Packing type application

Although the models for pressure drop have a basis in theory, all are fit empirically to data generated from specific equipment. Application of these models may not be relevant to machines of different configurations and packing types (9). 

This is used for the preparative scale separation of mixtures of compounds. There are many variations in detail of equipment and technique such as column type, column packing, sample application and fraction collection, many of which are a matter of personal choice and apparatus available. Typical arrangements are shown in Fig. 32.15 and for a detailed description of all these variations you should consult the specialist texts such as Errington (1997, p. 163), Harwood et al. (2000, p. 175) and Furniss et al. (1989, p. 209). 

In the first paper in 1952 we calculated the y-V relationship for the linear packing type. In this case, as criticized by Emmett in a private communication and later by Barrer et al., an approximation using (1) can lead to serious error. In addition, this type of packing is useless in actual applications, and so it was abandoned. In cases of the denser packing states considered here, errors due to (1) are not so large because a true spherical meniscus soon appears which encloses most of the sorbate liquid. 

Column Chemistry Column Packing Type pH Range Application... 

Although columns can be purchased commercially, they are often constructed in the laboratory since there is a substantial saving in cost and an increase in the control of variables (column length, diameter, type and concentration of packing) for application to specific research problems. Packed columns useful for analytical and preparative work are usually 1-50 ft in length and in. in diameter. For short columns, glass can be used but, under normal circumstances, copper, aluminum, or stainless steel tubing is preferable. Of these metals, copper is the cheapest and most flexible, and... 

Regular packing type Characterization Design Material Favored application Porosity (-) Specific surface (mVm ) Gas load factor Liquid flow rate (mV (m h)) No. of theoretical separation stages per m Specific stage pressure drop (mbar/m) ... 

Regular packing type Characterization Design Material Favored application Porosity (-)... 

With ROMBOPAK 4M and 9M two new packing types are available for applications requi- irrg very high titroughputs and extreme separation efficiencies. 

For vacuum rectification applications. Table 16.3 indicates the wire mesh packing type A3 to be well suited. This is in particular true for vacuum rectification at a column top pressure level of <20 mbar. The packing class A3 is a woven wire fabric of parallel corrugated elements and is completely self-wetting. Figure 16.6 illustrates the key performance data of Montz A3-500 packing related to pressure drop and separation efficiency. 

Ordered particle packings are also being used in other sensor type applications. Asher et al. ° described a system, where colloidal arrays of polymer particles were embedded in a gel-matrix. Changes in the environment of the particles caused the structures to shrink or expand, which could then be measured through the changes in the optical properties, as exemplified in Fig. 4. The same general idea can be applied to silica particles. This way, very specific sensors could be created when combined with appropriate surface modifications of the silica particles. The latter could be attached to the end of optical fibers or produced as a multisensor array on a chip. 

Next, the packing material type and size are selected. Among the different types of packing material available, of which mesh, rings, and saddles are the most common, the type most suited for a particular application is best determined based on available data for the different types. Information on each type includes pressure drop per foot, HETP, corrosion resistance, etc. Once a decision has been made regarding the packing type, its nominal size should be selected. Smaller... 

The height of a transfer unit is a function of the type of packing, liquid and gas flow rates, pollutant concentration and solubility, liquid properties, and system temperature. Tower height is primarily a function of packing depth. For most packed-tower applications, e height of a transfer unit can be estimated as 0.3-1.2 m (1-4 ft). The required depth of packing is deter-... 

Packed reactors. A packed reactor is more popular with very corrosive applications. A designer needs to allow for good distribution and avoid overly large packing and bed depth. Packing types include various kinds of rings and saddles. 

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