Mechanisms of formation of the active surface of irregular heat and mass transfer packing are analyzed. Widely spread packing like Raschig, Pall rings, circular packing GIAP-NZ as well as Intalox saddles are considered. Results of comparison of the effi ciency of packing GIAP-NZ of different size and at different loads are presented. At comparing the design of packing the concept of the coeffi cient of the utilization effi ciency of the packing volume is used.The most important characteristics of any industrial apparatus is the heat and mass transfer surface, which it can provide [1][2][3][4]. For apparatuses, where there is no direct contact of phases, for example, heat exchanger, the heat exchange surface is strictly determined by the design and overall dimensions of the apparatus: It is the wall separating, exchanging the heat fl ows. This allows referring the coeffi cients of heat output and heat transfer to the unit of heat exchange surface. They are measured in kcal m -2 h -1 °С.The situation is much more complicated in packed apparatuses, where exchange processes are realized at direct contact of phases and with evaluation of real surface, through which the heat and mass transfer is realized. The real surface of contacts, specifi c active surface, S a , can at different conditions (different size and form of packing, different loads by gas and liquid) to various extent differ from the geometric surface of packing S, m 2 . S= S sp V, where S sp is the specifi c surface of the packing, [m 2 m -3 or m -1 ], V is the volume of the packing loaded into the apparatus, m 3 .First of all, as known, not the whole surface of the packing is moistened by liquid except for in the regimes of fl ooding or at inundation of packing. But even at these regimes a certain fraction of the surface in points of contact of elements is deadened. Let us indicate it as ∆S c .In terms of industrial processes at film regime, a certain fraction of the surface of packing also is not moistened by liquid due to screening by the above lying elements. The degree of screening is caused fi rst of all by the form of elements. Let us indicate the fraction of the surface deadened as a result of screening as ∆S scr .The peculiarity of the form and design of packing elements to a certain extent prevent washing of their internal surface. This, fi rst of all, relates to circular non-perforated packing. It is necessary to mention in especially negative meaning the Raschig rings [5,6]. Let us indicate the internal non-washed surface of the packing as ∆S о .In stagnant areas of liquid stipulated by form and size of the packing, a fraction of the surface does not participate in the process of mass transfer. It will be indicated as ∆S stagn .Thus, the surface of the packing is never completely moistened by the moving liquid. And that is why actively moistened surface related to the unit of volume of packing layer: S m = S sp -∆S c -∆S scr -∆S о -S stagn .(1)The surface of the frontier layer of liquid contacting with gas on the surface of the packing at equ...
