Throughput scaleup factor

Plant sizes are usually characterized by their production capacity or throughput. Define the throughput scaleup factor as... 

Unless explicitly stated otherwise, the throughput and inventory scaleup factors will be identical since this means that the mean residence time will be constant upon scaleup ... 

If the pilot reactor is turbulent and closely approximates piston flow, the larger unit will as well. In isothermal piston flow, reactor performance is determined by the feed composition, feed temperature, and the mean residence time in the reactor. Even when piston flow is a poor approximation, these parameters are rarely, if ever, varied in the scaleup of a tubular reactor. The scaleup factor for throughput is S. To keep t constant, the inventory of mass in the system must also scale as S. When the fluid is incompressible, the volume scales with S. The general case allows the number of tubes, the tube radius, and the tube length to be changed upon scaleup ... 

A volumetric scaleup by a factor of 512 is quite large, and the question arises as to whether the large vessel wiU behave as a CSTR. The concern is due to the factor of 4 increase in mixing time. Does it remain true that tmix h/i and tmix t If so, the assumption that the large vessel wiU behave as a CSTR is probably justified. The ratio of internal circulation to net throughput—which is the internal recycle ratio—scales as the inverse of the mixing time and will thus decrease by a factor of 4. The decrease may appear worrisome, but if the increase in mixing time can be tolerated, then it is likely that the decrease in internal recycle ratio is also acceptable. 

This book deals with the scaleup of chemical reactors. The product from the scaled-up reactor should be the same as the product from the pilot reactor. The extent of reaction should be the same in the two reactors and thus the mean residence time t should held constant upon scaleup. According to Equation 1.40, inventory and throughput are increased by the same factor when t is held constant. Unless explicitly stated otherwise, it is understood that inventory, volume, and throughput all increase proportionately ... 

The turbulent scahng factors in Table 3.3 suggest that scaling a tubular reactor with constant heat transfer per unit volume and unit throughput at constant t is possible even with the further restriction that the temperature driving force be the same in the large and small units. Find the various scahng factors for this form of scaleup for turbulent hquids and apply them to the pilot reactor in Example 5.10. 

The volumetric scaleup by a factor of 512 anticipates an increase in throughput by the same factor. Is this possible while maintaining reasonable product quality ... 

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