Pumps flow rate range

Pump flow rate range, gradient mixing mechanism, gradient accuracy, and solvent-delivering capability... 

Gradient CEC system which includes two PU-980 HPLC pumps, flow rate range 1 pl/min to 10 ml/min, -30 or +30 kV. Electropak CEC columns. 

For quick pump selec tion, manufacturers often give the most essential performance details for a whole range of pump sizes. Figure 10-30 shows typical performance data for a range of process pumps based on suction and discharge pipes and impeller diameters. The performance data consists of pump flow rate and head. Once a pump... 

The maximum and minimum flow rate available from the solvent pump may also, under certain circumstances, determine the minimum or maximum column diameter that can be employed. As a consequence, limits will be placed on the mass sensitivity of the chromatographic system as well as the solvent consumption. Almost all commercially available LC solvent pumps, however, have a flow rate range that will include all optimum flow rates that are likely to be required in analytical chromatography... 

The 1-octene conversions averaged 50% at the current flow rate (residence time 30 minutes). We believe the scatter in the data is due to the drift in the pump flow rate, which alters the residence time, and not to a change in the catalyst itself. In all cases the linear to branch aldehyde selectivity was very high in the range of 5 1 linear to branch aldehyde. The reaction was ran under thermomorphic conditions for over 400 hours and we found that we maintained good conversion and good selectivity. 

For quick pump selection, manufacturers often give the most essential performance details for a whole range of pump sizes. Figure 10-40 shows typical performance data for a range of process pumps based on suction and discharge pipes and impeller diameters. The performance data consists of pump flow rate and head. Once a pump meets a required specification, then a more detailed performance data for the particular pump can be easily found based on the curve reference number. Figure 10-41 shows a more detailed pump performance curve that includes, in addition to pump head and flow, the brake horsepower required, NPSH required, number of vanes, and pump efficiency for a range of impeller diameters. 

Double-impeller combinations Bouaifi et al. (2001) derived the following correlations for stirred gas-liquid reactors with various combinations of double impellers. The impellers used were the lightning axial flow impeller (A-310), the four 45° pitched blade turbine pumping down (PBTD) and the Rushton disk turbine (RDT). Furthermore, the tank was a dish-bottom cylindrical tank equipped with four baffles, while the gas was introduced by a ring sprager. The gas-flow rate ranged from 0.54 to 2.62 L/s, whereas the rotational speed was from 1.66 to 11.67 s. The gas holdup is... 

Flow rate range is rather large. A pump is capable of delivering 0.001-9.99 mL/min in analytical mode. Some pumps are also capable of delivering up to 50 mL/min in preparative mode. In micro LC, the mobile phase is usually delivered at very low flow rates (0.1-100 yu,L/min). All pumps are equipped with an automatic device that stops the motor when pressure reaches a given value. 

Electric No degassing at low flow rates ranging from 100 to 300 ml/min Submersible pump Difficult after highly contaminated samples No limit No restriction... 

When classified in terms of flow rate, pumps may be defined as microbore, standard bore, or preparative, as illustrated in Figure 3.2. Standard-bore systems are the most commonly used pumping systems for analytical HPLC because they provide reliable operation at flow rates ranging from 100 yul/min to 10 ml/ min. These versatile systems are compatible with the less demanding applications of semipreparative work (12 mm columns) as well as with microbore operation (2 mm columns). 

HPLC covered in this book. Flow-rate ranges required for preparative work place special design constraints on instrumentation. Laboratory-scale pumps used for preparative work will typically function to 50 ml/min. 

Commercially available HPLC instrumentation was originally designed for use with standard-bore columns (4.6 mm I.D.). Detector flow cells were optimized for maximum sensitivity with these analytical columns, injectors were designed to introduce microliter quantities of sample, and pumps were designed to be accurate and reproducible in the milliliter flow-rate ranges commonly employed with standard-bore columns. However, these instruments are not well suited for use with small-bore columns, as the dispersion introduced by the large volumes is detrimental to the separation. In addition, the reproducibility and accuracy of the pumping system at the low flow rates required are questionable. 

In place of the diluent (or in addition to it, using more channels) one can add a buffer to obtain the optimum pH for the most efficient extraction. Or, one can add a reagent (or two, or more) and perform a pre-column derivatization, if that is required to improve separation or sensitivity. Multi-channel proportioning pumps are available with up to 28 channels, with pump tubes which can handle acids, bases, and most solvents at flow rates ranging from about 50 microliters per minute up to nearly four milliliters per minute. 

Brining This step involves the injection of brine into the resin bed. A brine maker or day tank is used to dissolve salt into a 25% solution. This solution is then diluted in line with service water to 10% and either pumped or educted into the resin bed. Flow rates range from 0.5 to 1.0 gpm/ft3. The low flow rate is nec-... 

Natural gas pipelines normally operate at elevated pressures. In many instances the gas is available at low pressures so must be pumped or compressed to higher pressure. If the volume of the gas stream is small, reciprocating compressors must be used. For larger gas volumes, rotary compressors of various types are available. Figure 20.910 shows pressure and flow rate ranges in which different types of compressors currently available are used. 

For the first preliminary experiments, a standard fuel oil burner system was purchased. Due to several reasons, however, a new pump and atomisation system was required, viz. a dedicated fuel punqp and a different spray nozzle. In this new set-up, primary air for a proper fiiel atomisation and secondary air for the combustion could be controlled separately. Furthermore, pumping and combustion of heavy fuel oil (sulphur content of 3.35 wt.% and a viscosity of 180 cP) was possible only, when mixed with diesel in a ratio of 60 40 (dicsehheavy firel oil). Besides, the flame tuimel had to be preheated to approx. TSO C using ordinary diesel or ethanol as a start-up fuel. When a steady state operation was observed (after approximately 10 minutes), the diesel flow to the flame tunnel could be replaced by a mixture of heavy fiiel oil and diesel (40 60), and the emissions of SOj are recorded (approx. 400 ppm). Then CEB is injected and subsequently the SO2 levels are recorded every 30 s. Usually, almost instantly a sharp decrease in the SOj concentration was observed, due to the reaction of the Ca wifti SO2. The experiments were carried out at various fiiel flow rates, ranging from 0.5 to 3 kg/hr, and at a CEB flow rate corresponding to Ca S ratios from 0 to 3. 

A series of experiments was conducted to study the AS transfer rate through the dialysis membrane by pumping a concentrated AS solution into the upper channel at 1 mL/min and water into the lower channel at varied flow rates ranging from 1 to 0.1 mL/min without sample injection. In these experiments, the AS input concentration into the upper channel and the AS output concentration from the lower channel were compared. The rate of the AS transfer rose, as expected, with the decreased flow rate through the water channel, and at a flow rate of 0.1 mL/min, the AS concentration collected through the lower channel reached nearly 100% that of the AS input in the upper channel. Whereas AS diffuses from the upper channel toward the lower channel, water in the lower channel is... 

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