Reactor throughput

This example found the reactor throughput that would give the required annual capacity. For prescribed values of the design variables T and V, there is only one answer. The program uses a binary search to find that answer, but another root-finder could have been used instead. Newton s method (see Appendix 4) will save about a factor of 4 in computation time. 

Wafer rotation, as previously mentioned, has been introduced in the hot-wall reactor (see Figure 1.10), which gives it a capacity of 3 x 2-inch (that is, three 2-inch wafers can be run simultaneously to increase reactor throughput). The uniformity in this reactor is routinely 1-2% in thickness and 5-7% in doping [Rune Berge, Epi-gress, private communication]. 

One of the problems with cold wall systems is the difficulty in maintaining a very uniform temperature on the wafers. Such concern can be eliminated if the entire reactor chamber is placed within a furnace maintained at a very uniform temperature. An ideal candidate for such a furnace is the standard diffusion tube furnace already in wide use for integrated circuit fabrication. If in addition, wafers could be loaded vertically as in a diffusion furnace, the reactor throughput could be substantial. 

These dimensionless numbers can also be combined. For example, the ratio DaR/DaD compares the dissolution rate to the reactor throughput while the product DurNnu compares the nucleation rate with the reactor throughput. The exact form of the dimensionless numbers would change as the reaction kinetics, the growth rate expressions, etc. change, but the meanings would remain the same. 

The wall cooling has a major effect when there are large changes in reactor throughput. When turning down a gasifier, the temperature of the bed will be lowered due to heat loss to the environment, and the thermal boundary layer will penetrate inwards to the central core. 

Developments by the polyolefin manufacturers in recent years have significantly changed the demands placed on plants processing these products. The new demands are due partly to greatly increased reactor throughputs. 

Tight temperature control is maintained in the reactor (3) to arrive at high yields using a multi-point hydrogen quench (4). In this way, conversion is controlled at the optimum level, which depends on reactor throughput, operating conditions and feed composition. 

Summarize the effects on ammonia production (/ip) and reactor throughput (nr) of changing each of the three input variables. 

Reactor operating costs (excluding raw materials) 0.07 kg of reactor throughput... 

Finding DII FEK-2. The proposed full-scale design for the TW-SCWO system involves a scale-up in reactor cross-sectional area by a factor of 2 from the Demo II test unit and an increase in reactor throughput by a factor of 35. Performance under these full-scale design conditions has not been demonstrated. 

As a first step in minimizing this unwanted reaction, we notice the crucial fact that the spectra of (1) and (2) (see Fischer, 1978) overlap almost completely, thus precluding the use of specific wavelengths to promote one reaction over the other. The only way to avoid excessive loss of 7-dehydrocholesterol by the wasteful reaction is to arrest the main reaction at a certain conversion, but this reduces the reactor throughput. Thus a second photochemical reaction was developed (Hoffmann-La Roche, 1985) in which the E-form was converted back to the desired Z-form. This so-called E/Z isomerization is carried out with a photosensitizer, as shown in reaction E26.1.2. 

The approach can also be used for multichannel reactors. Because of the small volume of a single channel, many channels have to be used in parallel to obtain sufficient reactor throughput. A uniform distribution of the reaction mixture over thousands of microchannels is necessary to obtain an adequate performance ofthe microstructured reactor. Flow maldistribution will enlarge the RTD in the multitubular reactor and lead to a reduced reactor performance along with reduced product yield and selectivity. Therefore, several authors have presented design studies of flow distribution manifolds [9-13]. 

---