Settling volume method

Vessel sized for liquid surge drum and vapor/liquid separation by gravity settling method can be used for final design. Vessel siz for vapor/liquid separation by mist eliminator method should be checked by the mist eliminator vendor to confirm its size. Vessel sized for Hquid/liquid separation by surge volume method or with coalescer pad is a rough preliminary sizing. Its size should be checked by vendor or an expert. 

Recovery of Bismuth from Tin Concentrates. Bismuth is leached from roasted tin concentrates and other bismuth-beating materials by means of hydrochloric acid. The acid leach Hquor is clarified by settling or filtration, and the bismuth is precipitated as bismuth oxychloride [7787-59-9] BiOCl, when the Hquors are diluted usiag large volumes of water. The impure bismuth oxychloride is usually redissolved ia hydrochloric acid and reprecipitated by diluting several times. It is then dried, mixed with soda ash and carbon, and reduced to metal. The wet bismuth oxychloride may also be reduced to metal by means of iron or 2iac ia the presence of hydrochloric acid. The metallic bismuth produced by the oxychloride method requites additional refining. 

For vaporAiquid separators there is often a liquid residence (holdup) time required for process surge. Tables 1, 2, and 3 give various rules of thumb for approximate work. The vessel design method in this chapter under the Vapor/Liquid Calculation Method heading blends the required liquid surge with the required vapor space to obtain the total separator volume. Finally, a check is made to see if the provided liquid surge allow s time for any entrained water to settle. 

An example of the second method of parenteral suspension preparation is testosterone suspension. Here, the vehicle is prepared and sterile-filtered. The testosterone is dissolved separately in acetone and sterile-filtered. The testosterone-acetone solution is aseptically added to the sterile vehicle, causing the testosterone to crystallize. The resulting suspension is then diluted with sterile vehicle, mixed, the crystals allowed to settle, and the supernatant solution siphoned off. This procedure is repeated several times until all the acetone has been removed. The suspension is then brought to volume and filled in the normal manner. 

Figure 10.8. Suspension of solids. Power and ratio of diameters of impeller and tank, with four-bladed 45° impeller, width/diameter = 0.2. [method of Oldshue [1983)]. (a) The factor on power consumption for slurry volume, F1. (b) The factor on power requirement for single and dual impellers at various h/D ratios, F2. (c) The effect of settling velocity on power consumption, F3. (d) Suspension factor for various horsepowers F4 = F,F2F3.

Actually, information regarding the internal structure of the swollen particle is not necessary since the change in particle volume is equal to the volume of water absorbed, and the expanded particle settles slower, as its average density decreases, according to Equation 2 in either case. As with other hydrodynamic methods, sedimentation does not offer easy access to information regarding particle morphology. 

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