Influencing factors agitation speed

Recently, the experimental design procedure was applied to low shear wet granulation with a factorial design used to evaluate the influence of such factors as binder strength and agitator speed. 

Several of the factors of Figure 3 controlling the activity and selectivity of the biphasic selective hydrogenation of ,/ -unsaturated aldehydes to allylic alcohols, for instance, 3-methyl-2-butenaldehyde to 3-methyl-2-buten-l-ol (Eq. 11) with rutheni-um-sulfonated phosphine catalysts were investigated [11], such as the effect of agitation speed and the influence of aldehyde, ligand, and metal concentrations. Under optimized reaction conditions, where gas-liquid mass transfer was not rate-determining, the kinetic equation (Eq. 12) was found to apply. A zero-order dependence with respect to the concentration of the ,/i-unsaturated aldehyde was found. 

If the rate increases by a factor of 1.2 or 1.3 Regime II is indicated, but if it increases by two to five times, Regime III is indicated. (This experiment decides whether the agitator speed effect was due to an influence on or... 

The key factors influencing the purity drop phenomena are considered at first. They must be the factors which enh ce primary nucleation or growth of attached tiny crystalline particles on the seed crystals therefore a list of factors would include solution supercooling (or supersaturation), agitation speed, suspension density, mass of seed crystals, pretreatment of seed crystals, cooling rate and phase equilibria of given systems. Effects of these factors investigated in literature are examined separately. 

Solid phase micro-extraction (SPME) allows isolation and concentration of volatile components rapidly and easily without the use of a solvent. These techniques are independent of the form of the matrix liquids, solids and gases can be sampled quite readily. SPME is an equilibrium technique and accurate quantification requires that the extraction conditions be controlled carefully. Each chemical component will behave differently depending on its polarity, volatility, organic/water partition coefficient, volume of the sample and headspace, speed of agitation, pH of the solution and temperature of the sample (Harmon, 2002). The techniques involve the use of an inert fiber coated with an absorbant, which govern its properties. Volatile components are adsorbed onto a suitable SPME fiber (which are usually discriminative for a range of volatile components), desorbed in the injection chamber and separated by a suitable GC column. To use this method effectively, it is important to be familiar with the factors that influence recovery of the volatiles (Reineccius, 2002). 

Agitation System. The particle size of polystyrene made in a suspension polymerization is influenced not only by the type of suspending agent but also is subject to mechanical factors such as shape and size of the vessel and speed of agitation. A review of such mechanical factors in large reactors (50 and 500 liters) was published recently (137). 

Thus, for a given reaction mass, the heat transfer coefficient of the internal film can be influenced by the revolution speed of the agitator and its diameter. The value of z, characterizing the internal part of the equipment factor, can be calculated using the geometric characteristics of the reactor. Some typical values of the agitator constant are given in Table 11.3. The value of y can either be calculated... 

The effect of agitation on secondary nucleation has been reported in the literature and several references are discussed by Mullin (2001). This discussion highlights the complex nature and unpredictability of these interactions. Moreover, the critical nature of these interactions is the key factor in causing difficulty in scale-up of nucleation-dominated crystallization processes, even with small quantities of seed. The critical mixing factors are impeller speed and type and their influence on local turbulence and overall circulation. Since neither the localized turbulence distribution nor the overall circulation time can realistically be... 

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