Friction Factor for Cement

Posted in: , on 22. Feb. 2009 - 10:15

hi every body,

i want to determine pressure drop in pneumatic conveyor for transport cement material with this specification:

Solids Conveying Rate (W): 120 ton/h

Pipeline characteristic: 42 m Vertical with 365 mm diameter and 9 m Horizontal with 350 mm diameter

Gas Temperature (T): 80 C

Gas velocity at inlet of conveying system (Vg): 16 m/s

Pipe line Roughness Factor: 0.0005

maximum gauge pressure of conveyer: 0.45 bar

altitude above sea level (m): 1581 m

but i dont have K (Solids Friction Factor) for cement.

please help me to solve this problem.

thanks a lot ■

Transport
Förderung
Pneumatische Förderung
Cement
Nichtmetallische & Mineralische Produkte
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Re: Friction Factor For Cement

Erstellt am 22. Feb. 2009 - 12:33

Dear Mr Meh shaken,

In case you do have a calculation method available, then the K-factor for cement is exclusively related to that algorithm.

For that matter is the only one who can give you the K-facter the one who set up that calculation program, which we are not aware of.

Based on your information, I preliminary calculated the pressure drop for your installation.

Air displacement = 1.6 m3/sec (Pipe area*pick-up velocity)

Barometric pressure 850 mbar (1581 m altitude)

Gas temperature at compressor intake 80 degrC

Ordinary cement.

For 120 tons/hr, the conveying pressure is approx 0.33 bar.

have a nice day

Teus ■

Teus

Re: Friction Factor For Cement

Erstellt am 23. Feb. 2009 - 07:30

Dear Mr teus

thank you very much for your guidance. but in your primary calculation, you get the temperature of the gas 80 C but in the system that i want to calculate the ambient temperature or gas intake temperature is 25 C and the temperature of gas in pipe is 80 C.

if it is possible for you that recalculate this system please do this.

I use the excell base method of Mr Agarwal for this Calculation but in this method we shall use K (Solid friction factor) to determine pressure drop. I want to discover the way of determining of K. please help me for this subject. ■

Re: Friction Factor For Cement

Erstellt am 23. Feb. 2009 - 08:56

Dear Mr Meh shaken,

You are welcome.

I recalculated the installation for 25 degrC air intake and a cement temperature of 80 degrC.

The Conveying temperature of the mix will then be close to the 80 degrC.

Along the pipeline there will be some cooling.

The pressure drop at 120 tons/hr is now calculated at 2955 mmWC (approx, 0.3 bar)

In your spreadsheet, you can now vary the K factor until you find the same pressure drop.

see screenshots of calculation

Success

Teus

Attachments

cementinstallationalt1581m (PDF)

■

Teus

Re: Friction Factor For Cement

Erstellt am 23. Feb. 2009 - 09:51

Dear Mr Teus

Thank you very much for your attention.

I find K for cement correspond your calculation. I want new result for check amount of K that I calculate from your calculation.

if it is possible for you please recalculate this pipe line for the same specification but this time with 150 ton/h capacity. and once more with 150 ton/h and 14 m/s for Vg (velosity of gas in input of pipeline)

best regards ■

Re: Friction Factor For Cement

Erstellt am 23. Feb. 2009 - 10:13

Dear Mr Meh shaken,

For the installation with 16 m/sec (Compressor 1.6 m3/sec), I made a full table calculation.

For an installation with 14 m/sec (compressor 1.4 m3/sec). the pressure at a capacity of 150 tons/hr, is calculated at 4420 mmWC

see attachment

BR

Teus

Attachments

cementinstallationalt1581m2 (PDF)

■

Teus

Software For Design Of Pneumatic Conveyor

Erstellt am 25. Feb. 2009 - 07:01

Dear teus

I compared the result that you give me and results that i calculate unfortunately this results dont equal together. if software for this calculation please guide me to get it.

thank a lot.

best regards ■

Re: Friction Factor For Cement

Erstellt am 25. Feb. 2009 - 08:37

Dear Meh shakeri,

I calculated the installation, using my own developed algorithm.

That algorithm is converted into a computer program. (Not on the market)

The screenshots are the calculation results.

For more information, please visit:

https://news.bulk-online.com/?p=65

With your calculation software, you should be able to calculate the K-factor back, by setting the pressure drop and capacity and iterating the K-factor.

I expect that you will find a variety of K-factors, which you should then relate to the SLR and the Reynold-number (Turbulence).

To get pneumatic conveying under control mathematically is a rather complex and time consuming job and involves many field observations.

(It is not an overnight science)

best regards

teus ■

Teus