Flow sheets nomenclature

The nomenclature used in solvent extraction has been defined in Chapter 1 and is illustrated in Fig. 8.1. Not all of the steps shown in this figure will be found in every extraction process, but equally there may be occasions where it is necessary to add additional steps for example, to recover the extractant from the scrub raffinate. So while Fig. 8.1 is not a completely general flow diagram it covers most of the processes likely to be found in practice. Variations of this flow sheet will become apparent during the remaining chapters. 

Instrummiaiion flow sheets are useful in determining the requirements for process control and instrumentation. The Instrument Society of America has pioneering standardization of instrumentation flow plan symbols. These systems of nomenclature are illustrated in Tables 3-1... 

A procedure to calculate the steam requirement Djj for a continuously operated-stage evaporation unit in parallel flow, including preheating of the solution by some of the evaporated solution, is given in Table 7-3. Connections, flow sheets and nomenclature can be found in Fig. 7-13. 

Table 7-3. Procedure to calculate the steam consumption Dff of an n-stage cocurrent evaporation unit including solution preheater (connections, flow sheet and nomenclature may be found in Fig. 7-13).

Using the nomenclature of Chapter 5, a unit cell or module is made up of an electrode pair. A number of modules form a cell stack. A notional flow sheet is shown in Fig. 6.1. 

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