Page 54 - Plant design and economics for chemical engineers

PROCESS DESIGN DEVELOPMENT 37
TABLE 6
Factors in equipment scale-up and design
l-
Approxi-
Maximum mate
SCalkWlp recom-
1:s pilot ratio based mended
1 slant Major variables on indi- safety or
Iusually for operational Major variables cated char- over-
Type of 1IeceS- design (other characterizing acterizing design
6 Zlly? than flow rate) size or capacity variable factor, %
- -
Agitated batch Yes Solubility- Flow rate >lCO:l 20
crystallizers temperature Heat transfer
relationship area
- -
Batch reactors Yes Reaction rate Volume >lOO:l 20
Equilibrium Residence time
state
- -
Centrifugal N o Discharge head Flow rate >lOO:l 1 0
pump* Power input >lOO:l
Impeller 1O:l
diameter
- -
Continuous Yes Reaction rate Flow rate >lOO:l 20
reactors Equilibrium Residence time
state
- -
Cooling towers N o Air humidity Flow rate >lOO:l 1 5
Temperature Volume 1O:l
decrease
- -
Cyclones N o Particle size Flow rate IO:1 1 0
Diameter of 3:l
body
- -
Evaporators N o Latent heat of Flow rate >lOO:l 1 5
vaporization Heat-transfer >lOO:l
Temperatures area
- -
Hammer mills Yes Size reduction Flow rate 6O:l 20
Power input 6O:l
- -
Mixers N o Mechanism of Flow rate >lOO:l 20
operation Power input 2O:l
System geometry
- -
Nozzle-discharge YeS Discharge Flow rate 1O:l 20
centrifuges method Power input 1O:l 20

(continued)