Utilities energy targets

Heat Exchanger Network and Utilities Energy Targets... 

Although the composite curves can be used to set energy targets, they are not a suitable tool for the selection of utilities. The grand composite curve is a more appropriate tool for understanding the interface between the process and the utility system. It is also, as is shown in later chapters, a useful tool for study of the interaction between heat-integrated reactors and separators and the rest of the process. 

The energy cost of the process can be set without having to design the heat exchanger network and utility system. These energy targets cam be calculated directly from the material and energy balance. Thus... 

In Chap. 10, modification of the process for reducing process waste was considered in detail. It also was concluded that to minimize utility waste, the single most effective measure would be improved heat recovery. The energy-targeting methods presented in Chaps. 6 and 7 maximize heat recovery for a given set of process conditions. However, the process conditions can be changed to improve the heat recovery further. 

Vapor Pressure. The Shiley Infusaid implantable infusion pump utilizes energy stored in a two-phase fluorinated hydrocarbon fluid. The pump consists of a refillable chamber that holds the dmg and a chamber that holds the fluid. The equiUbrium vapor pressure of the fluid, a constant 60 kPa (450 mm Hg), compresses the bellows, pumping the dmg through a bacterial filter, a capillary flow restrictor, and an infusion cannula to the target body site (56,116). 

Figure 17.9 shows a heat exchanger network designed with the minimum number of units and to satisfy the energy target at ATmi = 20°C. On the basis of the following utilities and cost data, it has a total annual cost of 14.835 x 106 ( -y 1). 

MALDI A soft (gentle) method for creating gas-phase ions that utilizes energy from a laser targeted onto a mixture of analyte and a chemical matrix. Analyte ions can be formed from a combination of vaporization of existing ions and by vaporization of neutrals followed by ionization in the gas phase (Hillenkamp et al., 1990). 

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