Heating-while-cooling

There are a variety of well known methods used to orient materials, as reviewed by Ward [21], Ciferri and Ward [22] and Hay [23]. Ductile thermoplastics can be cold drawn near room temperature whereas thermoplastics which are brittle at room temperature can only be drawn at elevated temperatures. Thermosets are oriented by drawing the precursor polymer prior to cross-linking, resulting in an irreversible orientation. Rubbers can be reversibly elongated at room temperature. The orientation in oriented rubbers is locked in place by cooling, while heating drawn thermoplastics causes recovery. 

The liquid product from the bottom of the ammonia stripper is clean water containing less than 50 ppm NH3 and less than 10 ppm H2S. Afrer passing through a heat exchanger, where it is cooled while heating the sour water feed stream, and after further cooling, if necessary, the water is suitable for reuse in refinery processes or for disposal with other waste waters. 

Nitrosobenzene [586-96-9] M 107.1, m 67.5-68 , b 57-59 /18mm. Steam distd, then cryst from a small volume of EtOH with cooling below 0°, dried over CaCl2 in a dessicator at atm pressure, and stored under N2 at 0°. Alternatively it can be distd onto a cold finger cooled with brine at —10 in a vac at 17mm (water pump), while heating in a water bath at 65-70° [Robertson and Vaughan J Chem Educ 27 605 1950]. 

The fill illustrated in Figures 9-1 lOA and B is typical of many cooling tower heat transfer evaporative cooling surfaces. The wooden splash type is the oldest in terms of length of usage, while the film types (some fabricated of plastic) have been in service about 40 years [148]. 

This is a more advanced partial combustion process. The feed is first preheated and then combusted in the reactor with a limited amount of air. The hot gases containing carbon particles from the reactor are quenched with a water spray and then further cooled by heat exchange with the air used for the partial combustion. The type of black produced depends on the feed type and the furnace temperature. The average particle diameter of the blacks from the oil furnace process ranges between 200-500 A, while it ranges between 400-700 A from the gas furnace process. Figure 4-4 shows the oil furnace black process. 

There are a number of methods of classifying polymers. One is to adopt the approach of using their response to thermal treatment and to divide them into thermoplastics and thermosets. Thermoplastics are polymers which melt when heated and resolidify when cooled, while thermosets are those which do not melt when heated but, at sufficiently high temperatures, decompose irreversibly. This system has the benefit that there is a useful chemical distinction between the two groups. Thermoplastics comprise essentially linear or lightly branched polymer molecules, while thermosets are substantially crosslinked materials, consisting of an extensive three-dimensional network of covalent chemical bonding. 

The phase inversion temperature (PIT) method is helpful when ethoxylated nonionic surfactants are used to obtain an oil-and-water emulsion. Heating the emulsion inverts it to a water-and-oil emulsion at a critical temperature. When the droplet size and interfacial tension reach a minimum, and upon cooling while stirring, it turns to a stable oil-and-water microemulsion form. " ... 

Temperature Two modes of temperature parametric-pumping cycles have been defined—direct and recuperative. In direct mode, an adsorbent column is heated and cooled while the fluid feed is pumped forward and backward through the bed from reservoirs at each end. When the feed is a binary fluid, one component will concentrate in one reservoir and one in the other. In recuperative mode, the heating and cooling takes place outside the adsorbent column. Parametric pumping, thermal and pH modes, have been widely studied for separation of liquid mixtures. However, the primary success for separating gas mixtures in thermal mode has been the separation of propane/ethane on activated carbon [Jencziewski and Myers, Ind. Eng. Chem. Fundam., 9, 216-221 (1970)] and of air/S02 on silica gel... 

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