Drying modes

The received results can be used at a choice of a drying mode for optimization of power expenses, at operation of drying installation, and correction of mineral stmcture. 

Once produced by atomization, the droplets have to be dried. The initial contact between the spray droplets and the drying air will control the evaporation rates and the product temperature. In order to have a smooth operation, the largest particles must be dry before hitting the chamber wall to avoid sticking to them. Three drying modes are currently encountered and illustrated in Figure 3.11 ... 

Analytical instmments have been developed recently to dry ash samples using thermal and microwave heating examples are the APION A dry mode mineralizer (Tessek, Czech Republic), MLS-1200 PYRO microwave ashing furnace (Milestone, USA), and MAS 7000 microwave ashing system (CEM, USA). 

Thermoporometry applying also on xerogels can give the answers. The effects of three drying modes on gel texture have been studied and compared ... 

The drying mode and drying operating parameters must be carefully chosen to minimize the gel texture modifications. 

The selection of the plant concept involves the drying modes illustrated in Figs. 12-93 through 12-96. For different products a range of plant concepts are available to secure successful drying at the lowest cost. Three different concepts are illustrated in Figs. 12-97,12-98, and 12-99. 

Two types of wood samples (namely Guilan spruce and pine) were selected for drying investigation. Natural defects such as knots, checks, splits, etc which would reduce strength of wood are avoided. All wood samples were dried to a moisture content of approximately 30%. The effect of drying temperature and drying modes on the surface roughness, hardness and color development of wood samples are evaluated. 

The separator can either be operated wet, treating a slurry, or dry, treating a fine powder. In the wet mode, the fluid drag provides the separating force between the magnetic contaminants and the nonmagnetic medium. In the dry mode, the matrix is vibrated. This fluidises the fute material as it floiA s through the matrix. 

Table 12.19 Classification of paint according to drying mode...

Drying mode Mechanism of film formation Examples... 

The physical transformations that may appear in foods are different according to the (fifferent drying modes. When the product temperature is high enough for the product water vapor pressure to be equal to the total ambient pressure, the drying mode is ebuOition. For example with a product with = 0.3, the boiling temperature... 

Convective hot air drying is the most frequently used drying mode. If water migrates in the liquid state from the center of a solid product towards the surface, some shrinkage vdll be observed as a function of evaporated water volume. 

Depending on the way to apply heat to the product the drying is differentiated in several different modes. The main drying modes are the Convection Drying and the Contact Drying but also Radiation Drying is becoming more popular. 

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