Spray Dryer (spray + dryer)

Distribution by Scientific Domains


Selected Abstracts


EXPERIMENTAL VACUUM SPRAY DRYING OF PROBIOTIC FOODS INCLUDED WITH LACTIC ACID BACTERIA

JOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 6 2009
YUTAKA KITAMURA
ABSTRACT This research aims to develop a vacuum spray dryer (VSD) that performs spray drying in a vacuumed drying tower at a lower temperature than the conventional spray drying. The VSD operational drying temperatures for the probiotic foods containing lactic acid bacteria were determined by the relationships between the temperature and the vapor pressure, and were correlated by Clapeyron's equation. The drying of the fermented milk starter at 35C drying tower was experimentally possible; however, powder from the lactic fermenting beverage was not obtained even at 50C, which resulted from the lower glass transition temperature of the material. Compared with ATP concentration of the fermented milk starter before and after the VSD drying, the lower the drying temperature, the higher the microbial activity is retained. The ATP ratio as 30% of the raw materials shows the high feasibility of VSD for dairy processing. PRACTICAL APPLICATIONS During the spray drying of liquid or slurry food, the heat-sensitive functional ingredients such as vitamin, enzyme or bacteria are usually degraded or lost because of the contact with hot air between 120 and 180C. Markets need food powder that involves a lot of functional materials and a long shelf life for the expansion of healthy food. The experimental vacuum spray dryer (VSD) showed a potential to dry probiotic foods involving lactic acid bacteria without their inactivation. Although the lactic acid bacteria contained in the powder at 35C,VSD was 30% of the raw material, it is more economical than using the liquid type fermented milk starter. With some mechanical or operational modifications for the high moisture content and low recovery ratio of the powder, VSD is applicable for dairy processing factories. [source]


OPTIMIZATION OF SPRAY DRYING CONDITIONS FOR PRODUCTION OF BIFIDUS MILK POWDER FROM COW MILK

JOURNAL OF FOOD QUALITY, Issue 4 2006
M. SELVAMUTHUKUMARAN
ABSTRACT Bifidus milk powder was prepared by supplementing cow's milk with predetermined level of additives to obtain slurry of desired concentration. The slurry was sterilized, cooled and inoculated with 24-h-old bulk culture of Bifidobacterium bifidum at 10% and incubated at 37C for 24 h, cooled and dried in SM Scientech Lab model spray dryer with predetermined spray drying conditions. The bifidus milk powder contains bifidobacteria counts from 1.88 × 109 to 15.80 × 109 cells/g dry weight and their percent survival was 4.17,35.11%. Maximum survival was obtained by using the following spray drying conditions: inlet temperature of 164.02C, slurry concentration of 25.62% total soluble solids and air pressure of 2.5 kg/cm2. The high temperature and air pressure of spray drying markedly influenced the color and appearance of final product. The inlet temperature and air pressure showed a significant effect on survival of bifidobacteria in the final product. [source]


Re-entrainment of wall deposits from a laboratory-scale spray dryer

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2007
M. J. Hanus
Abstract This work has determined the magnitude of re-entrainment and established the operational parameters that may be manipulated to influence re-entrainment of salt particles for a small-scale spray dryer (Buchi B-290). The wetness of the spray dryer wall deposits was found to significantly influence the magnitude of re-entrainment. It was shown both experimentally and numerically that wet deposits form at low nozzle air-to-liquid ratios (<2000), which form large droplets that dry slowly, while the initial droplet velocity did not have a large influence on wet deposition. Wet deposits form strong liquid and solid bridges, and thus deposits formed from wet particles were difficult to re-entrain. Less than 2% of deposits formed at nozzle air-to-liquid ratios less than 2000 were re-entrained, while 15.4 to 21.2% of dry deposited particles (formed at nozzle air-to-liquid ratios ranging from 2308 to 3409) were re-entrained. The threshold re-entrainment velocity of sodium chloride particles in the Buchi B-290 spray dryer was found to be between 4 and 7.7 ms,1, which is consistent with the lower-end threshold velocities presented in the literature. No significant trend relating relative humidity to the magnitude of re-entrainment was found in the 0.2,7.4% average relative humidity range, suggesting that the adhesive forces in spray dryer wall deposits are fairly constant across this relative humidity range. Decreasing wall deposit wetness through use of high (>2000) nozzle air-to-liquid ratios and use of high main gas velocities increased the re-entrainment of wall deposits in this spray dryer. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd. [source]


Dynamic energy and exergy analyses of an industrial cogeneration system

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 4 2010
Yilmaz Yoru
Abstract The study deals with the energetic and exergetic analyses of a cogeneration (combined heat and power, CHP) system installed in a ceramic factory, located in Izmir, Turkey. This system has three gas turbines with a total capacity of 13,MW, six spray dryers and two heat exchangers. In the analysis, actual operational data over one-month period are utilized. The so-called CogeNNexT code is written in C++ and developed to analyze energetic and exergetic data from a database. This code is also used to analyze turbines, spray dryers and heat exchangers in this factory. Specifications of some parts of system components have been collected from the factory. Based on the 720,h data pattern (including 43,200 data), the mean energetic and exergetic efficiency values of the cogeneration system are found to be 82.3 and 34.7%, respectively. Copyright © 2009 John Wiley & Sons, Ltd. [source]