Subhash,

To get a copy of the article please send this request to my email address given below:

Regards,

Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Email: polypcc@aol.com

Ph and Fax: 304 346 5125 ■

Dear Alex,

No, this calculation method is only for dilute phase. My article on dense phase calculations is waiting publication. In the meantime I will be glad to help you if you need help on dense phase.

Regards,

Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Email: polypcc@aol.com

Ph and Fax: 304 346 5125 ■

Dr. Agarwal,

Thanks for the paper that you sent to me on Pneumatic Conveyor Design. It will definitely help me as I complie the list of design options for pneumatic conveyor systems. Making the calcuations available in a spreadsheet format is an added bonus. Keep up the good work.

Oladiran Fasina ■

Dear Mr. Agarwal,

I would like to thank you for your paper on 'Theory and Design of Dilute Phase Pneumatic Conveying Systems'. The paper is very useful for me to understand the design of a new pneumatic conveying system.

Best Regards

Chris Huang ■

Dear Mr Armit Agarwal,

Really thanks alot for your article. It has definitely help me alot.

Cheers!

Q.W Chen ■

Alex,

I will be glad to send the dense phase calculation method. Please send a request to me at my email address given below:

Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Email: polypcc@aol.com

Ph and Fax: 304 346 5125 ■

Dear Mr.Armrit

Thank you for your advise about the theory and design of dilute phase pneumatic conveying systems, but i still have doubts about the Solids friction factor(K), Fanning friction factor equation, furthermore, can we assume that roughness in the pipe will be 0.0005 value all the time of calculation for safety factor and the solid powder is zeolite (for detergent) is the bulk at 300 g/l, particle size is around 3 - 4 um.

Thank you and best regards,

wichet

Process Engineer

wichetk@pqthai.com ■

Dear Mr. Agarwal,

i have read your information about your program for System Design Calculations for Pneumatic Conveying. Everybody says it´s very useful. I would be very grateful if you can send me a copy.

Regards. ■

Sorry Agarwall¡¡

i´m going to introduce myself...

Hero Espaa, s.a. is an infant nutrition factory from Spain. i work in the technical department (i´m projects engineer)

Federico Miarro

HERO ESPAA,S.A.

www.hero.es

federico.minarro@hero.es ■

Please send your request for this article to my email address given below:

Regards,

Amrit T. Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Email: polypcc@aol.com

Ph and Fax: 304 346 5125 ■

Dear Mr. Agarwal

Thank you very much for your article. Currently I am designing a pneumatic conveying system. It will definitely help me to estimate/verify my calculations.

Best regards,

Gary ■

Dear Mr Agarwal

I've received your article and it will be very useful.

Thanks a lot.

Ferran Griera

CMISA ■

Dear Amrit,

I will be very grateful if you can send me the article

the email zhonghuad@sina.com ■

Dear Mr. Agarwal,

I read the article that you sent me and it was very informative. I look forward to potentially reading other articles that you publish.

Daniel McClure

Louisiana Pigment ■

Amrit, I have read your article roughly, think it is useful and easy to understand.

Thanks again.

I am engaged in handling project of pneumatic conveying and components involved. In the future, I will consult you on related issues and wish to get help from you. ■

Dear Mr. Agarwal,

I need also! Can anyone send me?

My Email: sj@chinabulk.com

Many many thanks! ■

I also need one copy

Thanks ■

Dear Amrit,

thank you for the copy of the nice articel. It gives a short and helpful understanding of

the major pneumatic conveying aspects.

But I don`t agree with the formula Eq.7 to calculate the Fanning friction factor.

The result for log (n) for arguments less than one(1) becomes negative. This means that you get a negative friction factor for high Reynolds numbers.

Here I believe that the square bracket [ must include the log(n)

[log (E/3.7*D) + (7/Re)]^2

regards

Valentin Horstmann ■

Dear Valentin,

For calculating the Fanning friction factor, the equation given in my article is correct. It uses "natural Log" in the denominator. I don't know why you are getting a negative Friction Factor. If you send your calculations to me, I will be glad to review these.

Regards,

Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Email: polypcc@aol.com

Ph and Fax: 304 346 5125 ■

Thank you for your answer Amrit.

Right now I´m already at home and I have no excel on my private Computer.

May be someone else has the same problem - so let me explain what I mean.

Let aus consider just the denominator.

The abbreviation for a natural logarithm is ln (x)

Whenever the argument in (x) is less than 1, the result is negative.

Example: ln (0,5) = -0,69314

The same with ln (0,5) = -1,386

The denominator in eq.7 is of the type:

ln(a + b)

a = eps/(3.7*D)

b = 7/Re

Example:

D=1 --> a = 0,0005/3.7 = 1,351e-4

Re = 70000--> b = 0,0001

a + b =0,0002351

0,0002351=0,00000005527201

ln(0,00000005527201) = -16,71

Thanks

Valentin ■

Dear Mr Agarwal

I would be very grateful if you send me a copy of oyur both articles, that I may dfind very useful in the development of my job

My e mail is Aranchaesp@hotmail.com

Thank you very much in advance

Arancha Espadero ■

Dear Valentin,

The question that you asked was also asked by a few others. Its answer is quite simple. You have to follow the laws of Logarithms when an equation has a log in it. These laws are:

Log xy = Log x + Log y

Log x/y = Log x - Log y

If you follow the above, you should get a Fanning Friction Factor of about 0.0045.

If you still have problems, send me an email.

Regards,

Amrit Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Email: polypcc@aol.com

Ph and Fax: 304 346 5125 ■

Amrit,i have recieved your article.It's really helpful to me.Thank you very much. ■

Dear Amrit,

Thank you so much for your beautiful artical. It's really the most professional one I've read so far and really helpful for my job.

Waiting for your new published articals and don't forget to inform me then.

Regards ■

Dear Mr Agarwal,

I am a student ,can you send me a article about latest calculation for dense convying?If you have no such article I also thank you very much. ■

Dear mr Agarwal

I am very sorry,I forgot to tell you my Email which is sea-will@163.com .Thank you. ■

Obviusly basic mathamatics is a bigger problem than the right understanding of friction factors in pipes.

.

It was the work of J. Nicuradse in the 1930`s who presented his experimental studies of friction in form of 6 curves as a log - log plot for the friction versus Re for six different roughness values.

Since that time many theoretical approches have been published and turbulent flow over rough walls is still a phenomenon that is not easily to understand.

One of the pioneers in this theoretical approach was C.F.Colebrook. His equation is still the no.1 when pressure drop is to be calculated. Unfortunately this equation is implicit and can`t be solved directly. (numerically by Newton Cholesky).

In order to make it more convenient to use this equation many different approximations have been published. One of these equations is the EQ. No. 7 in Mr. Agarwal`s publication.

In order to get some background information about pressure drop of fluids in pipes, I attach an articel with the Colebrook equation ( in articel eq. no. 10).

Here you can easily see the relationship to Mr. Agarwal`s equation no.7 and why this equation is not correct.The Colebrook equation has a (-) minus sign and therefore you get positive friction numbers.

Valentin

Attachments

fluid1 (ZIP)

■

Dear Mr. Agarwal

Thank you for the article, it's well written and makes pneumatic conveying better understandable.

Best regards

Juerg ■

Valentin,

I have looked-up my notes and I have found that the mistake is due to the location of the parenthesis in the published equation. The term Logn should be inside the parenthesis, not outside. Most likely, this mistake was made during formatting of this article for its publication and went unnoticed by me.

Many thanks for bringing this to my attention. I will be glad to send the corrected equation to you if you need it.

Regards,

Amrit T. Agarwal

Consulting Engineer

Pneumatic Conveying Consulting

Email: polypcc@aol.com

Ph and Fax: 304 346 5125 ■

Dear Mr Agarwal

I should like to have your article on "Pneumatic Conveying" calculations and if you can send it to me I shall be most obliged.

Kind Regards

Mrio Mendes

mariosmendes@hotmail.com ■

Dear Amrit

i think your article is very useful to calculate and trouble shooting, also , i think everyone want to have a copy of your article if you like, so may I have a copy ?

thank you for your appreciation.

best regards

■

Dear Dr Agarwal,

I am really appreciate your email send me your paper "Theory and Design of Phase Dilute Pneumatic Conveying Systems", which is pretty useful to calculate and design a pneumatic conveying, specially the template and the worsheets explained step by step to avoid any doubt.

Thanks so much for your paper, I encourage to read this article if you are interested in design a pnematic conveying system.

Regards,

Alfredo Perez

Spain ■

Amrit,

Many thanks for the article. I am sure that it is very useful to me.

Regards,

Jeng-Tai Jeo ■