Vessels characteristics

Power number for several types of impellers and vessel characteristics (Perry and Green, 1984,... 

Liquid-liquid dispersion involves two phases a continuous phase (one with large volume), and a dispersed phase (one with small volume). When the volume fractions of both phases are nearly the same, phase inversion occurs. In this case, which of the two phases becomes a continuous one depends on the starting conditions as well as the physical properties of the system. The range of volume fraction within which either of two immiscible liquids may be continuous is primarily a function of the viscosity ratio it is not strongly dependent upon vessel characteristics or stirring speed (Selker and Sleicher, 1965). Here we briefly evaluate the minimum speed of rotation required to disperse one phase completely into the other, the interfacial area, and the mass-transfer coefficient in liquid-liquid dispersion. 

The range of volume fraction within which either of two immiscible liquids may be continuous is primarily a function of the viscosity ratio, but is only weakly dependent upon vessel characteristics or stirring speed. The coalescence frequency for the dispersed drops is, however, a strong function of impeller speed (i.e., frequency xN2,85). 

Also in these vessels characteristic changes are recognized reflecting waveform changes within the cavernosal arteries (Bertolotto et al. 2002). In particular, within the corpus cavernosum caverno-sal-spongiosal communications have arterial wave-... 

Vessel characteristic dimensions - Inner diameter 6.84 m - Height 2.94 m - Wall thickness 5.0 cm... 

Vessel characteristics and navigation conditions, including vessel types and size distributions, speed and loading conditions, navigation procedures, and hazards to navigation. 

Dipyridamole in combination with heparin or phenindione has been reported to prevent not only thrombosis in vessels during acute rejection but also the progressive narrowing of vessels characteristic of "chronic" rejection in cadaveric renal allografts. This supports the view that the intimal sclerosis which causes narrowing in the vessels of renal allografts results from deposition of mural thrombi ... 

Jemcov TK Morphologic and functional vessels characteristics assessed by ultrasonography for prediction of radiocephahc fistula maturation. J Vase Access 2013 14 356 363. Ferring M, Henderson J, Wilmink T, Smith S Vascular ultrasound for the pre-operative evaluation prior to arteriovenous fistula formation for haemodialysis review of the evidence. Nephrol Dial Transplant 2008 23 1809-1815. 

A knock out vessel may on the other hand be followed by a variety of dehydrating systems depending upon the space available and the characteristics of the mixture. On land a continuous dehydration tank such as a wash tank may be employed. In this type of vessel crude oil enters the tank via an inlet spreader and water droplets fall out of the oil as it rises to the top of the tank. Such devices can reduce the water content to less than 2%. 

Figure 5 Damage evolution in FRP vessel by means of characteristic AE classes.

The calculation was carried out using the ANSYS F.E.M. code. The pressure vessel was meshed with a 4 nodes shell element. Fig. 18 shows a view of the results of calculation of the sum of principal stresses on the vessel surface represented on the undeformed shape. For the calculation it was assumed an internal pressure equal to 5 bar and the same mechanical characteristics for the test material. 

Corrosion Resistant Fiber-Reinforced Plastic (FRP). Fiber glass reinforcement bonded with furfuryl alcohol thermosetting resias provides plastics with unique properties. Excellent resistance to corrosion and heat distortion coupled with low flame spread and low smoke emission are characteristics that make them valuable as laminating resins with fiber glass (75,76). Another valuable property of furan FRP is its strength at elevated temperature. Hand-layup, spray-up, and filament-win ding techniques are employed to produce an array of corrosion-resistant equipment, pipes, tanks, vats, ducts, scmbbers, stacks, and reaction vessels for industrial appHcations throughout the world. 

Filtration of viscose is not a straightforward chemical engineering process. The solution of cellulose xanthate contains some easy-to-deal-with undissolved pulp fibers, but also some gel-like material which is retarded rather than removed by the filters. The viscose is unstable and tends to form more gel as it ages. Its flow characteristics make the material close to the walls of any vessel or pipe move more slowly, get older, and gel more than the mainstream viscose. So while filtration can hold back gels arising from incomplete mixing, new gels can form in the pipework after the filters. 

As the vessel is only about half filled with slurry, the disks become coated with the cake when immersed, the cake is dewatered when the disks emerge from the slurry, and scraped or blown off, by reverse blow, into the central conveyor which takes the cake to one end of the vessel. The planetary action and the slow movement of the disks through the feed slurry ensure exceptionally good homogeneity of the cake which is critically important for good dewatering characteristics the typical speed of rotation of the planetary system of shafts is from 0.8 to 1 rpm. 

The third characteristic of interest grows directly from the first, ie, the high thermal conductance of the heat pipe can make possible the physical separation of the heat source and the heat consumer (heat sink). Heat pipes >100 m in length have been constmcted and shown to behave predictably (3). Separation of source and sink is especially important in those appHcations in which chemical incompatibilities exist. For example, it may be necessary to inject heat into a reaction vessel. The lowest cost source of heat may be combustion of hydrocarbon fuels. However, contact with an open flame or with the combustion products might jeopardize the desired reaction process. In such a case it might be feasible to carry heat from the flame through the wall of the reaction vessel by use of a heat pipe. 

The avadabihty of PMDI also led to the development of polyurethane-modified isocyanurate (PUIR) foams by 1967. The PUIR foams have superior thermal stabiUty and combustibiUty characteristics, which extend the use temperature of insulation foams well above 150°C. The PUIR foams are used in pipe, vessel, and solar panel insulation glass-fiber-reinforced PUIR roofing panels having superior dimensional stabiUty have also been developed. More recently, inexpensive polyester polyols based on residues obtained in the production of dimethyl terephthalate (DMT) have been used in the formulation of rigid polyurethane and PUIR foams. 

Variables It is possible to identify a large number of variables that influence the design and performance of a chemical reactor with heat transfer, from the vessel size and type catalyst distribution among the beds catalyst type, size, and porosity to the geometry of the heat-transfer surface, such as tube diameter, length, pitch, and so on. Experience has shown, however, that the reactor temperature, and often also the pressure, are the primary variables feed compositions and velocities are of secondary importance and the geometric characteristics of the catalyst and heat-exchange provisions are tertiary factors. Tertiary factors are usually set by standard plant practice. Many of the major optimization studies cited by Westerterp et al. (1984), for instance, are devoted to reactor temperature as a means of optimization. 

Thermal Methods Level-measuring systems may be based on the difference in thermal characteristics oetween the fluids, such as temperature or thermal conductivity. A fixed-point level sensor based on the difference in thermal conductivity between two fluids consists of an electrically heated thermistor inserted into the vessel. The temperature of the thermistor and consequently its electrical resistance increase as the thermal conductivity of the fluid in which it is immersed decreases. Since the thermal conductivity of liquids is markedly higher than that of vapors, such a device can be used as a point level detector for liquid-vapor interface. 

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