3 replies to this topic

[ravimkhatri]

Hello,

I need help for designing regarding design of Air Blower for Lime Kiln Opertation.

The air flow requirement is 10000 cfm,

Thank u,

Ravi

[kkala]

My graduating work was about heat transfer in a small rotary kiln (natural draft, 1972). Having followed rotary kilns from a theoretical point, I have not found something about sizing the blower or gas flows. Apparently you are interested in specifying head of the blower, that is flue gas ΔP along the kiln and downstream equipment, since you have already specified flow rate at 10000 cfm.
ΔP of downstream equipment (cyclones, filters, ducts) can be estimated, eventually taking info from suppliers. ΔP along the kiln is expected to be more complex than pressure drop through a big pipe. Flue gases contact the moving solids and entrain some dust downwards.
A. A. Boateng's "Rotary kilns", Elsevier, 2008, devotes Chapter 3 to "Freeboard Aerodynamic Phenomena". It can help understanding, but data to estimate ΔP has not been found. Induced draft fan is recommended at kiln outlet, which helps maintaining a slight sub atmospheric pressure in the kiln (thus avoiding flue gas escape). I do not know whether sited references could give something more useful.
Hopefully some member has specific experience on lime (or even cement) kilns to help. Otherwise you had better address the query to the supplier of the kiln. Or see some similar installations and take measurements.
They will also know whether there is data available in literature, or the web.
Hoping of happy end

[breizh]

Something is missing , there is no indication of the technology of the kiln . Is it a vertical kiln ?
You will need to take account the resistance of the solid bed ( lime , limestone and Coke) through the porosity and the height . Probably equation like Ergun will help to calculate the delta P .

I've added a reference with a spec sheet :
http://www.hbfj.cn/p...etail/id/8.html

Hope this helps

Breizh

Edited by breizh, 15 April 2012 - 03:08 AM.

[kkala]

Breitzh is right, there are rotary kilns (http://greatwallmill...CFQpb3wodVUhkkg '> http://greatwallmill...CFQpb3wodVUhkkg ) and vertical shaft kilns http://www.metso.com/miningandconstruction/mm_proj.nsf/WebWID/WTB-041202-2256F-19ACB/$File/Vertical_Shaft_Lime_Calcining_Systems_1.pdf '> http://www.metso.com/miningandconstruction/mm_proj.nsf/WebWID/WTB-041202-2256F-19ACB/$File/Vertical_Shaft_Lime_Calcining_Systems_1.pdf .
For various ways of limestone calcining, look at http://en.wikipedia.org/wiki/Lime_kiln '> http://en.wikipedia.org/wiki/Lime_kiln .