Page 1 of 2 12 LastLast
Results 1 to 10 of 17

Thread: Pressure Drop in Pneumatic Conveying

  1. #1
    Join Date
    Jul 10
    Posts
    16

    Pressure Drop in Pneumatic Conveying

    Pressure Drop in Horizontal & Vertical Conveying

    My case is as follows:

    Dia of pipe : 53mm
    Length of pipe : 5m
    Density of solids =2530 kg/m3
    air mass flow rate = 0.0324kg/s
    solid mass flow rate = 1.2184kg/s
    Particle size = 30 micron

    I want to find the pressure drop for this case in horizontal and vertical flow. Can anyone tell me what are pressured drop values . I want to do numerical simulation and compare the results.

    Thanks
    Regards
    PP

  2. #2
    Teus Tuinenburg

    Professional Experience 50 Years / 3 Month Teus Tuinenburg has 50 Years and 3 Month professional experience

    Discussions 1784 Teus Tuinenburg acceded to 1784 discussions, Articles 10 Teus Tuinenburg wrote 10 articles, Publications 0 Teus Tuinenburg Tuinenburg released 0 publications

    Searching Falsifications in my perception of pneumatic conveying

    Know-How conveying (1358) Teus Tuinenburg used this tag 1358 times, pneumatic conveying (1165) Teus Tuinenburg used this tag 1165 times, pneumatic (31) Teus Tuinenburg used this tag 31 times

    Dear pandaba,

    Based on your limited data, the pressure drop is calculated as:

    Horizontal:
    with 1 m2 filter: pressure drop = approx. 0.17 bar
    without filter: pressure drop = approx. 0.082 bar

    Vertical:
    with 1 m2 filter: pressure drop = approx. 0.22 bar
    without filter: pressure drop = approx. 0.13 bar

    The compressor conveing pressure can differ a lot by extra clean air piping and ambient and material temperatures.
    The material is unknown.

    Have a nice day
    Teus
    Teus

  3. #3
    Join Date
    Jul 10
    Posts
    16
    Thanks teus for kind reply.

    My case is flow of fly ash in a pipe . I need some data on particle - particle and particle-wall collision for pneumatic conveying of flyash.

    Thanks and regards
    PP

  4. #4
    Teus Tuinenburg

    Professional Experience 50 Years / 3 Month Teus Tuinenburg has 50 Years and 3 Month professional experience

    Discussions 1784 Teus Tuinenburg acceded to 1784 discussions, Articles 10 Teus Tuinenburg wrote 10 articles, Publications 0 Teus Tuinenburg Tuinenburg released 0 publications

    Searching Falsifications in my perception of pneumatic conveying

    Know-How conveying (1358) Teus Tuinenburg used this tag 1358 times, pneumatic conveying (1165) Teus Tuinenburg used this tag 1165 times, pneumatic (31) Teus Tuinenburg used this tag 31 times

    Dear pandaba,

    The material pressure drop in your system is only a small part of the total pressure drop.

    The Solid Loss Factor, which you are asking for, is related to the calculation algorithm that you are using.

    If I give you the SLF, I am applying, as 4.58*10^-12, it does not mean anything to you.

    What you can do is calculating with your own program the SLF, which matches the given pressure drops in the previous reply.

    Success
    Teus
    Teus

  5. #5
    Join Date
    Jul 10
    Posts
    16
    Hi Teus,

    I am again coming back to this discussion. I want to know What is meant by solid loss factor. Can you please explain a bit more .

    Also how to predict the pressure drop in horizontal gas solid flow. I found from simulation that the gas velocity, particle dia , density , pipe dia and loading ratio have high impact on pressure drop. Considering all these , how to predict pressure drop.

  6. #6
    Teus Tuinenburg

    Professional Experience 50 Years / 3 Month Teus Tuinenburg has 50 Years and 3 Month professional experience

    Discussions 1784 Teus Tuinenburg acceded to 1784 discussions, Articles 10 Teus Tuinenburg wrote 10 articles, Publications 0 Teus Tuinenburg Tuinenburg released 0 publications

    Searching Falsifications in my perception of pneumatic conveying

    Know-How conveying (1358) Teus Tuinenburg used this tag 1358 times, pneumatic conveying (1165) Teus Tuinenburg used this tag 1165 times, pneumatic (31) Teus Tuinenburg used this tag 31 times

    Dear pandaba,

    The Solid Loss Factor is a product related value that, in a formula, accounts for the energy losses, due to inter-particle- and wall collisions.

    The calculated energy loss is, through the appropriate formulas, expressed in a pressure drop.

    The total pressure drop is the sum of all partial pressure drops (air, elevation, suspension, acceleration, product)

    There exists no direct way to calculate the pressure drop in pneumatic conveying, as a calculated pressure drop is influenced by itself (Caused by the expansion of the air)

    An iterating, numerically integrating, algorithm can solve this problem. (Approx. 45 Mb VB software)

    Take care
    Teus
    Teus

  7. Check my software solution

    Hi there, have a look at my state diagram and software. It is an iterativ, numerical overall calculation, that apart from an interpolated estimated value for the pressure loss additional information provides. So, the given data belong to a dense phase conveying system near the instable transition area, and the pressure loss in a horizontal pipe will be around 0.11 bar. These results are confirmed by published field data of similar conveying lines. However, the question remains, how precisely the parameters can be read from the relatively rough state diagram.

    These are the published data for a comparable conveying system: Material SiO2, 10 microns, bulk solids throughput 4000 kg/h, gas flow 100 Nm3/h, pipe diameter 65 mm, horizontal pipe length 30 m, pressure loss 0.3 bar (that meets exactly the calculated value).

    Moreover shows the state diagram, that different conveying conditions are possible, so, for instance a lower gas flow at higher pressure loss. How can one say which the stable conveying conditions are? A good example for the wide variation of conveying conditions was published by

    Krambrock, W.: Dichtstromförderung. Chem.-Ing.-Tech. 54(1982)9, S.793-803

    The diagram shows a field of possible conveying conditions at maximum mass flow of bulk solids which lie on the left (upper) border of the state diagram.

    Click image for larger version. 

Name:	MassFlowMax.jpg 
Views:	170 
Size:	35.5 KB 
ID:	32201

    Kind regards
    ManfredH
    Last edited by ManfredH; 25th March 2012 at 14:05.

  8. #8
    Quote Originally Posted by pandaba View Post
    Pressure Drop in Horizontal & Vertical Conveying

    My case is as follows:

    Dia of pipe : 53mm
    Length of pipe : 5m
    Density of solids =2530 kg/m3
    air mass flow rate = 0.0324kg/s
    solid mass flow rate = 1.2184kg/s
    Particle size = 30 micron

    I want to find the pressure drop for this case in horizontal and vertical flow. Can anyone tell me what are pressured drop values . I want to do numerical simulation and compare the results.

    Thanks
    Regards
    PP
    Dear Pandaba,

    Please refer to my article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" for calculating the pressure drop values. In this article you will find that the pressure drop due to the flow of solids depends upon the solids friction factor. Unfortunately, this value has to be determined from actual test data for this solid, there is no analytical method available for its precise calculation. I can give you an approximate value if you send me a small sample.

    Regards,

    Amrit Agarwal
    Pneumatic Conveying Consulting
    polypcc@aol.com

  9. Are friction factors in dense phase conveying really needed?

    Quote Originally Posted by Amrit Agarwal View Post
    Dear Pandaba,

    Please refer to my article "Theory and Design of Dilute Phase Pneumatic Conveying Systems" for calculating the pressure drop values. In this article you will find that the pressure drop due to the flow of solids depends upon the solids friction factor. Unfortunately, this value has to be determined from actual test data for this solid, there is no analytical method available for its precise calculation. I can give you an approximate value if you send me a small sample.

    Regards,

    Amrit Agarwal
    Pneumatic Conveying Consulting
    polypcc@aol.com

    Dear Amrit,
    the state diagram, developed by me, does not use friction factors for the calculation of pressure losses, especially in the dense phase conveying of fine materials which are easy to fluidize. As the diagram indicates, is the main factor in such cases the state of the turbulent gasflow and the energy, that is provided through turbulent eddies and pressure gradients, for fluidizing a particular mass of bulk solids, that is thereby kept moving. Published field data show, that even moist sand of 200 microns, that is most likely considered for a cohesive material, fits in the state diagram, but with a very low gas flow rate at high pressure loss (plug conveying?!). For this reasons I am not sure whether at least in my diagram a friction factor is really needed. It is possibly a hidden parameter indicating stable conveying conditions or so.
    Kind regards
    ManfredH
    Last edited by ManfredH; 24th March 2012 at 15:28.

  10. #10
    Join Date
    Sep 13
    Posts
    4
    Hi all

    I have a requiremnt to fluidize coffee and the only information I have is physical properties of coffee.

    I have assumed the drag co-efficient of coffee as 0.1(assuming spherical beans), and calculated the terminal velocity.

    But I have no idea regarding the pick-up velocity or the required pressure drop to convey or fluidize coffee.

    I would really appreciate if anyone can suggest the procedure or a book which can help me more.

    Regards
    Vineet

Page 1 of 2 12 LastLast

Similar Threads

  1. Pressure Drop Calculation for Plastic Pellet Conveying
    By hthtieu in forum Pneumatic Conveying
    Replies: 11
    Last Post: 15th November 2007, 14:39
  2. Pressure Drop in Dense Phase Conveying System
    By guddu in forum Pneumatic Conveying
    Replies: 5
    Last Post: 3rd September 2007, 14:08
  3. Energy Method for Conveying Pressure Drop
    By RJB324 in forum Pneumatic Conveying
    Replies: 1
    Last Post: 4th August 2006, 9:19
  4. Pressure Drop in Vacuum Conveying
    By RJB324 in forum Pneumatic Conveying
    Replies: 6
    Last Post: 13th June 2006, 16:38
  5. Pressure Drop
    By alberto.carrea in forum Pneumatic Conveying
    Replies: 4
    Last Post: 16th December 2004, 4:00

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Single Sign On provided by vBSSO