Pitot probe

The pitot-venturi flow element is capable of developing a pressure differential 5 to 10 times that of a standard pitot tube. This is accomplished by employing a pair of concentric venturi elements in place of the pitot probe. The low-pressure tap is connected to the throat of the inner venturi, which in turn discharges into the throat of the outer venturi. For a discussion of performance and application of this flow element, see Stoll, Trans. Am. Soc. Mech. Eng., 73, 963-969 (1951). 

Pitot Probe - A simple pitot probe with "bouncing ball flow detector gives a qualitative indication of flare gas flow and can be used in the identification of leakage sources. 

The fuel and air mixture leaves the vaporizer and is fed to the combustor assembly, which consists of a diffuser, plenum with flow conditioning, nozzle, and combustor test section. The diffuser transits the flow from a 50.8-millimeter circular duct to a 160 X 120 mm rectangular-shaped plenum. The flow conditioning consists of two perforated plates, which enhance the flow uniformity and serve as effective flame arresters. The two-dimensional nozzle is constructed from sectors of a large-radius pipe and has an area ratio of 6 1. Pitot probe surveys showed that this setup produced a uniform top-hat velocity distribution across the area of the nozzle exit [2],... 

The equation governing the response of a Pitot probe is commonly given as (Becker and Brown 1974) [40] ... 

The EPA Method 2C concerns determination of the exhaust gas flow rate using a standard hemispherically nosed Pitot probe as shown in Figure 7.40. The previous equations for the S-Type Pitot probe apply to the standard Pitot tube, although the probe constant will be different. Becker and Brown [40] studied the response of Pitot probes in turbulent nonreacting gas streams. The following terminology is used to specify the recommendations of their study ... 

The EPA Methods 2G and 2F discuss the use of two-and three-dimensional Pitot probes, respectively, which are useful for swirling or cyclonic flows, but are used infrequently in industrial combustion applications and are therefore not discussed further here. The calibration procedures are considerably more difficult than those for one-dimensional Pitot probes. 

Flares are often tested with noncombustible gases such as air to study flow patterns. One example is the use of smoke generators in an air-assisted flare. Another uses handheld Pitot probes (see Chapter 4) to measure velocities. For the enclosed ground flare, a video camera is used to visually observe the combustion process. A gas analysis system can be used to measure the exhaust emissions. 

The flow patterns of single-phase liquids in tanks agitated by various types of impeller have been reported in the literature. The experimental techniques used include the use of coloured tracer liquid, mutually-buoyant particles, hydrogen bubble generation and mean velocity measurements using pitot probes, hot-rdm devices and lasers. 

By Verification regulation of pitot tube, velocity measurement with a pitot tube as standard, pitot probes should be consistent with the direction of flow, but due to the randomness of the operation and installation, cannot be absolutely consistent with the direction of flow, the resulting measurement error. In conjunction with its error to calculate installation probe deflection into uncertainty u(C2). 

Experiments show that, when the angle between the pitot probes and air reaches 5°, maximum error of measurement of wind speed is 0.25%. Set to uniform distribution, and k = 3, the uncertainty is... 

If the pitot probes are blocked at takeoff, air will be trapped at runway elevation static pressure. The failure symptoms are as follows ... 

Pitot probes or static ports blocked by insects, etc. 

Pressure (static and dynamic) Manometers, barometers, pressure taps, pressure probes. Microphones, pitot probes, bourdon tube... 

Flow Orifice systems, pitot probes, hydrometer, anemometers... 

At around 0202 h, the Captain left the cockpit. At around 0208, the crew made a course change of 12 degrees to the left, probably to avoid returns detected by the weather radar. At 0210 05, likely following the obstruction of the Pitot probes by ice crystals, the speed indications were incorrect and some automatic systems disconnected... (The co-pilots) were rejoined 1 min 30 s later by the Captain, while the airplane was in a stall situation that lasted until the impact with the sea at 0214 28. ... 

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