Propeller loop reactor

A schematic of the propeller loop reactor is shown in Fig. 37. In this case, the circulation flow of the fluid phases is created by a hydromechanical propeller flow drive. The use of a draft tube often improves the mass and heat transfer efficiency in these reactors (Blenke, 1967). This type of reactor involves complicated construction and leads to operating problems related to the sealing of the shaft. It is not suitable for biosystems due to possible damage to sensitive organisms in the high shear fields at the propeller. However, it is especially suitable for highly viscous polymeric fluids and for medium-size units. 

Design parameters for novel reactors such as rotating-cylinder reactors, thin-film reactors, propeller loop reactors, screw reactors, and multidisk reac-... 

This concept for the determination of the effective viscosity for mixing processes is also transferable to stirred vessels, because in the laminar flow range the above circumstances also apply for propeller loop reactors [351]. This was proved with tanks with pitched-blade stirrers [540]. The nO values could be better correlated with RSefr numbers, which were produced according to expression (3.25), than those which contained ft g according to expression (1.45) after Metzner-Otto. 

The propeller loop reactor with internal draft tube cum heat exchanger configuration has also been used by the author for an extremely exothermic (almost explosive) solid-liquid reaction ... 

The approach to use multiple components is based on the Level 2 Prometheus Requirement to meet the NASA Single Point Failure Policy. NASA experience indicates the prudence of having redundant components, even if they have demonstrated reliability, to ensure that manufacturing defects, human error, or an unexpected event does not lead to a mission ending failure. This is also consistent with NRPCT practice. For those components where redundancy is considered impractical, exceptions to the single point failure avoidance requirement is provided. For the currently envisioned Prometheus spacecraft, the reactor, the reactor coolant loop, the boom, and the xenon propellant tank all require such exceptions. 

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