1 / 13

FLOW MEASUREMENT DEVICES

FLOW MEASUREMENT DEVICES. VENTURIMETER. VENTURIMETER. INTRODUCTION. In this meter the fluid is accelerated on expense of static pressure by its passage through a converging cone of angle 15-20 degree.

stella
Download Presentation

FLOW MEASUREMENT DEVICES

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. FLOW MEASUREMENT DEVICES

  2. VENTURIMETER

  3. VENTURIMETER

  4. INTRODUCTION • In this meter the fluid is accelerated on expense of static pressure by its passage through a converging cone of angle 15-20 degree. • The pressure difference between the upstream end of the converging cone and the throat (minimum area section) is measured. • Throat length = throat diameter • The fluid is then retarded in a cone of smaller angle 5-7 degree in which large proportion of kinetic energy is converted back to pressure energy.

  5. VENTURIMETER

  6. PRINCIPLE USED Bernoulli's Principle same as orifice meter P↓ = V ↑

  7. DISADVANTAGES • Highly expensive in installation & replacement • Space requirement is more

  8. ADVANTAGES • High pressure recovery • Less possibility of becoming clogged due to smooth surface • Suited for large water flow • High coefficient of discharge

  9. VENTURIMETER SECTIONS • CONVERGING CONICAL SECTION • THROAT • DIVERGING SECTION

  10. CONVERGING CONICAL SECTION • Angle of converging conical section is about 21 ± 2 degree. • Velocity ↑ and static pressure ↓

  11. THROAT • Cylindrical section of Minimum Area • At this section V = MAX and P = MIN • Throat diameter = 0.25 – 0.5 of inlet diameter

  12. DIVERGING SECTION • Change of stream area back to the entrance area • Kinetic energy is converted into pressure rise in this section • Angle of diverging section is about 5-7 degree • Angle is kept less to having least tendency of flow separation from boundary of this section • With small angle length and cost ↑

  13. INTERESTING REASONING QUES. Why mercury is preferred as manometric fluid? • Good conductor of heat • Shining quality provide clear visibility • Mercury does not evaporate easily • Mercury's freezing point is much lower(-38.72 deg C) • More sensitive than water to the changes in the atmospheric pressure • Mercury is relatively denser than water • Does not stick on the walls of the tube of manometer, resulting in accurate measurements • Large temperature expansion coefficient

More Related