after checking &  doing everything with respet to reduction of DP of my coal mill filter i am unable to reduce the DP.

with new bags it runs for 20-25 days only & than Dp touches 150mmwg & coal mill production reduces.

I have 6ksc dry air pressure, high purging frequency,no jamming,no pipes loose or worn out,periodic drain of moisture, low air to cloth ratioo (~ 1).

Before bag filter i have a collecting cyclone.

 

to increase air amount in the system i have shortened the dip tube by 300mm . now the dip tube is just 80-90mm below the inlet entry height.

when we replace some bags by new one we get a relief on temporary basis but agter some days the position is same.

please suggest.

Coal residue is 4 to 6 % on 72 mesh

we sre grinding petrocoke + indian coal (80+20% mix.)

we have close circuit ball mill of  FLS  

 please do suggest.

 

rajesh