Hollow outlet temperature

FIGURE 1.15 Effect of outlet temperature and additives on the formation of hollow particles in spray-dried powders. Additives control (blend of GA/MD), gelatin (1%), A deca-glycerin monolaurate (0.14 wt%), ethanol (5%). (From Paramita, V. et al. Dry. TechnoL, 28, 323, 2010. With permission.)... 

Results gained at 0.1 bar, when both the inter- and intra-particular volumes are unfilled, are similar to bulk and tapped densities (data not shown). The density calculated after filling inter-particular spaces, known as the effective particle density, differed significantly for the three different outlet temperatures (Table 14.8). The lowest density was obtained for Tout = 67 °C with 0.832 g/cm, which results in spherical carrier particles. This shows that the hollow space volume is the largest for these particles. The effective particle density rises up to 1.111 g/cm for particles dried at Tout = 102 °C, which are particles with indentations. These particles show higher mechanical stability due to its higher material per volume ratio as mentioned before. 

The temperature of the kiln la determined by the appearance of the mouths and top outlet of the kiln, as well as by trial pieces. When. sufficient beat ia attained, and before the fires burn hollow, tho mouths are banked up with ashes to prevent the passage of cols Mr through the oven and the whole fa allowed... 

The continuous enzyme membrane reactor (CMR). (1) Temperature-controlled water-bath (2) Feed tanig (3) Stirrer motor for feed tank (4) Feed pump (5) Feed inlet line to the reaction vessel (6) Reaction vessel (7) Magnetic stirring table (8) Prefilter (9) Recycle pum (10) Flowmeter (11) Membrane inlet pressure gauge (12) Hollow fiber membrane cartridge (13) Membrane outlet pressure gaug (1 Pressure adjusbneut valve (15) Retentate recycle line (16) Air bath environment (17) Pemieate (product) line (18) Permeate collection vessel (19) Electronic balance... 

During the process, the aqueous silicate solution is introduced into the upper portion of the gas-fired spray dryer and passes through a spray nozzle or a disk atomizer (see Figure 22.5). The speed of the spray wheel may be about 11,000 rpm. The finely and evenly dispersed liquid comes into contact with upwardly directed hot air. Typical spray tower tanperatures are about 180°C [21] with inlet temperatures of about 260-300°C and outlet air temperatures of above lOO C. The resultant spray-dried droplets adopt the form of hollow microspheres. The silicate particles are collected at the spray dryer s bottom and are withdrawn by a screw conveyor. The amorphous sodium silicate may have a bulk density on the order of 250-500 g/L, an SiOjiNajO molar ratio of 2.04 1, and an ignition loss on the order of 19-20%. Its mean particle size can be on the order of 100-200 pm. The material may be subjected to further milling to modify the form and density of the powder [51,63]. 

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