CHAPTER 13: PROCESS CONTROL
SYSTEMS
OBJECTIVES
Students will understand:
• Level control system.
• Pressure control system.
• Flow control system.
• Temperature control system.
1/4/2022
403047- Chapter 13: Control loops
1
CONTENTS OF CHAPTER 13
13.1 Pressure control system.
13.2 Flow control system.
13.3 Level control system.
13.4 Temperature control system.
1/4/2022
403047- Chapter 13: Control loops
2
PRESSURE CONTROL LOOP
In tank
1/4/2022
403047- Chapter 13: Control loops
3
PRESSURE CONTROL LOOP
In tank
1/4/2022
403047- Chapter 13: Control loops
4
PRESSURE CONTROL LOOP
In tank
1/4/2022
403047- Chapter 13: Control loops
5
PRESSURE CONTROL LOOP
In tank
gas
gas
1/4/2022
403047- Chapter 13: Control loops
6
PRESSURE CONTROL LOOP
In pipe
1/4/2022
403047- Chapter 13: Control loops
7
FLOW CONTROL LOOP
Level control methods:
• Throttling the flow of material through the
regulator installed on the pipeline (valve,
gate,…).
• Changing the pressure in the pipeline by
means of an adjustable power (pump, fan, …).
• Bypass, transfer the excess material from the
main pipeline in the bypass line.
1/4/2022
403047- Chapter 13: Control loops
8
FLOW CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
9
FLOW CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
10
FlOW CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
11
FlOW CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
12
LEVEL CONTROL LOOP
• The level is an indirect measure of
equilibrium hydrodynamics in devices.
• Level equal:
𝑑𝐿
𝑆
= 𝐺𝑖𝑛 − 𝐺𝑜𝑢𝑡 ± 𝐺𝑔 ,
𝑑𝑡
where: S-area
Gin, Gout – inlet flow, outlet flow.
Gg - quality of liquid generated in time unit.
1/4/2022
403047- Chapter 13: Control loops
13
LEVEL CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
14
LEVEL CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
15
LEVEL CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
16
TEMPERATURE CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
17
TEMPERATURE CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
18
TEMPERATURE CONTROL LOOP
1/4/2022
403047- Chapter 13: Control loops
19
SUMMARY
In this chapter we have learnt:
• Pressure control loop
• Level control loop
• Flow control loop
• Temperature control loop.
1/4/2022
403047- Chapter 13: Control loops
20
ASSIGNMENTS
• Reading [3]: 432-441; 1512-1515; 16881696; 1756-1762.
[5]: 347-348.
1/4/2022
403047- Chapter 13: Control loops
21