Inlet zone

The capacity of polymer for highly-elastic (reversible) deformations also controls, in large part, the pressure loss effect at the inlet of the forming or measuring instrument. The inlet zone length (1) is related with the highly-elastic reversible deformation SR by the formula [192] ... 

Fibrous fillers have often been reported to increase considerably 1 in comparison with unfilled systems [171,176, 189, 197, 198]. In this case, however, the inlet loss is due not to the highly elastic properties of the melt but to other reasons, such as pushing of the binder through the package (plug) of filler in the inlet zone. Pushing of the filler package forth into the channel, etc. 

In Felix s experiments conducted on the surfaces prepared with arrayed defects and in lubricated contact [54], the dependence of deformation on the slide-to-roll ratio was also observed, but in a more complex mode, as presented in Fig. 24. In pure rolling, the defects deform and entrap lubricant underneath during their passage through the inlet zone. For the same reason as discussed above in single defect case, the... 

In this expression, the inlet-zone ( j = 0) concentrations are defined by 4> = and the inlet transport rates are denoted by /o,. Likewise, the outlet transport rates are denoted by fi. Thus, by definition, fi0 = fN+[, = 0. 

Figure 5.20. The flamelet model requires the existence of unmixed regions in the flow. This will occur only when the mixture-fraction PDF is non-zero at = 0 and = 1. Normally, this condition is only satisfied near inlet zones where micromixing is poor. Beyond these zones, the flamelets begin to interact through the boundary conditions, and the assumptions on which the flamelet model is based no longer apply.

As shown in Fig. 5.20, such regions normally occur only near the inlet zones where micromixing is poor. Further downstream, interaction between flamelets will become significant, and the assumptions on which the flamelet model is based will no longer apply.117 Reactors with recirculation zones are also problematic for flamelet models. For these reactors, partially reacted fluid is brought back to mix with the feed streams so that the simple non-premixed flow model no longer applies. 

The fixed-bed reactor consisted of a 4mm i.d, 40cm long quartz tube, with the catalyst section held by a small plug of calcined glass wool Preheat zone was 15cm of the inlet zone. The fluid-bed reactor used for the chlorinated feed (B) was a 1cm quartz tube fused onto an Q.flcn quartz tube. The lcm tube contained a fritted disc on which the catalyst was supported at a location in the middle of the heated zone. The fluid-bed used for other feeds was slightly smaller, but similar in configuration [2]. 

Inlet zone coagulant is fed into the influent of this mixing zone,... 

Sampling Syringe A microlitre syringe of 10-p.L capacity capable of accurately delivering 1 to 10 p,L of sample into the pyrolysis tube. Three-inch x 24-gauge needles are recommended to reach the inlet zone of the pyroloysis furnace. 

Reactant gas flow (oxygen), cm3/min 200 Carrier-gas flow (Ar, He), cm3/min 40 Furnace temperature, °C Inlet zone Pyrolysis zone Outlet zone... 

The systems using the larger packing are used in the treatment of relatively strong, low-suspended-solids industrial waste. These systems are closed columns usually run in an upflow mode with a gas space at the top. These are operated under anaerobic conditions with waste conversion to methane and carbon dioxide as the goal. Effluent recycle is often used to help maintain the pH in the inlet zone in the correct range 6.5-7.5 for the methane bacteria. Some wastes require the addition of alkaline material to prevent a pH drop. Sodium bicarbonate is often recommended for pH control because it is easier to handle than lime or sodium hydroxide, and because an overdose of bicarbonate will only raise the pH modestly. An overdose of lime or sodium hydroxide can easily raise the pH above 8.0. Table 22-48 gives... 

Inlet zone—In a sedimentation basin, the transition into the settling zone aimed at properly introducing the inflow into the tank. 

Because of the quick adsoiption of R+AT molecules on the catalyst surface in the riser inlet zone, the formation rate of is much greater than that of... 

The flammability limits depend on the temperature and pressure. At elevated temperatures and pressures, a given mixture may be flammable, even if this is not the case at ambient conditions. It is a key objective of the design of the inlet zone of a CPO reactor to prevent ignition and thermal combustion. 

In Fig 10.16 b) instantaneous fields of the dry H2 mole fraction and the gas velocity vectors after 10 seconds simulation time are shown. That is, the reactions were turned on 5 seconds after the flow was initiated. The hydrogen production is fast in the inlet zone and the hydrogen produced are transported toward the exit. 

S. Bair and M. Khonsari, An inlet zone analysis incorporating the second Newtonian, J. Tribology, 118(2), 341-343, 1996. 

Coke formation will always be a potential problem in any high temperature process involving hydrocarbons. Coke and tars formed during reaction can deposit on reactor surfaces or in quench heat exchangers, and several effects have been observed in a steam cracker tube (4, 9 ). As the reaction proceeds the tube will accumulate coke towards the reactor exit, while the inlet zone remains relatively coke free, as a result of the induction time associated with the formation of tars and coke (J ). Gas phase reactants may adsorb and react on this bare metal, and the components of the gas phase in the reactor should and do reflect this interaction (4, 9, JO). Since carbon formation depends on the nature of the gas phase species, these interactions should also influence coke formation towards the exit of the ractor. Again, this is found to be the case (4, 9 - 11). 

The curves shown in Fig.7 indicate that Cc in the riser inlet zone increases sharply as feedstock Qr increases, causing a rapid decay of catalyst activity. The sharpness of catalyst decay becomes less significant as Cc or tct further increases. There is little difference in a at the riser outlet among different feedstocks. Although has less impact on catalyst activity than Qal, the conversion of nesid oil cracking usually becomes lower than that of VGO cracking because of the rapid building-up of the on the catalyst and quick loss of catalyst activity in a riser zone. 

Those two nuclides deposit the same way in the inlet zone of the tubes, profiles and amounts being nearly the same in the three bundles. The same as Ag 110m, total activities in each bundle are very similar, 441 to 478 pCi Cs 137 and 59 pCi Cs 134. 

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