Heat drying method

The Megalopohs station (Fig. 4d) uses hot flue gas to dry the lignite. A cyclone separator and electrostatic precipitator permit rejection of some of the water vapor to the atmosphere rather than to the boiler. Another drying method uses a vertical shaft, heated by combustion gases, for partial drying prior to grinding. 

Special drying methods, such as superheated steam, solvent, vacuum, infrared radiation, and high frequency dielectric and microwave heating, are occasionally employed when accelerated drying is desired and the species being dried can withstand severe conditions without damage. None of these methods is of significant commercial importance. 

Milnes and Mostaghaci [5.5] compared the consequences of different drying methods on the density, the sinter rate and micro structures of sublimated TiO-, suspensions. Evaporation of water in a micro-oven and by radiation heating leds to strongly bound agglomerates, while freeze drying resulted in softly bound secondary clusters. The freeze dried powder reached in 2 h of sintering 98 % of the theoretical density, while differently dried powders needed twice as much time and had a less fine microstructure. 

Interaction of substituted arenediazonium salts with potassium O. O-diphenylphosphorodithioates gave a series of solid diazonium salts which decomposed explosively when heated dry [10], The unique failure of diazotised anthranilic acid solutions to produce any explosive sulfide derivatives under a variety of conditions has been investigated and discussed [6]. Preparation of diaryl sulfides from interaction of diazonium and thiophenoxide salts led to violent explosions, attributed to presence of some arenediazo sulfide during subsequent distillation of the diaryl sulfides. Precautions are detailed [11]. A safe method of preparation of diaryl sulfides from diazonium tetralluoroborates and sodium benzenethiolate in DMF is now available [12],... 

Mercury(II) chloride, like mercury(I) chloride, is most conveniently made by dry methods that involve either heating a mixture of mercury(ll) sulfate and sodium chloride or heating mercury metal with excess chlorine ... 

Fig. 2. Heat-input methods Tor freeze-drying processes la) conduction, tb) radiation, (cl microwave. CC = cold condenser RHS = radiam-heat device...

The heal required for sublimation (1200 Btu per pound of ice 664 kilogram-calories per kilogram of ice) can be supplied by conduction, radiation, electric resistance, microwave, or infrared heating. Three methods of heal input that have been investigated extensively are shown in Fig. 2. Depending on the method of heal transfer, the temperature gradient between Ihe sublimation interface and the heat source is limited by Ihe maximum temperature which can be tolerated on Ihe surface of the dry... 

Drying of Double-Base Solvent Propellants. If a volatile solvent, such as acetone, has been used to facilitate the gelatinization of NC with NG, the solvent must be removed for the same reason as described under Drying of Single-Base Propellants. Here the air-drying method is preferred to water-drying because the loss of NG, on evaporation in heated air, is not as great as the loss due to solubility of NG in water (Ref 1)... 

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