文档介绍：第3章均相等温反应器
Chapter 3 Homogeneous Isothermal Reactors
概述 General Introduction
In reactor design we want to know what size and type of reactor and method of operation are best for a given job. Because this may require that the conditions in the reactor vary with position as well as time, this question can only be answered by a proper integration of the rate equation for the operation.
This may pose(造成) difficulties because the temperature position of the reacting fluid may vary from point to point within the reactor, depending on the endothermic(吸热的) or exothermic(放热的) character of the reaction, the rate of heat addition or removal from the system, and the flow pattern of fluid through the vessel. In effect, then many factors must be accounted for in predicting the performance of a reactor. How best to treat these factors is the main problem of reactor design.
Operation types:
the batch (间歇)
the steady-state flow (连续)
the unsteady-state flow or semibatch reactor(半连续)
Flow pattern :Ideal flow and Non-ideal flow
Heat Transfer Methods:isothermal operation ,adiabatic operation,heat exchange and heat producing from reaction itself.
1、反应时间与停留时间Reaction Time and Residence Time
反应时间:从反应物料加人反应器后实际进行反应时算起至反应到某一时刻所需的时间,称为反应时间,以符号t表示。
停留时间:而所谓停留时间则是指从反应物料进人反应器时算起至离开反应器时为止所经历的时间。
Space-Time and Space-Velocity
空时:为在规定条件下,进入反应器的物料通过反应器体积所需的时间,用符号表示
Space-Time: Time required to process one reactor volume of feed measured at specified conditions
空速:为在规定条件下,单位时间内进入反应器的物料体积相当于几个反应器的容积,用符号SV表示
Space-velocity: Number of reactor volumes of feed at specified conditions which can be treated in uint time
We may arbitrarily select the temperature, pressure, and state at which we choose to measure the volume of material being fed to the reactor. Certainly the value for space-velocity or space-time depends on the conditions selected. If they are of the stream entering the reactor, the relation between sV and and the other pertinent variables is
The relation between