Utilities cooling water

A test water box was installed during a 2-week trial to monitor corrosion and fouling in a utility cooling water system. A baffle plate from the test box was removed after the test. Small, hollow incipient tubercles dotted surfaces (Fig. 3.28). Small amounts of carbonate were present atop and around each tubercle. Each tubercle capped a small depression no deeper than 0.005 in. (0.013 cm) (Fig. 3.29). This indicated local average corrosion rates were as high as 130 mihy (3.3 mm/y). 

Example 17.2 For the process in Figure 16.2, calculate the target for network heat transfer area for ATmi = 10°C. Steam at 240°C and condensing to 239°C is to be used for hot utility. Cooling water at 20°C and returning to the cooling tower at 30°C is to be used for cold utility. Table 17.1 presents the stream data, together with utility data and stream heat transfer coefficients. 

In addition to the Separation and dehydration facilities described above, the necessary utilities (cooling water, hot oil, compressed oir, fuel gos, flare system etc) hove been provided to support the process operations. 

Make specific allowances for distribution systems within the process area for the various utilities cooling water, high/low pressure steam/condensate, service water/air, nitrogen, instrument air, vent collection systems, etc. Lengths and sizes must be determined based on arrangement and flows. Allow at least 30 ft. of pipe from distribution system to each individual user. 

Utilizes cooling water with an inlet of 29°C and an outlet of 35 C. With the CH ICAD-SCDS... 

Determine the optimal and the targets for energy recovery with the streams listed in the Table 10.1. Consider as utilities cooling water at 20 °C and steam at 250 °C. 

The overall balance gives an excess of 1500 kW, so the problem does not require hot utility. There is need only for cold utility (cooling water). Thus, feed preheating may be covered exclusively by the exothermic reaction and save a significant amount of energy. However, a furnace is necessary before reactor to ensure constant temperature. The reactor outlet is quenched at 620 °C. Assume that the furnace has to preheat the reaction mixture from 520 °C to a reaction temperature of 630 °C. By simulation we find a duty of 3800 kW. The new stream population for heat integration becomes ... 

Utility (cooling water/hot steam) cost is given by a function of temperature (see Figure 2)... 

Shell-side utility (cooling water) requires carbon steel MOC... 

The modem refinery is not only concerned with meeting product specifications and demands, but also the energy and utility (cooling water, power) consumption of various units. Table 5.18 lists some of the utility consumption data based on various catalytic reforming processes. 

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