Flow measurements static temperature

Static temperature is the temperature of the flowing fluid. Like static pressure, it arises because of the random motion of the fluid molecules. Static temperature is in most practical instaUations impossible to measure since it can be measured only by a thermometer or thermocouple at rest relative to the flowing fluid that is moving with the fluid. Static temperature will increase in a diffuser and decrease in a nozzle. 

The electronic flow measurement for custody transfer system consists of a microcomputer, s chromatgraph, H20 and H2S analyzer, a differential pressure, static and temperature transducers for each... 

An unusual application is described by Fedoseeva, Nechaev, and Strel tsova, who measured the adsorption of thirty-five organic substances on snow surfaces. Toluene was used as solvent since it does not dissolve ice to any appreciable extent, and has a lower density than ice. Of the 34 substances studied only formic, monochloracetic, and trichloracetic acids, and methyl and ethyl alcohols were adsorbed. The type II isotherm for trichloracetic add seemed to exhibit a B-point , use of which led to a surface area of the snow sample of 2.8 0.3 m g, which is similar to the value obtained from the low-temperature N2 adsorption. Further work on the use of calorimetry for the determination of surface areas is described by Rahman, who compares flow and static measurements of the heats of adsorption of stearic add from n-heptane by Fc203 and FeS. It is reported that heats of adsorption determined by these two methods differ by a constant factor that depends to some extent on the operating conditions used in the flow calorimetry. Under standardized conditions and using an FcaOa sample as a reference material, it is considered that flow calorimetry using the adsorption of stearic acid from n-heptane is a reliable method of finding the surface area of oxides. 

The liquid flow into the line was determined by the continuous measurement of the decrease in static head of the liquid in the calibrated storage tank, and by measurement of the pressure drop across the remote on-off valve located near the storage tank. The flow from the end of the line was determined at the gas restrictor from differential pressure and fluid temperature measurements. Line flow measurements were checked at the receiver tank where the vented gas and liquid accumulation were measured. 

By measuring particular temperature it becomes clear that we do not live in a thermostatic equilibrium. Instead we reside in an obvious disequilibrium. This can be also witnessed in a series of a self-organized patterns and processes lying evidently outside the traditional concept of equilibrium. It links with a delicate interplay between chance and necessity, order and chaos as well as amid fluctuation and deterministic laws and it is always under subtle interactions between mass flows and heat flows. The idea of equilibrium is also reflected in our gradual development of the understanding of our Universe, which has progressed from a static view up to the present complex world of novelty and diversity, the description of which is also a modest aim of this book. 

The value of the recovery factor r depends on the type and design of the temperature-measuring probe it can be an3rwhere between 0 and 1.0. Often it is specified by the manufacturer for the specific designs of the temperature probes, or it should be determined experimentally. The difference between stagnation and static temperature increases rapidly as the flow Mach number increases. It is important therefore to know the value of the recovery factor in order to get an as accurate as possible evaluation of the temperatures of the moving gas. 

Knoop developed an accepted method of measuring abrasive hardness using a diamond indenter of pyramidal shape and forcing it into the material to be evaluated with a fixed, often 100-g, load. The depth of penetration is then determined from the length and width of the indentation produced. Unlike WoodeU s method, Knoop values are static and primarily measure resistance to plastic flow and surface deformation. Variables such as load, temperature, and environment, which affect determination of hardness by the Knoop procedure, have been examined in detail (9). 

Since this temperature requires the thermometer or thermocouple to be at rest relative to the flowing fluid, it is impractical to measure. It can be, however, calculated from the measurement of total temperature and total and static pressure. 

In order to avoid the need to measure velocity head, the loop piping must be sized to have a velocity pressure less than 5% of the static pressure. Flow conditions at the required overload capacity should be checked for critical pressure drop to ensure that valves are adequately sized. For ease of control, the loop gas cooler is usually placed downstream of the discharge throttle valve. Care should be taken to check that choke flow will not occur in the cooler tubes. Another cause of concern is cooler heat capacity and/or cooling water approach temperature. A check of these items, especially with regard to expected ambient condi-... 

By connecting manometer hoses to both output pressures given by the tube, the pressure difference Ap can be measured directly. The barometric pressure and the fluid temperature are required for the determination of the fluid density. The Pitot-static tube is not a suitable instrument for measuring low velocities. It can be applied in cases where the flow velocity is high... 

A different picture emerged from the comparison of IR measurements in static and flow conditions. The IR spectra recorded in the temperature range of 423-823 K during the catalytic reaction of NO with the CuZSM-5 are collected in Figure 2.24. The spectra are dominated by the broad and intense absorption bands centered at 1470, 1630 and 2224 cm-1, assigned to N02-related species such as surface nitrates N03 [77,78],... 

Nitrogen adsorption was performed at -196 °C in a Micromeritics ASAP 2010 volumetric instrument. The samples were outgassed at 80 °C prior to the adsorption measurement until a 3.10 3 Torr static vacuum was reached. The surface area was calculated by the Brunauer-Emmett-Teller (BET) method. Micropore volume and external surface area were evaluated by the alpha-S method using a standard isotherm measured on Aerosil 200 fumed silica [8]. Powder X-ray diffraction (XRD) patterns of samples dried at 80 °C were collected at room temperature on a Broker AXS D-8 diffractometer with Cu Ka radiation. Thermogravimetric analysis was carried out in air flow with heating rate 10 °C min"1 up to 900 °C in a Netzsch TG 209 C thermal balance. SEM micrographs were recorded on a Hitachi S4500 microscope. 

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