COMPARATIVE-STUDIES ON HYDRAULICS OF DUMP ED AND STRUCTURED PACKINGS

Experimental studies on the hydraulics for six dumped and five structu red packings under identical conditions were carried out. Technical da ta of the investigated packings were determined experimentally (Table 1). The investigations were carried out in the column of 250 mm in dia meter and 1 m heigh of packed bed for the air-water system at normal p ressure. The experiments included measurements of pressure drop on dry and wetted packings and column flooding. Pressure drop on dry packing is described by Eq. (11) where the wall factor K has been calculated from Eq. (10) and the friction factor psi has been calculated from Eq. (13). The Reynolds number Re-g was calculated from Eq. (12). The cons tant c and exponent A in Eq. (13) were determined on the basis of expe rimental data and (Table 2). In Figure 3 there are presented pressure drops on dry packings as a function of gas velocities for the investig ated metallic packings. Basing on the form of the equation for pressur e drop on wetted packing [10, 24] correlational equation (20) was deve loped. The values of estimated parameters a(0)-a(4) in Eq. (20) are li sted in Table 3. The dimensionless numbers Re-g, Re-c, Fr-c are define d by Eqs. (12), (18) and (19). The agreement between the calculated va lues of Delta P/H (Eq. (20)) and the experimental ones can be consider ed as satisfactory. By way of illustration the comparison between the calculated pressure drop using eq. (20) and the experimental data for PSL-25 packing is shown in Fig. 5. The flooding line can be calculated according to Eq. (22) for all investigated packings except for Raschi g-25 rings, for which Eq. (23) is valid. In Figure 6 there are compare d the values calculated from Eq. (22) with the experimental data for i nvestigated packings. The agreement between the calculated results and those obtained by measurement is satisfactory. The investigations sho wed that pressure drops on construction packings are much lower and li miting loads of gas and liquid phases much higher than those on dumped packings. It was found that the most desirable properties had constru ction packing X-30-100.