Steady-State Mass Balance and its Graph Representation

1 STEADY-STATE MASS BALANCE AND ITS GRAPH REPRESENTATION 

Generally, the mass balance of a unit (node) reads Lm - Lm =a  

It is also possible to regard a as a fictitious rate of mass flow directed outwards then a becomes one of the output flowrates and the RHS in Eq.(3.1.1) becomes zero. 

In a system of units n e N (set of units) connected by streams j e ] (set of streams), the (formally steady-state) balances can be written in the form 

C j = 1 if stream j is input into node n C j = -1 if stream j is output from node n C j = 0 if stream j is neither input nor output. 

---