Fractional recovery

Figure 10.7 shows the basic tradeoff to be considered as additional feed and product materials are recovered from waste streams and recycled. As the fractional recovery increases, the cost of the separation and recycle increases. On the dther hand, the cost of the lost materials decreases. It should be noted that the raw materials cost is a net cost, which means that the cost of lost materials should be adjusted to either... 

Separation Efficiency. Similarly to other unit operations in chemical engineering, filtration is never complete. Some soflds may leave in the hquid stream, and some Hquid will be entrained with the separated soHds. As emphasis on the separation efficiency of soHds or Hquid varies with application, the two are usually measured separately. Separation of solids is measured by total or fractional recovery, ie, how much of the incoming solids is coUected by the filter. Separation of Hquid usually is measured in how much of it has been left in the filtration cake for a surface filter, ie, moisture content, or in the concentrated slurry for a filter-thickener, ie, solids concentration. 

Other specifications often used in place of one or more of the last four listed are the fractional recovery of one component in either D or B and/or the concentration of one component in either D or B. 

Since there can be an infinite number of combinations of creep and recovery periods it has been found convenient to express this behaviour in terms of two dimensionless variables. The first is called the Fractional Recovery, defined as... 

Extensive tests have shown that if the final creep strain is not large then a graph of Fractional Recovery against Reduced Time is a master curve which... 

From equation (2.63) and the definition of Fractional Recovery, Fr, the residual strain is given by... 

The two phenomena, namely the effect of phase ratio on the fractional recovery and purity and the effect of saturation on purity, have thus far been... 

TOTAL PRODUCT NASS BALANCES AND RECOVERY FRACTIONS RECOVERY FRACTION SUMMATIONS FOR EACH COMPONENT... 

The hydrate was a hygroscopic powder melting at 95°C. Treatment of this with heat, acid, or alkali did not regenerate uridine quantitatively (the fractional recovery was not reported).51 5-Hydroxy-6-hydrouridine... 

Data are expressed as percent of homogenate activity per gram liver recovered in each fraction. Recovery is total percent of homogenate activity recovered in the various subcellular fractions. Assays were carried out at pH 6.5 and 38°. Animals had been fasted for 12 hr before use. 

Recovery of a certain fraction is the ratio between the masses of any fraction in the suitable product and in the original material. The recovery shows which part of useful particles contained in the feed gets into a suitable product. The coarse and fine fraction recoveries are expressed by yc = mcCc/m0C0, yf = mfFf/m0F0, respectively. Cleanness and dirtiness characterize quality of the separated products. In contrast, fraction recovery characterizes the separation efficiency. In particular if the original product is composed only of particles having cut size, its fraction recovery is 50%. 

Step 4a. For microwave-assisted, digestion, follow the procedure developed for the microwave system in the laboratory. Note that total dissolution of the solid is required for radioanalytical chemistry, whereas partial dissolution is acceptable for other analytical processes if the method has been tested for fractional recovery. Several references are given below that may be helpful in developing or using this method. 

Many laboratories have a criterion of performance based on the percent chemical yield. The recovery, for example, may have to exceed 50% to meet this criterion. The radiochemical yield is the fractional recovery of the amount of added tracer. Its measurement requires that the counter efficiency (e) is known (see Experiment 6). The counting efficiency can have been determined in a previous experiment and recorded with the detector information. 

The minimum vapor flow for the entire thermally coupled system is flat over a wide range of P Pp < P < Pr. This is the reason why dividing wall columns usually work well without tight coutrol of the vapor or liquid spht betweeu both sides of the partitiou. The optimally designed fully thermally coupled system should operate with a fractional recovery of B in the top product of the prefractionator placed somewhere between points P and R. The transition spht P is located at one end of the optimal section PR, and it is not a recommended design point for normal operation because process disturbances may move the operating point outside the optimal section PR shown in Fig. 13-70. 

When you have constructed the spreadsheet and duplicated the results just described for Run 1, (i) copy that row into the next three rows and change the values in the first six columns to duplicate those shown above (ii) let Runs 2 and 3 stand and (ill) in Run 4. vary the value of Ti to find the most cost-effective final temperature and pressure for the given feed conditions and fractional recovery, noting what happens to Pf, Cre/r. Ccomp and C,oi as you carry out your search. 

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