The invention relates to an open-surface component for transferring heat and/or material between a gas and a liquid that are conveyed in crosscurrent and/or countercurrent flows, comprising a plurality of panels (1) that are disposed next to one another and are provided with shaped portions (2) in the form of channels or channel portions for guiding the aforementioned fluid flows through, with the channel or channel portions enabling a spreading out, transverse to the directions of the main flows, of the respective fluid flows between two adjacent panels (1). In order at relatively low pressure drops to enable a high transfer capacity of the open-surface component, the panels (1) that are provided with channel-like shaped portions (2) are additionally provided with a shaping transverse to the two main dimensional directions of the panels (1), and in particular preferably via a semicircular, sinusoidal, or serpentine wavy configuration.

The invention relates to an open-surface component for transferring heat 
and/or material between a gas and a liquid that are conveyed in 
crosscurrent and/or countercurrent flows, the component comprising a 
plurality of panels that are disposed next to one another and are provided 
with shaped portions in the form of channels or channel portions for 
guiding said fluid flows through, with the channel or channel portions 
enabling a spreading out, transverse to the directions of the main flows, 
of the respective fluid flows between two adjacent panels. 
Such open-surface components for transferring heat and/or material between 
a gas and a liquid that are conveyed in crosscurrent and/or countercurrent 
flows are known in particular for cooling towers. In this connection, the 
liquid is applied as uniformly as possible via suitable distribution 
elements on the open-surface components, which are composed of a plurality 
of panels that are disposed next to one another; a film forms on the 
surface of the individual panels and flows along the channels or channel 
portions. The design of these channels or channel portions enables a 
spreading-out, transverse to the directions of the main flows, of the 
respective fluid flows between two adjacent panels, so that an evening out 
of the liquid applied to the surface of the panels results in the 
horizontal direction, and in particular independent of whether the gas is 
guided through a side inlet into the components in crosscurrent flow to 
the liquid, or is guided through an inlet at the bottom in countercurrent 
flow to the liquid. In both cases, a coupled heat and material transfer 
takes place between the two fluids. As process goals, the liquid and/or 
the gas can be cooled, pollutant gases can be absorbed in the liquid, or 
the gas can be moistened. 
The open-surface components, which form a film, comprise a plurality of 
shaped panels or thin plastic sheets that are adhered or connected 
together and are provided with shaped portions to form channels or channel 
portions. Where the flow channels extend all the way through, they extend 
at an angle to the vertical. During assembly, the individual panels are 
alternately turned by 180.degree., so that zig-zagged channels result. 
Thus, a more uniform distribution of the fluids that are brought into 
contact is achieved over the cross-sectional area of flow, and a longer 
flow path is achieved. Additional fine profilings, for example shaped 
portions of an order of magnitude of the thickness of the film, lead to a 
further intensification of the heat and/or material transfer. 
To improve this long-known state of development, in European patent 
application no. 115 455, instead of a linear, yet inclined channel course, 
a sinusoidal or serpentine channel-like shaped portion configuration is 
described in order with relatively low pressure loss to achieve transfer 
capacities at the same or even a higher level. 
To further intensify the process where wavy panels are used, European 
patent application no. 56 911 proposes providing these panels with 
suitable fine profilings. An additional measure in this direction is 
disclosed in European patent application no. 117 076, where vertical guide 
elements are disposed on wavy panels. 
European patent application no. 70 676 discloses panel deformations that 
result from the superimposition of two or more sinusoidal undulations, 
thus for the first time providing a three-dimensional flow guidance. 
The criss-crossing, sinusoidal channel guides disclosed in European patent 
application no. 115 455 are superior to zig-zagged channels from a flow 
standpoint; however, the advantages are only partially realized due to the 
extensive geometric similarity of the constructions. Simple wavy designs, 
even with the fine profilings of European patent application no. 56 911, 
cannot achieve the required high output values due to the relatively small 
volume-specific transfer surface. Although these values are improved by 
the vertical guide elements of European patent application no. 117 076, 
with this construction a transverse distribution of the fluids conveyed to 
the open-surface components is prevented, which has a negative impact, 
especially where the supply to the open-surface components is nonuniform. 
Although these drawbacks can be partially eliminated by multiply undulated 
panels pursuant to European patent application no. 70 676, these 
constructions, due to the undulations, lead to non-oriented or 
nondirectional flow configurations, so that the fluid flows are no longer 
guided in fixed paths, as was the case with the criss-cross channels. The 
result is a worsening of the transverse distribution. In addition, due to 
the superimposed undulations, a plurality of intermediate spaces that 
taper into one another at an acute angle and have reduced fluid flow 
densities result where adjacent panels contact one another, so that 
despite the high volume-specific transfer surfaces, the desired high 
transfer capacities are not achieved. Furthermore, the channel walls that 
taper toward one another at an acute angle at the contact points are 
susceptible to an increased fouling due to deposits, which during the 
course of operation is associated with an increasing drop in output. 
It is an object of the present invention to eliminate the aforementioned 
drawbacks of open-surface components of the aforementioned type, and to 
provide an open-surface component that with regard to a given 
cross-sectional area, pressure loss or drop, and material charge, achieves 
a considerably higher heat and material transfer capacity while at the 
same time being less susceptible to fouling. 
SUMMARY OF THE INVENTION 
To realize this object, the present invention is characterized primarily in 
that the panels, which are provided with shaped portions (first 
corrugations), are additionally provided with a shaping (second 
corrugations) transverse to the two main dimensional directions of the 
panels. 
Whereas with the heretofore known constructions the central lines of the 
channels or channel portions formed by shaped portions in the panels 
extend in a single plane, with the present invention there results a 
three-dimensional path of the center lines of tho channels, consequently 
resulting in considerable improvements from a flow standpoint and an 
increase of the surface that is available for the heat and/or material 
exchange. After the shaped and wavy panels have been adhered or connected 
together, the inventive open-surface component has a high inherent 
stability and resistance to compression. The three-dimensional channels or 
channel portions that result from the adhesion or connection lead due to 
their advantageous flow design to relatively low pressure drops and high 
transfer capacities. Since adjacent channel-like shaped portions 
criss-cross in a known manner, yet have a longer flow path due to the 
additional spatial guidance, the present invention achieves an improved 
transverse distribution or transverse mixing of the fluid streams that are 
in contact, thus resulting in a further improvement of the ratio of 
transfer capacity to pressure loss. The inventive open-surface components 
are less susceptible to fouling than are heretofore known constructions. 
The inventive, three-dimensionally shaped panels are preferably made of 
plastic and can be produced in a known manner in a vacuum deep-drawing or 
cupping process, so that fine profilings (third corrugations) can also be 
obtained in a straightforward manner. 
Pursuant to a further feature of the invention, the panels have a 
semicircular, sinusoidal, or serpentine wavy configuration. As a result of 
this undulation and due to the continuous path of the channel, a good flow 
condition for the open-surface component results. 
Pursuant to a preferred further development of the inventive open-surface 
component, the panels are additionally provided on their surface with a 
fine profiling. 
An advantageous further development can also be achieved if the central 
axes of the undulation of the panels that are provided with passages or 
channels extend vertically between an inlet and outlet in conformity with 
the main direction of flow of the liquid. 
It is furthermore proposed pursuant to the invention that the wavy panels 
be provided with channel-like shaped portions to guide the fluid flows 
through that essentially extend in a sinusoidal serpentine manner between 
the liquid inlet and outlet. Furthermore, the wavy panels can be provided 
with channel-like shaped portions to guide the aforementioned fluid flows 
through that extend at an angle and essentially linearly relative to the 
vertical main direction of flow of the liquid. 
It is finally proposed pursuant to the invention that the channel-like 
shaped portions at the inlet and outlet of the fluid flows preferably have 
an angle of 30.degree. relative to the vertical main direction of flow of 
the liquid.

DESCRIPTION OF PREFERRED EMBODIMENTS 
The open-surface component, which is intended for use in cooling towers, 
pollutant absorbers, or air-conditioning units, is composed of a number of 
shaped panels 1, with the outermost panel 1 being illustrated in 
elevation. From the drawing it can be seen that channel-like shaped 
portions are provided that have a trapezoidal cross-sectional 
configuration and that in the illustrated embodiment extend at an angle 
.gamma. of 30.degree. relative to the vertical. Indicated in the upper 
region of FIGS. 1 and 2 is a fine profiling 3 that leads to an improved 
moistening of the surface and to an increase in the degree of turbulence. 
FIG. 2 shows that the panels 1 that are used to form the open-surface 
component are additionally shaped transverse to the two main dimensions of 
the panel 1; in particular, in the illustrated embodiment the panels are 
shaped by a sinusoidal wave. In a manner that is advantageous to flow, 
this wave is formed from two parallel sine functions that are offset by 
the height "h" of the trapezoid, with these sine functions corresponding, 
in the side view, to the narrow delimiting walls 4.1 and 4.2 of the 
channel-like shaped portions 2. 
FIG. 3 clearly shows the shaping of the panel 1 in an elevational view, 
whereby in order to facilitate illustration, the fine profiling 3 is not 
indicated. As can be seen, the channel-like shaped portions 2 extend not 
only at an angle toward the side, but rather in addition have a depth in 
conformity with the selected wave geometry. 
The illustrated panels 1 are produced in a manner that is advantageous to 
production from thin plastic sheets in a vacuum deep-drawing or cupping 
process. To assemble the open-surface component, each second panel 1 is 
rotated about the vertical central axes M1 and M2 (see FIG. 2) by 
180.degree., and is adhered to the preceding panel 1 in a known manner or 
is connected therewith via formed members. This results in criss-crossing 
channel-like shaped portions 2 having a trapezoidal cross-sectional 
configuration between adjacent panels 1 as clearly shown in the 
perspective illustration of FIG. 4. The dashed lines show a wavy or 
helical channel pattern of the second panel 1. As a consequence of the 
cooperation of the channel-like shaped portions 2 of adjacent panels 1, a 
spatially serpentine or meandering direction of flow in given, fixed paths 
or channels is imparted to the fluid flows. 
Instead of the linear channel-like shaped portions 2 that extend at an 
angle and are illustrated in FIG. 1, channel-like shaped portions that 
extend in a sinusoidal or serpentine manner can also be provided in an 
advantageous manner that then are additionally superimposed by the 
sinusoidal and serpentine undulations of the panels 1. 
A further advantageous embodiment features linear, vertical channel-like 
shaped portions that have a relatively short path length and that to 
deliver an improved transverse distribution of the fluids, are 
transversely offset in sections and are provided with an additional 
sinusoidal undulation. 
The present invention is, of course, in no way restricted to the specific 
disclosure of the specification and drawings, but also encompasses any 
modifications within the scope of the appended claims.