。
1 1=3
A0 。qV。 。lV。 X D E U
ShV / ReVScV (51)
M qL
lL ðReL ÞðFrL ÞðWeLÞðReVÞad
。 Cy
× A0 m n
Cx 。
b c 45Þ
for random packings。 There is an additional effect of corrugation
inclination angle on the vapor-side mass-transfer coefficient for
VReV ScVcVDV þ ReLScLcLDL ð
sheet metal structured packings。 For these, we assume
ShV / Re1 Sc1=3
。 cosðhÞ 。s
(52)
transfer coefficients for the absorption of CO2 into water using Raschig rings and found
V V cosðp=4Þ
where ‘‘h’’ is the corrugation inclination angle in radians measured from the vertical。 The metal gauze ‘‘X’’ style structured packings (BX, DX, and EX) tend to have smaller flow channels with friction factors that are more strongly dependent on the vapor Reynolds number。 For them, we
kLam / L0:96 (59)
Van Krevelen and Hoftijzer35 postulated that
kLd
c0 Reb Sc1=3
(60)
assume
1=2
1=3
DL ¼ L L
ShV / ReV ScV (53)
The mass-transfer coefficient correlation
Potnis and Lenz36 studied liquid desiccant systems for gas drying using random as well as structured packings。 They reported that
for liquid film flow
ShL / Reb
1=2
Mathematical solution of the hydrodynamic and mass con- servation equations for the absorption of a slightly soluble
LScL (61)
with the exponent ‘‘b’’ ranging from 0。9 to 1。2。 Shetty and
37
gas into a laminar, falling, liquid film on a plane surface
Cerro
studied the flow of liquid films over periodic surfaces
gives the following result for the liquid-side mass-transfer coefficient30
similar to those found in structured packings。 They predicted
However, the liquid film’s flow regime in most packed columns is expected to be turbulent, partly due to the induced shear at the liquid interface due to the turbulent countercurrent flow of the vapor。 There is much less general
Given the wide variability in the values of the power-law exponents on the liquid Reynolds number and Schmidt num- ber, we have assumed that
ficient relation under these circumstances。 Two models often chosen to describe mass transfer in a turbulent liquid film are the penetration/surface renewal model and the film model。31,32 The film model predicts that the liquid-side mass-transfer coefficient is directly proportional to the binary diffusivity。 This implies that 填料塔的新传质相关性英文文献和中文翻译(13):http://www.youerw.com/fanyi/lunwen_81699.html