1. Piyush Modi Assist.Prof
Pacific School Of Engineering
Chemical Engineering
Presentation On Flow Measurement Devices
Guided By:-
Piyush Modi Assist.Prof
Chemical.Dept
Presented By:-
Pipaliya Pritesh
Kargavkar Ashish
Patel Sawan
Patel Nikunj
Alagiya Amit

2. Venturimeter
Figure:-
Venturimeter

3. Working & Construction:-
From the figure We can see that a conical inlet section leads to a throat section, then to a long discharge cone.
Pressure taps at the start inlet section and at the throat are connected to a manometer .
In the upstream cone the fluid velocity is increase and its pressure decrease
The pressure drop in this cone is used to measure the flow rate.
In the discharge cone the velocity is decreased and the original pressure largely recovered
The angle of the discharge cone is made small, between 50 to 150,to prevent boundary layer separation and minimize friction.
Typically 90 percent of the pressure loss in the upstream cone is recovered

4. Advantages & Disadvantages:-
It is widely used for high flow rates.
It is available in very large pipe sizes.
It has well-known characteristic.
It can be used at low and High beta ratio.
It causes low permanent pressure loss.
Disadvantages:-
Its cost is high.
It is generally not useful below 76.2 mm pipe size.
It is more difficult to inspect due to its construction.
It has the limitation of a lower Reynolds number of 150,000.

5. Rotameter
Figure:-
Rotameter

6. Working & construction:-
This is a one type of area meter in which pressure drops is constant
and the area through which the flow varies with the flow rate.
It consist essentially of a gradually tapered glass tube mounted vertically in a frame with the large end up.
The fluid flows upward through the tapered tube and suspends freely a float.
The float is the indicating element. The entire fluid stream must flow through the annular space between the float and tube wall
The tube is marked in division , and the meter is read from the scale reading at the edge of the float.
It is used for both gas and liquid . For use with opaque liquid at a high temperature and pressure the glass tube is impracticable , metal tube is used .
In this the float is invisible so that the rod is attaching with it that is called extension.

7. Advantages & Disadvantages :-
Its cost is relatively low.
Rotameters have good rangeability.
It handles wide variety of corrosives.
It has low pressure drop requirement.
It can be used in some light slurry services.
Viscosity-immune floats are available in rotameters.
Disadvantages:-
The glass tube type is easily subject to breakage.
It must be mounted vertically.
It is not good in pulsating services.
Rotameter are limited to relatively low temperature.
It requires in-line mounting.

8. Orifice Meter
Figure:-
Orifice meter

9. Construction & Working:-
A standard sharp-edged orifice is shown in figure. It consist of an accurately machined and drilled plate mounted between two flanges with the hole concentric with the pipe in which it is mounted.
The opening in the plate may be beveled on the down stream side.
Pressure taps, one above and one below the orifice plate, are installed and are connected to a manometer.
The position of the taps are arbitrary ,and the coefficient of the meter will depend upon the position of the taps.
The principle of the orifice meter is identical with that of the venturi.
The reduction of the cross section of the following stream in passing through the orifice increases the velocity head at the expense of the pressure head and reduction in pressure between the taps is measured by the manometer.

10. Advantages & Disadvantages:-
Its cist is low.
They can be used in a wide range of pipe sizes.
They can be used with differential pressure devices.
They are well-known and have predictable characteristics.
They are available in many materials.
Disadvantages:-
They cause relatively high permanent pressure loss.
They tend to clog, thus reducing use in slurry services.
They have square root characteristics.
Their accuracy is dependent on care during installation.
They have changing characteristics because of erosion, corrosion and scaling.

11. Thank You