Indirect cooling

Cooling, indirect A cooling system in which the medium to be cooled is affected b> another medium situated between it and the refrigerating apparatus. 

Under certain conditions, such as high water temperatures, insufficient water supplies and problems of blowdown disposal, systems that depend on convection and use air as the transport medium may be preferable. The two types of dry cooling towers are the direct and indirect systems. Figures 4.21 and 4.22 show these systems in operation for nuclear station cooling. Indirect units use a surface or jet condenser at the turbine to condense exhaust steam. Water from the condenser is pumped to the dry tower for cooling and recirculation back to the condenser. In the direct system, steam is condensed in cooling coils without interfacing with a condenser. 

Figure 13 shows a schematic diagram illustrating the configuration of a surface cooling (indirect heat transfer) crystallizer. Heat can be transferred to a coolant in an external heat exchanger, as shown, or in coils or a jacket... 

FIGURE 9.1 I Schematic diagram of the converter section of a contact sulfuric acid plant employing an interpass absorption system for both better sulfur conversion and emission abatement. Product acid (or oleum) is cooled indirectly with process water prior to storage for sale. 

Determine the manimum yield nad slurry concentration obtained if a feed cotesining 80% naphthalene and 20% heozene is cooled indirectly to 45 °C. 

Crystal lizer Temperature <"C) Adiabatic Cooling Indirect Cooling ... 

Determine the maximum yield and slurry concentration obtained if a feed containing 90% naphthalene and 20% benzene is cooled indirectly to 4S°C. 

Solvent polymerization. For the synthesis of low-molecular-weight polyethene, the solvent proeess ean be used [77,78]. Cyclohexane or another appropriate solvent is heated to 140 to 150 °C. After addition of the catalyst, very rapid polymerization starts. The vessel must be cooled indirectly by water. Temperature control is also achieved via the ethene pressure, which can be varied between 0.7 and 7 MPa. 

As the spherical catalyst is prepared by quencher in water or aqueous solution, there are some differences between the spherical catalyst and the irregular catalyst cooled indirectly (such as air-cooled or water jacket cooled catalyst) as follows ... 

After integration of the catalyst bed(s) - if so desired after interbed cooling indirectly or by quench and calculation of lower heat exchanger - the sequence may be repeated in order to determine optimum operating temperatures, when the desired calculation has been performed, the results are edited and printed in a report. 

The chlorine gas can be cooled indirectly in a tubular titanium heat exchanger so that the cooling water is not contaminated and the pressure drop is small. The resultant condensate is either fed back into the brine system of the mercury process or dechlo-rinated by evaporation in the case of the diaphragm process. 

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