EP3572760B1 - Package for heat and/or material transfer - Google Patents

Description

The invention relates to a packing for heat and / or mass transfer between liquid and gaseous media in countercurrent, in particular for water cooling by air in cooling towers, with a large number of film elements profiled by corrugations, the corrugations providing flow channels and the film elements being formed of contact points are arranged one behind the other in the thickness direction, with adjacent film elements being connected to one another at their contact points and with the large areas of adjacent film elements facing one another having a fine profile.

Cooling towers for water cooling in general and cooling fixtures for cooling towers - also called packings - in particular are well known per se from the prior art.

Cooling towers are used in particular to cool liquid media, i.e. fluids such as water, by means of ambient air. For this purpose, previously known cooling towers have a fluid cooling device which in turn has cooling components, that is to say so-called packings, and a fluid distribution device. The fluid to be cooled is sprayed above the packs by means of the fluid distribution device and trickles along the packs, namely downwards following the force of gravity. The packings are preferably flowed through by air for the purpose of cooling in countercurrent to the fluid to be cooled. As a result of the contact of the fluid to be cooled with the air inside the packs, the fluid to be cooled is cooled as intended.

In order to guide the ambient air serving as cooling air through the cooling tower in the manner explained above, a fan is provided which promotes the air flow through the cooling tower and in particular through the cooling installations. This is typically arranged in the vertical direction of the cooling tower above the fluid cooling device. In normal operation, the fan sucks in ambient air from below the fluid cooling device, which air flows through the fluid cooling device arranged in the vertical direction of the cooling tower below the fan as cooling air. The ambient air sucked in by the fan is released into the atmosphere as heated ambient air after flowing through the packs upwards.

A cooling tower of the type described above is for example from WO 2009/149954 A1 known.

In order to achieve the most effective heat exchange possible between the media involved, a packing construction is known from the prior art, according to which a multiplicity of foil or plate elements profiled by corrugations is provided. These film elements are arranged one behind the other in the direction of thickness, the corrugations providing flow channels. Adjacent film elements are connected to one another at their points of contact. Furthermore, the large areas of adjacent film elements facing one another have a fine profile. This fine profiling serves to optimize the heat exchange even further.

A generic pack is from the DE 41 22 369 C1 known.

Furthermore, from the DE 27 22 424 A1 a built-in element for mass and heat exchange columns known. The built-in element consists of touching, folded lamellae made of film-like material, arranged parallel to the column axis. The folds of the lamellae lie at an angle to the column axis. The folding walls of the slats are also finely corrugated and the slats have a plurality of holes distributed over their surface. The corrugation results from roughening the surface of the lamellas by means of grooves or embossing patterns.

From the DE 27 22 556 A1 a packing made of sheet-like material with trickle surfaces for columns for mass and heat exchange is known. It is provided that the flow surfaces have alternating smooth and finely corrugated sections, the individual sections extending over a height of at least 5 mm.

The DE 39 18 483 A1 relates to a packing for heat and mass transfer in countercurrent. The filler body has a plurality of vertically and obliquely standing, superimposed and interconnected corrugated or folded foils or plates, which are designed and / or placed on top of one another and connected to one another such that the corrugations or folds of adjacent foils or plates cross. The corrugations or folds of neighboring foils or plates only intersect in the upper part of the filling body, while they run parallel to each other in the lower part.

The US 6,578,829 B2 relates to a packaging section which has a plurality of vertically oriented, diagonally cross-shaped corrugated packaging sheets. The packaging sheets define a section height, the section having a base region, a volume region and a top region. The base region has a first specific geometry that differs from a geometry of the volume region. The upper area also has a specific, second geometry which also differs from the geometry of the volume area as well as from the geometry of the base area.

The EP 0 056 911 B1 relates to a filling part for filling purposes in a water cooling tower, which in the basic state has vertical sheets of malleable material everywhere with a generally zig-zag-shaped, downward-pointing spiral pattern. Each sheet has a pair of opposite sides which are intended to be wetted by heated water flowing downwards over the same. The malleable material is equipped with horizontal ribs that form angled depressions. It is also provided that the filling part has water cooling pockets at the sinus curve between each rib and that the pockets of the depressions are arranged at an angle with respect to the horizontal.

The EP 1 078 684 A1 discloses an ordered packing for separation columns which has profiled layers and channels arranged in them. The channels are oriented obliquely to a main flow direction. The layers are formed into a profile from film-like and fabric-like material strips.

Although the DE 41 22 369 C1 the previously known construction of a packing for the heat and mass transfer between liquid and gaseous media has proven itself in everyday practical use, there is a need for improvement. In particular, the aim is to increase the efficiency even further. And this preferably without significant additional costs for production. It is therefore the object of the invention to further develop a pack of the generic type in such a way that, in normal operation, an improved exchange of heat and substances between the media involved is achieved.

To solve this problem, the invention proposes a packing of the type mentioned at the outset, which is characterized in that the fine profiling has ribs running transversely to the flow channels with rib webs and rib grooves, a rib groove being arranged between two adjacent rib webs, the transitions are formed between successive rib webs and rib grooves essentially free of radii.

The fine profiling formed on the large surfaces of the film elements is formed according to the invention as ribbing. The ribbing runs transversely to the flow channels of the film elements. For example, ribbing can be provided which runs parallel to the input or output edge of the film elements.

According to the invention, the ribbing has rib webs on the one hand and rib grooves on the other hand, a rib groove being arranged between two adjacent rib webs. This results in an alternating arrangement of rib webs and rib grooves in the longitudinal direction of the film elements.

According to the invention, the transitions between rib webs and rib grooves that follow one another in the longitudinal direction of the film elements or in the transverse direction of the ribs are formed essentially free of radii. In this context, “essentially” means a design without transition radii, provided that it is possible in particular from a production point of view. According to the invention, it is therefore important to avoid transition radii between the successive rib webs and rib grooves, so that the result is a "sharp-edged" configuration.

Investigations by the applicant have shown that, as a result of the radii-free design of the transitions between successive rib webs and rib grooves, an improved degree of efficiency is achieved. This improved efficiency can be explained by the fact that, during operation, a fluid film forms on the vertically aligned large surfaces of the foil elements, which film flows along the large surfaces following the force of gravity. The ribbing of the fine profiling running transversely to this ensures, due to the sharp-edged design of the rib webs and grooves, that turbulent flow conditions occur in the areas of the transitions between successive rib webs and rib grooves. These turbulent flow conditions ensure a better exchange of heat and substances between the fluid to be cooled, for example water, and the gaseous medium, such as the ambient air, which is passed through the packing in countercurrent thereto. As a result, a further optimized mode of operation of the pack according to the invention can be achieved.

The deliberate design of transition radii between rib webs and rib grooves is therefore provided according to the prior art in order to be able to better remove the film elements, which are mostly made of a plastic material, from a molding tool. It was not recognized that transition radii minimize the barrier effect of fine profiling, which has a positive effect on the efficiency of a packing, and thus promote the formation of a laminar flow. The sharp edges of both the rib webs and the rib grooves, which are now provided according to the invention as a departure from the prior art, provide a remedy here, since as a result of this structural design, turbulent flow conditions develop during operation, which causes an improved mixing of the two media involved, which ultimately leads to leads to an increased heat exchange. A disadvantage of the sharp-edged design of the transitions between rib webs and rib grooves provided according to the invention is that the gas-side, i.e. increased air-side pressure loss. This results in an increased energy expenditure for the fan for conveying the cooling air flowing through the pack. However, this disadvantage is deliberately accepted. Because overall, the construction according to the invention achieves an overall increased overall efficiency. This has significant advantages for the operation of corresponding systems in a wide variety of branches of industry in the form of smaller and thus more cost-effective systems and overall lower total operating costs.

According to a further feature of the invention it is provided that the corrugations provide inclined flow channels in the longitudinal direction of the film elements, preferably zig-zag flow channels, the film elements being arranged alternately in the thickness direction so that the flow channels of adjacent film elements extend with opposite inclinations and under Cross training of the points of contact.

According to this embodiment of the invention, the flow channels are not aligned in a straight line in the longitudinal direction of the film elements, but rather inclined thereto. A zigzag configuration is preferred. The inclination of the flow channels to the vertical has the positive effect that a flow path that is lengthened in relation to the height extension of the packing according to the invention results, which results in an improved heat exchange.

The width of a rib web, in particular the width of the plateau terminating a rib web on the upper side, can serve as a reference variable for the design of the transition radii. It is therefore proposed according to a further feature of the invention that the transition radii are formed <20%, preferably <10%, even more preferably <5% of the rib web plateau width of the associated rib web. If the rib web plateau width measures, for example, 5 mm, the result is a transition radius of preferably <0.5 mm, even more preferably of <0.25 mm.

The smaller the selected transition radii, the slower the demolding speed can be when a film element is demolded from the mold during manufacture. This disadvantage is consciously accepted with the design according to the invention, since the later efficiency of the film element formed in this way is significantly improved compared to the prior art. For manufacturing reasons, a transition radius of zero cannot be achieved. “Essentially” within the meaning of the invention therefore means that the transition radii are to be designed as small as possible when using conventional manufacturing processes. The more "sharp-edged" the rib design, the clearer the effect of a turbulent flow in normal operation.

According to a further feature of the invention, it is provided that a rib groove has a groove depth of 2.0 mm to 3.0 mm, preferably 2.2 mm to 2.8 mm, even more preferably 2.4 mm to 2.6 mm, most preferably 2.5 mm. As studies by the applicant have shown, a groove depth in the specified range achieves an optimized degree of efficiency. If the groove depth falls significantly smaller or significantly larger, then flow effects occur on the rib webs and / or the rib grooves in normal operation, which oppose an effective heat and / or mass transfer between the media involved. In addition, if the groove depth is too large, the pressure loss within the air drawn through the pack by the fan increases significantly, which has to be compensated for by a higher fan output, which has a negative effect on the overall energy consideration. With a groove depth in the size range according to the invention, a synergetic effect is achieved to the extent that, on the one hand, a turbulent flow required for improved heat and / or mass transfer is achieved and, on the other hand, the pressure loss that occurs as a result of ambient air flowing through the packing is minimized.
According to a further feature of the invention it is provided that a rib groove has a groove width of 4.0 mm to 6.0 mm, preferably of 5.0 mm. A ratio of groove depth to groove width of 0.6 to 0.4, preferably 0.5, is particularly preferred. So if the groove depth is, for example, 2.5 mm, the groove width should be 5 mm.

For the reasons mentioned above, it is therefore also preferred to equip the large surfaces of the film elements facing one another with fine profiling as comprehensively as possible in the sense of the invention. Preferably, only some areas of the large surfaces of the film elements are to be left out, such as, for example, the input and output end regions of the film elements.

To further reduce the pressure loss on the air side, a further feature of the invention can provide that the inclination of the flow channels to the vertical in the final assembled state is <22 °, preferably between 19 ° and 15 °, even more preferably 17 °. The inclination of the flow channels to the vertical has the positive effect of lengthening the total flow path to be covered, which also results in improved heat and / or mass transfer. The greater the inclination to the vertical, the greater the pressure loss that occurs in the air flow during operation. In the manner already described, this leads to an inevitably necessary increase in the fan output, which has a negative effect on the overall energy balance. To minimize performance, the aim is basically to have the flow channels parallel in To run in the longitudinal direction, which then again leads to a deteriorated heat and / or mass transfer due to the shortened flow path. The fine profiling according to the invention makes it possible to bring these conflicting interests into an optimized balance with one another. This enables increased heat and / or mass transfer, so that in order to minimize the pressure loss in the cooling air it is possible to make the angle of inclination of the flow channels to the vertical smaller than usual, namely smaller than 20 °. This was not to be expected against the background of the known prior art.

The groove depth averaged over the groove width is preferred as the groove depth in the context of the invention. Alternatively, the groove depth with reference to the groove width in the middle of the groove can be used as a reference value.

According to a further feature of the invention, it is provided that the end regions of a film element which are opposite one another in the longitudinal direction are designed without fine profiling.

In particular with regard to the edge or end region of the pack provided on the liquid inlet side in the intended use, it is preferred to design this free of fine profiling. This is so that an optimized distribution of the liquid dispensed by the liquid distribution device arranged above the packing can take place over the individual flow channels of the packing. In this way, a more uniform application of liquid to all flow channels is achieved. Such a uniform liquid distribution can also be supported by the provision of corresponding nozzles of the liquid distribution device.

According to a further feature of the invention, it is provided that in the end regions of the film elements which are free of fine profiling, grooves running obliquely to the longitudinal extension of the film elements are formed. These grooves are preferably formed in the film elements on the liquid inlet side and the liquid outlet side of the pack. They serve in particular to allow the liquid to flow out of the pack after flowing through the pack in an improved manner and to allow it to drip off. As a result of this measure, a reduced pressure loss on the gas or air side is also achieved. This is special in this context it is preferred that two channels are provided for each flow channel, which are aligned with one another in a V-shape. The liquid film that forms on the inner side walls of the flow channels in the intended use can thus flow off better on the outlet side without the formation of liquid waves that would create an increased resistance to the air flowing in the opposite direction, as is the case with the prior art. This improved outflow or dripping effect can also be supported by the fact that the two channels open into a common outlet which is oriented in the direction of the longitudinal extension of the film elements. This results in structures similar to Δ on the outlet side of the flow channels, which results in an improved outflow of the liquid applied to the packing.

It is provided according to a further feature of the invention that the mutually facing flow channels of adjacent film elements form a film or plate pair channel which has a hexagonal channel cross section on the inlet and outlet sides.

The mutually facing flow channels of adjacent film elements form a film pair channel in the final assembled state of the film elements. In this respect, each film element provides a flow channel that is open on one side. In the final assembled state of the pack, these flow channels of the individual film elements interact with the respective formation of a film pair channel. On the inlet and outlet sides, the film pair channels preferably have a channel cross-section that is polygonal, preferably hexagonal. The division dimension, that is to say the height of each flow channel in the depth of the formation of the film element, is preferably 12 mm, 20 mm or 30 mm. This results in a channel width for a film pair channel of 24 mm, 40 mm or 60 mm on the input or output side of the pack, based on the film spacing or film division. Since adjacent film elements are at their points of contact and are preferably connected to one another, wide channels of 24 mm, 40 mm or 60 mm are initially created on the input side or output side, which channels then later on due to the inclined inclined arrangement on the opposite channels of the neighboring ones Hit the secondary film so that a channel width of 12 mm, 20 mm or 30 mm is set at the narrowest points of the channels. This value essentially determines the Material expenditure and is decisive for the behavior of the pack according to the invention in the intended use. Because the smaller the distance, the closer the pack becomes. However, the higher the power density of the pack is due to this measure, the more it becomes soiled in long-term operation, ie the so-called fouling behavior deteriorates. In this respect, a careful selection and specification of these parameters is necessary, taking into account the operating conditions prevailing at the operating site.

The corrugations of the film elements have a polygonal channel cross-section on the input or output side, preferably a hexagonal cross-section, the edge lengths of which are preferably of different lengths. In this context, it is preferred that the corrugations of the film elements have a first strip section running in the longitudinal direction of the film elements and a second and third longitudinal strip arranged thereon along its respective longitudinal edges, the second and third strip sections being oriented at an incline to the first strip section. The second and third strip sections are designed to be of equal width and each have a width that exceeds the width of the first strip section. So the smaller the short edge length, i.e. the smaller the width of the first strip section, the more the preferably hexagonal channel cross-section of a film pair channel approximates a quadrangular configuration. Investigations by the applicant have shown that the preferred ratio of short to long hexagonal sides, i.e. the width ratio of the first strip section and the second strip section or third strip section is between 0.3 and 0.4, preferably 0.35. This results in a favorable for an optimized heat and mass transfer, i.e. as uniform as possible a thickness of the liquid film forming on the surfaces of the flow channels.

The width of the first strip section or the short edge length of the channel cross-section depends on the pitch, but is at least 5 mm. With a 20 division, for example, the edge length is between 8 mm and 12 mm, preferably 10 mm. If the short edge length, ie the width of the first strip section, is significantly below these value parameters, a comparatively narrow liquid channel is created, which in the case of operation leads to a collection of liquid in this Can lead channel and what reduces the overall effectiveness of the packing according to the invention.

Further investigations by the applicant have shown that the measures according to the invention can bring about an increase in the efficiency of the packing compared to the previously known designs of up to 8%, optionally 10%. Furthermore, it has been shown that with the packing according to the invention, considerable savings can be achieved in terms of installation height and resulting installation volume compared to known designs. Depending on the design of the cooling tower, these are between 20% and 30%, which leads to significant cost reductions in the construction of cooling towers or in their new equipment with packs according to the invention.

Fig. 1

in schematischer Seitenansicht ein Kühlturm nach dem Stand der Technik;

Fig. 2

in schematischer Seitenansicht ein Folienelement einer erfindungsgemäßen Packung gemäß einer ersten Ausführungsform;

Fig. 3

in geschnittener Ansicht das Folienelement nach Fig. 2 gemäß Schnittlinie B-B nach Fig. 2;

Fig. 4

in einer stirnseitigen Ansicht das Folienelement nach Fig. 2;

Fig. 5

in einer Schnittdarstellung das Folienelement nach Fig. 2 gemäß Schnittlinie A-A nach Fig. 2;

Fig. 6

in schematisch perspektivischer Darstellung ausschnittsweise den austrittsseitigen Endabschnitt des Folienelementes nach Fig. 2;

Fig. 7

in einer schematischen Perspektivansicht den ausgangsseitigen Endabschnitt nach Fig. 6;

Fig. 8

in schematischer Ansicht eine erfindungsgemäße Packung;

Fig. 9

in einer Stirnansicht die Packung nach Fig. 8;

Fig. 10

in schematischer Schnittdarstellung die Packung nach Fig. 8 gemäß Schnittlinie AA nach Fig. 8;

Fig. 11

in schematisch perspektivischer Darstellung die erfindungsgemäße Packung nach Fig. 8;

Fig. 12

in schematischer Ansicht ein Folienelement einer erfindungsgemäßen Packung gemäß einer zweiten Ausführungsform und

Fig. 13

in schematischer Schnittdarstellung das Folienelement nach Fig. 12 gemäß Schnittlinie A-A nach Fig. 12.

Further features and advantages of the invention emerge from the following description with reference to the figures. These show

Fig. 1

a schematic side view of a cooling tower according to the prior art;

Fig. 2

a schematic side view of a film element of a pack according to the invention according to a first embodiment;

Fig. 3

in a sectional view of the foil element Fig. 2 according to section line BB Fig. 2 ;

Fig. 4

in a front view the film element after Fig. 2 ;

Fig. 5

in a sectional view of the film element Fig. 2 according to section line AA Fig. 2 ;

Fig. 6

in a schematic perspective illustration, the exit-side end section of the film element according to a section Fig. 2 ;

Fig. 7

in a schematic perspective view the output-side end section according to Fig. 6 ;

Fig. 8

a schematic view of a pack according to the invention;

Fig. 9

in a front view of the pack Fig. 8 ;

Fig. 10

the pack according to FIG Fig. 8 according to section line AA Fig. 8 ;

Fig. 11

in a schematic perspective view of the pack according to the invention Fig. 8 ;

Fig. 12

a schematic view of a film element of a pack according to the invention according to a second embodiment and

Fig. 13

in a schematic sectional view of the film element according to Fig. 12 according to section line AA Fig. 12 .

Fig. 1 shows a cooling tower 1 as it is from the prior art, for example according to the WO 2009/149954 A1 is known.

The cooling tower 1 has a liquid cooling device, which in turn has a liquid distribution device 14 on the one hand and cooling fixtures 12 on the other. The liquid distribution device 14 is arranged in the vertical direction 13 above the cooling fixtures 12.

The liquid distribution device 14 has a plurality of distribution pipes 15 which are connected to a common inlet pipe 5 on the liquid side. The distribution pipes 15 of the liquid distribution device 14 are equipped on the cooling component side with nozzles 16 which, when in operation, distribute the liquid fed to the liquid distribution device 14, for example water, in the direction of the arrows 17 to the cooling components 12.

In normal operation, the cooling tower 1 uses a suction fan wheel 8 as the cooling medium to supply ambient air in accordance with arrows 18 and 19 with reference to the plane of the drawing Fig. 1 guided from bottom to top. In the course of the passage of the ambient air through the cooling tower 1 the air passes the cooling fixtures 12, which in the embodiment shown are designed in three layers.

The liquid to be cooled by means of the cooling tower 1, for example water, is introduced into the liquid distribution device 14 via the feed pipe 5. Here it reaches the distributor pipes 15, which are equipped with full cone nozzles 16, preferably tangentially attached, for the purpose of dispensing liquid. The distance between the outlet openings of the nozzles 16 and the upper edge of the cooling fixtures 12 determines the spray height, which is 600 mm, for example.

The water evenly distributed over the cooling fixtures 12 by means of the liquid distribution device 14 trickles through the cooling fixtures 12 in countercurrent to the cooling air conveyed from the bottom to the top.

The water that has cooled down after trickling through the cooling fittings 12 drips off from the cooling fittings 12 and is collected in the water collecting pan 3.

As can be seen from the representation after Fig. 1 also results, support struts 6 are provided to support the liquid cooling device against the water collecting trough 3, which support the liquid cooling device, ie the liquid distribution device 14 and the cooling components 12.

A cooling tower jacket 2, which houses the fan wheel 8, is provided in the vertical direction 13 above the liquid cooling device. The fan wheel 8 is part of an axial fan 7, which also has a gear arrangement 9, a motor 10 and a shaft 11 coupling the motor 10 to the gear arrangement 9. The gear arrangement 9, together with the fan wheel 8, is supported by a column 4 protruding through the liquid cooling device.

The cooling fixtures 12 provided in the vertical direction 13 below the liquid distribution device 14 contain packings of the type according to the invention, the structure of which is derived from the other Figures 2 to 13 results.

A pack 20 according to the invention (cf. Fig. 8 and Fig. 11 ) for a heat and / or Mass transfer between liquid and gaseous media in countercurrent, in particular for water cooling by air in a cooling tower 1 Fig. 1 , has a multiplicity of film elements 21 profiled by corrugations 22. Such a film element 21 is shown in a first embodiment in FIG Fig. 2 shown in a side view.

The corrugations 22 of the film element 21 provide flow channels 25, as can be seen in particular from the sectional view Fig. 3 reveals. As can be seen from this illustration, the corrugation 22 of the film element 21 is composed of successive wave crests 23 and wave troughs 24, a wave trough 24 being arranged between two wave crests and a wave crest 23 between two wave troughs 24. With reference to the drawing plane after Fig. 3 The corrugation 22 provides flow channels 25 both on the top side and on the underside of the film element 21.

The flow channels 25 run as shown in the view Fig. 2 can be seen in the longitudinal direction 26 of the film element 21, ie in the intended installation in the vertical direction from top to bottom or from bottom to top.

The preferred embodiment of the invention according to the Figures 1 to 7 shows a film element 21, accordingly the corrugations 22 provide flow channels 25 running inclined in the longitudinal direction 26, namely flow channels 25 running in a zigzag shape. This can be seen in particular from the illustration Fig. 2 . The film elements 21 provided for forming a pack 20 according to the invention are arranged alternately in the thickness direction 40 - also called the depth direction - as can be seen from the illustration Fig. 8 results, so that the flow channels 25 of adjacent film elements 21 extend with opposite inclination and intersect with one another to form contact points 29. In the contact points 29, adjacent film elements 21 are connected to one another, for example by gluing and / or welding.

The film elements 21 have their large surfaces 30 according to FIG Fig. 5 each has a fine profiling 31. This fine profiling 31, also called micro-corrugation or microstructure, has ribbing 32 running transversely to the flow channels 25 Rib webs 33 and rib grooves 34, as can be seen in particular from the side view Fig. 4 and the sectional view Fig. 5 results.

As in particular the sectional view after Fig. 5 can be seen, a rib groove 34 is arranged between two adjacent rib webs 33 of the ribbing 32. According to the invention, the transitions between successive rib webs 33 and rib grooves 34 are designed essentially free of radii. To this extent, there is a sharp-edged transition between the rib webs 33 and the rib grooves 34.

In the context of the invention, “essentially” designed without radii means a configuration without transition radii, provided that this is possible in particular from a production point of view. It is therefore important to avoid transition radii between the successive rib webs 33 and rib grooves 34, so that the result is a "sharp-edged" configuration. “Essentially” within the meaning of the invention means in particular that the transition radii are to be designed as small as possible in the context of the use of conventional manufacturing processes. This is because the more "sharp-edged" the rib design, the more clearly the effect of a turbulent flow that is desirable to be achieved occurs in normal operation.

Like this, for example, the Figures 2 and 4th As can be seen, the end regions 35 of the film element 21 lying opposite one another in the longitudinal direction 26 are free of fine profiling. This ensures in particular an improved exit of water from the pack 20 according to the invention. This positive effect is further supported according to the invention by the fact that grooves 36 and 37 running obliquely to the longitudinal extension 26 of the film elements 21 are formed in the finely profiled end regions 35 of the film elements 21, like this a synopsis of the Figures 6 and 7 reveals. Here, a film element 21 has two channels 36 and 37 for each flow channel 25, which are aligned with one another in a V-shape. These two channels 36 and 37 open into a common outlet 38 which is oriented in the direction of the longitudinal extension 26 of the film elements 21.

The Figures 8 and 10 show a pack 20 according to the invention which, for the sake of clarity, has only two in the illustrated embodiment Thickness direction 40 has foil elements 21 arranged one behind the other.

When used as intended, the pack 20 is shown with reference to the plane of the drawing Fig. 8 charged with air from below, as indicated by the arrows 27. The air flows into the flow channels 25, flows through the pack 20 and leaves it with reference to the plane of the drawing Fig. 8 on top again. In countercurrent to this, the pack 20 is charged with water, specifically with reference to the plane of the drawing Fig. 8 from above in correspondence with the arrows 28. The water trickles through the pack 20 with reference to the plane of the drawing Fig. 8 from top to bottom and leaves the pack 20 with respect to the plane of the drawing Fig. 8 over the lower end region 35.

The flow channels 25 of the film elements 21 arranged one behind the other in the thickness direction 40 complement one another to form film pair channels 39, as is shown in particular in the sectional illustration Fig. 10 reveals.

Fig. 11 It can be clearly seen that the film elements 21 arranged one behind the other in the direction of thickness 40 each provide zigzag running flow channels 25, the flow channels 25 of adjacent film elements 21 extending with opposite inclination and crossing one another to form the contact points 29. The wave peaks 23 and wave troughs 24 of a corrugation 22 of the profile elements 21 adjoin one another in the width direction 41, as is also the case Fig. 11 can be seen.

According to a second embodiment of the invention, which in the Figures 12 and 13 As shown, the film elements 21 are equipped with flow channels 25 running in a straight line in the longitudinal direction 26, the flow channels 25 being divided into sections which are offset from one another in the width direction 41. In contrast to the preferred embodiment according to the above Figures 2 to 11 thus no zigzag-shaped configuration of the flow channels 25 is provided.

According to the preferred embodiment according to Figures 2 to 11 it is also provided that the fine profiling 31 of the film elements 21 extends over the entire surface of the large areas 30 with the exception of the end region 35. The alternative Embodiment according to the Figures 12 and 13 shows a fine profiling 31, which is interrupted in the longitudinal direction 26 of the film element 21 by areas 42 without fine profiling. Such a configuration can arise in particular for manufacturing reasons.

The fine profiling according to the invention is formed by ribbing 32, as already described above with reference to FIG Fig. 5 described. The ribbing 32 has rib webs 33 and rib grooves 34 following one another in the longitudinal direction 26, each rib web 33 providing a rib web plateau 43. According to the invention, it is provided that the transitions between successive rib webs 33 and rib grooves 34 are formed essentially without radii. With regard to the width of the rib web plateaus 43, that is to say with regard to the extent of the rib web plateaus 43 in the longitudinal direction 26, it is preferred that the transition radii <20%, preferably <10%, even more preferably <5% of the rib web plateau width of the associated rib web 33 are trained.

The combination of the flow channels 25 of two adjacent film elements 21 results in a film pair channel 39, as shown in the sectional illustration Fig. 10 in particular reveals. A polygonal, preferably hexagonal configuration of the film pair channel 39 is preferred, as in FIG Fig. 10 shown.

For the purpose of designing the film pair channel 39, which is hexagonal in cross section, a flow channel 25 delimited by three strip elements 44, 45 and 46 is provided for each film element 21. The edge lengths, that is to say the widths of the strip elements 44, 45 and 46 differ from one another.

The width of the strip elements 45 and 46, that is, their edge length in relation to the cross section, is the same size and exceeds the width of the first strip section 44 or, in relation to the cross section, its edge length. The edge length S1 of the first strip element 44 and the edge lengths S2 of the second strip element 45 and third strip element 46 are shown in FIG Fig. 10 drawn in as an example. The width or edge ratio S1 / S2 is preferably between 0.3 and 0.4, most preferably 0.35. <b> Reference signs </b> 1 Cooling tower 24 Trough 2 Cooling tower jacket 25th Flow channel 3 Water collecting pan 26th Longitudinal direction 4th pillar 27 air 5 Inlet pipe 28 water 6th Support strut 29 Point of contact 7th Axial fan 30th Large area 8th Fan wheel 31 Fine profiling 9 Gear arrangement 32 Ribbing 10 engine 33 Rib web 11 wave 34 Rib groove 12 Cooling installations 35 End area 13 Height direction 36 Gutter 14th Liquid distribution device 37 Gutter 15th Distribution pipe 38 Outlet 16 jet 39 Foil pair channel 17th arrow 40 Thickness direction 18th arrow 41 Width direction 19th arrow 42 Area 20th pack 43 Ribbed plateau 21st Foil element 44 first strip section 22nd Curl 45 second strip section 23 Wave mountain 46 third strip section

Claims (13)

1. A package for a heat and/or material transfer between liquid and gaseous media in the counter-current, in particular for the water cooling by means of air in cooling towers, comprising a plurality of foil elements (21) profiled by undulations (22), wherein the undulations (22) provide flow channels (25) and wherein the foil elements (21) are arranged one after the other in the direction of thickness (40) while forming contact points (29), wherein adjacent foil elements (21) are connected to each other in their contact points (29) and wherein the large surfaces (30) of adjacent foil elements (21), which large surfaces are facing each other, comprise a fine profiling (31), characterized in that the fine profiling (31) comprises a ribbing (32) having rib webs (33) and rib grooves (34), which ribbing (32) extends transversely with respect to the flow channels (25), wherein a rib groove (34) is arranged between two adjacent rib webs (33), wherein the transitions between successive rib webs (33) and rib grooves (34) are essentially radius-free.
2. A package according to claim 1, characterized in that the undulations (22) provide flow channels (25) inclined in the longitudinal direction (26) of the foil elements (21) and preferably extending in a zig-zag shape, wherein the foil elements (21) are arranged in an alternating manner in the direction of thickness (40), such that the flow channels (25) of adjacent foil elements (21) extend with an opposite inclination and cross each other while forming the contact points (29).
3. A package according to claim1 or 2, characterized in that the transition radii are smaller than 20%, preferably smaller than 10% and more preferably smaller than 5 % of the rib web plateau width of the associated rib web (33).
4. A package according to one of the preceding claims, characterized in that a rib groove (34) comprises a groove depth comprised between 2 mm and 3 mm, preferably between 2,2 mm and 2,8 mm and more preferably between 2,4 and 2,6 mm, most preferably of 2,5 mm.
5. A package according to one of the preceding claims, characterized in that the end portions (35) of a foil element (21), which end portions (35) face each other in the longitudinal direction (26), are formed without fine profiling.
6. A package according to claim 5, characterized in that grooves (36, 37) that extend obliquely with respect to the longitudinal extension (26) of the foil elements (21) are formed in the end portions (35) without fine profiling of the foil elements (21), into which grooves (36, 37) merge the flow channels (25).
7. A package according to claim 6, characterized in that a foil element (21) comprises two grooves (36, 37) for each flow channel (25), which grooves are aligned with respect to each other in a V-shape.
8. A package according to claim 7, characterized in that the two grooves (36, 37) merge into a common outlet (38) which is oriented into the direction of the longitudinal extension (26) of the foil elements (21).
9. A package according to one of the preceding claims, characterized in that the flow channels (25) facing each other of adjacent foil elements (21) form a foil pair channel (39) with comprises a polygonal, preferably hexagonal channel cross section both at the entry and at the exit.
10. A package according to one of the preceding claims, characterized in that the undulations (22) of the foil elements (21) comprise a first strip portion (44) extending in the longitudinal direction (26) of the foil elements (21) as well as a second and a third strip portion (45, 46) arranged along the respective longitudinal edges of the first strip portion (44), wherein the second and the third strip portion (45, 46) are oriented in an inclined manner with respect to the first strip portion (44).
11. A package according to claim 10, characterized in that the second and the third strip portion (45, 46) comprise the same width and respectively comprise a width which exceeds the width of the first strip portion (44).
12. A package according to claim 11, characterized in that the width ratio of the first strip portion (44) and the second strip portion (45) or the first strip portion (44) and the third strip portion (46) is comprised between 0.3 and 0.4, and is preferably 0.35.
13. A package according to claim 10 or 11, characterized in that the width of the first strip portion is at least 5 mm, preferably comprised between 7 mm and 18 mm, more preferably comprised between 8.5 mm and 9.5 mm.

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