Heads separation factor

Other useful measures of the degree of separation effected by a stage are the heads separation factor 0, defined by... 

Such a simple cascade, with an infinite number of stages each performing an infinitesimal amount of separation, is equivalent to type A differential st e separation. Equation (12.51) is equivalent to the form of the Rayleigh equation (12.35), when one recognizes that w in the simple cascade is equivalent to the heads separation factor 0 in differential stage enrichment, and a in the simple cascade is equivalent to the local separation factor a. ... 

This result is of great importance for isotope separation plants. It states that the total flow in the plant is the product of two factors, the first a function only of the heads separation factor p, and the second a function only of the flow rates and composition of feed, product, and tails. 

In the ideal cascade discussed up to this point, each stage receives as feed two streams of the same composition, a tails stream from the stage next higher in the cascade and a heads stream from the stage next lower in the cascade. In such a cascade the heads separation factor /, tails separation factor 7, and overall separation factor a are related by... 

An extension of this development to the general, p-up, <7-down ideal cascade shows that the heads separation factor (I is... 

The cascade receives feed of fraction Zp at flow rate F and produces an upper product of fraction yp at flow rate P, a lower product of fraction yg at flow rate Q, and tails of fraction Xw at flow rate W. For this two-up, one-down cascade, p = 2, q = I, the heads separation factor /3 is... 

If the heads separation factor p is constant throughout such a simple cascade, the fraction of deuterium that may be recovered depends on the number of stages n and the overall enrichment oj in accordance with... 

A high, but attainable, overall separation factor of a = 7 will be used. A heads separation factor such as the one that would be used in an ideal recycle cascade of 3 = y/a = y/f = 2.646 will be assumed. Then the number of stages n is given by... 

In Fig. 13.15, the first m—2 stages constitute a simple cascade, operated without recycle, with constant heads separation factor 0. The recovery of deuterium from a simple cascade of m—2 stages operated at constant 0 is... 

An electrolytic hydrogen plant fed with natural water containing 0.0149 percent deuterium is operated as a simple cascade, without recycle, to produce water containing 0.142 percent deuterium. The stage separation factor a has the value 7.0, and the heads separation factor 0 is independent of stage number. 

A gas centrifuge 300 cm long and 40 cm in diameter is to be run at 300 K and 500 m/s peripheral speed. It is fed at the midplane with UFs at a rate of 0.03 g UFe/s. The longitudinally uniform heavy-stream flow rate is 0.20 g UF /s. Heads and tails flow rates are set so that there is no mixing loss at the point of feed injection. Find the heads separation factor, tails separation factor, and separative capacity. Note /], I3 and /(/ i/a) are given in Table... 

How far apart the compositions of the two product streams are is indicated by ajj- But this index does not indicate how much richer the exiting stream 1 is in species 1 compared to the feed stream. That is expressed by the heads separation factor (Benedict et aZ., 1981, chap. 12) ... 

The separation index f thus combines the descriptive features of the heads separation factor a% and the component cut 91 or 02- Note that indicates the degree of enrichment of the Ught fraction in species 1 with respect to the feed stream, with 0i providing an estimate of the extent of recovery of species i if there is separation. Some special cases of relation (2.2.15) are given in the following. 

The double-entry separator performance is often characterized for a two-component system by the equilibrium ratio Ki (definition (2.2. If)) as well as by the separation factor ajj (definition (2.2.2a)). Both definitions relate the two product stream compositions and are related to each other by (2.2.2i). The compositional differences between the light fraction and feed stream 1 may be indicated by a heads separation factor... 

Obtain the following relation between the separation factor afj, the heads separation factor a%, the cut 0 and Xii for a single-entry separator and a binary feed ... 

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