The mass transfer rate was measured around the cross flow which is a kind of sheet flow. The limiting current technique employing 0.01 M ferri-ferro cyanide in 1.0 M sodium hydroxide support solution was used to measure the mass transfer rate.
Local mass transfer rates were measured using 16 small nickel plates which resembled cross sectional area and was arranged to fit cross sectional area.
Each angle of cross flow (θ), mass transfer rate depended on flow rate in the lower chamber ($Re^{\ast}$), geometry of flow chamber (AR1) and the ratio of flow rate (AR2). Here AR1 is the ratio of the height to width of lower chamber then it represents the wall effect of flow chamber and AR2 is the ratio of average velocities in the upper and lower chamber.
The angles of cross flow studied were 45°, 90° and 135°. The flow rates in the lower chamber ($Re^{\ast}$) were varied from 100 to 3200, AR1 was changed from 0.125 to 0.5 and AR2 from 0.5 to 2.5. When θ=135℃, the mass transfer rates were highly dependent on $Re^{\ast}$.
The following correlations were obtained experimentally
$ Sh = 15.78 Re^{\ast0.399} AR1^{-0.193}AR2^{0.207}$ (θ = 45°)
$ Sh = 14.42 Re^{\ast0.475} AR1^{-0.042}AR2^{0.177}$ (θ = 90°)
$ Sh = 5.82 Re^{\ast0.661} AR1^{0.212} AR2^{0.220}$ (θ = 135°)
The rate of mass transfer in cross flow was always larger than that in the straight channel flow. The rate of increase appeared significant with the increase of flow rate in the lower chamber, AR1 and AR2.
This was more significant when angle of cross flow was larger.
