Inducers inlet

Free-vortex prewhirl. This type is represented by r Ve = constant with respect to the inducer inlet radius. This prewhirl distribution is shown in Figure 6-13. Vg is at a minimum at the inducer inlet shroud radius. Therefore, it is not effective in decreasing the relative Mach number in this manner. 

Klassen, H.A., Effect of Inducer Inlet and Diffuser Throat Areas on Performance of a Low-Pressure Ratio Sweptback Centrifugal Compressor, NASA TM X-3148, Lewis Research Center, January 1975. 

Fig. 6.13 Comparison of streamlines from rotating-disk solutions at two rotation rates. Both cases are for air flow at atmospheric pressure and T = 300 K. The induced inlet velocity is greater for the higher rotation rate. In both cases the streamlines axe separated by 27tA4< = 1.0 x 10-6 kg/s. The solutions are illustrated for a 2 cm interval above the stagnation plane and a 3 cm radius rotation plane. The similarity solutions themselves apply for the semi-infinite half plane above the surface.

A rotational speed of 6000 rpm was selected for optimum efficiency at a specific speed of 500. The radial type of impeller element determined by this specific speed was expected to operate satisfactorily at suction specific speeds nss of beyond 8000 and up to 20,000. For reliability, a value of 12,000 was selected. The gap between this capability of the impeller and an ascertained nss requirement of 70,000 (36-in. liquid level at the inducer inlet) was equivalent to 0.75 psi. Therefore, the inducer was designed for a head rating of at least this amount. 

The inducer seen in Fig. 7 was a double helix vane convolution of variable pitch. The optimum degree of prerotation at the inducer inlet could only be speculated. An inlet bell was therefore provided with guide vanes for modification, as previously discussed. 

By being able to obtain an unequivocal relative molecular mass, or even a molecular formula derived from that mass, the hybrid mass spectrometer becomes a powerful tool for investigating single substances or mixtures of substances. With an APCI inlet, fragmentation can be induced to obtain structural information (see Chapter 9). 

Fig. 6. Approaches to minimising entrapment and impingement of fish and large aquatic invertebrates, eg, blue crabs, on trash screens at intakes, (a) An inlet pump house with vertical traveling screens mounted flush with a river shoreline to minimise obstmctions to animal movements (b) parallel flow to direct fish to a recovery chamber that returns to the water body (c) a velocity cap atop a vertical, offshore inlet induces a horizontal flow which fish avoid...

Most of the commercial gas—air premixed burners are basically laminar-dow Bunsen burners and operate at atmospheric pressure. This means that the primary air is induced from the atmosphere by the fuel dow with which it mixes in the burner passage leading to the burner ports, where the mixture is ignited and the dame stabilized. The induced air dow is determined by the fuel dow through momentum exchange and by the position of a shutter or throtde at the air inlet. Hence, the air dow is a function of the fuel velocity as it issues from the orifice or nozzle, or of the fuel supply pressure at the orifice. With a fixed fuel dow rate, the equivalence ratio is adjusted by the shutter, and the resulting induced air dow also determines the total mixture dow rate. 

A double-entry inducer system halves the inlet flow so that a smaller inducer-tip diameter can be used, reducing the inducer-tip Mach number however, the design is difficult to integrate into many configurations. 

The largest disturbances can occur when the supply jet is disturbed or deflected by the process. In this case the jet can blow in unwanted directions, such as to the side or backward into the surroundings. The operator can disturb the horizontal jet by standing too close to the jet inlet and also by preventing the induced flow from passing the contaminant source. 

Induction terminal unit An air terminal assembly which by virtue of the configuration of the primary air inlet(s) within the unit can induce secondary air from the surrounding atmosphere before being discharged to the treated space. The tlow rate of the primary air may or may not be variable. The inlet aperture(s) for the secondary air may be fixed or adjustable by means of manual remote control. 

A more serious limit to this implementation is due to the volume of the recycling pump and associated equipment such as flowmeters and pressure sensors. As the pump moves with respect to the zones, its volume leads to a dead volume dissymmetry, which can lead to a decrease extract and raffinate purities. This decrease can be significant for SMB with short columns and/or compounds with low retention. However, it can be easily overcome by using a shorter column or asynchronous shift of the inlets/outlets [54, 55]. This last solution is extremely efficient and does not induce extra costs because it is a purely software solution. 

Recirculation the portion of exit or outlet air from the tower that recirculates back to the inlet of the fresh air to the tower. To keep this low it is important to space towers away from each other as well as from any structures which can deflect the exit moist air back to the inlet. Due to recirculation the wet bulb temperature at the tower inlet may be different from that at a point 100 yards away. The recirculation of induced draft towers is usually less than forced draft due to the upward velocity of discharge of the air. 

Normal recirculation in average installations for forced draft may run 3-10% of total inlet air, and 1-8% for induced draft towers, all depending upon the location and wind conditions during any day or season. Some towers can be arranged to have less than 1% recirculation. If conditions are suspected of being conductive to recirculation, it should definitely be allowed for in design of the tower. Recirculation increases the wet bulb temperature of entering air, increases the total air required (and hence size of... 

The tower pressure losses are (1) tower packing or fill (70-80% of loss) (2) air inlet if induced draft (3) mist eliminators at top (4) air direction change losses and entrance to packing on forced draft units. These losses are a function of air velocity, number and spacing of packing decks, liquid rate and the relation between L and Ga. 

For study purposes the effects of performance as related to fan horsepower may be patterned after Figures 9-121 and 9-122. The conditions for actual air inlet condiuons for an induced draft fan must be obtained from Equation 9-127 read from a diagrtim similar to Figure 9-109. 

Figure34.12 Mixing forced draft with induced. The overloaded forced-draft tower with excess plume results in elevated wet bulb at air inlets on new tower. Removing the forced draft and adding one more cell to the induced draft resolved the problem...

Fig. 4. Sectional view of one stage of a new type of gas-liquid contactor without pressure drop. (1) Vaned-disk impeller (2) stator (3) contacting tank (4) impeller shaft (5) gas inlet pipe (gas is self-induced through this pipe into the dispersion) (6) gas outlet thermometer (7) thermometer pocket (8) drainage tank (9) lid [after Gal-Or (G4)].

CO2, N2 and N2O production as a function of the catalyst potential, UWR> obtained at 62IK for fixed inlet pressures of NO and CO. A sharp increase in reaction rate and product is observed as the catalyst potential is reduced below 0 V, i.e., upon Na supply to the Pt catalyst. The selectivity to N2, Sn2, is enhanced from 17% to 62%. This dramatic enhancement in catalytic performance is due to (a) enhanced NO vs CO chemisorption on Pt with decreasing potential and (b) Na-induced dissociation of chemisorbed NO. 

Since variations In the pressure Induced by fluid dynamic effects are negligible for MOCVD reactor flows, the Inlet pressure, Pq, Is used. In formulating the energy balance, the contributions from pressure changes, viscous dissipation and Dufour effects may neglected for MOCVD conditions (14.15) so the equation becomes ... 

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