Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H3/00—Air heaters
  • F24H3/02—Air heaters with forced circulation
  • F24H3/06—Air heaters with forced circulation the air being kept separate from the heating medium, e.g. using forced circulation of air over radiators
  • F24H3/065—Air heaters with forced circulation the air being kept separate from the heating medium, e.g. using forced circulation of air over radiators using fluid fuel
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F1/00—Tubular elements; Assemblies of tubular elements
  • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F1/00—Tubular elements; Assemblies of tubular elements
  • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
  • F28F1/40—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only inside the tubular element
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F1/00—Tubular elements; Assemblies of tubular elements
  • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
  • F28F1/42—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being both outside and inside the tubular element
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F1/00—Tubular elements; Assemblies of tubular elements
  • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
  • F28F1/42—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being both outside and inside the tubular element
  • F28F1/422—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being both outside and inside the tubular element with outside means integral with the tubular element and inside means integral with the tubular element
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F2215/00—Fins
  • F28F2215/10—Secondary fins, e.g. projections or recesses on main fins

Definitions

• the invention relates to an air heater for small rooms, in particular for mobile rooms such as caravans, mobile homes, boats or the like, according to the preamble of claim 1.
• a tubular combustion chamber is surrounded by a heat exchanger insert made of an inner jacket which is ribbed on both sides.
• this insert is open at one end, while at the other end it has a cover cap placed on the inner jacket for deflecting the combustion gases rising in the flame or combustion chamber tube into a heating chamber formed between the flame tube and the inner jacket of the insert, into which the combustion gases are led downwards and through an exhaust gas duct to the outside.
• Another formed between the inner jacket and an outer jacket The annulus is used to heat air flowing through it.
• This known heat exchanger insert is designed with its inner and outer ribs as an extruded profile part.
• the inner and outer ribs which protrude radially from the inner jacket and extend over its full length, are wing-shaped with flat surfaces.
• a heat exchanger insert has inner and outer ribs which are positioned opposite one another on the inner jacket and the inner ribs are alternately wider and narrower. This heat exchanger insert is produced in the casting process in the form of a hood, which can only be used for a certain size of device and is also complex and expensive.
• the outer ribs end with their mostly pointed outer edges at a greater distance from the outer jacket in order to prevent the outer jacket from overheating in places.
• the invention is therefore based on the object of creating an air heater with a suitable heat exchanger insert.
• fen which consists of a simple molded part with enlarged heat transfer surfaces that are particularly suitable for optimal airflow.
• the heat exchanger insert of which is provided with an inner jacket with favorably designed inner and outer fins, particularly large heating surfaces can also be achieved in a dense arrangement without being made difficult by extrusion molding.
• the compression of the inner fins by wide and narrow fins alternately distributed over the circumference ensures that the flow of combustion gas in the boiler room is largely fanned out, without creating an excessive constriction of the throughflow spaces on the free inner edges of the fins.
• the material stresses and the heat flow paths are shortened by inner and outer ribs placed at the same point on the inner jacket, and the transverse webs projecting at least on one side on the outer edges of the outer ribs also increase the outward-radiating surfaces, so that the outer ribs with the outer transverse webs can extend up to close to the outer jacket without fear of excessive heating of the outer jacket in places.
• Particularly large radiation areas result when the crosspieces protrude from the outer ribs on both sides and approach each other with their ends, or when they unite to form a closed circumferential jacket, between which and the outer jacket a separate air flow is created, which is compared to that between the main air flow guided outside ribs has an insulating effect on the outside.
• Additional transverse extensions on the outer ribs have also proven to be advantageous, since they not only increase the heat transfer areas, but also protrude into the air flows between the ribs.
• the surfaces of the ribs on extruded profiles can be expanded with a variety of design options. Wavy or serrated surface longitudinal profiles have proven to be particularly favorable.
• the ribs can have cross-sections that are the same throughout or taper towards the free edges. A further enlargement of the transmission areas on the inner and outer ribs could finally be achieved by means of serpentine cross sections.
• FIG. 1 shows an axial section through an air heater
• FIG. 2 shows a plan view of a heat exchanger insert according to FIG. 1,
• FIG. 3 shows a plan view of an enlarged inner rib
• FIG. 4 shows a detail section with modified ribs
• FIG. 5 ribs with a corrugated surface, enlarged
• FIG. 6 serpentine ribs
• Fig. 7 is a plan view of a heat exchanger insert with a closed peripheral jacket.
• a heat exchanger insert 2 according to the invention is inserted between a flame or combustion tube 1 and an outer jacket 3 made of a suitable material (FIG. 1).
• This insert (FIG. 2) consists of an inner jacket 4 with inner ribs 8 and outer ribs 10. Together with the flame tube 1, the inner jacket 4 delimits a heating chamber 6 through which the combustion gases 5 are deflected from the combustion chamber 5, while the inner and outer jacket 4, 3 an annular space 7 for heating form an air flow.
• the inner and outer ribs are placed opposite each other on the inner jacket, their radial widths are approximately the same and they extend over the entire length of the inner jacket.
• narrow inner ribs 9 In order to accommodate as many inner ribs as possible, they can be divided alternately into wide inner ribs 8 and narrow inner ribs 9 (FIG. 4). On the other hand, the narrow inner ribs 9 can also be replaced by short rib extensions 9 '(FIG. 2). This tight rib arrangement enables the combustion gas flow to be fanned out to a large extent, but without creating an excessive channel narrowing on the inner edges 11 of the flame tube. The flame tube 1 can rest directly on these inner edges, so that the heat from the flame tube is transferred directly to the heat exchanger insert.
• the flame tube extends upwards in the interior of the heat exchanger insert 2, where it ends with its upper outlet opening shortly before a ceiling surface 14 which covers the heat exchanger insert or its inner jacket and which is expediently welded on.
• a ceiling surface 14 which covers the heat exchanger insert or its inner jacket and which is expediently welded on.
• the combustion gases rising in the flame tube are deflected into the heating chamber 6, from which the combustion gases on the burner side of the insert are in turn discharged into the open via an exhaust gas connection 22 and a chimney or the like.
• the air to be heated flows in counterflow to the combustion gases in the heating space.
• the air to be heated enters the annular space on the burner side, often acted upon by a blower (not shown), and at the other end either directly or via an air heating system into the space to be heated.
• the outer ribs likewise contribute to a strong fanning out of the air flow and bring about its rapid and intensive heating, in particular through the transverse webs 13 and transverse extensions 15 projecting into the air flows.
• the extrusion process also makes it possible to, in particular, the surfaces of the ribs the inner ribs, with wavy or serrated surfaces.
• Corrugated inner ribs 16 are shown enlarged in FIG. 5, for example, these ribs additionally showing a taper 17 towards their free ends in order to adapt to the material stresses that occur.
• an inner rib 8 with serrated surfaces is shown enlarged in FIG. 3. As FIG.
• the ribs can also have a serpentine shape 20 in cross-section, which can also be achieved well in particular on the inner ribs in conjunction with corrugated or serrated surfaces.
• Screw channels 21 can also be formed in some of the outer ribs, into which screw threads can be cut at the fastening end of the heat exchanger insert in order to fasten them on a base plate.
• the transverse webs on the outer ribs can approach each other even more or finally a closed circumferential form jacket 40, which closes the annular space 7 to the outside (Fig. 7).
• this peripheral jacket forms an additional air flow space 41, which surrounds the annular space 7 to the outside and forms an insulating jacket, after the air flowing through will not heat up as high as that in the annular space 7.
• the heat exchanger insert according to FIG. 7 also shows outer ribs 10, which are distributed at greater intervals than that in FIG. 2 on the circumference of the inner jacket 4 and which also have somewhat longer transverse extensions 15.
• the heat exchanger insert according to the invention as an extruded profile can be connected particularly advantageously to a base block 25, which forms two concentrically arranged ring channels, an exhaust gas channel 26 and an outer supply air channel 27.
• the supply air duct is penetrated at one point by a radially projecting exhaust gas connection 22, which is surrounded by a jacket tube 28 to form a preheating air duct 29 around the exhaust gas connection.
• the base block With its central ring wall 30, the base block forms a mounting base 31 for the inner jacket 4 of the heat exchanger insert with the interposition of a sealing ring 32.
• the flame tube 1 can be plugged onto a central tube piece 33 that closes the base block inwards, while a burner tube 35 with its gas and air inlets is inserted into this central pipe section.
• the exhaust and supply air channels 26, 27 are the boiler room 6 and the annular space 7 adapted so that sealed flow spaces arise. At the other, usually upper end of the heat exchanger insert, the air heated in the annular space 7 can either exit directly into the space or be brought together to form a connection 36 for an air heating system.

Landscapes

• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Geometry (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
• Details Of Fluid Heaters (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6432169

Family Applications (1)

Country Status (5)

Cited By (13)

Families Citing this family (10)

Citations (4)

Family Cites Families (6)

• 1991
  • 1991-05-22 DE DE4116692A patent/DE4116692A1/de not_active Ceased
• 1992
  • 1992-05-18 CZ CS923670A patent/CZ281280B6/cs not_active IP Right Cessation
  • 1992-05-18 DE DE59206911T patent/DE59206911D1/de not_active Expired - Lifetime
  • 1992-05-18 EP EP92910390A patent/EP0544853B1/de not_active Expired - Lifetime
  • 1992-05-18 WO PCT/EP1992/001085 patent/WO1992020975A1/de active IP Right Grant
  • 1992-05-18 HU HU9203699A patent/HU214723B/hu not_active IP Right Cessation

Patent Citations (4)

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