Separator applications, liquid particles

Sizing, 451, 453, 455, 459, 462 Sonic flow, 461 Types, illustrations, 411-421 Rupture disk, liquids, 462, 466 Rupture disk/pressure-relief valves combination, 463 Safely relief valve, 400 See Relief valve Safety valve, 400, 434 Safety, vacuum, 343 Scale-up, mixing, 312, 314—316 Design procedure, 316-318 Schedules/summaries Equipment, 30, 31 Lines, 23, 24 Screen particle size, 225 Scrubber, spray, 269, 270 Impingement, 269, 272 Separator applications, liquid particles, 235 Liquid particles, 235 Separator selection, 224, 225 Comparison chart, 230 Efficiency, 231... 

Electrostatic precipitation is one of the fundamental means of separating solid or liquid particles from gas streams. This technique has been utilized in numerous applications, including industrial gas-cleaning systems, air cleaning in general ventilation systems, and household room air cleaners. 

Table 4-7 summarizes liquid particle separators as to the general process-qqte application. 

Another potential application for zeolite/polymer mixed-matrix membranes is the separation of various liquid chemical mixtures via pervaporation. Pervapora-tion is a promising membrane-based technique for the separation of liquid chemical mixtures, especially in azeotropic or close-boihng solutions. Polydime thy 1-siloxane (PDMS), which is a hydrophobic polymer, has been widely used as the continuous polymer matrix for preparing hydrophobic mixed-matrix membranes. To achieve good compatibility and adhesion between the zeolite particles and the PDMS polymer, ZSM-5 was incorporated into the PDMS polymer matrix, the resulting ZS M -5/ P DM S mixed-matrix membranes showed simultaneous enhancement in selectivity and flux for the separation of isopropyl alcohol from water. It was demonstrated that the separation performance of these membranes was affected by the concentration of the isopropyl alcohol in the feed [96]. 

Membrane polymeric materials for separation applications are made of polyamide, polypropylene, polyvinylidene fluoride, polysulfone, polyethersulfone, cellulose acetate, cellulose diacetate, polystyrene resins cross-linked with divinylbenzene, and others (see Section 2.9) [59-61], The use of polyamide membrane filters is suggested for particle-removing filtration of water, aqueous solutions and solvents, as well as for the sterile filtration of liquids. The polysulfone and polyethersulfone membranes are widely applied in the biotechnological and pharmaceutical industries for the purification of enzymes and peptides. Cellulose acetate membrane filters are hydrophilic, and consequently, are suitable as a filtering membrane for aqueous and alcoholic media. 

The PDT that is a central feature of this book dates from this period (Widom, 1963 Jackson and Klein, 1964), as does the related but separately developed scaled-particle theory (Reiss et al, 1959). Both the PDT and scaled-particle approaches have been somewhat bypassed as features of molecular theory, in contrast to their evident utility in simulation and engineering applications. Scaled-particle theories have been helpful in the development of sophisticated solution models (Ashbaugh and Pratt, 2004). Yet the scaled-particle results have been almost orthogonal to pedagogical presentations of the theory of liquids. This may be due to the specialization of the presentations of scaled-particle theory (Barrat and Hansen, 2003). 

When a simple cross-flow of carrier liquid is used, the method is known as flow FFF and this has been represented as having the widest range of application of any single FFF technique [95,96]. This technique has been used to separate and characterize particles in the 0.01 to 50 pm size range. 

Particle-particle interaction is central to a wide range of engineering applications and processing industries. Examples include coagulation, flocculation, dispersion, emulsification, and froth flotation. In these applications, the particle size is small, and the overall particulate behavior is determined by forces associated with the surface properties rather than those related to mass or volume. The surface properties of a particle in a liquid medium are the result of a complex interaction between molecules, atoms, and ions at the particle surface and in the surrounding liquid. If a number of particles are present, interactions also take place between particles at short separation distances, and it is this interaction that is of most interest as it can determine the overall stability or instability of dispersions and/or suspensions. 

Mass-separating agent intra-particle diffusion in a porous sorbent. Energy-separating agent application of an electric field across a liquid phase to accelerate the charged particles relative to neutrals. 

Ion pairing agents in liquid-liquid systems in reversed-phase mode have included dihydrogenphos-phate for separation of tricyclic amines, octyl sulfate for catecholamines, and tetrabutylammonium for aromatic carboxylates and anions of sulfonamides, to exemplify some of the comparatively few applications. Liquid stationary phases coated on the alkyl-bonded phase include 1-pentanol, butyronitrile, and tributylphosphate. In normal-phase liquid-liquid ion pair chromatography aqueous perchlorate solution has been coated on to silica particles for ion pair separation of catecholamines and related compovmds and tetrabutylammonium ion at neutral pH for carboxylates and anions of sulfonamides. The organic mobile phase often contained dichloromethane and butanol. In the normal-phase mode on silica alternative separation systems have been described with aqueous perchloric acid in methanol added to dichloromethane as mobile phase for separation of amines such as drug substances. This is not an extensively utilized, but quite useful, kind of separation, which has been named ion pair adsorption chromatography. 

Classification of the separation techniques according to those involving phase change or mass transfer from one phase to another, known as diffusional operations, and those that are useful in the separation of solid particles or drops of a liquid and that are generally based in the application of an external physical force, known as mechanical separations. 

---