Each environmental engineering system is unique when considered at a fine resolution. This unique detail can be overwhelming when first attempting to develop a conceptual picture of the system and a corresponding functional model. It has frequently proven helpful to consider systems from the perspective of an idealized reactor or a set of idealized reactors. Idealized reactors help to establish a coarse resolution picture and functional model of the system. Finer resolution can then be built on top of these idealized reactors when and where this finer resolution is warranted. Although idealized reactors are referred to as a “reactor” it is not necessary for any chemical transformations to take place within them.
The three idealized reactors are a batch reactor, a plug flow reactor (PFR) and a continuous stirred tank reactor (CSTR). A batch reactor is a closed system meaning that there is no inflow or outflow. A plug flow reactor has no mixing in the direction of flow leading to first in first out (FIFO) behaviour. A continuous stirred tank reactor is perfectly mixed leading to uniform properties everywhere within the system.
Batch Reactor
Plug Flow Reactor
Continuous Stirred Tank Reactor
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