Flow, pumping method

Determine the flow measurement method to be used during the test, i.e., flowmeter or pitot tube measures of the nearest available water outlets on the system. Ensure that the flow measurement devices are calibrated or adjusted for the fire pump maximum flow output. 

There are many variants on this simple theme. For instance, many other methods for mixing have found use. In a design offered by Lurgi, the phases are mixed in what is essentially an axial flow pump, and then pass down a relatively long pipe where the turbulence of flow keeps the phases mixed while the extraction takes place. In another design, the individual phases are pumped and then join and pass through a static mixer. There are no particular physicochemical reasons for preferring one type of mixer to... 

Automation is especially advantageous for analysing large numbers of samples on a routine basis. The flow injection method requires low sample volumes, hut even the recommended 600 pi loop size can be reduced to approximately 100 pi without substantial losses in sensitivity, accuracy or precision. In certain applications involving ICPs samples as small as 20 pi have been reported [7]. There is Httle doubt that sample introduction with a flow-injection valve and driven by a peristaltic pump or another... 

The liquid pumping in the microfluidic chip is mostly achieved by using electro-osmotic flow (EOF) [324]. Other liquid pumping methods have also been employed for microfluidic flow. Flow has been employed for fraction collection and generation of concentration gradient. Laminar flow in the microfluidic channel allows liquid-liquid extraction and microfabrication to occur within the channels. Moreover, valving and mixing are needed in order to achieve a better flow control. All these microfluidic flow operations are further described in subsequent sections. 

Alternatively, electroosmotic pumping could be used in this application. For generation of electroosmosis it is necessary to apply an electric voltage at both ends of the column. However, when we used electroosmotic flow instead of a pressurized pumping method, we encountered several problems. The hardest problem was evolution of gas at the electrode due to electrolysis. Elimination of this gas from the chromatographic system was one of the key challenges we faced in designing our system. 

Axial flow pumps, 134, 136, 140 applicafion range, 150 Azeotrope separation, 387,388,420-426 Azeotropic distillation, 420-426 acetonitrile/water separation, 422 commercial examples, 421-424 design method, 424 ethanol/water/benzene process, 424 n-heptane/toluene/MEK process, 424 vapor-liquid equilibrium data, 421, 423, 425,426... 

I tp 7. Stirred-flow reactor method experimental setup. Background solution and solute are pumped from (he reservoir through thc stirred reactor containing the solid phase and are. (tlkcied us aliquots by (he fraction collector. Separation of solid and liquid phases is accom-plished by a membrane filter al the oiillel end of the stirred reactor. 

In larger, pumped systems the variable volume/variable flow rate method ensures optimum operating conditions the collector flow rate is increased as the solar radiation input increases thus the output temperatme remains near constant. If there is a hot water draw-off from the tank during a no-sun period (e.g., at night), the tank water level is allowed to drop, that is, no make-up water is admitted (which would reduce the tank temperatme), until the next day s solar input period. 

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