Processing and spray

The egg products are finally processed and spray-dried. Sometimes Hquid egg whites are concentrated before spray-drying by ultrafiltration (qv) or reverse osmosis procedures. Table 5 presents the effect of egg quaUty on the different egg product manufacturing processes. 

Various methods are applied to the synthesis of titania particles including sol-gel method, hydrothermal method [2], citrate gel method, flame processing and spray pyrolysis [1]. To utilize titania as a photocatalyst, the formation of ultrafme anatase titania particles with large crystallite size and large surface area by various ways has been studied [4]. 

Physical properties of the three test fuels are presented in Table I. Except for the surface tension of No. 6 fuel oil, which was a typical value, all properties were measured for the specific samples tested. The primary differences between the SRC-II middle distillate and the No. 2 fuel were the higher specific gravity, surface tension, and viscosity of the SRC-II. The No. 6 grade fuel, a residual fuel oil, had a much higher viscosity than either of the distillate fuels. Both the SRC-II and No. 2 fuel oil were sprayed at a nominal temperature of 80°F to simulate usage in a non-preheat combustion system. The No. 6 fuel oil was sprayed at temperatures ranging from 150° to 240°F in order to assess spray formation processes and spray quality over a broad range of viscosities. 

Gunsel, W.C. Lachman, L. Comparative evaluation of tablet formulations prepared from conventionally processed and spray-dried lactose. J. Pharm. Sci. 1963,52 (2), 178-182. Van Kamp, H.V. Bolhuis, G.K. Kussendrager, K.D. Lerk, C.F. Studies on tabletting properties of lactose. IV. Dissolution and disintegration properties of different types of crystalline lacose. Int. J. Pharm. 1986, 28, 229-238. Ondari, C.O. Kean, C.E. Rhodes, C.T. Comparative evaulation of several direct compression sugars. Drug Dev. Ind. Pharm. 1983, 9 (8), 1555-1572. 

Gunsel WC, Lachman L. Comparative evaluation of tablet formulations prepared from conventionally-processed and spray-dried lactose. J Pharm Sci 1963, 52 178-82. 

Foaming Process of Resol-Type Foam. The foaming processes for phenolic foam of both the resol type and benzylic-ether type are the same as those for rigid polyurethane foams. The block-foaming process (slab foaming), pouring process, continuous-laminate process, and spray process are used. See Figure 57. 

Aluminum coatings can be applied to steel by hot dipping, cementation, ion vapor deposition, and spraying. Ion vapor deposition is a relatively new process, and spraying is the only process that has been used extensively over a long period of time. Pack cementation is widely used for gas turbine components. In soft waters aluminum is cathodic with respect to steel however, in seawater or some fresh waters containing chloride ions or sulfate ions, aluminum may become anodic to steel, and aluminum coatings should therefore corrode sacrificially and provide cathodic protection to steel. However, as noted below, this may not always be the case. 

Two basic methods are used for the appHcation of protective coatings to metal containers, ie, roUer coating and spraying. RoUer coating is used if physical contact is possible, eg, coating of metal in sheet and coil form. Spraying techniques are used if physical contact is not possible, eg, to coat the inside surface of two-piece drawn and ironed can bodies (see Coating processes). 

Reaction times can be as short as 10 minutes in a continuous flow reactor (1). In a typical batch cycle, the slurry is heated to the reaction temperature and held for up to 24 hours, although hold times can be less than an hour for many processes. After reaction is complete, the material is cooled, either by batch cooling or by pumping the product slurry through a double-pipe heat exchanger. Once the temperature is reduced below approximately 100°C, the slurry can be released through a pressure letdown system to ambient pressure. The product is then recovered by filtration (qv). A series of wash steps may be required to remove any salts that are formed as by-products. The clean filter cake is then dried in a tray or tunnel dryer or reslurried with water and spray dried. 

Graining, flaking, and spraying have all been used to make soHd ammonium nitrate particles. Most plants have adopted various prilling or granulation processes. Crystallized ammonium nitrate has been produced occasionally in small quantities for use in specialty explosives. The Tennessee Valley Authority developed and operated a vacuum crystallization process (25), but the comparatively small crystals were not well received as a fertilizer. 

Other. Numerous other supercritical fluid processes and techniques have been and are continuing to be developed. The novel spray appHcation UNICARB uses supercritical CO2 to replace volatile diluents in coating formulations, thereby reducing the volatile organic compound emissions by up to 80% (128). Rapid expansion of CO2 iu the spray can also improve the quaUty of coatings, thus performance benefits are obtained in a process developed for environmental advantages. 

Spray Pyrolysis. In spray pyrolysis, a chemical solution is sprayed on a hot surface where it is pyrolyzed (decomposed) to give thin films of either elements or, more commonly, compounds (22). Eor example, to deposit CdS, a solution of CdCl plus NH2CSNH2 (thiourea) is sprayed on a hot surface. To deposit Iu202, InCl is dissolved in a solvent and sprayed on a hot surface in air. Materials that can be deposited by spray pyrolysis include electrically conductive tin—oxide and indium/tin oxide (ITO), CdS, Cu—InSe2, and CdSe. Spray pyrolysis is an inexpensive deposition process and can be used on large-area substrates. 

The volume of thermosetting powders sold exceeds that of thermoplastics by a wide margin. Thermoplastic resins are almost synonymous with fluidized-bed appHed thick-film functional coatings whereas thermosetting powders are used almost exclusively in electrostatic spray processes and appHed as thin-film decorative coatings. 

Manufacturing Processing and Uses. In commercial production, aqueous urea solution is mixed with acetaldehyde in 1 1 molar ratios. An acid catalyst is introduced into the reaction mixture which is staged at various process temperatures. After neutralization with a base, the CDU is separated from the mother hquor by filtration or spray drying. 

The dry powder process has several additional advantages over the wet process. For example, much less waste of enamel occurs because the dry over-spray is airborne and recycled in a closed system. No-pidde ground coats have broadened the apphcation of both wet-process and dry-process systems. These enamels are appHed over cleaned-only metal. Thus the problems of disposing of pickling acid wastes containing iron sulfates and nickel wastes are eliminated (see Metal surface treatments) (7). 

Solution. Figure 12-8 shows the path on a psychrometric chart. The leaving dry-bulb temperature is obtained directly from Fig. 12-2 as 72.2 F. Since the spray water enters at the wet-bulb temperature of 70 F and there is no heat added to or removed from it, this is by definition an adiabatic process and there will be no change in wet-bulb temperature. The only change in enthalpy is that from the heat content of the makeup water. This can be demonstrated as follows ... 

---