Powdered detergents atomization

Spray drying is used to dry pharmaceutical fine chani-cals, foods, dairy products, blood plasma, numerous organic and inorganic chemicals, rubber latex, ceramic powders, detergents, and other products. Some of the spray-dried products are listed in Table 9.1, which also includes typical inlet and outlet moisture content and tanperatures together with the atomizer type and spray dryer layout used. 

The existence of choline dehydrogenase was first demonstrated by Mann and Quastel in 1937 247, 248) in extracts of rat liver and kidney. These authors also obtained evidence that the first oxidation product of choline was betaine aldehyde. Others showed subsequently that choline oxidase activity resided in the mitochondrial fraction of rat liver and is linked to the respiratory chain 249, 250). Detergents 251, 252), solvent treatment of fragmented mitochondria 253), and venom phospholipase 254-256) have been used for extraction and solubilization of choline dehydrogenase. Among these, the best method reported to date appears to be the digestion of acetone-powdered mitochondria with venom phospholipase. Choline dehydrogenase, partially purified from phospholipase extracts of rat liver mitochondria, contains 1 mole of flavin and 4 g-atoms of nonheme iron per 850,000 g protein. The flavin is claimed to be acid-... 

Figure 12-94a shows a cocurrent cone-based tall form chamber with roof gas disperser. This chamber design is used primarily with pressure nozzle atomization to produce powders of large particle sizes with a minimum of agglomeration. The chamber can be equipped with an oversize cone section to maximize powder discharge from the chamber bottom. This type of dryer is used for dyestuffs, baby foods, detergents, and instant coffee powder. 

Figure 12-94 > shows a countercurrent flow chamber with pressure nozzle atomization. This design is in limited use because it cannot produce heat-sensitive products. Detergent powder is the main application. 

Inductively coupled plasma-atomic emission spectrometry allows the determination of anionic surfactants (LAS and AS) and inorganic compounds (phosphate, silicate, zeolite, sulfate). Other techniques, such as X-ray fluorescence spectroscopy and X-ray powder diffraction, have been used for the qualitative analysis of inorganic detergents. For surface analysis, optical light microscopy, scanning electron microscopy, and transmission electron microscopy characterize particles, deposition of surfactant, or other detergent ingredients on fabric. 

The sodium silicates are differentiated first of all by their molar ratio (or Rm), which traditionally is written Si02/Na20. The sodium metasilicates with Rm = 1 are often crystallized products, certain of which are used in dishwasher detergents. These crystallized products may be anhydrous, found as white powders of variable particle size, or they may be hydrated one of the most commonly used hydrates is the pentahydrated form, containing five molecules of water per silicon atom. 

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