Cake height

Defining the ratio of cake volume to filtrate volume as x , then the cake volume is x V, The cake volume also may be expressed by the product h,A, where h,. is the cake height in m. Hence,... 

We denote the ratio of cake volume to filtrate volume as Xq. Hence, the cake volume is XoV. An alternative expression for the cake volume is hcA where he is tire cake height in meters. Consequently ... 

Volume the cake should be of the correct volume (cake height should be appropriate to the correct volume hlled, not showing variation of low or high hll). 

Color Back Melting Pockets of Moisture Volume Variation (Cake Height) Bad Crimping Air Bubbles (Class Defect) Broken or Cracked Other ... 

In addition to the product specifications other attributes peculiar to lyophilized products should be verified. These may include uniformity of cake, cake color, cake height, reconstitution time, moisture content (if not a product specification), and short-term (accelerated) and long-term stability. 

The relative contribution to performance loss (TMP rise at constant flux) of resistance PF or CEOP depends on the particle size. For particles >0.5 pm the resistance is relatively small (see effect of particle size in Equation 6.4) and CEOP due to cake height, 8C, is the major effect [48], It is also observed that biofilms can contribute substantial CEOP effects as well as resistance, and in a recent biofouling study more than 50% of the required TMP rise was due to CEOP effects [32]. 

Here, Tc is the filter cake resistance, is the cake height and is the resistance of the filter cloth, h is calculated from the following equation ... 

All minerals subjected to the shear strength measurement have been compressed for half an hour at varying pressures to obtain a stable cake height. This compression time (half an hour) has been chosen according to the typical compression kinetics of Ti02 as an example given in Fig.2. As it is seen in Fig.2, the cakes have reached to a constant height in 3-5 minutes by compression at 4-20 bar and therefore to make sure 30 minutes has been taken as the compression time in each experiment. 

Filtration on a laboratory scale is usually performed with relatively small amounts of API and thus relatively small filter cake heights. Because the time for cake formation scales quadraticaUy with cake height, potential filtration issues on a large scale are often unforeseen in early phase process development. The filtration time of a suspension on plant scale, tp, as a function of filtration time, tp, and cake height, hp, on a laboratory scale is determined by Equation 18.3 ... 

For washing with a constant cake height. Equation 18.4 is used in which filtration time scales linearly with cake height ... 

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