle of pitch .
• the heat exchanger is especially intended for use in the exchan ⁇ ge of heat, preferably in counter flow, between flowable media, particularly between media that are employed as materials in a process for biogas production, and media that have been employed in such a process.
• the heat exchanger according to the invention is not limited to the above mentioned use, but can be used in other fields .
• a heat exchanger of the above mentioned type is known from the German patent specification No. 178,080. This describes a heat exchanger which is intended for use in the exchange of heat, either in concurrent flow or counter flow, between liquid or gaseous media, and which comprises a double helix . This helix is formed by helical surfaces, which divide the interior of the heat exchanger into two helical passages, which either have equal size or different sizes .
• pro ⁇ blems can arise from clogging in the areas of the inlet and the outlet, and it is therefore important to construct the inlets and outlets in such a manner as to ensure good flow conditions through the heat ex ⁇ changer.
• the features characteristic of the invention are that the inlet and the outlet of the heat exchanger, which are connected to the helical passages, are constructed substan ⁇ tially without change of the cross-sectional area through the inlet/out- let and the helical passages, that the inlet and the outlet, which preferably consist of pipe stubs of suitable shape, are each directed tangentially relatively to the core and are disposed in a plane which together with a plane perpendicular to the longitudinal axis of the helical passages forms an angle, which substantially corresponds to the angle of pitch of the helical surfaces, that the pipe stubs are connected with the cylindrical wall of the casing, and that at the ends of each stub a guide plate is provided between two adjacent helical surfaces, said guide plate extending tangentially from the core towards the cylindrical wall of the casing.
• the pipe stubs are connected directly with the mouth of the helical passa ⁇ ges so that it becomes unnecessary to provide guide plates or the like means .
• the pipe stubs are connected directly with the mouth , care should be taken that the inlet and the outlet are so directed as above mentioned in order to ensure the optimum flow conditions.
• Fig . 1 is a diagrammatic view of one end of an embodi ⁇ ment of the heat exchanger according to the in ⁇ vention, where an inlet and an outlet are passed through a cylindrical wall of a casing of the heat exchanger
• Fig . 2 an end view of the heat exchanger of Fig . 1
• Fig . 1 is a diagrammatic view of one end of an embodi ⁇ ment of the heat exchanger according to the in ⁇ vention, where an inlet and an outlet are passed through a cylindrical wall of a casing of the heat exchanger
• Fig . 2 an end view of the heat exchanger of Fig . 1
• Fig . 2 an end view of the heat exchanger of Fig . 1
• Fig . 3 a diagrammatic part section through one end of the heat exchanger of Figs . 1 and 2 along the line I l l - I l l of Fig . 2.
• an embodiment of the heat exchanger according to the invention is illustra ⁇ ted , only one end being shown for the sake of clarity, the other end being constructed in the same manner.
• This heat exchanger 1 has two helical passages 2, 3 formed by two helical surfaces 4, 5, which are provided in the form of two plate strips, which are helically coiled and are welded along their inner edges to a core in the form of a tube 6, while their outer edges are welded to the cylindrical wall 10 of the casing 7.
• the two plate strips 4, 5 have the same angle of pitch ⁇ and are arranged substantially midway between one another so that the helical passages have approximately equal cross-sectional areas .
• the cylindrical wall 10 may either consist of a cylindrical tube or may be provided in the form of coiled plate strips, which are welded to the outer edges of the plate strips 4, 5 so as to close the spaces between the plate strips 4,5 and thereby to provide the helical passages 2,3.
• the plate strips 4,5 may alternatively be arranged at a displacement relative to one another so that the helical passages 2, 3 will have different cross-sectional areas.
• an inlet 8 and an outlet 9 are welded to the cylindrical wall 10 of the casing 7 in such a manner that there will be no sudden changes of direction, cavities or substan ⁇ tial changes of the cross-sectional area.
• a window is provided in the wall 10 for each of the pipe stubs 8,9. These windows will now be described with reference to the inlet pipe stub 8 shown in the drawing.
• the window which extends across an angle of approxi ⁇ mately 90°, Is delimited at a first side by a first generatrix 12 of the cylindrical wall 10.
• the first generatrix 12 is located at the line of Intersection between a tangential plane to the cylindrical wall and the wall 10 Itself.
• the window has a width corresponding to the distance between two adjacent plate strips 4,5 and is thus delimited in the longitudinal direction of the heat exchanger by two edges 13, 14 located at the welding line between the plate strips and the wall .
• the last side of the window is delimited by a second generatrix 15 of the cylindrical wall 10.
• the second generatrix 15 is located at the point - of intersection between the wall 10 and a plane, which is parallel to the beforementioned tangential plane, and which is a tangential plane to the tube 6.
• the pipe stubs 8,9 are arranged in such a manner that a front wall 16, as viewed from the end (see Fig . 2) , is directed tan ⁇ gentially relatively to the wall 10 of the casing 7 and is welded to this wall along the first generatrix 12.
• the pipe stubs 8,9 have two side walls 18, 19, which connect the front wall and the rear wall and are welded to the wall 10 along the edges 13 and 14.
• the pipe stubs 8,9 are arranged in a plane, which together with a plane perpen ⁇ dicular to the longitudinal axis of the helical passages forms an angle ⁇ (see Fig . 1 ) , which is identical to the angle of pitch ⁇ of the plate strips 4,5 (see Fig . 3) .
• the pipe stubs 8,9 are gradually changed to a circular shape (not shown) from the approximately polygonal shape at the connection with the wall 10, whereby It becomes possible to connect the heat exchanger with other equipment by means of conven ⁇ tionally produced cylindrical pipes (not shown) .
• the pipe stubs 8,9 are shown with an exaggerated length and can be shorter than shown .
• two guide plates 20, 21 are connected by welding between two adjacent plate strips 4, 5, and these guide plates are directed tangentially relatively to the tube 6.
• the guide plate 20 is moreover welded to a first generatrix 22 of the tube 6 and the above mentioned second generatrix 15 of the cylindrical wall 10.
• the heat exchanger constructed as above described will have very advantageous flow conditions, and it is particularly suitable for use in the exchange of heat between materials employed in a pro ⁇ cess for biogas production, and materials that have been used in such a process . I n such an inhomogenous mass there will be a minimum of precipitation and deposition owing to good flow conditions, and conse ⁇ quently it will rarely be necessary to clean the heat exchanger by flushing .
• the heat exchanger according to the invention can also be constructed in other ways.
• the pipe stubs can be welded directly to the mouth of the helical passages as long as the orientation of the pipe stubs in space, as above described, is observed .
• it is pos ⁇ sible to produce the connections between the individual parts of the heat exchanger otherwise than by welding, e.g . by means of an adhesive.

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)

Priority Applications (1)

Applications Claiming Priority (2)

Publications (2)

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ID=8100091

Family Applications (1)

Country Status (4)

Cited By (1)

Family Cites Families (6)

• 1985
  • 1985-03-06 DK DK102085A patent/DK102085A/da not_active Application Discontinuation
• 1986
  • 1986-03-06 DE DE8686901823T patent/DE3661295D1/de not_active Expired
  • 1986-03-06 EP EP19860901823 patent/EP0216831B1/de not_active Expired
  • 1986-03-06 WO PCT/DK1986/000019 patent/WO1986005262A1/en active IP Right Grant

Non-Patent Citations (1)

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