Latest in Your Instrumentation

Find your career in Instrumentation # We are not responsible for any error/ mistakes in the contents of this blog # Please send us the updates/ Articles/ Conference lists to us for a free publication in this blog >> # Welcome to "Your Instrumentation" # Contact me through yourinstrumentation@gmail.com # Find out your successful career in Instrumentation

Monday, October 17, 2011

Venturi Meter: Theory, Operations & Working


Basic principle:

When a venture meter is placed in apipe carrying the fluid whose flow rate is to be measured, a pressure drop occurs between the entrance and throat of the venturimeter. This pressure drop is measured using a differential pressure sensor and when calibrated this pressure drop becomes a measure of flow rate.

Construction of Venturi meter

The following are the main parts and areas of venture meter:



The entry of the venture is cylindrical in shape to match the size of the pipe through which fluid flows. This enables the venture to be fitted to the pipe.
After the entry, there is a converging conical section with an included angle of 19’ to 23’.
Following the converging section, there is a cylindrical section with minimum area called as the throat.
After the throat, there is a diverging conical section with an included angle of 5’ to 15’.
Openings are provided at the entry and throat (at sections 1 and 2 in the diagram) of the venture meter for attaching a differential pressure sensor (u-tube manometer, differential pressure gauge, etc) as shown in diagram.


Operation of venturi meter:

The fluid whose flow rate is to be measured enters the entry section of the venturi meter with a pressure P1.
As the fluid from the entry section of venturi meter flows into the converging section, its pressure keeps on reducing and attains a minimum value P2 when it enters the throat. That is, in the throat, the fluid pressure P2 will be minimum.
The differential pressure sensor attached between the entry and throat section of the venturi meter records the pressure difference(P1-P2) which becomes an indication of the flow rate of the fluid through the pipe when calibrated.
The diverging section has been provided to enable the fluid to regain its pressure and hence its kinetic energy. Lesser the angle of the diverging section, greater is the recovery.


Applications:

  • It is used where high pressure recovery is required.
  • Can be used for measuring flow rates of water,gases,suspended solids, slurries and dirty liquids.
  • Can be used to measure high flow rates in pipes having diameters in a few meters.



Advantages of venturi meters

  • Less changes of getting clogged with sediments
  • Coefficient of discharge is high.
  • Its behaviour can be predicted perfectly.
  • Can be installed vertically, horizontally or inclinded.


Limitations


  • They are large in size and hence where space is limited, they cannot be used.
  • Expensive initial cost, installation and maintenance.
  • Require long laying length. That is, the veturimeter has ti be proceeded by a straight pipe which is free from fittings and misalignments to avoid turbulence in flow, for satisfactory operation. Therefore, straightening vanes are a must.
  • Cannot be used in pipes below 7.5cm diameter.

11 comments:

  1. hi! very nice blogs your site is good.have shared useful information ......Thankq for Aircraft weighing

    Weight transducer

    ReplyDelete
  2. Wow, surprisingly I never knew this.I have been reading your blog a lot over the past few days and it has earned a place in my bookmarks.Thanks for sharing with us.Heavy duty cooling fans

    ReplyDelete
  3. Hi it’s a nice site..! Have useful information about cells.
    Our Weight Transducer is high performance pressure sensor designed especially for critical applications of pressure and other environmental conditions.

    ReplyDelete
  4. Epoch Load Cell has experienced and expert Manufacturers for Electrical
    weight transducer
    . Which are considered for the capacity of the changes of weight of separate plants.

    ReplyDelete
  5. thhanks for this wonder job.....

    ReplyDelete
  6. Sir,

    We can deliver financial service/instrument(BG/SBLC/MTN/DLC/LC) at affordable price to our customers in other to derive maximum utility. We understand that finding the right company to provide financial instrument is not easy. We are certified financial company that delivers banking instrument for lease which we adhere to our terms and condition. Over 96% of our clients are satisfied with our work whether it is business or financial service.

    Once transaction is in progress, we ensure we keep you posted on the progress of your paper. We also get you connected to the provider for personalized service. Instead of stressing yourself out looking for financial instrument or company why not let professional like us deliver financial instrument to you within the time frame required by you.

    For further details contact us with the below information....

    Thank you.
    Agapito Gomez Martinez
    Contact: martigapito.broker@gmail.com
    Skype ID: martigapito.broker

    ReplyDelete
  7. Are you seeking BG leasing and and Monetizing ? We only provide BG from HSBC UK, Barclays UK , RBS, Deutsche Bank AG. Our leasing rate is 3% + 1%. Delivery Pre-advise MT799 and MT760 (Bank to Bank Swift) Payment MT103 and Hard copy by bonded Courier Serive within 14 banking days.
    We also have BG monetizer should you require at 95% LTV + 2% commission. Loan can be up to 30 years with 2.5% interest.
    Feel free to contact me should you have any questions.

    Mr:Nguyen Dinh Huynh
    Email: (bgmandate.nh99@gmail.com)
    Skype: (nguyendinh9212)

    ReplyDelete
  8. ARE YOU AN INDIVIDUAL BUSINESSMAN OR A BUSINESS ORGANISATION THAT WISHES TO EXPAND IN BUSINESS, WHY NOT SOURCE FOR BG/SBLC FROM SORIN LASSMANN BROKERS WHO HAVE BG/SBLC SPECIFICALLY FOR LEASE AT A LEASING PRICE OF 5+2 OF FACE VALUE ISSUANCE BY HSBC LONDON/HONGKONG OR ANY 25 TOP AA RATED BANK IN EUROPE, MIDDLE EAST OR USA. WE ALSO SECURE FUNDING PROJECT LOANS FOR 3% APR

    Finally I will assure you of our total commitment to achieving this transaction as I always look forward to doing more business with you in future

    Contact : Mr. Sorin Lassmann
    Email: providermandate.ls@gmail.com
    Skype ID: ls.nicu

    ReplyDelete
  9. ARE YOU AN INDIVIDUAL BUSINESSMAN OR A BUSINESS ORGANISATION THAT WISHES TO EXPAND IN BUSINESS, WHY NOT SOURCE FOR BG/SBLC FROM SORIN LASSMANN BROKERS WHO HAVE BG/SBLC SPECIFICALLY FOR LEASE AT A LEASING PRICE OF 5+2 OF FACE VALUE ISSUANCE BY HSBC LONDON/HONGKONG OR ANY 25 TOP AA RATED BANK IN EUROPE, MIDDLE EAST OR USA. WE ALSO SECURE FUNDING PROJECT LOANS FOR 3% APR

    Finally I will assure you of our total commitment to achieving this transaction as I always look forward to doing more business with you in future

    Contact : Mr. Sorin Lassmann
    Email: providermandate.ls@gmail.com
    Skype ID: ls.nicu

    ReplyDelete

Related Posts Plugin for WordPress, Blogger...