5 Block Flow Diagrams

Learning Objectives

By the end of this section, you should be able to:

Construct block flow diagrams (BFDs) for chemical processes

Block Flow Diagrams

We typically break down chemical and biological processes (or any other process) into units representing equipment. These are called unit operations and are drawn as circles or squares:

Lines with arrows represent the flow of materials in streams to and from units. These lines have only 1 arrowhead:

Materials in each stream are labeled above or beside the stream:

Exercise: BFD Components

What are some errors in the following flowsheet? How would you change the flowsheet to address these errors?


We can correct the BFD to following:




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Foundations of Chemical and Biological Engineering I Copyright © 2020 by Jonathan Verrett is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, except where otherwise noted.

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