Instrumentation and process control:
Objective of control system:
1. To ensure the stability of the process
2. To reduce the effect of external disturbances
3.To optimize the overall process
4. To keep the process variables within limit
5. To give desire purity
6. To maintain the production composition
HARD WARE ELEMENT:
To monitor and control the operation of process there are seven hardware elements as
1.Process
2.Measuring device
3. Transducer
4. Transmission lines
5.Controller
6. Final control element
7. Recorder
PROCESS
It represent the material equipment together with physical and chemical operations
MEASURING DEVICE
The instruments by which process is controlled and under required enviornrment is created for process
TRANSDUCER
It is interface between process and control system and its job is to convert the sensor signal into control system
TRANSMISSION LINES
These lines carry signal from transducer to control system . in modern systems transmission lines are mot used as they require investment in capital cost . now in modern system signal are transferred by electrical signals which don't require any transmission lines
CONTROLLER
Controller is the brain of whole plant . its objective is to compare output signal and set point and give correction to the system as required
FINAL CONTROLLE ELEMENT
Final control element work on the instruction of controller. final control element mostly is control valve
RECORDER
Recorder , records the all process variable for monitoring purpose.GENERAL CONTROL SYSTEM
Following are the control system
1.Open loop system
2. Close loop system
3. Feed forward system
4. Feed backward system
5.Combined control system
6. Cascade control system
7.Ratio control system
MODES OF FEED BACK CONTROL SYSTEM
1.Proportional control
2. Proportional integral control
3.Proportional derivative control
4.Pid control
MEASURING DEVICES
In any chemical process we usually measure
1. Temperature
2. Pressure
3. Flow rate
4. Level
INSTRUMENTATION ON DISTILLATION COULUMN
No comments:
Post a Comment