Fluid Dynamic And Polymeric Coating Of Forest Seeds Of Senna Macranthera (collad.) Irwin Et Barn In Conical Spouted Bed

Senna macranthera (Collad.) Irwin et Barn trees have been used in urban forestry because of their small size and beauty and in reforestation, due to their rapid development. Aiming to preserve the seeds of S. macranthera, a polymeric film coating of the seeds is proposed in this work. To analyze the coating process a fluid dynamic study of the particles in a conical spouted bed was performed before the seeds covering in the same equipment. Fluid dynamic was analyzed with loads of 150, 250, 450, 750 and 1000 grams and, through the analysis of bed pressure drop versus gas flow curves, were obtained the parameters of maximum pressure drop, stable spout pressure drop and minimum spouting velocity. It was verified that for loads of 250 and 450 grams, the seeds showed a wide range of stable spouting regime with good circulation of particles resulting in good fluid-solid contact. As a result of the fluid dynamic analysis, the load of 450 grams was chosen to perform the coating process. Operating conditions were determined to obtain an adequate coverage for the seeds: atomization pressure of 115 kPa, flow rate of the coating suspension of 2ml/min and air inlet temperature of 70 °C. For these conditions, the efficiency of the process was 63 % and the average growth of seeds was 24.8%. © 2011.24667672Carvalho, N.M., Nakagawa, J., (2000) Seeds, Science, Technology and Production,Funep, , 4th Ed., Jaboticabal, Brazil (in Portuguese)Floriano, E.P., (2004) Germination and Dormancy of Seeds Forest, , Anorgs, 1st Ed., SantaRosa, Brazil (in Portuguese)Geldart, D., Types of gas fluidization (1973) Powder Technology, 7, pp. 285-292Mathur, K.B., Gishler, P.E.A., Technique for contacting gases with coarse solid particles (1965) Aiche Journal, 1, pp. 157-157Lorenzi, H., (1998) Brazilian Trees: Manual Identification and Cultivation of Native Tree of Brazil, , Plantarum, 2nd Ed., Nova Odessa, Brazil (in Portuguese)Mathur, K.B., Epstein, N., (1974) Spouted Beds, , Academic Press, LondonOliveira, J.A., Pereira, C.E., Guimaraes, R.M., Vieira, A.R., Silva, J.B.C., Performance of green pepper seeds covered with different materials (2003) Brazilian Journal of Seeds, 25, pp. 36-47Pallai, I., Nemeth, J., Analysis of flow forms in a spouted bed apparatus by the so-called phase diagram (1969) International Congress Chemical Engineer, , Prague, Czechoslovak Society for Industrial ChemistrySan Jose, M.J., Alvarez, S., Morales, A., López, L.B., Salazar, A.O., Diluted spouted bed at high temperature for the treatment of sludge wastes (2010) Chemical Engineering Transactions, 19, pp. 137-142San Jose, M.J., Alvarez, S., Morales, A., López, L.B., Salazar, A.O., Expansion of uniform beds of wastes in clean technology of conical spouted beds with a draft tube (2010) Chemical Engineering Transactions, 20, pp. 303-308Santos, P.E.C., Silva, J.B.C., Nascimento, W.M., Evaluation of materials for pelletization of lettuce seeds (2000) Brazilian Horticulture, 18, pp. 1036-1037. , PortugueseSantarém, E.R., Aquila, M.E.A., Influence of the methods for surpassing dormancy and storage on the germination of seed of Senna macranthera (Colladon Irwin ampBarneby (leguminosae) (1995) Brazilian Journal of Seeds, 17, pp. 205-209. , (in Portuguese)Silva, J.B.C., Nakagawa, J., (1998) Production and Testing of Lettuce Seed PelletsBrazilian Horticulture, 16, pp. 151-158. , Portugues