EP1507126A2 - Gas heating device and fin for same - Google Patents

Abstract

A unit (1) for heating gas streams, especially for motor vehicle interiors and engine air inlets comprises a tubular heater (2) with laminas (7) attached to the outside of the tube to warm the gas, especially air. The laminas extend radially from the tube and have embossing projecting from their surfaces.

Description

The invention relates to a device for heating Gas streams, in particular for heating interior spaces, such as of motor vehicles, for heating the intake air of engines or the like, with at least one substantially tubular heating unit with arranged on this Fins for heat dissipation to the gas to be heated, in particular Air. It is also on a lamella of such Device directed.

For heating the passenger compartment of motor vehicles it is known, using waste gas heat exchangers, the waste heat to use the drive motor. The disadvantage here is that especially at low ambient temperatures the Warming up the interior or the passenger compartment with significant delay occurs after several minutes, which is for, the inmates are extremely uncomfortable. Furthermore modern engines have a higher efficiency, so that they generate less waste heat, which is used to heat the Interior of the vehicle in the cold, not more sufficient.

DE 198 48 169 A1 describes a generic device for the heating of interiors, in particular of Motor vehicles. The device has a plurality of for dissipating heat to the gas to be heated lamellae on which in a parallel arrangement on a heated Heating unit in the form of one or more parallel profile tubes, in particular square tubes, sit clamped, with the square tubes or the one or more recesses of the slats push through. For improved heat transfer between the Square tubes and the slats is provided, which the Square tubes facing edges of the openings of the slats forming tubes in contact with each other Turn tabs out of the slat plane. Further are the slats at their heat to be heated to the Gas serving areas extending in the longitudinal direction the fins radially away from the tubes or between them extend, with bent out of the lamellar plane Clamps equipped, which at the adjacent one Slat elastic come to rest and the arrangement thus stabilize a large number of slats next to one another. Finally, the slats - in the longitudinal direction the same considered - the side of the breakthroughs arranged and extending in the longitudinal direction of the slats Beading on which the clamping seat of the slats Stabilize the square tubes.

Due to the clamping seat of the slats on the profile tubes can change the dimensions of temperature changes balanced both the slats and the pipes be so durable and against vibration stable seat of the slats while ensuring a constant heat transfer between square tube and lamellae is ensured.

Although such a heating element leads due to its independence from the waste heat of the drive motor proportionally quickly warms the passenger compartment and becomes also with vehicles with modern engines with high efficiency a permanent warming of the passenger compartment as well ensured at low ambient temperatures. however have the slats of the known device on the one hand a relatively poor dimensional stability, in particular in the case of vibration, as in operation inevitably occur in a motor vehicle Noise leads and also manufacturing problems entails, the lamellae e.g. on the occasion of punching process and incurred as a committee. On the other hand, in particular, the heat transfer the lamellae needed to be improved, which primarily related to the being heated Gas flow the available heat exchange surface of the Slats happened relatively quickly. Moreover, it can especially in the case of surface irregularities of the Profile tubes occur that in contact with these, arranged at the edges of the openings of the slats Tabs only partially, e.g. only selectively, to the Profile tubes abut, so that here too inadequate Heat transfer takes place.

Based on this prior art, the invention the task is based, in a device of the above mentioned type or in a lamella of such a device for improved heat transfer and at the same time for to provide increased dimensional stability of the slats.

According to the invention, this object is achieved in a device of the type mentioned solved in that the slats are provided with embossments, which of the lamellar plane protrude.

To solve this problem, the invention also provides a lamella for such a heater before that they provided with embossments, which of the lamellar plane protrude.

Due to the embodiment of the invention is on the one hand a considerably improved over the prior art Heat transfer to the gas to be heated, in particular air, ensured by the imprints on the one hand the Heat exchange surface is increased, on the other hand in particular generates local turbulence of the gas stream to be heated which are favorable for the heat transfer are. It is also possible, in particular, for a flow velocity, which in a conventional - level - Formation of the slats to a laminar flow leads to achieve a turbulent flow, so that the Formation of a substantially constant temperature gradient the gas flow in the area of the surface of the slats prevents and driving the heat transfer temperature difference between lamella and gas flow as a result of Turbulence in the area of the fin surface is increased. At the same time, the turbulence of the gas stream also its contact time with the lamellar surface and thus the increases the heat transfer available residence time. Moreover, it is by appropriate arrangement of Imprints possible for a respective desired line or To provide diversion of the gas stream to be heated, which in particular in case of using the heater in Motor vehicles is advantageous, which by design usually have air ducts with multiple curvatures. Furthermore, the embossings according to the invention confer the lamella increased dimensional stability, so on the one hand Noise of the heater as it is under the action of Vibrations can occur, reliably prevented. This applies both to the use of the invention Device for heating the passenger compartment of motor vehicles as well as in the case of their use for preheating the intake air of internal combustion engines, as it mainly carried out in diesel engines. On the other hand Bending of the lamellae in the manufacture or in the Further processing, e.g. during punching, avoided, so that effective mass production is by far the most Prevention of rejects is ensured.

With "embossing" of the slats in the context of the invention are in the rest only such deformations of the general level slat plane addressed which the lamellar plane do not enforce, i. At any rate, they are not the ones Slats penetrating openings or holes in the area the imprints exist, which the dimensional stability could affect the slats. The invention Embossments of the slats are therefore exclusively under Maintaining an unbroken surface on the Slats arranged. Such imprints while maintaining an uninterrupted lamellar plane have further especially for reasons of better heat conduction within the fins of their with the tubular heating unit in thermally conductive contact areas proved to be favorable to the peripheral region of the slats.

In an expedient embodiment, the embossments are at least at the serving for heat dissipation to the gas to be heated Area of the slats, which extends in the longitudinal direction of the slats substantially radially of the at least one tube stretches away, arranged to be there for a flawless Heat transfer to provide the gas to be heated.

The fins are preferably clamping on the outside arranged of the tube, as it is quoted from the above DE 198 48 169 A1 is known.

In an advantageous embodiment, a plurality of in Flow direction of the gas to be heated in a row arranged slats may be provided, in particular successively arranged rows of embossments of the slats can be provided. This particular in rows arranged embossments may preferably in the flow direction to be arranged offset of the gas to be heated. A Such a design of the slats is on the one hand easy and inexpensive to produce, on the other hand can be in particular a large number of turbulences of the lamellar plane sweeping gas flow and in particular also turbulence, which - as already mentioned - for an improved heat transfer of the fins to the gas flow as well as for improved heat conduction within the Gas flow is favorable.

To heat transfer between the embossments of the slats and to further improve the gas flow to be heated, sees a particularly preferred embodiment, that the embossing the fins one in the flow direction of the to be heated Gases steep rise and a flatter contrast Have waste. In this way, a kind Stagnation point of the inflowing gas and are thus on effective Produces turbulence or turbulence. While the angle of the rise of the imprints against the Slat surface preferably between about 45 ° and about 90 °, in particular between about 60 ° and about 90 °, e.g. between can be about 70 ° and about 90 °, the angle can be the waste of the imprints against the lamellar surface preferably between about 1 ° and about 45 °, in particular between about 1 ° and about 30 °, e.g. between about 5 ° and about 20 °, amount.

A preferred embodiment provides that the imprints the lamellae formed substantially round or polygonal are, for example, quadrangular, in particular essentially trapezoidal or rectangular could be.

Another preferred embodiment provides that the embossments the lamellae formed substantially V-shaped are, with the top of the "V" of the substantially V-shaped Embossing of the lamellae with advantage against the oncoming, can be arranged to be heated gas. Also through such trained lamellae can be on the one hand Create turbulence of the gas stream, on the other hand act the V-shaped embossments in the lamellar plane in the manner of Baffles, so that the inflowing gas from its direction of flow deflected outwards along the thighs of the "V" and the contact time of the gas flow at the surface the fins is increased.

The legs of the "V" of the substantially V-shaped embossments The lamellae can either have an approximately linear extension direction or also an approximately circular or elliptical segment-shaped Have extension direction, wherein at the latter alternative advantageously one of the direction of flow of the gas considered convex curvature have to divert the gas flow such that a As long as possible contact time with the lamellar surface results.

Preference is given to several V-shaped embossments of the slats in Flow direction of the gas to be heated in a row arranged, wherein the opening angle of the "V" of the V-shaped Embossments of the slats can be different in size. In In this case, it may further be provided that the opening angle of the "V" of the direction of flow to be heated Gas successively arranged V-shaped embossments of Slats in the direction of flow of the gas increases, so that one each of the V-shaped embossments for further deflection the gas flow and thus at the same time for effective turbulence of the same worries.

Of course, the embossing, depending on the application, can also be designed differently, for example, in the manner of rectilinear and / or curved Stegen, which is particularly useful if the Slats passing gas flow is to undergo a diversion, as in particular in curved air ducts Of motor vehicles is often the case.

To solve the problem underlying the invention sees the invention in a generic device, in which the slats are clamped on the outside of the Pipe are arranged, further, that the slats at least surrounding a designed as a profile tube tube Have breakthrough and at least two opposite Edges of the openings under formation of the Lamellar plane bent out tabs are bent, wherein the opposite edges through substantially perpendicular interrupted slots arranged for the breakthrough are, so that a plurality of in the extension direction of the Edges edges arranged side by side is formed. By such a configuration, not only the heat transfer becomes the lamellae to the gas to be heated, but in particular, the heat transfer of the heated profile tubes improved to the slats by the plurality of slits spaced by slots which are on the outside the profile tubes clamped, a possible have large contact area with the heated profile tube. In particular, this also surface imperfections the profile tubes balanced as the side by side arranged tabs on the one hand compared with a continuous tab are shorter and thus the elasticity the material of the lamella certain unevenness of the profile tube can compensate better; on the other hand, each of the Tabs with the profile tube in clamping contact, so that yourself at relatively large bumps of the profile tube each the tabs on at least one contact point with the Profile tube is in clamping contact.

Such an embodiment is particularly advantageous, if the profile tube, on which the lamella clamped sit up, clamped in the interior of the pipe PTC elements or similar, jammed devices is heated, since in this case a subsequent Expansion of the equipped with the seated slats Tube for achieving an improved clamping seat of the slats on the outside of the tube to loosen the in Lead inside the pipe clamped heaters would and thus excretes. The inventive training the slotted lugs of the slats makes in any case such expansion of the tube dispensable and ensures perfect heat conduction between the profile tube and the outside clamped Lamellae.

In most cases it is sufficient that at least two opposite edges of the openings of the slats each at least two slots to form each at least three adjacent tabs are provided. Of course, depending on the required Heat transfer coefficient only two or more as three side by side arranged tabs on the Breakthroughs of the fins limiting edges provided be.

For example, as a tubular heating unit relatively flat profile tube with substantially rectangular cross-section used, so in particular also the two opposite longitudinal edges of Breakthroughs of the slats by the substantially vertical interrupted slots arranged for the breakthrough while the two other opposite transverse edges the openings of the slats formed continuously are.

To the clamping seat of the slats on the tubular heating unit To stabilize the slats in their with respect to their longitudinal direction of lateral areas the breakthroughs each have at least one further imprint , wherein the further embossments with advantage in Shape of parallel to the longitudinal direction of the lamellae arranged beads may be formed, as it is made the initially cited DE 198 48 169 A1 known per se is.

To the majority of on the tubular heating unit arranged side by side and on this jammed fins also against each other to fix or clamped support, is provided in training that the slats at least one bent out of the lamellar plane clamping strap which are elastic to a plant is provided in each case adjacent lamella. In this way are separate components for mutual support and Fixation of the slats dispensable, with the respective adjacent lamella in contact clamping lugs Furthermore, for heat transfer of the slats with each other can serve, allowing local cooling of some fins as far as possible due to a non-uniform flow prevents and the overall efficiency of the device is increased.

In a preferred embodiment, it is provided that the Clamping tabs on at least two opposite ends of Slats are arranged, in particular of at least a part of the bent out of the lamellar plane Cross edges of the slats can be formed.

The slats and optionally the tubular heating unit Conveniently consist of a material with good Thermal conductivity, such as a metal sheet, preferably made of aluminum or an aluminum alloy.

Fig. 1

eine Seitenansicht einer Ausführungsform einer erfindungsgemäßen Heizvorrichtung;

Fig. 2

einen Querschnitt durch ein Profilrohr der Heizvorrichtung gemäß Fig. 1;

Fig. 3

eine Draufsicht eines Rohlings einer Wärmeabgabelamelle vor dem Anbringen von Prägungen und vor der Ausbildung von Laschen;

Fig. 4

eine Draufsicht einer Ausführungsform einer Wärmeabgabelamelle;

Fig. 5

eine Schnittansicht der Lamelle gemäß Fig. 4 entlang der Linie V-V;

Fig. 6

eine Seitenansicht der Lamelle gemäß Fig. 4 und 5;

Fig. 7

eine Draufsicht einer anderen Ausführungsform einer Wärmeabgabelamelle;

Fig. 8

eine Schnittansicht der Lamelle gemäß Fig. 7 entlang der Linie VIII-VIII;

Fig. 9

eine Schnittansicht der Lamelle gemäß Fig. 7 und 8 entlang der Linie IX-IX gemäß Fig. 7; und

Fig. 10

eine vergrößerte Detailansicht X des Querschnittes der Lamelle gemäß Fig. 9.

The invention is explained in more detail below with reference to preferred embodiments with reference to the drawings. Showing:

Fig. 1

a side view of an embodiment of a heating device according to the invention;

Fig. 2

a cross section through a profile tube of the heater of FIG. 1;

Fig. 3

a plan view of a blank of a Wärmeabgabelamelle before applying embossing and before the formation of tabs;

Fig. 4

a plan view of an embodiment of a Wärmeabgabelamelle;

Fig. 5

a sectional view of the blade of Figure 4 along the line VV.

Fig. 6

a side view of the blade of FIG. 4 and 5;

Fig. 7

a plan view of another embodiment of a Wärmeabgabelamelle;

Fig. 8

a sectional view of the blade of Figure 7 along the line VIII-VIII.

Fig. 9

a sectional view of the blade of Figure 7 and 8 along the line IX-IX of FIG. 7. and

Fig. 10

an enlarged detail X of the cross section of the blade of FIG. 9.

The heater shown in Fig. 1 according to the invention 1, in the illustrated embodiment, two in the drawing plane successively arranged tubular heating units in the form of profile tubes 2, of which in Fig. 1, only the front profile tube 2 is visible.

As can be seen in particular from Fig. 2, each of the profile tubes 2 integrally formed in the form of a square tube and inside, e.g. with a not shown in Fig. 2 Heating device in the form of resistance elements provided with a mounting frame made of insulating material, like polyamide (Ultramid®, BASF AG), several plate-shaped PTC elements included in the mounting frame are arranged one over the entire mounting frame extending contact track and the contact track covering Insulating plate include (also not shown). The mounting frame can otherwise according to the Mounting frame according to DE 198 48 169 A1 be formed. Furthermore, the PTC elements used for heating, which are familiar as such, for example according to the EP 0 379 873 B1.

As can be seen from FIG. 2, the edges are the designed as a square tubes profile tubes 2 respectively rounded. This does not only apply to the outer edges 3, but also for the edges arranged inside 4. The height h of the profile tubes 2 changes over its width b, with the lowest height about in the Center is reached. These height changes are only slightly and are in the range of about 0.4 mm. Because the Height of the longitudinal leg 5 of the profile tubes 2 substantially is constant, the same applies to the inner diameter the profile tubes 2. The profile tubes 2 therefore have at Inside 6 of their longitudinal legs 5 a spherical training or a concave shape, whereby an excellent Clamping arranged in the interior of the profile tubes 2 and for heating the same serving PTC elements (not shown) in the profile tubes 2 is achieved.

As can be seen from Fig. 1, sit on the outside of the Profile tubes 2 by means of clamping connections friction and heat-resistant Slats 7, which for heat to be heated Gas, e.g. Air, serve and in parallel order arranged in the direction of extension of the tubes 2 one behind the other are. The direction indicated by the arrow A flow the fins 7 with the gas to be heated is approximately parallel to the lamellar plane and perpendicular to the extension direction the profile tubes 2 provided so that the gas flow between the profile tubes 2 and the lamellae 13 arranged thereon passes through while sweeping the lamellar plane.

The provided with the slats 13 profile tubes 2 are on its one end 2a on a plug-in flange 8 and on her other end 2b fixed to a screw 9. The Ends 2a, 2b of the profile tubes 2 are in recesses 10 in the plug-in flange 8 and in corresponding recesses (not shown) inserted in the screw 9 and by caulking on the support frame thus formed established. The flanges 8, 9, for example, also made of Ultramid. The material of the profile tubes 2, e.g. Aluminum or an alloy thereof is optional for better fixation at the ends 2a, 2b of Profile tubes 2 slightly compressed. The between the profile tubes 2 and the support frame provided clamping connection can in the rest of the DE 198 48 169 A1 described Be formed manner.

Fig. 3 shows a plan view of a blank of a Wärmeabgabelamelle 7 (see Fig. 4 to 10), which of a e.g. obtained by a punching process flat blank an aluminum sheet is obtained. The blank is provided with two openings 11, which in the area of his longitudinal ends are provided and substantially in the transverse direction of the blank or the thereof to be obtained Extend lamella. The openings 11 are used for Pass each one of the two profile tubes 2 of the heater 1 of FIG. 1. For this purpose, as below Referring to Fig. 4 ff explained in more detail, the Breakthroughs 11 delimiting edges to form tabs bent out of the lamellar plane, leaving itself a reliable and permanent clamping connection of the slats 7 on the outside of the profile tubes 2 results. The Longitudinal edges of the apertures 11 are perpendicular from two to these slots 12 arranged approximately equidistant divided so that when bending these edges three in the direction of extension of the edges arranged side by side Tabs (Fig. 4 ff) show that a flawless Contact with the profile tubes 2 (Fig. 1) and thus a good Ensure heat transfer. The training of the two Breakthroughs 11 is identical.

The blank is also at its transverse edges with an approximately central projecting area 13 equipped, which by perpendicular to the transverse edges Slits 14 is limited. As also below Referring to Fig. 4 et seq., The protruding ones are used Areas 13 of the transverse edges of the blank for training one clamping lug bent out of the lamellar plane, which for elastic conditioning on a respectively adjacent Slat 7 is provided (see Fig. 1) and the parallel Arrangement of a plurality of lamellae 7 on the Profile tubes 2 thus stabilized.

While in Figs. 4 to 6 a first embodiment of a Heat release blade 7a is shown, Fig. 7 to show 10 shows a second embodiment of a heat-dissipating blade 7b, which have each been obtained from a blank according to FIG. 3 are. The lamellae 7a, 7b differ only by the embodiment of the explained below in detail Imprints 15 on much of her between the Breakthroughs 11 arranged central area, which serves to dissipate heat to the gas to be heated and in Longitudinal direction of the slats 7a, 7b substantially radially from the two openings 11 passing through the profile tubes 2 (Fig. 1) extends away.

As can be seen in particular from FIG. 10, the two are in the longitudinal direction of the lamellae 7a, 7b opposite Edges, which limit the apertures 11, arcuate with the formation of bent out of the lamellar plane Tabs 16 bent. In the transition area 17 of Tabs 16 to the main part of the slats 7a, 7b is the Distance d of the same at least the height h (Figure 2) of the profile tube, while the clear distance b of the faces of the Tabs 16 is less than the height h of the profile tube 2, as long as the slats 7a, 7b not yet on the profile tubes 2 have been pushed. Furthermore, the slots 12 provide for a subdivision of the tabs 16 in the longitudinal direction the breakthroughs 11 limiting longitudinal edges, so that three adjacent tabs 16a, 16b, 16c (Fig. 4, 5 and 7, 8) are formed, which is slightly concave configuration of the longitudinal leg 5 of the Adjust profile tubes 2 (Fig. 2) and for a flawless Clamping seat of the slats 7a, 7b on the profile tube 2 and in particular for a good heat transfer between them to care.

As can also be seen in particular from FIG. 10, are the two in the transverse extension direction of the slats 7 a, 7 b opposite edges, which the openings 11 limit arcuate to form two more the lamellar plane bent tabs 18 bent, wherein the tabs 18 are formed continuously. The tabs 18 have one over their direction of extension one constant distance to each other, the substantially the width b (Fig. 2) of the profile tubes 2 corresponds. These tabs 18 serve to stabilize the clamping seat the lamellae 7a, 7b on the profile tubes. 2

For stiffening the slats 7a, 7b in the region of the openings 11 are also parallel to the tabs 18 extending Seams 19 are provided, which with respect to the longitudinal direction the lamellae 7a, 7b laterally of the openings 11 are arranged and stamped out of the lamellar plane. The stamping can be opposite or corresponding the deflection of the tabs 16, 18 be provided wherein the embossment is carried out such that the slat surface is not broken. Stabilize the beads 19 the lamellae 7a, 7b in the region of the openings 11th

Due to the described design of the tabs 16, 18th the lamellae 7a, 7b frictionally on the profile tubes 2 are pushed and sit on this clamped on. By the clamping seat and in particular by the Slits 12 broken tabs 16 are the slats 7a, 7b with their profile tubes 2 facing sides of the Tabs 16, 18 largely flat against the outside of the Profile tubes 2 pressed and lie on this outside that a safe heat transfer to the slats 7a, 7b is ensured.

As seen from the top view of the slats 7a, 7b of FIG. 4th or 7 can be seen (see also Fig. 3) are between the each adjacent tabs 16, 18 each rounded Transition regions 20 formed for a reliable Put it on the profile tube 2. Furthermore, the in Transverse direction of the apertures 11 extending tabs 18 at their long sides towards their free ends easily tapered trained. The same applies to the outer Tabs 16 a, 16 c of the longitudinal direction of the openings 11th extending tabs 16 at its the rounded transition areas 20 facing end.

The projecting central portions 13 of the opposite Transverse edges of the fins 7a, 7b are under formation in each case a clamping tab 21 approximately arcuately from the slat plane bent out, the clamping tabs 21 for elastic attachment to a respective adjacent lamella 7a, 7b of the heating device 1 according to FIG. 1 are provided. The clamping tabs 21 can in the same or in the opposite Direction as the edges of the apertures 11 bent be and with the lamellar plane an angle α of For example, form about 50 ° (Figures 6 and 9).

Both the slat 7a shown in FIGS. 4 to 6 and also the lamella 7b according to FIGS. 7 to 10 is finally embossed 15 provided, while maintaining a continuous surface of the lamella 7 of the lamellar plane protrude, without the lamella 7 to form breakthroughs to enforce. The embossments 15 are practical over the entire heat to be heated to the Gas serving area arranged, which is in the longitudinal direction the lamellae 7a, 7b substantially radially of the the apertures 11 passing through the profile tubes 2 (Fig. 1) extends away. In the illustrated embodiments, which are equipped with two openings 11 and accordingly for a heating device 1 with two profile tubes 2 provided that this area is the between the apertures 11 arranged portion of the slats 7a, 7b.

The fin 7a has embossments 15a with a substantially rectangular base and one in essence trapezoidal, obliquely upwardly projecting from the lamellar plane Surface on, with a plurality of in the flow direction A of the gas to be heated arranged one behind the other Rows of such embossments 15 a is provided, which with respect to the flow direction A are arranged offset. In this case, the embossments 15a are the - in the present embodiment four - series of embossments 15a of identical Shape and so on by means of an embossing process applied to the lamellar plane, that the embossments 15 a indeed protruding from the lamellar plane or at the opposite Side of the blade 15a withdrawn with respect to the lamellar plane are, but - as already mentioned - the lamella 7a not enforce. The individual imprints 15 are in this case designed such that they are one in the flow direction A of the gas to be heated steep increase of, for example about 85 ° and on the other hand flatter, itself over the entire height of the obliquely upwardly projecting Trapezes of the embossments 15 extending waste of example about 10 ° (see in particular Fig. 5).

The embossings 15a give the lamellae 7a on the one hand a increased dimensional stability, so that it is stiffened and it even with continuous exposure to vibration not to an undesirable noise development comes. on the other hand each of the embossments 15a generates swirls of the same sweeping gas flow (arrow A) and increase additionally the heat exchange surface of the fin 15a, so that the heat exchange between the fin 15a and the one to be heated Gas is significantly improved. All the more so as by the turbulences occurring at the embossings 15a the gas stream A can achieve a turbulent flow.

The embossings 15b of the lamella 7b according to FIGS. 7 to 9 differ from the embossments 15a of FIG. 4 to 6 shown lamina 7a by their substantially V-shaped Shape. The tip of the "V" is the imprint 15b against the flow direction A of the inflowing, too heated gas, so that at the top of the "V" is a stagnation point formed and the gas along the Leg of the "V" is deflected laterally. Here too on the one hand generates a large number of turbulences, on the other hand becomes the contact time of the gas on the lamellar surface increased due to the deflections.

In the present embodiment, the legs of the "V" on a linear extension direction, where they Of course, also circular or elliptical segment-shaped may be formed bent. Furthermore, several, e.g. three, in the flow direction A of the gas arranged one behind the other Embossments 15b provided, wherein the opening angle β of the "V" of these embossings 15b is different and increases in the flow direction A of the gas. In this way the gas passing over the lamellar plane undergoes several more Deflections or multiple turbulences, so that too Here, a turbulent flow can be achieved and the heat exchange between the fin 15b and the gas flow especially is effectively improved.

Of course, the embossments 15 on any Be fashion differently designed, as long as they are on the one hand to stabilize the board which the blade 7 is made, on the other hand in particular Turbulence in the sweeping gas stream A produce.

Claims (28)

Device (1) for heating gas streams, in particular for heating interior spaces, such as motor vehicles, having at least one substantially tubular heating unit (2) with lamellae (7) arranged thereon for dissipating heat to the gas to be heated, characterized in that Slats (7) are provided with embossments (15) which project from the lamellar plane. Apparatus according to claim 1, characterized in that the embossings (15) at least at the serving for heat to the gas to be heated area of the fins (7), which in the longitudinal direction of the fins (7) substantially radially of the at least one tube ( 2) extends away, are arranged. Apparatus according to claim 1 or 2, characterized in that the lamellae (7) are arranged by clamping on the outside of the tube (2). Device according to one of claims 1 to 3, characterized in that a plurality of in the flow direction (A) of the gas to be heated successively arranged embossments (15) of the lamellae (7a) is provided. Apparatus according to claim 4, characterized in that successively arranged rows of embossments (15a) are provided. Apparatus according to claim 5, characterized in that the rows of embossments (15a) are arranged offset in the flow direction (A) of the gas to be heated. Device according to one of claims 1 to 6, characterized in that the embossments (15) of the lamellae (7) have a steep in the flow direction (A) of the gas to be heated rise and a contrast flatter waste. Apparatus according to claim 7, characterized in that the angle of increase of the embossments (15) relative to the fin surface between about 45 ° and about 90 °, in particular between about 60 ° and about 90 °. Apparatus according to claim 7 or 8, characterized in that the angle of the decrease of the embossments (15) relative to the fin surface between about 1 ° and about 45 °, in particular between about 1 ° and about 30 °. Device according to one of claims 1 to 9, characterized in that the embossments (15a) of the lamellae (7a) are formed substantially round or polygonal. Device according to one of claims 1 to 10, characterized in that the embossments (15a) of the slats (7a) are square, in particular substantially trapezoidal or rectangular, are formed. Device according to one of claims 1 to 9, characterized in that the embossments (15b) of the lamellae (7b) are formed substantially V-shaped. Apparatus according to claim 12, characterized in that the tip of the "V" of the substantially V-shaped embossments (15b) of the lamellae (7b) is arranged opposite to the inflowing gas to be heated. Apparatus according to claim 12 or 13, characterized in that the legs of the "V" of the substantially V-shaped embossments (15b) of the lamellae (7b) have an approximately linear extension direction. Apparatus according to claim 12 or 13, characterized in that the legs of the "V" of the substantially V-shaped embossments (15b) of the lamellae (7b) have an approximately circular or elliptical segment-shaped extension direction. Device according to one of claims 12 to 15, characterized in that a plurality of V-shaped embossments (15b) of the lamellae (7b) in the flow direction (A) of the gas to be heated are arranged one behind the other, wherein the opening angle of the "V" of the V-shaped Embossments (15b) of the slats (7b) is different in size. Apparatus according to claim 16, characterized in that the opening angle (β) of the "V" in the flow direction (A) of the gas to be heated successively arranged V-shaped embossments (15b) of the lamellae (7b) increases in the flow direction (A) of the gas , Device (1) for heating gas streams, in particular for heating interior spaces, such as motor vehicles, with at least one substantially tubular heating unit (2) with lamellae (7) arranged thereon for dissipating heat to the gas to be heated, the lamellas being clamped the outside of the tube are arranged, in particular according to one of claims 1 to 17, characterized in that the lamellae (7) at least one of the profiled tube (2) formed tube surrounding breakthrough (11) and at least two opposite edges of the openings (11 ) are bent over to form lugs (16, 18) bent out of the lamellar plane, wherein at least two opposite edges are interrupted by slots (12) arranged substantially perpendicular to the opening (11), so that a plurality of these edges extend in the extension direction next to one another arranged tabs (16a, 16b, 16c) is formed. Apparatus according to claim 18, characterized in that at least two opposite edges (16) of the openings (11) of the lamellae (7) each have at least two slots (12) forming at least three adjacent lugs (16a, 16b, 16c) are provided. Device according to claim 18 or 19, characterized in that two opposite edges of the apertures (11) of the lamellae (7) bent over to form the tabs (16a, 16b, 16c) extend through the slots arranged substantially perpendicular to the aperture (11) (12) are interrupted, while two further opposite, forming the tabs (18) bent edges of the openings (11) of the lamellae (7) are formed continuously. Device according to one of claims 18 to 20, characterized in that the lamellae (7) each have at least one further embossing (19) in their lateral extent with respect to the longitudinal extension areas of the openings (11). Apparatus according to claim 21, characterized in that the further embossments (19) in the form of parallel to the longitudinal direction of the lamellae (7) arranged beads are formed. Device according to one of claims 1 to 22, characterized in that the lamellae (7) have at least one bent out of the lamellar plane clamping lug (21) which is provided for elastic engagement with a respective adjacent lamella (7). Apparatus according to claim 23, characterized in that the clamping straps (21) are arranged on at least two opposite ends of the slats (7). Device according to claim 24, characterized in that the clamping straps (21) are formed by at least one part (13) of the transverse edges of the slats (7) bent out of the slat plane. Device according to one of claims 1 to 25, characterized in that the lamellae (7) and optionally the tubular heating unit (2) consist of aluminum or an aluminum alloy. Slat (7) for a heating device, in particular according to the preamble of claim 1, characterized in that it is provided with embossments (15) which project from the slat plane. Slat according to claim 27, characterized by the features of at least one of claims 2 to 26.

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