Dividing walls

Distillation. There is a large inventory of boiling liquid, sometimes under pressure, in a distillation column, both in the base and held up in the column. If a sequence of columns is involved, then, as discussed in Chap. 5, the sequence can be chosen to minimize the inventory of hazardous material. If all materials are equally hazardous, then choosing the sequence that tends to minimize the flow rate of nonkey components also will tend to minimize the inventory. Use of the dividing-wall column shown in Fig. 5.17c will reduce considerably the inventory relative to two simple columns. Dividing-wall columns are inherently safer than conventional arrangements because they lower not only the inventory but also the number of items of equipment and hence lower the potential for leaks. 

Use the divided wall column shown in Fig. 5.17c to reduce the inventory relative to two simple columns, and reduce the number of items of equipment and hence lower the potential for leaks. 

If complex distillation columns are being considered, then these also can bring about significant reductions in capital cost. The dividing-wall column shown in Fig. 5.17 not only requires typically 20 to 30 percent less energy than a conventional arrangement but also can be typically 30 percent lower in capital cost than a conventional two-column arrangement. ... 

Lestak F, Smith R and Dhole VR (1994) Heat Transfer Across the Wall of Dividing Wall Columns, Trans IChemE, 49 3127. 

Mutalib MIA and Smith R (1998) Operation and Control of Dividing Wall Distillation Columns Part I Degrees of Freedom and Dynamic Simulation, Trans IChemE, 76A 308. 

Shultz MA, Stewart DG, Harris JM, Rosenblum SP, Shakur MS and O Brien DE (2002) Reduce Costs with Dividing-Wall Columns, Chem Eng Prog, May 64... 

Divergent exo-receptors, 26 774 DiverseSolutions software, 6 17 Diversity searches, 6 14-18 DiversitySolutions software, 6 15, 17 Dividing flow manifolds, 23 272 Dividing wall distillation columns, 20 750-751... 

M.I. Abdul-Mutalib and R. Smith. Operation and control of dividing wall distillation columns. Part I Degrees of freedom and dynamic simulation. Trans. IchemE, 76(Part A) 308-318, f998. 

K. Muralikrishna, K.P. Madhavan, and S.S. Shah. Development of dividing wall distillation column design space for a specified separation. Trans. IchemE, 80(Part A) 155-165, 2002. 

M. Serra, A. Espufia, and L. Puigjaner. Control and optimization of the divided wall column. Chem. Eng. Process., 38 549-562, 1999. 

Dividing wall in ordnance storage magazines 5 D1524... 

In case safety devices carry still a too high restend risk, additional measures in construction like bunkers or dividing walls are necessary. 

For certain applications, such as the separation of ternary mixtures, divided wall columns may be of interest, [9] which have shown to reduce the energy requirements and increase exergy efficiency. 

The polymer is sheared and then rotated by 90° by the dividing wall, the interfaces between the fluids increase. The interfaces are then re-oriented by 90° once the material enters a new section. The stretching-re-orientation sequence is repeated until the number of striations is so high that a seemingly homogeneous mixture is achieved. Figure 3.26 shows a sequence of cuts down a Kenics static mixer2. It can be seen that the number of striations... 

In general, any dividing wall between two cavities. Example the thin liquid films (lamellae) between bubbles in a foam. 

When a fluid is present in contact with each solid wall, there will be an additional resistance to heat transfer in each fluid boundary layer or film . The combined mechanism of heat transfer from a hot fluid through a dividing wall to a cold fluid has many similarities to conduction through a composite slab reviewed earlier. 

Figure 5 shows hot and cold fluids separated by a flat, conducting, dividing wall. Overall, heat is transferred from the bulk of the hot fluid to the bulk of the cold fluid. In detail, hot fluid in the turbulent bulk will be at a uniform temperature Th. Next to the wall will be a boundary layer through which heat is transferred to the wall. Heat is then transferred through the dividing wall by conduction to the cold fluid, and temperature drops from Tx to T2. Next to the wall on the cold side will be another boundary layer, through which heat is transferred into the cold side turbulent bulk, temperature Tc. 

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