Drying characteristics

The drying characteristics of the material can be investigated by laboratory and pilot plant tests which are best carried out in consultation with the equipment vendors. 

This problem could be boring or it could be exciting. You are to determine, by theoretical calculations, the drying characteristics of a wet washcloth. 

Newitt, D. M. and Coleman, M. Trans. Inst. Chem. Eng. 30 (1952) 28. The mechanism of drying of solids. Part III. The drying characteristics of China clay. 

Grabowski, S., Marcotte, M., Poirier, M. and Kudra, T., Drying characteristics of osmotically pretreated cranberries - energy and quality aspects, Drying-Tech., 20 (2002) 1989-2004. 

Han, W., Mai, B. and Gu, T., Residence time distribution and drying characteristics of a continuous vibro-fluidized bed. Drying Tech., 9 (1991) 159-181. 

Shah, R.M. and Goyel, S.K., Drying characteristics of tea fluidised on a vibrating bed. 11 Handling of dust grades and its impact on quality. Drying Tech., 13 (1995) 1523-1541. 

With the aid of this approximate equation, the drying characteristics of many substances can be assessed. If K and q have been determined for various temperatures and vrater vapor partial pressures, the values for other temperatures are easily interpolated, so that the course of the drying process can be calculated under all operating conditions. With the aid of a similarity transformation, one can further compare the course of drying process of a material w/ith knovm properties w/ith that of a material w/ith different properties. 

PCC is normally used in fatty acid coated form in thermoplastic applications. The means by which the coating is applied is treated as proprietary by most producers but it is probably by the wet coating method, with a solution of the fatty acid salt added to an aqueous slurry of the filler, followed by filtration and drying. As described earlier, the use of fatty acid coatings can improve product filtration and drying characteristics. 

Material to be granulated Average particle size Size distribution Shape and porosity Drying characteristics Density and density differences ... 

Since the contact time is short, heat-sensitive materials with good drying characteristics are particularly suited to this kind of... 

Won-Aqueous Dispersions (NADs). These arc the solvcnt-bomc analogues of latexes. They were used as automotive finishes in the 1970s, but their use is now declining. The use of NADs as an auxiliary binder, however, is increasing as it has been found that the addition of a small amount of NAD can improve a coating s drying characteristics and rheology. 

Tambunan, A.H.,Yudistira, Kisdiyani, Hemani Freeze-drying characteristics of medical herbs. Drying Technol. 19, 325-331, 2001... 

Soysal, Y. (2004) Microwave drying characteristics of parsley. Biosystems Engineering 89(2), 167-1 73. 

In most spray towers, the air flow rate and the temperature are adjusted at the inlet ports to maintain balanced air/temperature patterns. When the atomized slurry is sprayed into the drying chamber, the air flow pattern is disturbed and becomes very turbulent. This effect can cause localized temperature gradients (hot or cold spots) and affect the particle drying characteristics. It is possible to have... 

It is usual with electrothermal atomisers to pipette between 5 and 100 pi samples into the device using a micropipette. With petroleum samples dissolved in organic solvents this may be a problem. Due to the low surface tension of many of these solvents they do not pipette easily and often dry irregularly in the atomiser, both factors giving rise to poor reproducibility. The problem of poor drying characteristics may be overcome with many solvents by pipetting into a pre-heated atomiser at approximately 80°C. The solvent is removed immediately, leaving the analyte on a reproducible spot each time. This technique, however, requires some care so as not to melt or contaminate the pipette tip. 

For coatings dispersed in water it is recommended that component surfaces are pre-heated to a uniform temperature of about 60°C to improve the drying characteristics of the film, but where organic solvents are used they are selected to give satisfactory drying at ordinary room temperature. However, fiim application will often be unsatisfactory if the atmosphere is too cold or damp. 

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