Pumping flow rate

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 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. 

Establish control charts of instrumental performance. Day-to-day variations in pump flow rate, relative response factors, absolute response to a standard, column plate counts, and standard retention times or capacity factors are all useful monitors of the performance of a system. By requiring that operators maintain control charts, troubleshooting is made much easier. The maintenance of control charts should be limited to a few minutes per day. 

Another interesting development, in which continuous flow was combined with discrete sample titration, is continuous flow titration by means of flow injection analysis (FIA) according to Ruzicka and co-workers70. Fig. 5.16 shows a schematic diagram of flow injection titration, where P is a peristaltic pump, S the sample injected into the carrier stream of diluent (flow-rate fA), G a gradient chamber of volume V, R the coil into which the titrant is pumped (flow-rate fB), D the detector and W waste. 

The //PLC system described in this chapter is equipped with 24 parallel columns for liquid chromatography, each with its own sample introduction port and exit port for connection to detectors of choice (UV absorbance and/ or fluorescence). Flow from a binary solvent delivery system is divided evenly across 24 channels and results in 1/24 of the programmed pump flow rate through each column (i.e., total flow of 300 /zL/ min will produce a flow of 12.5 /zL/ min in each column). Samples are introduced to the columns by a multichannel autosampler configured to sample from either 96-or 384-well SBS standard plates. Figure 6.2 depicts a general view of the system. 

In order to evaluate pump flow rate reproducibility and pulsation, one method is commonly used to assess gradient formation capability. A certain amount of an analyte with adequate molar absorptivity at the wavelength employed for detection is introduced into one of the mobile phases employed to create the gradient. In the case described, 5% acetone was introduced into the mobile phase, distributed to the system by pump B. No UV-absorbing analyte was introduced into mobile phase A. The fractional flow rate of pump B relative to the total flow rate of the system (mandated by the sum of the flow rates of pumps A and B) was increased in individual steps to account for 0, 3,6,12.5,25, 50, and 100% fractional rates. The total flow for the system was maintained at 300 /jL/ min (for 24 columns), resulting in a per column flow rate of 12.5 /iL/min/column. 

Novolac molecular weights were measured in THF at 35°C by high pressure size exclusion chromatography using a Waters Model 510 pump (flow rate=1.0 ml/min), 401 differential viscometer detector and a set of Dupont PSM 60 silanized columns. A universal calibration curve was obtained with a kit of 10 narrow molecular weight distribution, linear polystyrene standards from Toya Soda Company. Data acquisition and analysis were performed on an AT T 6312 computer using ASYST Unical 3.02 software supplied with the Viscotek instrument. 

There are different ways to connect the columns to build a SMB system. An important aspect is always the position of the recycling pump. The recycling pump ensures the internal flow of the mobile phase. Most often the recycling pump is placed between the last and the first column, i. e. columns 12 and 1 in Fig. 2. Once the recycling pump is fixed with respect to the columns, it moves with respect to the zones and is alternatively located in zones IV, III, II, and I. The flow rates required in the different zones are different and so the pump flow rates vary from... 

Anolyte mixer operation —Anolyte circulating pump flow rate —Total organic level in anolyte circuit... 

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. 

Pump flow rate accuracy and gradient accuracy Detector linearity of response, noise, drift, and wavelength accuracy Injector precision, linearity, and carryover Column heater temperature accuracy... 

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

Pump flow rate accuracy and gradient accuracy... 

Pump Flow rate accuracy 2% of the set flow rate 6 months... 

Pump flow rate 0.6 ml/min Column oven temperature 25°C Injection volume 10 (al UV monitor 260 nm. 

Where sand filters are installed to remove suspended matter in recirculating cooling water, it is usually sufficient to provide capacity based on 1 to 5% of the pumped flow rate. Smaller systems with highly rated cooling towers or evaporative condensers, or systems with high cycles of concentration, will tend to need filters installed in a bypass configuration at 4 to 5% of... 

When the pump is being used for its primary purpose of introduction of modifier for extractions, the actual amount of modifier that is delivered is a function of four variables and these variables can be controlled. The variables include, the length and diameter of line between pump and inlet port to the column, the allowable pressure limit of the pump, the pump flow rate and the amount of material including air in the columns. The first factor can be accounted for by measuring the volume of the lines between the inlet port and the pump head. This volume can then be subtracted from the calculated amount delivered to the first extraction vessel filled in a series. The second and third variables are parameters that can be set on the pump. The fourth variable was rarely a problem, but can be controlled by placing a vacuum pump in position 3 or 4 to evacuate the column and the connected lines. 

Problem 3 Inconsistent or too slow pump flow rate. 

Table 15.4 Rejection values vs. Ti02 concentration measured with pump flow rate of 10 Lh 1 and 46 Lh-1 [94].

This analysis is performed using a Dionex Model 12 ion chromatograph with 200pL sample loop, an eluent flow rate of 2.3ml min 1 (30% of full capacity) and a sample pump flow rate of 3.8ml min 1 (50% of full capacity). Pulse damper is installed just before the injection valve to reduce flow pulsation. A Dionex amperometric detector... 

Eluent pump flow rate of 35-40% (161-184ml IT1), maintained system pressure between 500 and 700psi. Both the sample and regeneration pumps were operated at 50% flow rate (230ml IT1). 

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. 

The hydrodynamic parameters that are required for stirred tank design and analysis include phase holdups (gas, liquid, and solid) volumetric gas-liquid mass-transfer coefficient liquid-solid mass-transfer coefficient liquid, gas, and solid mixing and heat-transfer coefficients. The hydrodynamics are driven primarily by the stirrer power input and the stirrer geometry/type, and not by the gas flow. Hence, additional parameters include the power input of the stirrer and the pumping flow rate of the stirrer. 

In volume limited applications, high density propellant combinations are favored and some appropriate trade-off between performance and density is established. In a truly volume limited system as shown in section IV. A. 1., the appropriate performance parameter is the product of the specific impulse and the propellant bulk density, a quantity usually labeled the density impulse. Conceivably, mixture ratio may be determined by yet other vehicle system considerations. If a new propellant combination is to be utilized in an existing vehicle, the optimum mixture ratio may be influenced by such considerations as existing pump flow rate capacities, tank volumes, and structure load carrying capacities. Even other system considerations, such as the desirability of operating at equal fuel and oxidizer volume flow rates to allow interchange of fuel and oxidizer flow hardware, may determine the propellant mixture ratio. 

The important design parameters for a stirred slurry reactor are the power input by the stirrer, the pumping flow rate of the stirrer, which affects the... 

Pour the pre-swelled Sephadex into an MPLC column (2.5 cm diameter and 40 cm long) and leave it to settle. About 5 cm of space should be left at the top of the column to allow 3-4 cm of buffer to sit on the top. Set the pump flow rate to about 4 mL/min. 

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