Processed products cooling

Atomic- Vapor Laser Isotope-Separation. Although the technology has been around since the 1970s, laser isotope separation has only recently matured to the point of industrialization. In particular, laser isotope separation for the production of fuel and moderators for nuclear power generation is on the threshold of pilot-plant demonstrations in several countries. In the atomic vapor laser isotope-separation (AVLIS) process, vibrationaHy cooled U metal atoms are selectively ionized by means of a high power (1—2 kW) tunable copper vapor or dye laser operated at high (kHz) repetition rates (51,59,60). 

Exothermic processes, with cooling through heat transfer surfaces or cold shots. In use are sheU-and-tube reactors with smaU-diameter tubes, or towers with internal recirculation of gases, or multiple stages with intercoohng. Chlorination of methane and other hydrocarbons results in a mixture of products whose relative amounts... 

In a typical process a jacketed still fitted with a stirrer and reflux condenser in charged with 240 parts 37% w/w (40% w/v) formalin and the pH adjusted to 8.0-8.5 using sodium carbonate solution with the aid of a pH meter. One hundred and twenty six parts of melamine (to give a melamine formaldehyde ratio of 1 3) are charged into the still and the temperature raised to 85°C. The melamine goes into solution and forms methylol derivatives. For treatment of fabrics, paper and leather this product may be diluted and cooled for immediate use. It may also be spray dried to give a more stable product. Cooling the solution would yield crystalline trimethylolmelamine, which may be air dried but which is less soluble in water than the spray-dried product. 

Functional property tests were conducted in duplicate. AACC (21) methods were used for the determination of water hydration capacity (Method 88-04) and nitrogen solubility index (NSI) (Method 46-23). Oil absorption capacity was measured by the procedures of Lin et al. (22) and oil emulsification by a modification (22) of the Inklaar and Fortuin (23) method. Pasting characteristics of 12.0% (w/v, db) slurries of the flours and processed products were determined on a Brabender Visco/Amylograph (Method 22-10). The slurries were heated from 30 to 95°C before cooling to 50°C to obtain the cold paste viscosity value. Gelation experiments were conducted by heating 15% (w/v db) slurries in sealed stainless steel containers to 90°C for 45 min in a water bath C3). 

Campbell has studied the separation of technetium by extraction with tributyl phosphate from a mixture of fission products cooled for 200 days. Nearly complete separation of pertechnetate is achieved by extraction from 2 N sulfuric acid using a 45 % solution of tributyl phosphate in kerosene. Ruthenium interferes with the separation and is difficult to remove without loss of technetium other radioisotopes can be removed by a cation-exchange process. However, this separation procedure has not been widely applied because of the adverse influence of nitrate. 

By heat losses capable of stopping propagation we mean those processes which lower the combustion temperature. These include (1) heat transfer from the heated explosive mixture to the tube walls, (2) evacuation of heat from the reaction zone itself to the walls of the container and (3) evacuation of heat from the reaction zone to the combustion products which depends on the cooling of the reaction products—cooling of the products creates a drop in temperature as one moves away from the reaction zone and a corresponding longitudinal (in the direction opposite the direction of propagation) heat flux. 

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