Mixing actuator

Mixing actuator Component designed to mix two airflows without controlling the volume. 

The sudden mixing of large amounts of reactants under heating, instead of cooling, caused a runaway reaction. Once the pressure reached 16 bar pressure safety devices were actuated, the temperature at that point had reached 160°C,... 

In chemical micro process technology there is a clear dominance of pressure-driven flows over alternative mechanisms for fluid transport However, any kind of supplementary mechanism allowing promotion of mixing is a useful addition to the toolbox of chemical engineering. Also in conventional process technology, actuation of the fluids by external sources has proven successful for process intensification. An example is mass transfer enhancement by ultrasonic fields which is utilized in sonochemical reactors [143], There exist a number of microfluidic principles to promote mixing which rely on input of various forms of energy into the fluid. 

The reactors are cylindrical in shape and can carry up to 30 mg of resin. Polymer sieves at the top and bottom of the cylinders serve for liquid feed and withdrawal. The array of reactors is attached to a capillary system allowing feed to either columns or rows. This distribution system is said to provide uniform charges to the various reactors. A specific detail of the reaction system is that mixing is achieved by pneumatic actuation using a fluoropolymer membrane (Figure 4.36). 

A series of experiments were run to find the probable cause of these explosive events. A 20-liter bucket was placed on the ground and a second bucket placed on a stand above it with a remotely actuated tipping device. In alternate experiments, water was poured on LNG and LNG on water. Foamed ice was formed, but no explosions occurred. The tests were extended by adding either additional LNG or water after the initial mixing of LNG and water had taken place. The further addition of LNG had no effect. However, when water was added to an already mixed quantity of LNG and water, an explosive event occurred which threw the contents of the bucket upward about 5 m. 

Yu, K.H., and K.C. Schadow. 1994. Cavity-actuated supersonic mixing and combustion control. Combustion Flame 99 295-301. 

When mixing two surfactants species in a SOW system, an equilibrium takes place between the oil and water phases and the interface for each species. Since the two species do not necessarily exhibit the same affinity for the interface and the oil and water bulk phases, the compositions of the surfactant mixtures at interface and in the phases might be different. For instance if a very hydrophilic species is mixed with a very lipophihc one, as often recommended in the old formulation literature, then the hydrophihc surfactant has a strong tendency to partition in water, whereas the lipophihc one would partition in the oil. In this case the surfactant mixture in water will contain a large majority of hydrophilic species, i.e., it will be very hydrophilic, whereas the oil phase will predominantly contain the hpophihc species, with the remaining adsorbing at interface. This situation in which each species actuates on its own, more or less independently of the other, has been called non-collective behavior. Since the surfactant mixture composition at interface is often the one that commands the actual property of the system, such as the interfacial tension or the stabihty of the emulsion, it is most important to know how to calculate or measure the characteristics of the mixture present at interface. Such methods will be discussed in the next section. 

An extrusion is comprised of a basket (cylinder) to contain the mix and a hydraulically actuated piston to press the mass through multiple extrusion dies. The baskets are jacketed for temperature control and contain internal screens to retain large agglomerates. Since the casting powder strands are unperforated, the dies are simple cylindrical barrels with conical lead-in sections. Extrusion rates are normally controlled by orifices in the hydraulic supply line however, constant-rate positive displacement devices are also used. As they extrude, the strands are collected separately in suitable containers. 

We undertook the study of this reaction, employing conditions where limited amounts of oxygen (or hydrogen peroxide) were allowed to react with mercaptoacetate in the presence of iron ions. The amount of Fe(III) (OH) (RS)2-2 produced was determined spectrophotometrically. Since the rate of bleaching of this complex was fast under some of the conditions, a rapid-mixing device was employed. This consisted of a spring-actuated syringe, patterned after one described by Stem and Du Bois (12), which injected one of the reaction mixtures into the other contained in a spectrophotometer cell. 

Modifiers can also be added to the supply pump by using a high pressure modifier addition valve. This valve normally has a loop of known volume (i.e. 1-5 mL) that can be filled with liquid modifier and then channeled directly into the supply pump after valve actuation. The fluid is then mixed in the reservoir of the supply pump and delivered as a mixed fluid to the SFE oven. In most cases, this method of mixing should be viewed as being approximate in rapidly screening modifiers at different concentration levels. 

Figure 4 Schematic production sequence for the manufacture of metered-dose inhalers by pressure filling (1) suspension mixing vessel (2) can cleaner (3) can crimper and filler (4) check weigher (5) can coder and heat tester (6) priming and spray testing (7) labeler (8) feeds for tested cans and actuators. (Courtesy of Ellis Horwood Publishers, Ref. 10.)...

S. Hleli, C. Martelet, A. Abdelghani, N. Burais and N. Jaffrezic-Renault, Atrazine analysis using an impedimetric immunosensor based on mixed biotinylated self-assembled monolayer, Sens. Actuators B Chem., 113(2) (2006) 711-717. 

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