Packing characteristics height

Determination of Packing Characteristics The packing characteristics are normally obtained from the tower manufacturer. Figure 8 illustrates the relationship between the height of a transfer unit for ammonia stripping and the GIL ratio for one type of packing... 

An awareness of crystal packing characteristics and polymorphism helps one to understand incompatibility problems of different fats. As shown in Fig. 8.2, if the three fatty acids in the triacylglycerol are saturated and approximately of the same length, each of the layers in the fat bilayer will be approximately two fatty acid chains in height. If the fatty acid on the number 2 glycerol carbon is appreciably shorter than those on the 1 and 3 carbons, each of the layers will be three chains thick. If the triacylglycerol is symmetrical, with either the number 2 glycerol carbon or both the 1 and 3 carbons unsaturated,... 

Figure 9-111. Typiccil effect of hot water temperature on tower characteristic, KaV/L at constant L, Ga wet buib temperature and packed height. Note L and G shown in chart are hourly rates. Reproduced by permission of the American Institute of Chemical Engineers, Kelly, N. W., and Swenson, L. K., Chemical Engineering Progress, V. 52, No. 7 (1956) p. 263 all rights reserved.

Figure 3.8. Crystal structure of CsCl. The positions of the centres of the atoms in the unit cell are shown in (a). In (b) the same cell is described by means of its characteristic sections taken at the height 0, A, and 1 of the third axis. In (c) a projection of the cell on its square basis is presented the values of the third (fractional) coordinate are indicated. In (d) the shortest interatomic distances are shown dCs-ci = a)3/2 = 411.3 X 0.866025. = 356.2. In (e) the subsequent group of interatomic distances (d = a = 411.3) involving six atoms in the adjacent cells is presented. A group of eight cells is represented in (f) to suggest that the actual structure of CsCl corresponds to a three-dimensional infinite repetition of unit cells and to show that the coordination around the white atoms is similar to that around the black ones shown in (d). The unit cell of the CsCl structure is shown as a packed spheres model in (g).

The simplest way of scaling-up of chromatography is to simply increase the column diameter. In this case, good care must be taken of the distribution of the mobile phase liquid over the cross section of the column. When particles of the same dimension and characteristics are packed in a larger-diameter column with the same height, the linear velocity and the sample volume per unit cross-sectional area should be kept unchanged to obtain the same resolution. 

Use of HTU and K a Data In estimating the size of a commercial gas absorber or liquid stripper it is desirable to have data on the overall mass-transfer coefficients (or heights of transfer units) for the system of interest, and at the desired conditions of temperature, pressure, solute concentration, and fluid velocities. Such data should best be obtained in an apparatus of pilot-plant or semiworks size to avoid the abnormalities of scale-up. Within the packing category, there are both random and ordered (structured) packing elements. Physical characteristics of these devices will be described later. 

From this and the gas mass velocity, it is determined that 3 towers are needed, each one with a diameter of 18.5 ft. The tower height is determined by the height of a transfer unit which is 20.7 ft. 05). Therefore, the height of the packed tower is 41.4 ft. Other detailed tower characteristics are given in Table III. 

Therefore, the gas mass velocity is 1372 lb/hr ft for 60% flooding condition with a gas mass flow of 1.28 x 10 lb/hr. It is determined that 3 towers are required each one 17.6 ft in diameter. The height of a transfer unit is a 11.4 ft and the total height of a packed tower is 22.8 ft. Pressure drop in the tower is 0.41 lb/in2. A summary of the composition of various streams is given in Table IV and stripper characteristics are given in Table III. 

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