Cooling extensibility

The effect of the residence time of the particles in the plasma jet was studied in two ways—by varying the gas flow through the jet and by varying the length of the water cooled extension tube (see Figure 3). 

Figure 1. Horizontal x-ray target with water-cooled extension...

Perfluoro(tetraphenylpyridazine) (6a 140 mg. 0.19 mmol) was sublimed from a heated lube (280 C) in vacuo (0.002 Torr) through a silica lube loosely packed with silica wool heated to 725 C for ca. 20 inin. Crystals condensed in two zones in a cool extension to the furnace to give unchanged substrate 6a (44 mg) and product 7a yield 84mg (90%) mp 120-122.4 C (EtOH). 

Photograph 7-30 Ragged belite from very slow cooling. Extension of fingers into matrix. Note dotlike impurities. Kiln coating. Coal-fired, dry-process kiln, 2350 tons/day. (S A6650)... 

Tubing die n. A die with an annular opening used to extrude plastics tubing. The core (mandrel) of the die may be fitted with a water-cooled extension that aids in chilling the extrudate and bringing its internal diameter within tolerances. 

Moiybdic Acid — 300 149 B S s formed by reaction of MoS . oxygen and 5% HNOv H SOo cone goes to 20%. Jacketed vessel allows heating-cooling Extensive aeration... 

Syngas requires cooling Extensive cleaning for compounds) Higher particle loading ... 

Place 84 g. of iron filings and 340 ml. of water in a 1 - 5 or 2-litre bolt-head flask equipped with a mechanical stirrer. Heat the mixture to boiling, stir mechanically, and add the sodium m-nitrobenzenesulphonate in small portions during 1 hour. After each addition the mixture foams extensively a wet cloth should be applied to the neck of the flask if the mixture tends to froth over the sides. Replace from time to time the water which has evaporated so that the volume is approximately constant. When all the sodium salt has been introduced, boU the mixture for 20 minutes. Place a small drop of the suspension upon filter paper and observe the colour of the spot it should be a pale brown but not deep brown or deep yellow. If it is not appreciably coloured, add anhydrous sodium carbonate cautiously, stirring the mixture, until red litmus paper is turned blue and a test drop upon filter paper is not blackened by sodium sulphide solution. Filter at the pump and wash well with hot water. Concentrate the filtrate to about 200 ml., acidify with concentrated hydrochloric acid to Congo red, and allow to cool. Filter off the metanilic acid and dry upon filter paper. A further small quantity may be obtained by concentrating the mother liquid. The yield is 55 g. 

Breweries. Air conditioning and the extensive use of refrigeration are necessary to provide controEed temperature in wort cooling, fermentation, storage, and final packaging of the finished beer. Sanitation and removal of carbon dioxide are important aspects of this appHcation (see... 

The composition of an oxidizing mixture is altered extensively by the passage of a cool flame (66,83,84). Before passage of the flame, oxygenated materials are present. In the case of hexane oxidation, ROO radicals are reportedly displaced by HOO radicals above 563 K (85), in concordance with previous work (86,87). After the passage of a cool flame, olefins, some conjugate and others of lower molecular weight, are observed. 

Effect of Pressure. The effect of pressure in VPO has not been extensively studied but is informative. The NTC region and cool flame phenomena are associated with low pressures, usually not far from atmospheric. As pressure is increased, the production of olefins is suppressed and the NTC region disappears (96,97). The reaction rate also increases significantly and, therefore, essentially complete oxygen conversion can be attained at lower temperatures. The product distribution shifts toward oxygenated materials that retain the carbon skeleton of the parent hydrocarbon. 

Propane. The VPO of propane [74-98-6] is the classic case (66,89,131—137). The low temperature oxidation (beginning at ca 300°C) readily produces oxygenated products. A prominent NTC region is encountered on raising the temperature (see Fig. 4) and cool flames and oscillations are extensively reported as compHcated functions of composition, pressure, and temperature (see Fig. 6) (96,128,138—140). There can be a marked induction period. Product distributions for propane oxidation are given in Table 1. 

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