Pumps flow inducer

Use an impeller inducer. An impeller inducer looks like a corkscrew device that fits onto the center hub of the primary impeller and extends down the suction throat of the pump. It is actually a small axial flow impeller that accelerates the fluid toward the primarv impeller from further down the suctittn throat of the pump. Some inducers bolt onto the impeller and others are cast into the main impeller. The inducer has a low NPSHr for the system feeding it, and it increases the Ha to the primary impeller. 

Figure 14.1 presents the main components of a typical in situ SVE system.910 Vertical extraction wells are installed inside the contaminated zone at appropriate distances from one another. The SVE wells are typically constructed of PVC pipe, with a screened interval, which is placed within the contaminated zone. The wells are connected to blowers or vacuum pumps, which induce a continuous airflow through the pores of the unsaturated zone. The soil surface is sometimes covered with an impermeable seal, made from high density polyethylene (HDPE) or bentonite clay for example, to prevent the vertical influx of air from the surface, which might cause short-circuiting problems, and promote horizontal gas flow through the contaminated area. The airstream, which contains the contaminant vapors, passes initially through an air-water separation unit to remove the entrained moisture and is then directed to the gas treatment unit, where the contaminants are thermally destroyed or removed by adsorption. 

All of the data in Fig 7.5 were analyzed using linear regression. The summation of the helix and core-regressed flow rates are plotted in Fig. 7.5 as the red dotted line. The experimental superposition for the flows induced by the screw elements essentially overlaid the regression line for the screw configuration rate. Thus, it was concluded that the helix is the pump in the single-screw extruder, and core rotation reduces the flow by dragging the fluid back toward the extruder inlet. 

The interference process in this collinear approach is, however, different from the interference realized by mixing the local oscillator and the CARS field on a beam splitter. Interference takes place in the sample, which, in the presence of multiple frequencies, mediates the transfer of energy between the beams that participate in the nonlinear process. The local oscillator mixes with the anti-Stokes polarization in the focal volume, and is thus coherently coupled with the pump and Stokes beams in the sample through the third-order polarization of the material. In other words, the material s polarization, and its ability to radiate, is directly controlled in this collinear interferometric scheme. Under these conditions, energy from the local oscillator may flow to the pump and Stokes fields, and vice versa. For instance, when the local oscillator field is rout of phase with the pump/Stokes-induced anti-Stokes polarization in the focal interaction volume, complete depletion of the local oscillator may occur. The energy of the local oscillator field is not redistributed in terms... 

The partial electrochemical fluorination of benzene (I), phenol, chlorobenzene (2), ethylbenzene (3), and naphthalene (4) was investigated31 in a cell with a platinum anode (3x17 cm) and a Monel cathode (distances between the electrodes 1.5 to 2.0 mm), in Et3N 3HF as electrolyte with a voltage of 3 to 5 V (5 mA cm-2). The electrolyte was pumped through a degasifier with a HF resistant flow inducer (30 to 50 mL min-1). The reaction mixture was dissolved in HzO and extracted with CH2C12. The products are indicated below. 

Fig. 4 Flow-induced corrosion of a pump impeller. (View this art in color at www. dekker.com.)...

Sugioka H (2008) Suppression of reverse flows in pumping by induced-charge electro-osmosis using asymmetrically stacked elliptical metal posts. Phys Rev E 78(5) 057301 1-057301 4... 

Peristaltic pumps are mechanical displacement pumps that induce flow in a fluid-fllled, flexible-walled conduit through peristalsis - transport due to traveling contraction waves. While macroscale peristaltic pumps appear in a variety of configurations, micropumps based on this principle almost exclusively use the sequenced contraction and expansion of a small number of discrete actuators - typically three - placed along the fluid channel. 

In multiphase microfiuidics, transient phenomena can be divided into fluctuations that are flow induced (inside the channel) and induced by external fluctuations. Kraus et al. [69] measured statistical properties (distribution of liquid slug and gas bubble lengths) in segmented gas-liquid flow and documented the sensitivity to external disturbances (e.g. syringe pump pressure fluctuations). Van Steijn et al. [87] investigated such fluctuations in detail for low-velocity flow in a short... 

Ultrasonic pumps are pumps that use acoustic streaming to create a fluid motion inside microchannels. Acoustic streaming is the time-averaged flow induced hy an ultrasonic wave (periodic pressure oscillation). Attenuation of the acoustic energy (via reflection and other distortion) generates a body force within the fluid and converts acoustic energy into kinetic energy of the fluid [1]. 

The ability of the mixer impeller to pump or induce flow is measured and defined by a nondimensional flow factor ... 

Some jet pump components are subject to flow induced vibration. Fatigue is a potentially significant degradation mechanism for the jet pump and further evaluation of programmes to effectively manage age-related degradation is required. 

Mechanical wear has been identified as degradation mechanism at specific locations in the RPVIs due to flow induced vibrations. Recently the wear phenomenon has been reported in the jet pump wedge in some plants. However, as a result of monitoring systems (vibration, loose parts), this degradation mechanism is of minor importance concerning RPVIs capability to perform its safety function. 

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