Experiments were carried out on the rate of crystal growth in a seeded solution of CuSO
4·5H
2O within a metastable zone where crystal may grow without forming new nuclei.
The mass transfer coefficient
kG and the over-all growth coefficient
KG are experimentally determined by the dissolution and crystallization in a batch agitated vessel containing about 0.70 lit, of solution at a constant temperature of 20, 30 and 40°C, respectively.
The values of
kd and
KG obtained at each temperature are plotted against the Reynolds number (=
NDi2/ν) as shown in Figs. 1 and 2, and
KG (C-Cs) vs.
(Ci-Cs) at 30°C is plotted in Fig. 3. From the latter plot the value of
n is found to be unity, and Eq.(4) is reduced to Eq.(13). The former plot indicates that kd and
KG are approximately proportional to
Re1.7 for
Re>4, 000-6, 000, where the particles of crystal are suspending. Therefore, 1/
KG and 1/
kd vs. 1/
Re1.7 are plotted to obtain the value of
kr as an intersect with the ordinate as shown in Fig. 4.
kr thus obtained at each temperature is expressed by Eq.(14) as shown in Fig. 5. Fig.
6 shows a comparison of the experimental and calculated values of
kd by plotting a value of (
kddp/DL)(
Sc)
L-1/2 and a modified Reynolds number,
Re0, recommended by Oyam and Endoh (CA, 51, 2338 d).
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