Crystallizers multiple-effect

Freeze Crystallization. Freezing may be used to form pure ice crystals, which are then removed from the slurry by screens sized to pass the fine sohds but to catch the crystals and leave behind a more concentrated slurry. The process has been considered mostly for solutions, not suspensions. However, freeze crystallization has been tested for concentrating orange juice where sohds are present (see Fruit juices). Commercial apphcations include fmit juices, coffee, beer, wine (qv), and vinegar (qv). A test on milk was begun in 1989 (123). Freeze crystallization has concentrated pulp and paper black hquor from 6% to 30% dissolved sohds and showed energy savings of over 75% compared with multiple-effect evaporation. Only 35—46 kJ/kg (15—20 Btu/lb) of water removed was consumed in the process (124). 

Elimination of Instrumental Broadening and Crystal Size Effect. Fourier transform of Eq. (8.13) turns the convolutions into multiplications (Sect. 2.7.8)... 

In general, the absence of a negative ion will endow a site with a positive effective charge. Multiple effective positive charges can exist and are written using superscript n . An oxide ion (O2-) vacancy in a crystal of CaO will bear an effective positive charge of... 

Multiple chemical sensitivity, 1 817 Multiple consortia technology transfer partnership model, 24 390 Multiple controllers, 20 698 Multiple downcomer plate, 8 764-765 Multiple-effect crystallizers, sodium carbonate recovery via, 22 789 Multiple-effect evaporators, 23 238... 

The main criticism of the forward-feed system is that the most concentrated liquor is in the last effect, where the temperature is lowest. The viscosity is therefore high and low values of U are obtained. In order to compensate for this, a large temperature difference is required, and this limits the number of effects. It is sometimes found, as in the sugar industry, that it is preferable to run a multiple-effect system up to a certain concentration, and to run a separate effect for the final stage where the crystals are formed. 

All lanthanide ions, with the exception of gadolinium(III) and europium(II), are likely to be relaxed by Orbach-type processes at room temperature. In fact, the f" configurations n l) of lanthanides(III) give rise to several free-ion terms that upon strong spin-orbit coupling, provide several closely spaced energy levels. Table III reports the multiplicity of the ground levels, which varies from 6 to 17, and is further split by crystal field effects. 

Consider multiple effects if crystallizing component is <75% of feed. 

We have already considered the multiplicity of asymmetric units and shall now discuss the positioning of chemically equivalent atoms at different point positions. Table III.4 shows the splitting of the 3SC1 NQR frequencies at 77 °K in benzene derivatives 126>. Only substances with one asymmetric unit in the unit cell are considered. One recognizes the spread of the frequencies for chemically equivalent chlorine atoms. The crystal field effect Av is within the limit of Av % 500 kHz. 

Muller et al. (206) have been concerned with the Lii ni white lines for Ca, Ti, Cr, Co, and Cu and LHi white lines for Sr, Zr, Nb, Ru, Rh, and Pd. In the latter series the shape of the white lines with increasing atomic number is determined by (i) the narrowing and increase of the 4d density of states and (ii) progressive filling of the 4d band. Crystal structure effects are much less conspicuous in the L-edge spectra than in the K-edge spectra. The shapes of the individual L, white lines of the 3d elements Ca, Ti, Cr, Co, Ni, and Cu are similar to those encountered in the 4d series, but the 2p1/2-2p3/2 spin-orbit splitting here is so small (from 6 eV for Ca to 20 eV for Cu) that the Lji and LfH spectra are superimposed. The relative size of the Lm and L white lines follows approximately the multiplicity ratio 2 to 1 of the 2p3/2 and 2pi/2 core states. 

Amorphous solids differ from crystalline solids because no long-range order occurs. So, variable coupling exists between the vibrational modes of similar or equivalent structural units. Consequently, amorphous solids can be treated in the same way as liquids and gases. The vibrational spectra of amorphous materials can present a smaller number of broader features than those of corresponding crystalline materials, where crystal coupling effects can produce multiple sharp features. 

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