Venturi tube

Measurement of Fluid Flow hy Means of Orifice Plates, Nobles and Venturi Tubes Inserted in Circular Cross Section Conduits Punning Full, ISO 5167-1980(e), International Organization for Standardization, Geneva, Switzerland, 1980. 

The pneumatic deposition of the filament bundles onto the moving belt results in formation of the web. A pneumatic gun uses high pressure air to move the filaments through a constricted area of lower pressure but higher velocity, as in a venturi tube. Pneumatic jets used in spunbonded production have been described (17,24). Unfortunately, the exceUent filament uniformity coming out of the spinnerette is lost when the filaments are consoHdated going through a gun. 

Accuracy Square-edged orifices and venturi tubes have been so extensively studied and standardized that reproducibihties within 1 to 2 percent can be expected between standard meters when new and clean. This is therefore the order of reliabihty to be had, if one assumes (1) accurate measurement of meter differenfial, (2) selection of the coefficient of discharge from recommended published literature, (3) accurate knowledge of fluid density, (4) accurate measurement of critical meter dimensions, (5) smooth upstream face of orifice, and (6) proper location of the meter with respect to other flow-disturbing elements in the system. Care must also be taken to avoid even sh t corrosion or fouliug during use. 

Some manufacturers are using relatively low-pressure air (100 kPa, or 15 Ibfiin", instead of 690 kPa, or 100 Ibf/in") and are eliminating the venturi tubes for clean-gas induction. Others have eliminated the separate jet nozzles located at the individual bags and use a single jet to inject a pulse into the outlet-gas plenum. 

Main fuel injector. This unit is designed to deliver a fuel-air mixture to the catalyst that is uniform in composition, temperature, and velocity. A multi-venturi tube (MVT) fuel injection system was developed by GE specifically for this purpose. It consists of 93 individual venturi tubes arrayed across the flow path, with four fuel injection orifices at the throat of each venturi. 

Orifice plates. Either the concentric orifice, eccentric orifice, or segmented orifice-type. Choice depends on the quality of the fluid handled. Venturi tubes. These consist of a well-rounded convergent section at the entrance, a throat of constant diameter, and a divergent section. Their accuracy is high however, installation, unless planned for in advance, is very difficult in the field. 

The discharge coefficient of the venturi tube depends on the convergent of the venturi, but is given as a constant value for a specified device. The range is from 0.984 for a rough-cast convergent to 0.995 for a machined convergent. 

ISO 5167-1 1991. Measurement of Fluid Flow by Means of Pressure Differential Devices-Fart 1 Orifice Plates, Nozzles and Venturi Tubes Inserted in Circular Cross-section Conduits Running Full. International Organisation for Standardisation, 1991. 

Saug-. suction, sucking, absorbing, absorbent, aspirating, -ader, /. Anat.) absorbing vessel, lymphatic vessel, -aderdriise, /. lymphatic gland, -apparat, m. suction apparatus aspirator. -druck, m. suction pressure, -diise, /. suction nozzle Venturi tube. 

Saug-luft, /. vacuum, suction inlet air. -luft-anlage, /. vacuum equipment or plant, -liifter, m. exhauster, -luftkessel, m. vacuum vessel, -maschine, /. exhauster aspirator, -messer, m. vacuometer. -nkpfchen, n. suction cup. -papier, n. absorbent paper, -pipette, /. suction pipet(te). -pumpe, /. suction pump, -raum, m. suction chamber, -rohr, n., -rohre,/. suction tube or pipe, sucking pip siphon Venturi tube, -rdhrehen,... 

Flow Rate. The values for volumetric or mass flow rate measurement are often determined by measuring pressure difference across an orifice, nozzle, or venturi tube. Other flow measurement techniques include positive displacement meters, turbine flowmeters, and airflow-measuring hoods. 

Orifice Plate in Quick Change Fitting Venturi Tube or Flow Nozzle ... 

Pitot ube or Pitot Venturi Tube Turbine or Propeller Type Element Rotameter... 

These conditions are similar to flow through orifices, nozzles, and venturi tubes. Flow through nozzles and venturi devices is limited by the critical pressure ratio, r,. = downstream pressure/upstream pressure at sonic conditions (see Figure 2-38C). 

Figure 2-38C. Critical Pressure Ratio, r, for compressible flow through nozzles and venturi tubes. By permission, Crane Co., Technical Paper 410, 1957. Also see 1976 edition. See note at Figure 2-18 explaining details of data source for chart. Note P = psia p= ratio of small-to-large diameter in orifices and nozzles, and contractions or enlargements in pipes.

Venturi Tube or Flow Nozzle Self-Contained Regulating Valve 0- - Computer Set... 

Included in the class of fluid-entrainment pumps are not only pumps that use a fast-streaming vapor as the pump fluid, but also liquid jet pumps. The simplest and cheapest vacuum pumps are water jet pumps. As in a vapor pump (see Fig. 2.46 or 2.51), the liquid stream is first released from a nozzle and then, because of turbulence, mixes with the pumped gas in the mixing chamber. Finally, the movement of the water - gas mixture is slowed down in a Venturi tube. The ultimate total pressure in a container that is pumped by a water jet pump is determined by the vapor pressure of the water and, for example, at a water temperature of 15 °C amounts te about 17 mbar. 

Type 4 Mk 1 Launching Rocket ( Baka Motor) was cylindrical in shape with conical nose and venturi tube tail. It contd 97.8 lbs double-base proplnt of compn listed under PROPELLANTS, item f. Three of such devices, located in fuselage of Baka , served as the main propulsion units (Ref 2, p 118, Fig 89)... 

There was also Special Mk 1 Rocket Motor Model 21 which consisted of a cylinder 80.3 inches long 11.8 inches in diam with rounded nose and a venturi tube attached at the rear. 

TURBINE AND PUMP ASSEMBLY COMBUSTION CHAMBER VENTURI TUBES 4 STABILIZING FINS... 

Gas flow is usually quoted in terms of velocity (cm/s) or mass flow (standard cmVs). Velocity may be measured by a venturi tube pointing into the flowing stream with a pressure transducer or manometer connected to the venturi tube. The two schemes which are more attractive for small-scale apparatus are... 

Reactive extraction is closely related to the droplet phenomena, and thus most theoretical models are based on droplet consideration. Their experimental evaluation can be done using either a rising (falling) droplet apparatus (Figure 10a) for short residence times or a Venturi tube for long contact times (Figure 10b) (56). 

Figure 10 (a) Rising-droplet apparatus and (b) Venturi tube for droplet mass transfer experiments. (1—feed storage, 2—metering pump, 3—double-flow valve, 4, 5—pumps, 6—heat exchanger, 7—collecting funnel, 8—stream to analysis, 9—valve). 

Monodispersed droplets can be produced and in the latter case captured by the counterflowing continuous phase in the conus of the Venturi tube (see Figure 10b). 

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