Please enable JavaScript.
Coggle requires JavaScript to display documents.
Process Instrument & Control Week 5, Patthiya Srimahaprom 61010789 -…
Process Instrument & Control
Week 5
Level control
Required when there is a V/L or L/L interface
Many smaller vessels are sized based on level control response time
Pressure Control
Venting a gas or vapor
Prevent the occurrence of over pressure
Most common is direct venting
Condensers
Control the pressure by changing the condensation rate
Flow Control
Control valve downstream of a pump or compressor
Variable speed drive
More efficient
Higher capital cost
Reciprocating Pump
Positive-displacement pumps
Constant flow rate
Control the flow by manipulating a spill-back to the pump feed
Vaporizer
Prevent liquid accumulation
Use level controller to actuate heat input
Temperature Control
Heat Exchangers
Manipulating the flow through a bypass
Temperature can be controlled on only one side of the exchanger
Air Coolers
Controlled by manipulating a bypass
Use a variable speed motor, louvers, or variable pitch fans
Distillation Control
Controlling condenser pressure and level in the sump
Distillation column
Material balance (split)
Energy balance (heat input or removed)
Needs two controllers
Temperature Pattern Control
Composition
Used to adjust reflux rate and reboiler heat input
Tray locations for temperature detectors
Tray temperature
Used to infer composition
Material Balance Control
Distillate composition
Bottoms composition
Batch Distillation
Reflux flow control adjusted based on T
Patthiya Srimahaprom 61010789