This is an open access article published by the IET under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/)
Particle size is a key quality parameter of a powder detergent as it determines its performance, the bulk density and the look and feel of the product. Consequently, it is essential that particle size is controlled to ensure the consistency of performance when comparing new formulations. The majority of study reported in the literature relating to particle size control, focuses on the spray produced by the atomisation technique. One approach advocated to achieve particle size control is the manipulation of the ratio of the mass slurry rate and mass flow rate of gas used for atomisation. Within this study, ratio control was compared with an automatic cascade loop approach using online measurements of the powder particle size on a small-scale pilot plant. It was concluded that cascade control of the mean particle size, based on manipulating the mass flow rate of gas, resulted in tighter, more responsive control. The effect of a ratio change varied with different formulations and different slurry rates. Furthermore, changes in slurry rate caused complications, as the impact on particle size growth in the dryer is non-linear and difficult to predict. The cascade loop enables further study into the effect of particle size on detergent performance.
References
-
-
1)
-
1. Langrish, T.A.G.: ‘Multi-scale mathematical modelling of spray dryers’, J. Food Eng., 2009, 93, (2), pp. 218–228 (doi: 10.1016/j.jfoodeng.2009.01.019).
-
2)
-
7. Birchal, V.S., Huang, L., Mujumdar, A.S., Passos, M.L.: ‘Spray dryers: modeling and simulation’, Drying Technol., 2006, 24, (3), pp. 359–371 (doi: 10.1080/07373930600564431).
-
3)
-
6. Seydel, P., Blömer, J., Bertling, J.: ‘Modeling particle formation at spray drying using population balances’, Drying Technol., 2006, 24, (2), pp. 137–146 (doi: 10.1080/07373930600558912).
-
4)
-
4. Williams, A.M., Jones, J.R., Paterson, A.H.J., Pearce, D.L.: ‘Effect of fines on agglomeration in spray dryers : an experimental study effect of fines on agglomeration in spray dryers : an experimental study’, Int. J. Food Eng., 2009, 5, (2), pp. 1–36 (doi: 10.2202/1556-3758.1635).
-
5)
-
5. Oakley, D.E.: ‘Spray dryer modeling in theory and practice’, Drying Technol., 2004, 22, (6), pp. 1371–1402 (doi: 10.1081/DRT-120038734).
-
6)
-
2. Mulhem, B., Schulte, G., Fritsching, U.: ‘Solid–liquid separation in suspension atomization’, Chem. Eng. Sci., 2006, 61, (8), pp. 2582–2589 (doi: 10.1016/j.ces.2005.11.035).
-
7)
-
7. Birchal, V.S., Huang, L., Mujumdar, A.S., Passos, M.L.: ‘Spray dryers: modeling and simulation’, Drying Technol., 2006, 24, (3), pp. 359–371 (doi: 10.1080/07373930600564431).
-
8)
-
8. Lipp, C.W.: ‘Sprays’, in (Eds.): ‘Kirk-othmer encyclopedia of chemical technology’ Vol. 23 (John Wiley & Sons, Inc., New York, 2000).
-
9)
-
3. Genskow, L.R., Beimesch, W.E., Hecht, J.P., Kemp, I.C., Langrish, T.: .
-
10)
-
4. Williams, A.M., Jones, J.R., Paterson, A.H.J., Pearce, D.L.: ‘Effect of fines on agglomeration in spray dryers : an experimental study effect of fines on agglomeration in spray dryers : an experimental study’, Int. J. Food Eng., 2009, 5, (2), pp. 1–36 (doi: 10.2202/1556-3758.1635).
-
11)
-
11. Gea, N.: ‘Nozzle atomizers’, 2013. , pp. 251–254.
-
12)
-
2. Mulhem, B., Schulte, G., Fritsching, U.: ‘Solid–liquid separation in suspension atomization’, Chem. Eng. Sci., 2006, 61, (8), pp. 2582–2589 (doi: 10.1016/j.ces.2005.11.035).
-
13)
-
6. Seydel, P., Blömer, J., Bertling, J.: ‘Modeling particle formation at spray drying using population balances’, Drying Technol., 2006, 24, (2), pp. 137–146 (doi: 10.1080/07373930600558912).
-
14)
-
9. Mulhem, B., Fritsching, U., Schulte, G., Bauckhage, K., Str, B.: ‘IFPRI project – annual report 2004 control of droplet characteristics in liquid atomization with suspended particles 2. Background and project overview’, Chem. Eng., 2004, pp. 1–27.
-
15)
-
1. Langrish, T.A.G.: ‘Multi-scale mathematical modelling of spray dryers’, J. Food Eng., 2009, 93, (2), pp. 218–228 (doi: 10.1016/j.jfoodeng.2009.01.019).
-
16)
-
5. Oakley, D.E.: ‘Spray dryer modeling in theory and practice’, Drying Technol., 2004, 22, (6), pp. 1371–1402 (doi: 10.1081/DRT-120038734).
-
17)
-
10. Allen, R.M., Bakker, H.H.C.: ‘Spray dryer control based on online particle size analysis’, Trans. IChemE, 1994, 72, .
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