1. Chapter 13 Pinch Technology
Don Scott
3/9/6
ENCH 430

2. Pinch Point
In a system, a point where energy or mass exchange is at a minimum is the pinch point.
A pinch point needs to be located and used to design the system.

3. Heat Integration- Matching points of heat addition and heat loss
Choose a minimum approach temperature.
Construct a temperature interval diagram.
Construct cascade diagram-minimum utility requirement, pinch temperatures.
Calculate minimum no. of heat exchangers above and below pinch.
Construct the heat exchanger network.
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4. Estimate Area A=(Q)/(U*delta Tlm*F) A: heat transfer area
Q: amount of heat to be transferred
U: film heat transfer coefficient
delta Tlm: log-mean temperature.
F: log-mean temperature correction factor

5. Equivalent Annual Operating Cost
EAOC=FCI(i(1+i)n)/((1+i)n-1)+utility costs
FCI= total cost of network
‘n= number of years
i=before tax hurdle rate

6. Other considerations Material Operating pressure Multiple Utilities
Phase Changes

7. Mass Exchange
Analogous to heat exchange.
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