Slurry behavior, under conditions

Slurri/ behavior under conditions of reactor blanket operation. It is anticipated that the slurry would be contained in a low-permeability graphite v iiliin the reactor blanket. For heat removal and processing, the slurry would be circulated e.xternally through pipes and heat exchangers fabricated of low-chromium steel or comparable material. During circulation for lieat removal, the slurry would be subjected to thermal cycling between a probable maximum temperature of 550 C in the blanket and a possible... 

Since it is not likely that the viscous slurries which exhibit Bingham plastic behavior will frequently reach Reynolds numbers appreciably greater than 200,000 it is possible to conclude that Fig. 14 may be used to predict pressure drops accurately under all conditions of interest except in the transition regions. If a problem happens to fall into what may appear to be a transition region, use of Fig. 7 is recommended instead of Fig. 4. 

The above described reactor is useful for the measurements of heat of reaction as well as thermal behavior of gas-liquid or gas- liquid-solid, high-pressure, high-temperature reactions. Since the reactor can be operated under adiabatic conditions, it simulates the commercial operation. The reactor was successfully utilized by Bhattacharjee et al. (1986) for investigating thermal behavior of slurry phase, catalytic synthesis gas conversion. 

All three processes considered here are exothermic. Since slurry reactors on an industrial scale are operated under close to adiabatic conditions, a major scaleup problem is that of the thermal control of such reactors. Recently, Shah and Carr (10) have described a custom made agitated adiabatic slurry reactor, which can be used to evaluate the thermal behavior of the large scale reactors. 

Design considerations on a large scale FT slurry plant. The presented model predicts reasonably and, at least, qualitatively in a correct manner the behavior of FT slurry reactors operated under industrial conditions (Rheinpreussen-Koppers demonstration plant). Also other observations in leib-scale apparatuses are in agreement with model simulations. Therefore, the model is thought to offer the possibility to estimate production capacities rather reliably. 

In the dry pad condition, however, the friction force remained constant with the wafer velocity since there is no lubrication fihn under the wafer surface. This can be illustrated in terms of interaction with pad and abrasives (Figure 1.5). In the condition of high downforce or low wafer velocity, the wafer moves on the pad with thinner slurry film. This can cause increased interaction between the wafer surface and the abrasives supported by the polishing pad. In the condition of low downforce or high wafer velocity, wafCT behavior can be the opposite. Wafer can slide on the pad with thicker slurry film. This can result in less interaction between the wafer and the abrasives. 

It is therefore necessary to determine the slurry film thickness under the various sawing conditions. The hydrodynamic behavior of slurry films has been studied in lubrication or polishing processes, where many fundamental aspects have been derived from experimental and theoretical results [15, 16]. An important aspect is that the wire, and to some extent the crystal, can deform elastically in response to the slurry pressure. Considering that the wires are thin and long it is very likely that mainly the elastic response of the wire has to be considered when the slurry transport is analyzed. In the following the main aspects of the problem are derived from a one-dimensional treatment of the hydrodynamic slurry transport below a flexible wire. 

For other elements of variable valence, su( h as technetium, the amount of the element in solution is determined by the stable valence state under reactor conditions. In general, the higher valence states lietter resist hydrolysis and remain in solution. Thus at 275°C in 0.02 m UO2SO4 Tc(VII) is reduced to Tc(IV) if hydrogen is present, and only 12 mg/kg H2O remains in solution. However, a slurry of TCO2 in the same solution but with oxygen present dissolves to give a solution at 275 C with a technetium concentration of more than 9 g/kg H2O. The same qualitative behavior is observed with ruthenium. Selenium and tellurium in the hexapositive state are much more soluble than when in the tetrapositive state [4]. 

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