Performance Evaluation of a Laboratory Scale Wetted-wall Column

Author : Almario, Maria Lourdes Dales
Major Adviser : Arquiza, Apollo C.
Committee Members : Last Name, First Name Middle Initial
Year : 1994
Month : March
Type : Thesis
Degree: BS
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The performance of a laboratory scale wetted wall column for humidification of air was evaluated.

Results indicate a common trend wherein both the mass transfer rate, Nₐ, and overall mass transfer coefficient, k?, increase with increasing water and air flowrates. The highest Nₐ value obtained were 1.2691×10⁻³ lb-mole/hr at gas and liquid flowrates of 5.287×10⁻⁴ lb/s and 30.04 ml/s, respectively. The highest mass transfer coefficient obtained using logarithmic humidity change as a driving force was 0.077065 lb-mole/[ft²(lb-H₂O/lb-da)hr] while the highest k? was 0.04856 lb-mole/ft²-atm-hr using the logarithmic pressure difference. Plotting k? and the air Reynold’s number, Nᵣₑ, showed that at Nᵣₑ ≤ 35.7149, the k? are not affected by the water flowrate. At Nᵣₑ > 35.7149, the k? values increased with increasing water flowrate. The k? values for Nᵣₑ ≤ 35.7149 were averaged and then correlated. The resulting equation obtained is :

k? = 6.8401⁻⁴ Nᵣₑ + 0.0017318                          (at air Nᵣₑ < 35.7149)

The efficiency was calculated for each test run and the highest value obtained was 79.2 % for air and water flowrates of 2.3534×10 lb/s and 15.51 ml/s, respectively.

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