xxxx
232 posts
TimePosted 06/12/2012 07:57:07
xxxx says

mill vent fan inlet water dropping

dear all

we have a tube mill , two chamber , 30 tph OPC , in open circuit.

The mill ventilation is with a bag filter & than a fan.

the diffrential pressure of bag filter is only 10mmwc & the fan load is only 0.6 kw.

the mill discharge cement temp. is 125 deg., gas temp. is 115 deg. while the bag filter outlet temp. is 85 deg.

We have a problem that the steam condenses & drops at the inlet of the vent fan & some vapor also drops from the fan outlet stack continously.

Now If I increase the vent fan speed , my product blaine reduces a lot.

water spray in the II chamber is also not high as we are maintaining cement temp. high upto 125 deg. to reduce water spray.

what is the way to avoid this steam condensation & dropping of water without decrease in  output, fan load & cement temp.

The false air or leakage is not much at all. Bag filter & mill outlet duct to bag filter are insulated.

What I am thinking is put some small media in II chamber to increase fineness & than increase the vent volume to compensate for the output & quality . But in that case I will have to increase the water spray which may choke the diaphragm etc. It will also increase my fan power.

Also I can reduce the compressed air purging in  the bag filter but it will later on increase the DP & fan speed .

Yes the velocity through mill is very lesds ( less than 0.5 m/s) which is abnormal.

So please suggest.

 

ENGR

Reply


Know the answer to this question? Join the community and register for a free guest account to post a reply.

gks
125 posts
TimePosted 09/12/2012 02:16:43
gks says

re mill vent fan inlet water dropping

 Dear 

      Due to condensation of water vapour on this temp.( 85 .0 c) . Pl check dew point of venting air.

       Regards

   GKS

 

Reply

xxxx
232 posts
TimePosted 09/12/2012 16:21:20
xxxx says

re mill vent fan inlet water dropping

Dear GKS

yes I kow it is the condensation of steam . But my problem is how to avoid it ?

I do not want to increase the vent fan speed & load.

ENGR

Reply

gks
125 posts
TimePosted 10/12/2012 16:26:35
gks says

re mill vent fan inlet water dropping

Dear xxx

          Send your mill design data

            Mill size ,grinding media charging , mill feed temp, water spray kg/hr,mill load kw&bag filter inlet &outlet temp.

            For calculation of  kg water/ m3 air in vent fan flow

     GKS 

Reply