Rotor-Stator

Still very popular for in-line dispersion are the class of rotor-stator mixers. These devices look more like pumps than like stirred tanks. Volumes are small but rotational speeds and powers are high, giving high local energy dissipation. They are often staged with several rotors separated by stators that reduce bypassing. 

The literature is small on rotor-stator devices, as discussed in Chapter 8. [They are also discussed in Chapter 12, since this is the process result (liquid-liquid and solid-liquid) that these devices are most used for.] It should be mentioned that because of their very high speed they can produce turbulent motion in some rather high viscosity fluids. Also see Cohen (1998), Dietsche (1998), and Myers et al. (1999) for general information about the industrial application of rotor-stator mixers versus other mixing options. 

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High Speed Fluid Energy Mills. This type of equipment is used primarily for preparation of relatively low viscosity mill bases for inks and paints. The first is an impeller type which achieves dispersion by the appHcation of shear. The second type is in the form of a rotor—stator, and the dispersion is achieved by impingement or impact. 

Vibration peaks at specific speeds/high axial vibration is often present. Siib-harmomc Usually occurs as a result of loose components or as a result of aerodynamic or hydrodynamic excitations areas to be investigated for coiTection are seals, thrust clearance, couplings, and rotor/stator clearance... 

Pedestal-bearing motors consists of shaft, pedestal-type bearings, rotor, stator, and base. 

The SDRs reported so far are mainly applicable to liquid reaction systems and their main limitations are short residence times and low production capacities. These problems are addressed by the so-called rotor-stator SDR, which allows a countercurrent gas-liquid contacting at higher throughputs and longer residence times [104]. 

Compact heat exchangers MicroChannel heat exchangers Rotor/stator mixers Rotating packed-bed Centrifugal adsorber... 

Rotor bodies, in steam turbines, 23 231 Rotor electrostatic separators, 16 643-644 Rotor rotating converter, 16 151 Rotors, molecular, 17 59-61 Rotor spinning cotton yarn, 3 17 Rotor-stator devices, 10 127 Rotor-stator disperser, 3 701 Rotor-stator mills, 13 65 Rotor-stator mixers, 16 674-675 Rotosil process, 22 412 Roughages, as ruminant feeds, 10 863 Roughing, in mineral separation, 16 604 Roughing services, magnetic drums used in, 15 446... 

Sparks, T. G., Brown, D. E. and Green, A. Assessing rotor/stator mixers for rapid chemical reactions using overall power characteristics (BHR conference series. Publication 18. Mechanical Engineering Publications Ltd. London, 1995). 

The drug dissolved or dispersed in the melted lipid is poured into an aqueous emulsifier phase of the same temperature. By means of a rotor-stator homogenizer (e.g., an Ultra-Turrax), an o/w preemulsion is prepared and is then homogenized at high pressure and at a temperature at least 10°C above the melting point of the lipid. In most cases, nanoemulsion arises after only three to live homogenization cycles at 500 bar. Nanoparticles are formed by cooling the nanoemulsion to room temperature. 

The vertical rotor - stator configuration provides optimum flow conditions of... 

Maa Y-F, Hsu C. Liquid-liquid emulsification by rotor/stator homogenization. J Contr Rel 1996 38 219-228. 

Deaggregators Rotor Stator Greerco Koruma (Romaco) Barinco... 

This group normally operates only under high shear conditions. Subclasses are differentiated by how the high shear is introduced into the material, such as by a dispersator with serrated blades or homogenizer with rotor stator. 

A less gentle, but widely used, solubilization device is the common electric blender. This method may be used for plant or animal tissue, but it is not effective for disruption of bacterial cell walls. A blender that is more scientifically designed is the rotor stator homogenizer. The stator is a hollow tube and the rotor, attached to the stator, is a rapidly turning knife blade. Cells are torn apart by the turbulence and shear generated by the rotor. 

High-intensity inline devices are often used to mix fluids in the process industries. Such devices include simple pipes, baffled pipes, tees, motionless mixers, dynamic mixers, centrifugal pumps, ejectors, and rotor/stator mixers. In addition to their traditional application in physical processes such as mixing and dispersion, such devices can provide very effective environments for mass transfer and chemical reaction to take place. Furthermore, combining effective inline mixing with heat transfer is the basis of combined heat exchanger reactors (HEX reactors). 

A turbomolecular pump is a multi-stage, bladed turbine in which the rotor is driven at high rotational speeds so that the peripheral speed of the blades is of the same order of magnitude as the thermal velocity (c) of the gas particles to be pumped. The combination of a rotor and stator disc is one stage in a TMP. Pumped gas is compressed along the rotor-stator assembly and passed to a backing pump/pump-set for further compression to atmospheric pressure. 

Size (P-m) Hammer Mill Universal and Pin Mill Jet Mill Jet Mills with Internal Classifier Media Mills Toothed Rotor- Stator Colloid Mill... 

Toothed Rotor Stator Mills. Rotor-stator mills (Fig. 8.4a) consist of a rotating shaft (rotor), with by an axially fixed concentric stator. Toothed rotor-stator mills have one or more rows of intermeshing teeth on both the rotor and the stator with a small gap between the rotor and stator. Variations in the number of teeth, teeth spacing, angle of incidence, etc., all impact the milling efficiency of toothed rotor-stator mills. 

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