Browsing by Author "Rohani, S."

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    Isoelectric Precipitation of Sunflower Protein in a Tubular Precipitator
    (Wiley, 1995) Raphael, Matheo L.; Rohani, S.; Sosulski, F.
    Isoelectric precipitation of sunflower protein was carried out in a 10-m long, 6-mm internal diameter glass tubular precipitator. The effects of feed flow rate, protein concentration in the feed stream, and volumetric feed ratio of precipitant (HCl aqueous solution) to protein solution on solid protein recovery and particle size distribution were studied. The dispersion range of the tubular precipitator was modelled to predict the experimental results. Calculated initial growth rates of protein particles were found to: increase with increases in feed flow rate and protein concentration in the feed stream, and decrease with increases in volumetric feed ratio.
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    Isoelectric Precipitation of Sunflower Protein in an MSMPR Precipitator: Modelling of PSD with Aggregation
    (Elsevier, 1996) Raphael, Matheo L.; Rohani, S.
    Isoelectric precipitation of sunflower protein was carried out in a 273 ml MSMPR precipitator. Experimental results showed a bimodal particle-size distribution (PSD) of protein particles when the solids concentration or the mean residence time was low. Increasing the solids concentration and the mean residence time transformed the bimodal PSD to a unimodal PSD. Protein particle growth by turbulent collision mechanism and breakage by shear mechanism were modelled using an approach similar to Glatz et al. A.I.Ch.E. J.32, 1196–1204 (1986). The model results showed that the breakage of large aggregates results in the birth of two daughter fragments. Also at high solids concentrations the particle growth rate was linear with respect to particle size. At low solids concentrations the growth rate constant was larger than the breakage rate constant and vice versa at high solids concentrations.
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    On-Line Estimation of Solids Concentrations and Mean Particle Size Using a Turbidimetry Method
    (Elsevier, 1996) Raphael, Matheo L.; Rohani, S.
    On-line measurement of solids concentrations was performed using a turbidimetry method. Four different samples (PVC, sand, protein and KCl particles) with solids concentrations up to 10 wt.% were used in this study. At higher solids concentrations the measured light intensity approached zero. The extrapolated Beer-Lambert's equation in polynomial form, ln (transmission) as a function of ln(solids concentration), was found to best fit the experimental data. For protein particles with mean sizes less than 50 μm the fifth or sixth order polynomial equation was required to give the best fit (regression coefficient greater than 0.98). Whereas, larger particles were best fit using Beer-Lambert's equation with the mean particle size as one of the parameters. Transmission data from samples with unimodal particle size distribution (KCl samples) were used to estimate the optical parameters of the KCl suspension. With known optical parameters and on-line turbidity and solids concentrations the mean particle size of the flowing suspension was estimated. The calculated and experimental mean particle sizes are within ± 10%.