FCC process description adapted by permission from Fluid Catalytic Cracking Handbook, R. Sadeghbeigi, Gulf Publishing Company, Houston, Texas, 2000, pp. 3—17.  [c.141]

Since 1977, Reza Sadeghbeigi has been involved in various aspects of cat cracking at major and independent oil companies focusing on technical services, troubleshooting, process design, and project management—including major FCC revamps.  [c.369]

Fluid catalytic cracking handbook / Reza Sadeghbeigi. 2nd ed. p. cm.  [c.374]

The three main goals of a molecular mechanics program for small molecules are calculation of geometiy, energy, and spectial absorbances due to vibrational excitation. Hagler (Hwang, Stockfish, and Hagler, 1994) has categorized force fields into class 1, intended to achieve the first of these increasingly demanding objectives class 2, to achieve the first two and class 3 to achieve all three objectives. Research and development on class 3 force fields is an active enterprise, as is extension of class 1 and class 2 force fields to less common molecules and larger, biologically important species. We have already introduced geometiy determination in Chapter 4.  [c.131]

The highly stable and heat-resistant Silicone oils are very satisfsu tory. Midlsind Silicone or Dow-Coming fluid 650 or 600 (or the equivalent I.C.I. product) is recommended. Their only drawback is their high cost.  [c.78]

Optical Absorption. Today, CA resists are being used ia advanced duv photohthography apphcations where the exposure wavelength is between 190 and 250 nm. Most organic compounds absorb strongly ia this spectral range, however, and the design of polymers for CA resists that maintain acceptable optical transparency while satisfyiag ah. other functional requirements is a challenge. The optimum optical absorbance for a nonbleaching photoresist is about 0.4 absorbance units per micron, representing a balance between condicting requirements for high transparency to provide uniform illumination through the depth of the film, and high absorption to suppress thin-fihn optical redectivity effects that reduce process latitude (97,98). To maximize light absorption by the photosensitizer, a rule of thumb is that the absorbance of the polymeric component should not exceed 0.2 per micron at the exposure wavelength.  [c.130]

An open-loop system positions the manipulated variable either manually or on a programmed basis, without using any process measurements. This operation is acceptable for well-defined processes without disturbances. An automanual transfer switch is provided to allow manual adjustment of the manipulated variable in case the process or the control system is not performing satisfac torily.  [c.718]

On/Off Control An on/off controller is used for manipulated variables having only two states. They commonly control temperatures in homes, electric water-heaters and refrigerators, and pressure and liquid level in pumped storage systems. On7off control is satisfac-toiy where slow cychng is acceptable because it always leads to cycling when the load hes between the two states of the manipulated variable. The cycle will be positioned symmetrically about the set point only if the normal value of the load is equidistant between the two states of the manipulated variable. The period of the symmetrical cycle will be approximately 40, where 0 is the deadtime in the loop. If the load is not centered between the states of the manipulated variable, the period will tend to increase, and the cycle follows a sawtooth pattern.  [c.726]

Low Fins Low-finned tubing is generally used in shell-and-tube configurations. For sensible-heat transfer, only minor modifications are needed to permit the shell-side method given earher to be used for both heat transfer and pressure [see Briggs, Katz, and Young, Chem. Eng. Prog., 59(11), 49-59 (1963)]. For condensing on low-finned tubes in horizontal bundles, the Nusselt correlation is generally satisfac toiy for low-surface-tension [o < (3)(10 )N/m (30 dyn/cm)] condensates fins of finned surfaces should not be closely spaced for high-surface-tension condensates (notably water), which do not drain easily.  [c.1053]

The heavy-duty jacketed type (Fig. ll-62a) is a special custom-built adaptation of a heavy-duty vibratory conveyor shown in Fig. 11-60. Its apphcation is continuously to cool the crushed materi [from about 177°C (350°F)] produced by the vibratoiy-type caster of Fig. 11-53. It does not have the liqmd dam and is made in longer lengths that employ L, switchback, and S arrangements on one floor. The capacity rate is 27,200 to 31,700 kg/h (30 to 35 tons/h) with heat-transfer coefficients in the order of 142 to 170 W/(m °C) [25 to 30 Btii/(h ft °F)]. For heating or drying applications, it employs steam to 414 kPa (60 IbFin ).  [c.1096]

When large ground areas are available, cooling ponds offer a satisfac-toiy method of removing heat from water. A pond may be constructed  [c.1171]

Once a given type and size of dryer has been installed, the product characteristics and diying capacity can be changed only within relatively narrow limits. Tnus it is more economical and far more satisfac-  [c.1186]

Automated equipment for the addition of hquids can be worked into the overall mixing plant when necessary. For dust-reduction purposes, a volumetric method of metering is satisfac tory. However, should a critical batch ingredient be added in hquid form, a more precise method of metering may be necessary.  [c.1768]

Package testing is manditoiy for chemical products which are deemed as hazardous, as set forth in CFR 49, Part 172.101. A package for hazardous material being offered by a supplier must be tested By them or by a qualified third party. The tester must certify that the package complies with the DOT regulations and the design has been tested satisfac torily for a given packing group. The purchaser does not have to be concerned with the testing itself but only that it has been done and that the suppher can certify that the package has passed the required tests.  [c.1952]

Thus wheel arrangement is dictated by the smallest container that the line will handle. Only flat-bottomed containers can be handled on wheel conveyors, with the exception of fairly stiff-walled bags, which handle satisfac torily. This is due to the fact that the separate roller supports tend to pull the bag wall taut and flatten it out. Roller conveyors, on the contrary, tend to ripple the bag surface and prevent its movement. Wheel conveyors may also be specially designed for handling smooth-walled cyhndrical shapes.  [c.1977]

Valves and pumps that have a potential path for contaminating organisms are taboo for aseptic operations. Rising stem valves could bring organisms to the sterile side by the in and out motion as the valve operates. Diaphragm valves are still commonly used, but heating, cooling, and the abrasion by solids in the nutrient media are somewhat severe conditions leading to occasional rupture of a diaphragm and contamination of a run. Ball valves or plug valves do not have an absolute seal to the outside, but the direction of motion does not tend to bring organisms in. Contamination is seldom attributed to these valves they are designed for easy maintenance in place, and there is the very nice human advantage that a glance at the handle tells easily whether the valve is open or closed. Many runs have been spoiled or impaired because a manual valve was left in the wrong position. For plant operations, pumps with diaphragms are satisfac tory. In the lab or pilot plant, peristaltic pumps (also known as tubing squeezers) predominate.  [c.2138]

If the drum length is less than two to three times the diameter, the design is satisfactory. If h is greater than 3D, assume a larger diameter and repeat the calculation until a satisfac toiy L/D ratio is achieved.  [c.2298]

Circulating AFBCs handle bituminous and subbituminous coals equally well, and their coal preparation and feeding systems are far simpler than those of bubbling versions. The coal is crushed to a top size of 12 mm [ M in), without drying, and fed by gravity into the lower refractoiy-lined portion of the boiler. The feed points are close to the pressure balance point and so there is little, if any, back pressure this greatly reduces the seahng reqmrements. In addition, and sometimes ternatively, the coal can be introduced into the cyclone ash return lines. A minimum of four coal entiy points is required to achieve uniform feed distribution in the 110-MWe unit, corresponding to one per 30 m" (300 ft") of freeboard cross section. High turbulence and the absence of in-bed tubing facihtate adequate mixing of the coal across the combustor. The sorbent is prepared to a top size of 1 mm (0.04 in) and dried so that it can be pneumatically fed to the combustor. Experience showed that no less than eight sorbent feed points were required on the 110-MWe unit (one per 15 m" [150 ft"] of freeboard cross section) to achieve satisfac toiy performance. Load control is achieved primarily by reducing coal feed rate, with a corresponding reduction in air flow, to lower combustor temperature.  [c.2400]

Acrylonitrile butadiene styrene (ABS) polymers have good resistance to nonoxidizing and weak acids but are not satisfac tory with oxidizing acids. The upper temperature limit is about 65°C (150°F).  [c.2457]

Both primary factors and lesser secondary factors affect our sense of satisfac tion with the thermal environment. The primaiy factors have significant reproducible effects and directly affect heat transfer and the occupant s thermal state, Secondar factors that may affect one s sense of satisfaction with a space are conditions such as color and ambiance, local climate, age, physical fitness, sound, food, and illness. These secondary factors have smaller to negligible effects on one s thermal state and will not be discussed here, but such information is available.  [c.175]

As an alternative, Alexander [166] has proposed a model which places the oil and the water on lattice sites and distributes the amphiphiles on the bonds. The interactions between two neighboring oil and/or water particles depend on whether or not the connecting bond is occupied by an amphi-phile. As long as the amphiphiles themselves do not interact with each other, the sum over possible bond states can be carried out independently, and the model turns out to be equivalent to an Ising model with temperature dependent interactions. Hence this simplest version does not capture the specific properties of amphiphihc systems, and additional amphiphile interactions have to be included. A variety of different interaction terms has been implemented bending energies, edge energies, corner energies, special penalties if amphiphilic sheets meet or cross each other etc. Different versions of the model have been explored in Monte Carlo simulations by Ebner and coworkers [167] and Stockfisch and Wheeler [168]. The model displays lamellar phases and three-phase coexistence between an oil rich, a water-rich, and a disordered phase with intrinsic structure. Moreover, the amphiphiles were shown to reduce the interfacial tension between oil and water by a factor of up to 1000 [168]. The interfacial tension was determined with the histogram method of Binder [169], which will be discussed in more detail below.  [c.657]

Stock-fisch, m. stockfish (esp., dried codfish), -fischlebertran, m. cod-liver oil. -fleck, m. moldy stain, moldy spot, mildew, stockfleckig, a. spotted with mold, moldy  [c.430]

Other reactor sources with instruments like D4C but with much lower flux, and hence longer data collection times, are the Laboratoire Leon Brillouin (LLB, Saclay, France), on the instrument 7C2, and the NFL (Studsvik, Sweden), on the instrument SLAD  [c.130]

Mr. Sadeghbeigi received his B.S. in chemical engineering from Iowa State University and his M.S. from Oklahoma State University. He is a registered professional engineer in Texas and Louisiana and is president of RMS Engineering, Inc. (RMS). RMS is based in Houston, TX, and is an independent engineering firm supplying engineering services to the refining industry in the area of fluid catalytic cracking (FCC) and related processes, since 1994. Should you have any questions or comments on this book or FCC s in general, please feel free to contact Reza at (281) 333-0464 (U.S.) or by e-mail (reza  [c.369]

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Turboexpanders and Process Applications (0) -- [ c.141 ]