Chapter 2 - FLOW MEASUREMENT MEASUREMENT

Chapter 2 FLOW MEASUREMENT.ppt

1. FLOW
MEASUREMENT
CHAPTER 2

2. OBJECTIVES
After you study this chapter, you should be able to
1.Define flow measurement.
2.Describe the importance of flow measurement.
3.Explain the basic operation, list the
advantages and disadvantages of each flow
measurement device.

3. TOPIC COVERED
Introduction to Flow Measurement
Flow Measuring Device:
1.Differential Pressure Meter
-Orifice, Venturi. Nozzle
2. Electromagnetic Flowmeter
3. Vortex Flowmeter
4. Turbine Flowmeter
5. Ultrasonic Flowmeter

4. INTRODUCTION
What is flowrate??
Amount of material passing one point for
certain time
Give one simple method to measure
1. Water flowrate from tap water.
2. Gas flowrate –filling in a bottle

5. INTRODUCTION
Why flow is prime important parameter?
Most process involves moving material from one
part of the plant to another
Flow of
1.Material -Gas, liquid, solid particle
2.Energy –Power
3.Thermal energy

6. TASK 1
Discuss in group, write the basic operation
of each instrument given. Each group
members must be able to explain the
basic operation of the instrument. List
the advantagesand disadvantagesof
the instrument.

7. Flow Nozzle
Consist of an elliptical converging section and
cylindrical throat section.
Suitable for high-velocity, non-viscous, erosive flows.
Flow Nozzles have a smooth elliptical inlet leading to
a throat section with a sharp outlet. This restriction in
the fluid flow causes a pressure drop.
This device has a greater overall pressure loss or
operating cost in terms of head pressure than a
Venturi but offers lower installation costs.

8. Orifice
Venturi
Nozzle

9. Electromagnetic Flowmeter

10. Vortex Flowmeter
Bluff Body ~ obstruction to flow
Pressure difference ~ main stream and
bluff body ~ vortices

11. Turbine Flowmeter
Pulse frequency
is proportional to
the velocity

12. Ultrasonic Flowmeter
Ultrasonic flowmeters ~ clamped on / inline
Doppler Model
-frequency shift
-Particles in the fluid

13. Time Transit Model
-Difference in frequency proportional to
average fluid velocity ~ flowrate

14. Minute Paper

15. To be continued