Outline of the Design Problem

When temperatur.e..gradients- exist-in the-reactor, analytical solution of the differential equations, is not possible,. Then the design process entails the numerical solution of a set of coupled differential equations. A stepwise procedure is employed, starting at the entrance to the reactor and moving along radially and longitudinally in increments the size of the pellet diameter. This process is carried out by machine computation. The first step is to convert the differential equations to a difference form. The whole procedure is illustrated in Sec. 13-7 with an SO2 oxidation problem. In this case, to reduce the number of calculations, the increment size is larger than the pellet diameter. With machine computation the number of calculations is not so important, and an increment the size of the pellet is practical. 

The complexity of the design problem depends primarily on the amounT OT teffiperlLtur In the reactor. T reactants enter the 

The difliculty in the design calculations depends directly bn the type and magnitude of temperature variations that need be taken into 

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