The product streams can be a vapor and a liquid or two immiscible liquids. The process may consist of a single equilibrium stage, as with a flash drum or single mixer-settler, or of a cascade of equilibrium stages, as with staged distillation or extraction. Multistage separations are usually arranged with countercurrent flow of the phases between the stages. The calculation of all such equilibrium separations is based on enthalpy and component material balances over the separation stage, in combination with the requirements that, for each component, the fugacities be equal in the two streams exiting the stage.  [c.110]

All that can be done is to make a reasonable initial assessment of the number of stages. Having made a decision for the number of stages, the heat flow through the system is temporarily fixed so that the design can proceed. Generally, the maximum temperature in evaporators is set by product decomposition and fouling. Therefore, the highest-pressure stage is operated at a pressure low enough to be below this maximum temperature. The pressure of the lowest-pressure stage is normally chosen to allow heat rejection to cooling water or air cooling. If decomposition and fouling are not a problem, then the stage pressures should be chosen such that the highest-pressure stage is below steam temperature and the lowest-pressure stage above cooling water or air cooling temperature.  [c.87]

All combustion processes work with an excess of air or oxygen to ensure complete combustion of the fuel. Excess air typically ranges between 5 and 20 percent depending on the fuel, burner design, and furnace design. As excess air is reduced, theoretical flame temperature increases as shown in Fig. 6.28. This has the effect of reducing the stack loss and increasing the thermal efficiency of the furnace for a given process heating duty. Alternatively, if the combustion air is preheated (say, by heat recovery), then again the theoretical flame temperature increases as shown in Fig. 6.28, reducing the stack loss.  [c.190]

Figure 6.28 Increasing the theoretical flame temperature by reducing excess air or combustion air preheat reduces the stack loss. Figure 6.28 Increasing the theoretical flame temperature by reducing excess air or combustion air preheat reduces the stack loss.
This section will look at formation and fluid data gathering before significant amounts of fluid have been produced hence describing how the static reservoir is sampled. Data gathered prior to production provides vital information, used to predict reservoir behaviour under dynamic conditions. Without this baseline data no meaningful reservoir simulation can be carried out. The other major benefit of data gathered at initial reservoir conditions is that pressure and fluid distribution are in equilibrium this is usuaily not the case once production commences. Data gathered at initial conditions is therefore not complicated  [c.125]

Basic MWD technology was first introduced more than ten years ago, and was initially restricted to retrievable inserts for directional measurements and then natural gamma ray logs. These developments were quickly followed by logging tools integrated into drill collars, and over the last five years logging while drilling (LWD) development has progressed to the stage where most of the conventional wireline logging tools can be effectively replaced by a LWD equivalent. LWD and MWD can be considered as synonymous.  [c.134]

Other information that can be obtained from such map is the location of faults, the status and location of wells and the location of the fluid contacts. Figure 5.45 shows some of the most frequently used map symbols. Structural maps are used in the planning of development activities such as well trajectories/targets and the estimation of reserves.  [c.140]

At the stage of field development planning, reservoir simulation would normally be used to generate production profiles and well requirements for a number of subsurface development options, for each of which different surface development options would be evaluated and costs estimated.  [c.214]

The end of field life is often determined by the lowest reservoir pressure which can still overcome all the pressure drops described and provide production to the stock tank. As the reservoir pressure approaches this level, the abandonment conditions may be postponed by reducing some of the pressure drops, either by changing the choke and separator pressure drops as mentioned, or by introducing some form of artificial lift mechanism, as discussed in Section 9.7.  [c.226]

Capital and operating costs will increase as more separator stages are added to the process line, so a balance has to be struck between increased oil yield and cost. It is uncommon to find that economics support more than 3 stages of separation and one or two stage separation is more typical. The increased risk of separation shut down is also a contributing factor in limiting numbers.  [c.244]

The main types of compressor used in the gas industry are reciprocating and centrifugal compressors. The power requirements of a reciprocating compressor are shown in Figure 10.17. Notice that at compression ratios above 5 and 25, two stage and three stage compression respectively becomes necessary to accommodate inter-stage cooling. Apart from the need for inter-stage cooling, additional compression capacity may be installed in phases through the life of a gas field as reservoir pressure declines.  [c.253]

The first three phases listed above are sometimes defined collectively as the pre-project stage. This is the stage in which ideas are developed and tested, but before large funding commitments are made.  [c.292]

Many oil and gas companies do not consider the detailed design and construction of production facilities as part of their core business. This is often the stage at which work is contracted out to engineering firms and the client company will switch manpower resources elsewhere, although some degree of project management is commonly retained.  [c.300]

This work has been supported by the Swedish Nuclear Power Inspectorate (SKI) and ABB TRC. References  [c.95]

The paper discusses the application of dynamic indentation method and apparatus for the evaluation of viscoelastic properties of polymeric materials. The three-element model of viscoelastic material has been used to calculate the rigidity and the viscosity. Using a measurements of the indentation as a function of a current velocity change on impact with the material under test, the contact force and the displacement diagrams as a function of time are plotted. Experimental results of the testing of polyvinyl chloride cable coating by dynamic indentation method and data of the static tensile test are presented.  [c.239]

The radiation and temperature dependent mechanical properties of viscoelastic materials (modulus and loss) are of great interest throughout the plastics, polymer, and rubber from initial design to routine production. There are a number of laboratory research instruments are available to determine these properties. All these hardness tests conducted on polymeric materials involve the penetration of the sample under consideration by loaded spheres or other geometric shapes [1]. Most of these tests are to some extent arbitrary because the penetration of an indenter into viscoelastic material increases with time. For example, standard durometer test (the "Shore A") is widely used to measure the static "hardness" or resistance to indentation. However, it does not measure basic material properties, and its results depend on the specimen geometry (it is difficult to make available the identity of the initial position of the devices on cylinder or spherical surfaces while measuring) and test conditions, and some arbitrary time must be selected to compare different materials.  [c.239]

The quality of visible image is mainly determined at the stage of a latent image formation and depends on speetral, angular and spatial distribution of eleetrons and quanta, emitted from electrodes and produced in a gas. The electron density distribution in GDC structure members was determined through solution of transport equations using Monte-Carlo method. These transport equations have been solved for sources of X- and y-radiation with photon energy in the range from several tens of keV to 70 MeV.  [c.539]

Here a - surface tension pa - atmospheric pressure 9 - contact angle of crack s wall wetting by penetrant n - coefficient, characterizing residual filling of defect s hollow by a penetrant before developer s application IT and h - porosity and thickness of developer s layer respectively W - minimum width of crack s indication, which can be registered visually or with the use of special optical system. The peculiarity of the case Re < H is that the whole penetrant volume is extracted by a developer. As a result the whole penetrant s volume, which was trapped during the stage of penetrant application, imbibes developer s layer and forms an indication of a defect.  [c.614]

While adjusting the machine for its job the limits of the current for magnetizing the part have to be fixed as well as the magnetization time. During operation the machine will control for each part that the current-flow through the part and the time will be appropriate for a good magnetization. This is controlled by a hall sensor installed into the switch cabinet.  [c.630]

Since one of the important features required of the CamuS system was the facility for monitoring and recording the inspection coverage actually achieved, a means of recognising the status of the acoustic coupling between the probe and the test object was required. This can be accomplished by observing the signal from the probe, either by ensuring that an echo from a known geometric reflector (eg the back wall) is present, or by noting the presence of (small amplitude) echoes produced by scattering within the material. In either case, it is likely that  [c.767]

The status bar displays information about the current status of the acquisition system the position of each of the four axes of the probe position monitor the maximum amplitude of the signal within the gate for both the coupling channel and the signal (flaw detection) channel and the current operating mode of the system, which may be record-  [c.768]

As the cursor is moved over the rendered 3D data, the eo-ordinates and amplitude of the eell giving rise to the pixel under the cursor are displayed in the status bar. This provides a basic method for measuring the location and dimensions of flaws. However, it is more convenient and accurate to perform sizing operations on 2-dimensional slices, so several slicing and sizing tools are incorporated.  [c.772]

The development and improvement of scientific-technical level of NDT and TD means for safety issues is connected with the necessity to find additional investments that must be taken into account at the stage of new technogenic objects designing, when solving new arising problems in social, economic, ecological and medical safety. It is not accidental, that the expenses for safe nuclear power plants operation cover 50% of total sum for construction work capital investments. That is why the investments for NDT and TD have to cover 10% of total amount for development and manufacturing of any product.  [c.915]

The DART system has been qualified according to the new regulations for ISI issued by the Swedish Nuclear Power Inspectorate.  [c.1031]

Instability of Cylindrical Columns. C. V. Boys, in his elegant little monograph of 1890 [3], discusses an important property of quasistatic cylindrical films that was first studied in cylindrical columns of fluids by Lord Rayleigh in 1879. If the soap film in Fig. II-4a were made to be cylindrical by adjusting the gas pressure inside, it, like a cylindrical thread of fluid, would be unstable to surface waves whose length exceeds the circumference of the cylinder. The column would contract at one end and bulge at the other, as illustrated in Fig. II-4b, before breaking up into a smaller and larger bubble (or drop) as shown in the photographs of a liquid stream in Fig. II-5 [4]. The mechanism is associated with the nonzero curvature of the static state and the fact that fluctuations establish capillary pressure gradients that drive the fluid away from the equilibrium. It is now recognized that capillary breakup is a particularly simple example of the geometric instability of states of static equilibrium in the presence of surface tension. For a general description dealing with pendant and sessile drops, finite cylinders (capillary bridges) and other capillary surfaces, see Michael [5]. A detailed discussion of the capillary break up of jets, including several interesting practical applications, is given by Bogy [6]. The case of one liquid in a second, immiscible one is discussed in Refs. 6a and 7. A similar instability occurring in a thin annular coating inside a capillary can have important consequences for capillary columns in chromatography [8].  [c.9]

An example of a two-stage hydrolysis is that of the sequence shown in Eq. IV-69. The Idnetics, illustrated in Fig. IV-29, is approximately that of successive first-order reactions but complicated by the fact that the intermediate II is ionic [301]  [c.154]

In general it is necessary to distinguish static and kinetic coefficients of friction, Us and uk- The former is given by the force needed to initiate motion, and the latter, by the force to maintain a given sliding speed. There is a general argument to show that Us > Uk- Suppose that Us were less than uk, then, for a load W, Fj = Wus, and Fk = Wuk, that is, Fs < Fk- Now if a force were applied that lay between these two values, a paradoxical situation would exist. Since F would be greater than Fs, the rider should move, but since F is less than Fk, the rider should not move the contradiction is inescapable and leads to the conclusion that the static coefficient must be equal to or greater than the sliding or kinetic coefficient. Note Problem XII-8 for a practical application of this point.  [c.436]

The static coefficient of friction tends to increase with time of contact, and it has been argued that Us for zero time should be equal to uk- Actually, uk is a function of sliding speed and appears to go through a maximum with increasing speed. This maximum occurs below 10 cm/sec for titanium, at about 10 " cm/sec for indium, and at about 1 cm/sec for the very soft plastic, Teflon [13]. Thus most materials show a negative dependence of uk on sliding speeds in the usual range of 0.1 cm/sec. It might be noted that most junctions caused by the seizure of asperities seem to be about 0.001 cm in size so that it is necessary to traverse about this distance to obtain a meaningful value of Uk - practical limit is thus set on experiments at very small sliding speeds.  [c.436]

The Washburn equation has most recently been confirmed for water and cyclohexane in glass capillaries ranging from 0.3 to 400 fim in radii [46]. The contact angle formed by a moving meniscus may differ, however, from the static one [46, 47]. Good and Lin [48] found a difference in penetration rate between an outgassed capillary and one with a vapor adsorbed film, and they propose that the driving force be modified by a film pressure term.  [c.470]

In Fig. 6.27, the flue gas is cooled to pinch temperature before being released to the atmosphere. The heat releaised from the flue gas between pinch and ambient temperature is the stack loss. Thus, in Fig. 6.27, for a given grand composite curve and theoretical flcune temperature, the heat from fuel amd stack loss can be determined.  [c.190]

As with the steam turbine, if there was no stack loss to the atmosphere (i.e., if Qloss was zero), then W heat would he turned into W shaftwork. The stack losses in Fig. 6.34 reduce the efficiency of conversion of heat to work. The overall efficiency of conversion of heat to power depends on the turbine exhaust profile, the pinch temperature, and the shape of the process grand composite.  [c.197]

If the string indeed cannot be retrieved by overpull, an explosive or chemical charge is lowered inside the pipe to the top of the stuck interval and the pipe above the stuck point is recovered after severing the string. Since drilling assemblies and redrilling of the borehole in a sidetrack are expensive, a further attempt to retrieve the tubulars (often called a fish ) left in the hole will then be made. This is one application of fishing operations as described below.  [c.58]

The oil and gas samples are taken from the appropriate flowlines of the same separator, whose pressure, temperature and flowrate must be carefully recorded to allow the recombination ratios to be calculated. In addition the pressure and temperature of the stock tank must be recorded to be able to later calculate the shrinkage of oil from the point at which it is sampled and the stock tank. The oil and gas samples are sent separately to the laboratory where they are recombined before PVT analysis is performed. A quality check on the sampling technique is that the bubble point of the recombined sample at the temperature of the separator from which the samples were taken should be equal to the separator pressure.  [c.113]

The development of UTDefect has been sponsored by the Swedish Nuclear Power Inspectorate (SKI) and this is gratefully acknowledged.  [c.161]

An example of the time effects in irreversible adsorption of a surfactant system is shown in Fig. XI-8 for barium dinonylnapthalene sulfonate (an oil additive) adsorbing on Ti02 (anatase). Adsorption was ineversible for aged systems, but much less so for those equilibrating for a short time. The adsorption of aqueous methylene blue (note Section XI-4) on TiOi (anatase) was also irreversible [128]. In these situations it seems necessary to postulate at least a two-stage sequence, such as  [c.405]

However, it was still a long time even after Dalton before anything definite could be known about the internal motions in molecules. The reason was that the microscopic nature of atoms and molecules was a bar to any knowledge of their internal constituents. Furthemiore, nothing at all was known about tlie physical laws that applied at the microscopic level. The first hmts came in the late 19th century, with the classical Maxwell-Lorentz theory of the dynamics of charged particles interacting through the electromagnetic field. The electron was discovered by Thomson, and a little later tlie nuclear structure of the atom by Rutherford. This set the stage in the 20th century for a physical understanding in temis of quantum theory of the constituents of molecules, and the motions of which tliey partake.  [c.53]

See pages that mention the term Two-stage : [c.191]    [c.301]    [c.157]    [c.161]    [c.198]    [c.443]    [c.89]    [c.110]    [c.112]    [c.612]    [c.919]    [c.1040]    [c.183]    [c.502]    [c.126]   
Turboexpanders and Process Applications (0) -- [ c.0 ]